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Postanesthesia Care of Adults

Michael Jay Katz, MD, PhD

Wild Iris Medical Education is an approved provider (#PA-54) of continuing nursing education by the Washington State Nurses Association, an accredited approver by the American Nurses Credentialing Center's Commission on Accreditation. Our courses fulfill continuing nursing education requirements in all 50 states.
Wild Iris Medical Education (CBRN Provider #12300) is approved as a provider of continuing education for RNs, LVNs, and respiratory therapists by the California Board of Registered Nursing.
Nurse practitioners may apply these contact hours to pharmacy continuing education and prescriptive authorization.

This course includes straightforward answers to basic questions about the PACU for nurses and other health professionals who advise patients over the telephone (see Part 6: Telephone Counseling).

Surgery's many stresses—arising from anesthesia, muscle relaxants, and tissue injury—push a patient's body to the edge of its ability to rebound naturally. The challenge to patients who are ill is even greater. The physiologic responses of people with pre-existing problems such as heart disease, lung disease, kidney disease, or diabetes are weaker than normal and after surgery some of these patients cannot regain a normal physiologic equilibrium on their own. Nonetheless, even these patients usually recover successfully from surgery. A key factor in these recoveries is the highly effective postanesthesia care available in recovery rooms throughout the developed world.

Today's recovery room is called a postanesthesia care unit, or PACU. The PACU is actually a short-term intensive care unit. It is staffed by specially trained nurses, and it is organized to maintain nurse-to-patient ratios of 1:1 when needed. In a PACU patients are monitored continually so that any difficulties that develop as they emerge from anesthesia are quickly recognized. The PACU is largely self-sufficient: it contains a full complement of the tools needed for resuscitation and for managing a wide range of emergencies, along with a staff experienced in handling crises (Marcon, 2006).

In surgery, an anesthesiologist controls certain aspects of patients' physiology, such as their breathing and fluid levels. When fully recovered, the patient's body re-assumes complete control of its own life functions. During the transition from anesthesia to recovery, some patients need medical assistance to maintain a safe internal physiologic balance. This transition also brings discomfort, such as nausea and vomiting and the awareness of pain. To manage both the potential life-threatening complications and the inevitable discomforts, specialized medical units are devoted solely to recovery from anesthesia. The American Society of Anesthesiologists has established basic guidelines for PACU care. These guidelines begin by stating:

During their recovery, all anesthesia patients should be monitored in a PACU-type unit unless the attending anesthesiologist orders otherwise. (ASA, 2004)

The PACU is the care unit to which patients are transferred directly after surgery. Later, when postoperative patients are awake, alert, and stable, either they are transferred from the PACU to step-down units or hospital wards, or they are discharged home. Those patients in critical condition are usually monitored in the PACU until the effects of anesthesia have worn off and are then transferred to an ICU.

In some hospitals, the PACU is called a Level 1 PACU or a Phase 1 PACU, and there is a step-down unit called a Level 2 PACU or a Phase 2 PACU. (There can also be Level 3 PACUs.) In the following course, the PACUs that we will be examining are Level 1 PACUs.

THE PHYSICAL FACILITIES

Location

A PACU is a critical care unit. As in an ICU, activity is occasionally intense: many different things can be going on simultaneously, and life-threatening crises can arise suddenly. Unlike an ICU, however, a PACU has a quick turnover of patients, with the average patient stay being only a little more than an hour.

The fast turnover, the occasional crises, and the unpredictability of events make the location of the PACU important. Patients need to get from the operating room (OR) to the PACU—and, sometimes, from the PACU back to the OR—speedily. Specialty support staff must be nearby; PACU nurses must be able to quickly enlist the help of anesthesiologists, surgeons, and specialty technicians and their equipment (eg, imaging devices).

For these reasons, the ideal location for a PACU is in the middle of the operating suite. This way, operating rooms are next door, and the OR staff of anesthesiologists, surgeons, OR nurses, and specialty technicians are in the immediate vicinity.

Layout

The typical PACU is a single open room, so staff can get to all areas quickly. This room should be spacious enough for easy movement of patient beds and gurneys, and it should have large doors and good lighting. Effective ventilation is especially important; anesthetic gases exhaled by patients need to be cleared from the room, because a commonly used sedative, nitrous oxide, can be a health risk for female staff of childbearing age.

The floor plan of the PACU usually has the nurse and physician station and the collective monitoring devices in an open area in the center. The bed spaces are then arrayed individually around the perimeter of the room.

Equipment

A PACU needs its own stocks of supplies that are replenished on a regular schedule; likewise, the PACU equipment should be rechecked periodically.

Much of the patient care in a PACU involves respiratory problems. The unit needs a full complement of airway equipment, including oxygen masks and cannulas, oral and nasal airways and tubes, tracheostomy tubes, appropriate airway scopes, ventilation bags, tracheotomy trays, chest tube trays, ventilators, and aerosol treatment equipment. It also needs cardiac equipment, including a defibrillator, pacing devices and wires, electrocardiogram (ECG) equipment, an array of vascular catheters, vascular cut-down trays, and infusion pumps. There should be an advanced life-support crash cart and a complete stock of cardiopulmonary rescue drugs.

Patients in the PACU require intensive monitoring for short times. The number of patients needing PACU care at any one time cannot be completely predicted in advance, so to ensure that the unit is prepared and appropriately staffed, the patient load must be re-evaluated continuously. To this end, the unit needs a large chart, board, or computer screen with frequently updated statistics, including

• Number of currently available beds
• Status and anticipated discharge time of current PACU patients
• Anticipated admission time of current and pending OR patients
• Anticipated admission time of non-OR patients, if any

Patient Bed Spaces

The rule of thumb is that a PACU should have at least 1.5 beds for each of the operating rooms it serves.

GENERAL BEDS

Most bed spaces in the PACU should be outfitted for general use. Around each bed, there must be sufficient room to fit intravenous (IV) poles, pumps, a ventilator, and mobile imaging equipment. An area of ≥120 square feet should be allotted for each bed space, and no two adjacent beds should be closer than 7 feet apart.

For each bed, there should be separate:

• Lighting
• Oxygen, air, and vacuum outlets
• Electrical outlets
• Supports for IV fluids and pumps
• Monitoring equipment, including:
• Pulse oximeter
• Automated noninvasive blood pressure monitor
• Oxygen flow meter
• Cabinet with basic supplies, including:
• Gloves and masks
• Alcohol wipes
• Pads, sponges, drapes, and tape
• Needles and syringes
• Catheters, tubing, and connectors

Each bed space should have a computer or notebook for keeping a chronologic record of all measurements and events. In addition, an ECG monitor should be available for each bed (Freeley & Macario, 2005; Morgan et al., 2006).

CRITICAL CARE BEDS

A PACU should also have some bed spaces with additional equipment for seriously and critically ill patients. These bed spaces need monitors that can simultaneously record two or more pressures (eg, direct arterial, central venous, pulmonary artery, or intracranial). Critical care bed spaces should also be set up to control a patient's body temperature, with temperature monitors and with warming and cooling equipment, such as forced-air devices or thermal blankets.

QUARANTINE BEDS

An additional walled-off and separately ventilated bed space is also useful for patients who are either immune-compromised or infectious.

THE STAFF

The PACU is a division of the anesthesiology department, and there is always an anesthesiologist assigned to be responsible for final medical decisions in the PACU. Usually, however, a charge nurse, who also acts as a back-up care nurse when the PACU gets busy, supervises the minute-to-minute operation. In at least one hospital with a large PACU, an advanced practice nurse with advanced cardiac life-support expertise has been trained specifically to direct the PACU, under the supervision of the anesthesiology department (Frederico, 2007).

Each patient's postoperative care remains under the direction of the operating anesthesiologist, who makes decisions related to the patient's vital functions (ie, respiration, circulation, fluid and metabolic balance) and analgesia. The operating surgeon is responsible for decisions about the results of the operation.

The PACU Nurse

BASIC TRAINING REQUIREMENTS

Skilled nurses provide the direct postoperative patient care in a PACU. PACU nurses should be trained in airway management, basic life support, and the special needs of postoperative patients emerging from anesthesia. They should also be adept at caring for acute surgical wounds and a variety of drainage catheters. For each PACU, a healthcare professional trained in advanced cardiac life support should always be available (Morgan et al., 2006).

NURSE-TO-PATIENT RATIOS

As they begin to emerge from anesthesia, patients are more likely to have medical difficulties than later in their recovery; therefore, for the initial 15 minutes in the PACU, it is necessary to have one nurse caring exclusively for that patient.

After about 15 minutes, patients who are conscious and stable can usually be monitored by a nurse who is simultaneously watching one or even two other similar patients. Patients who are stable, conscious, and uncomplicated, and who have been in the PACU for more than a half hour, can be watched even less closely. On the other hand, patients who are unstable or who have airway complications (eg, artificial airways or mechanical ventilation) require constant close monitoring no matter how long they have been in the PACU (Freeley & Macario, 2005).

RECOMMENDED NURSES PER PATIENT, LEVEL I PACUs

Nurse:patient ratio	Patient status
2:1*	Critically ill Unstable Complicated problems
1:1*	Newly admitted On mechanical ventilation with an artificial airway Requiring isolation precautions Overflow from an ICU Unstable and requiring transfer to ICU
1:2*	Both patients CSU** or One patient CSU** and the other unconscious, but stable and uncomplicated
1:3 to 1:6*	All CSU** and being considered for discharge
*With a second nurse available. In general, the American Society of PeriAnesthesia Nurses recommends that "two RNs, one competent in Phase I postanesthesia nursing, will [always] be in the same room where the patient is receiving Phase I level of care" (ASPAN, 2005). **CSU = conscious, stable, and uncomplicated Source: Kiekkas et al., 2005c; Torgerson, 2005; Dexter et al., 2006.

NURSING TIME PER PATIENT

PACU nurses estimate that it takes at least 60 minutes to admit a patient, manage the patient's recovery, get the patient ready for discharge from the PACU, and complete all the paperwork (Freeley & Macario, 2005).

Scheduling

CONSTRAINTS

Quality care in a PACU requires that nurses monitor patients closely and, as noted earlier, PACU standards recognize that there is a limit to the number of patients that can be cared for simultaneously by a single nurse. Therefore, for adequate staffing, the number of patients in the PACU dictates the required number of nurses.

The complication in scheduling PACU nurses is that the number of postoperative patients varies during the day. Many operations are scheduled for first thing in the morning, so PACUs often have few patients in the early morning. The peak patient load usually comes in the middle of the day, when the morning surgeries have been completed. Afternoons bring fewer patients, and only emergency patients are admitted in the evening or at night.

On many days, there is a steady influx of postoperative patients, and sufficient numbers of PACU nurses must always be available. However, the intra-day variation means that the number of PACU nurses who are needed varies during the day. This variation is made less predictable by prolonged surgeries and emergency surgeries.

Ideally, PACUs should schedule extra PACU nurses during all shifts throughout the day. Limited budgets, however, force the anesthesiology department to trim the number of nurses to a minimum, and maintaining the balance between minimum staffing and an adequate safety factor is a challenge.

In addition to the fact that PACU patient admissions are unpredictable and vary during the day, there are other constraints that make scheduling nurses for a PACU different from scheduling nurses for ICUs, operating rooms, emergency departments, hospital wards, or clinics. These constraints include:

• PACUs can only use specially trained nurses.
• All PACU patients will require the full attention of at least one nurse at some time in their stay. (Although, at other times, PACU nurses can care for more than one patient simultaneously.)
• PACUs have no waiting rooms, and they must minimize delays in admissions.

MAKING A DAILY ROSTER

Making daily nursing rosters for the PACU is a skill. Planning begins by including one nurse for each active operating room. When only one OR is active, a second nurse must still be scheduled, because PACU standards require that two nurses should be in the unit at all times.

With this baseline, additional nurses are added to the schedule to match the planned surgeries, using the estimation that an average PACU admission occupies one nurse for an hour. Finally, the nursing roster is adjusted to match the actual patient loads that have been seen on similar days in the past. (The past four months has been suggested as a good period to use when planning for the future.)

The nursing roster will always be a "best guess." As a safety factor for coping with an unexpected surfeit of patients, PACU schedulers try to assign an extra PACU nurse to less critical duties in nearby facilities, especially during peak hours. For instance, the extra PACU nurse may do preoperative preparation of patients, while being prepared to switch to the PACU if the patient load suddenly increases (Dexter et al., 2006).

Efficient scheduling of the nursing shifts for a large PACU (ie, a PACU with >4 nurses) is complex. For a large PACU, balancing budget constraints with the necessary postoperative patient care is too complex to be done by hand with a spreadsheet program; instead, it is best done by specially devised computer programs (Dexter et al., 2006; Meyer et al., 2006). The scheduling difficulty is not always apparent at first glance, and it can be necessary for PACU directors to take the time to explain to hospital administrators the unique problems posed by the job of efficiently staffing a large PACU (Marcon, 2006).

Postanesthesia care is a continuation of intraoperative anesthesia management and is under the direction of the operative anesthesiologist. Here is how the responsibilities of anesthesiologist and PACU nurse are apportioned:

• The anesthesiologist accompanies the patient during transport to the PACU.
• At the PACU, the anesthesiologist reassesses the status of the patient.
• The anesthesiologist then reports the patient's relevant medical history and gives the postanesthesia care orders to the PACU nurse who is assuming responsibility for the patient's continuing care.
• In the PACU, nurses monitor the patient continually, provide direct care, and notify the anesthesiologist immediately of any problems.
• When a patient fulfills the criteria for discharge, a PACU nurse contacts the anesthesiologist, who takes the final responsibility for discharging the patient to the next stage of care (ASA, 2004).

THE COURSE OF A ROUTINE RECOVERY

Patients stay in the PACU until they have become awake and alert, with autonomously stable vital signs. This recovery normally takes 30 to 70 minutes. A PACU stay is usually routine and uneventful (Sherwood et al., 2008).

During a typical recovery, a PACU nurse checks the patient frequently. Every 15 minutes (or more often), the nurse records the patient's vital signs, blood oxygen saturation, level of consciousness, independence of breathing, and ability to make voluntary movements.

When all signs have returned to pre-admission levels and have remained there for 30 minutes, the nurse checks to see whether all the discharge criteria have been met. Typically, the discharge criteria include having a high score on a standardized scale, such as the Aldrete Score (introduced later). At this point, the anesthesiologist is contacted to discharge the patient.

A routine postoperative recovery comprises four phases, each with its own protocols and potential problems: transport to the PACU, admission to the PACU, stay in the PACU, and discharge from the PACU.

Transport to the PACU

Officially, postanesthesia care begins when a PACU nurse assumes responsibility for the patient. However, care begins immediately after the surgery and continues during the transport of a patient from the OR to the PACU. During this trip, the patient requires special attention from the anesthesiologist, because patient monitors, resuscitation equipment, and emergency medications are usually not immediately at hand.

GURNEYS

After ensuring that the patient has a patent airway and sufficient ventilation, the OR staff transfers the patient to a gurney with side rails. Patients are typically transported lying on their side to reduce the likelihood of aspiration or airway blockage from secretions, bleeding, or vomiting. During the journey, hypovolemic patients are often transported with their head lower than their feet, while patients with pulmonary problems may be transported with their head elevated.

CARE EN ROUTE

The anesthesiologist takes direct responsibility for care of the patient during the trip from the OR to the PACU. Two aspects of the patient's condition need special attention: the airway and the blood oxygen level.

The transport crew ensures that the patient's airway remains clear during transport. Stable patients will often have been extubated in the operating room, and care must be taken to keep the patient's tongue forward. Unstable patients are left intubated and are accompanied to the PACU by oxygen, ventilation equipment, vital signs monitors, and a tray of emergency medications.

Even during a short trip to the PACU, most postoperative patients become mildly hypoxemic (ie, their blood oxygen saturation, SpO₂, drops to <95%) when breathing room air. On room air, about 10% of patients become more hypoxic and arrive at the PACU with SpO₂ <90%. Older patients and overweight patients have the highest risk of developing transport hypoxemia. Due to the risk of hypoxemia, many anesthesiologists recommend giving most postoperative patients supplemental oxygen during transport, unless the PACU is immediately adjacent to the operating room (Morgan et al., 2006).

Admission to the PACU

THE ANESTHESIOLOGIST'S REPORT

When patients are admitted to the PACU, they should always be accompanied by their operative anesthesiologist. On arrival at the PACU, the anesthesiologist checks and records the patient's vital signs. Next, the anesthesiologist gives the PACU nurse a verbal report, which is used by the PACU staff to set priorities and to individualize the patient's care.

PACU nurses generally know few details about patients before their arrival; therefore, the anesthesiologist's report, while brief, should be comprehensive. The report should give the patient's name, age, surgical procedure, medical problems, and allergies. A description of the patient's preoperative mental status and any communication disabilities will help the PACU nurses to identify any new problems that appear during recovery.

Information about the surgery should include the preoperative medications, the intraoperative anesthetics and medications, an input/output record of blood, fluids, and gastric contents, and information about any intraoperative complications. The report should end with specific recovery orders and a telephone or pager number at which the doctor can always be reached.

There are advantages to having background medical information delivered before a patient is admitted; however, PACU nurses report that a face-to-face oral presentation by the anesthesiologist is invaluable. In a direct conversation, nurses can ask questions immediately, get any unclear details explained, and review the orders aloud. Moreover, PACU nurses find that they make better sense of the medical information when they can see the patient while they are hearing the report.

An admission is a busy time. The anesthesiologist is rechecking the patient, while the PACU nurse is setting up monitors. In the midst of this activity, it is worthwhile for the nurse and the anesthesiologist to attempt a brief but uninterrupted conversation, because full concentration on the admission report makes for the most accurate and informative handover of medical responsibilities (Curry et al., 2006).

A RISK FACTOR PROFILE

In the admission report, the anesthesiologist warns of the possibility of certain complications. The receiving nurse can also screen for patients at risk for complications by asking whether the patient is similar to any of four basic profiles identified in the box below.

INITIAL NURSING ASSESSMENT

PACU nurses must make their own admission assessment of each patient. First, the nurse checks the patient's identity. Next, the nurse checks the patient's airway patency, vital signs, and blood oxygen saturation. Finally, these values are compared to those reported by the anesthesiologist.

Recovery in the PACU

The American Society of Anesthesiologists (ASA) has published guidelines for PACUs (ASA, 2004). The ASA recommends that the operation of a PACU should include these basic policies and procedures:

• All medical care in the PACU should be supervised by an anesthesiologist.
• An appropriately trained physician should always be immediately available for consultation, management of complications, and cardiopulmonary resuscitation.
• The PACU staff should maintain full written records of all measurements and events during a patient's stay.
• All PACU patients' breathing, blood oxygenation, circulation, and temperature should be monitored continually, and each time these parameters are measured, they should be recorded using a numerical scale.
• In addition, a standardized recovery score should be calculated for each patient on admission, at appropriate intervals during the PACU stay, and on discharge.

Within the bounds of these requirements, most PACUs follow similar protocols during a typical patient's recovery from anesthesia.

ROUTINE MONITORING

After general anesthesia, most patients take 15 to 30 minutes to become fully awake, to be breathing normally, and to be physiologically stable. Until a patient is awake and stable, vital signs and blood oxygen saturation are recorded every 5 minutes. Subsequently, blood pressure, pulse rate, and respiratory rate are measured every 15 minutes. The patient's temperature is measured and recorded at least once early in the PACU stay.

Postoperative patients take time to regain effective muscular control. The ability of a patient voluntarily to maintain muscle contractions is assessed at regular intervals. For example, when patients are awake they should be asked to lift their head off the bed and hold it up for 5 seconds.

Depending on the patient, other physiologic parameters that might be monitored regularly are pain, nausea, bleeding, drainage from catheters, fluid input and output, central venous pressure, and intracranial pressure. All assessments are quantified, not simply descriptive.

OXYGEN SUPPLEMENTATION

All patients recovering from general anesthesia should receive 30% to 40% oxygen during their emergence because temporary hypoxemia can develop, even in patients without major pre-existing medical problems. When patients have become alert, are breathing smoothly on their own, and have stable signs, supplemental oxygen is usually no longer needed.

Even after regaining consciousness, though, a patient can become hypoxemic. Patients should have their blood oxygen saturation monitored until they are physiologically stable, breathing spontaneously and sufficiently, and maintaining a normal level of blood oxygen.

Certain patients have a greater than normal risk of developing hypoxemia and may need supplemental oxygen during their entire stay in the PACU. Patients at higher risk include older adults, patients with pre-existing lung problems, and patients who have had thoracic or upper abdominal surgery. Blood oxygen saturation should routinely be monitored in these patients even after they are awake and alert. Patients who are prone to hypoxemia fare better when lying with their head elevated throughout their recovery (Morgan et al., 2006).

RECOVERY FROM ANESTHESIA

The PACU team's aim is for patients to emerge gradually from anesthesia. The goal is to temper any sudden changes in physiology, to minimize pain, nausea, or vomiting, and to recognize and quickly correct airway obstruction, peaks or troughs in blood pressure, decreases in blood oxygenation, temperature changes, and delirium.

Patients come to the PACU after three classes of anesthesia, which have been monitored by an anesthesiologist: general anesthesia, regional anesthesia, and sedation anesthesia.

General anesthesia is also called inhalation anesthesia. General anesthesia uses anesthetic gases, such as fluorinated ethers (eg, desflurane, enflurane, isoflurane, sevoflurane) and nitrous oxide. These anesthetics directly affect the brain, and they produce unconsciousness.

Regional anesthesia uses local anesthetics (eg, bupivacaine, lidocaine, procaine) to block nerve conduction to a part of the body. These anesthetics can be injected adjacent to the spinal cord (as spinal, epidural, or caudal blocks) or adjacent to large nerve trunks. Local anesthetics do not affect consciousness.

Sedation anesthesia uses an IV sedative-hypnotic (eg, etomidate, propofol, a barbiturate, or a tranquilizer) to produce decreased consciousness, amnesia, and lowered anxiety. When needed, a local anesthetic and an opioid can be added to provide analgesia. Patients usually continue breathing autonomously when they are under sedation anesthesia (Tarrac, 2006).

Intrinsic characteristics of an anesthetic can prolong the time needed for recovery. These include:

• Duration of action. Each anesthetic has own characteristic rate of onset and duration of action. Longer-acting anesthetics require more recovery time. For example, the regional anesthetic bupivacaine (Marcaine) remains effective longer than procaine (Novocain); therefore, patients recover more slowly from bupivacaine than from procaine.
• Solubility. Anesthetics that are more soluble will dissolve in body fluids at higher concentrations, so more of the soluble anesthetic becomes sequestered in the body. For example, the inhaled anesthetic isoflurane is more soluble than desflurane; therefore, patients recover from isoflurane more slowly than from desflurane (Freeley & Macario, 2005).

Characteristics of the patient and the surgery can also prolong the time needed for recovery. For example:

• Duration of surgery. Longer surgeries build higher concentrations of anesthetic that is stored in tissues throughout the body. Therefore, patients tend to recover more slowly from long operations.
• Ventilation ability. Gaseous anesthetics are released from the body through the lungs. Postoperative patients with poor ventilation take longer to reduce their anesthesia load, and these patients require more recovery time.
• Pre-existing medical problems. Some anesthetics are broken down by the body's metabolic processes, and some anesthetics are excreted in the urine. Patients with metabolic or excretory problems, such as liver disease or kidney disease, tend to recover more slowly from anesthesia (Morgan et al., 2006).

COUNTERACTING MUSCLE RELAXANTS

Neuromuscular Blockade

During surgery, patients often receive nondepolarizing neuromuscular blockers (muscle relaxants). Nondepolarizing neuromuscular blockers compete with the neurotransmitter acetylcholine for receptor sites on muscle cells; this makes nerve-to-muscle signals ineffective, and the muscles become paralyzed. Commonly used neuromuscular blockers include mivicurium, rocuronium (Zemuron), and vecuronium.

Reversal Agents

As patients emerge from anesthesia, they need to breathe autonomously, swallow normally, cough and clear lung secretions, and sit up. To do these things, almost all the effects of neuromuscular blockers must be gone. However, on their own, muscle relaxants wear off slowly. Therefore, after surgery, the anesthesiologist usually gives an "anti-muscle relaxant," a reversal agent. Reversal agents—anticholinesterases such as edrophonium (Enlon), neostigmine (Prostigmine), and pyridostigmine (Mestinon)—increase the signaling effect of the body's acetylcholine by slowing its normal breakdown.

Reversal agents are effective at speeding up patients' abilities to uses their muscles. Unfortunately, the reversal agents can cause their own side effects: bradycardia, narrowing of the bronchi, contraction of intestinal muscles, and excess salivary and bronchial secretions. These side effects are caused by stimulation of the muscarinic form of the cholinergic receptors, while the reversal effects are cause by stimulation of the nicotinic form of the cholinergic receptors. Therefore, the unwanted side effects can be selectively blocked by administering muscarinic anticholinergic drugs (atropine or glycopyrrolate) along with the reversal agent (Dorian, 2005).

Monitoring Muscle Function

In the OR, anesthesiologists usually monitor the state of neuromuscular function by assessing the strength and number of muscle twitches produced by an electrical nerve stimulator. In the PACU, nurses usually assess the recovery of neuromuscular strength by the ability of patients to lift their head for 5 seconds, to squeeze the nurse's hand for 5 seconds, or to stick out their tongue for 5 seconds (Barone et al., 2004).

Discharge from the PACU

The PACU nurses monitor postoperative patients for a minimum 30 minutes, but often the PACU stay is longer. There is no fixed upper limit on the length of a patient's stay in a PACU: patients are watched and cared for until they can safely be transferred to a less intensively monitored unit. A typical PACU stay is approximately an hour.

As baseline requirements, the American Society of Anesthesiologists guidelines for discharges (ASA, 2004) state:

• A PACU nurse will usually make the recommendation that a patient is ready to be discharged.
• A physician must be responsible for each discharge from a PACU.
• The patient's records should contain details of their condition at discharge.

From the PACU, patients can be discharged to a variety of settings. In some hospitals, the frontline PACU is called a Level I PACU, and there is a sequence of step-down units (Levels II and III PACUs) offering decreasing amounts of monitoring and care. Other hospitals have a single PACU from which patients are transferred either to hospital wards, to transition areas in which they prepare to go home, or to specialty care units, such as ICUs.

When a patient is transferred to a hospital care unit, the PACU nurse provides a comprehensive medical report to that unit. When the patient is being sent home, an adult must assume responsibility for the patient, and a PACU nurse then gives the patient and the accompanying adult written instructions for continuing care, including a telephone number for getting answers to any questions.

DISCHARGE CRITERIA

Unless they are going to an ICU, patients who have had general anesthesia are not discharged from the initial PACU until they:

• Are awake, oriented, and able to call for help if it becomes necessary
• Have clear airways, can breathe autonomously, and are maintaining a satisfactory level of blood oxygenation
• Have active airway protection reflexes
• Have been physiologically stable with acceptable vital signs for 15–30 minutes
• Are not hypothermic
• Are not actively bleeding and have no apparent postsurgical complications
• Have controlled and tolerable levels of postoperative pain
• Are not vomiting and have, when necessary, an anti-emesis regimen in place
• Have orders and prescriptions for all required oxygen, iv fluids, and medicines (Aldrete, 1998; Smith & Hardy, 2007; Sherwood et al., 2008).

In addition, those patients who have had regional anesthesia are not discharged until the sensory and motor blocks have worn off (Kiekkas et al., 2005a; Morgan et al., 2006).

An anesthesiologist must approve each patient's discharge from a PACU.

CHECKLISTS AND SCORING SYSTEMS

Besides the clinical criteria outlined above, hospitals use standardized written criteria as part of the decision to discharge a patient from the PACU, and the criteria should be listed in the patient's discharge note. Standardized discharge criteria are especially helpful to PACU nurses, who have the task of deciding when it is time to get an anesthesiologist's approval for a patient's discharge.

For some hospitals, the standardized criteria are a checklist of specific functional conditions, such as those noted in the section above above. In other hospitals, the standardized criteria are summarized in a single numerical score, which signals "all clear to discharge" when it is above a specified threshold value.

The Aldrete Scoring System (or a modified version of it) and the Postanesthesia Discharge Scoring System (PADSS) are two numerical summary techniques that are widely used for evaluating the level of recovery of patients after general anesthesia (Ead, 2006). Each system is formulated so that a score of 9/10 or 10/10 suggests the patient is ready for discharge from a PACU. (See Modified Aldrete Scoring System and Postanesthesia Discharge Scoring System, below.)

The outcome of a checklist or scoring system should always be put into a clinical context by the judgment of a physician. An "all clear to discharge" score should be over-ridden when a patient's pre-existing medical problems or the occurrence of postoperative complications make continued monitoring the prudent medical course of action.

Typically, a modified Aldrete score of 9 or 10 is needed to discharge a patient (Aldrete, 1998). The exact Aldrete score that is used, however, can vary from hospital to hospital and from situation to situation (eg, Williams & Hadzic, 2005).

Typically, a PADSS of 9 or 10 is needed to discharge a patient, although the exact threshold value can vary (Freeley & Macario, 2005; Ead, 2006).

Medical complications during recovery include the following:

• Postoperative nausea and vomiting (PONV)
• Postoperative pain
• Respiratory problems
• Cardiovascular problems
• Body temperature problems
• Blood sugar level abnormalities and diabetes
• Postoperative agitation and delirium
• Delayed emergence

The body's responses to the stress and injury of surgery include secretion of cortisol, catecholamines, cytokines, and glucagon. There is a decrease in insulin release, and there is an increase in metabolic rate and oxygen consumption. In addition, antidiuretic hormone (ADH) is released (Ali, 2005). Some of the effects of these metabolic responses are contradictory, and together the body's responses to surgery can unbalance important physiologic functions. At the same time, the lingering effects of anesthesia and muscle relaxants weaken the body's normal ability to re-establish the physiologic balance needed to remain healthy.

Approximately one-quarter of inpatients and one-twelfth of outpatients have complications in the PACU and need individualized medical interventions (Freeley & Macario, 2005; Tarrac, 2006). The most frequent problems involve patients' upper airways. Nausea and vomiting are the next most common problems, followed by cardiovascular abnormalities, including hypotension, hypertension, and dysrhythmias (Freeley & Macario, 2005; Miller, 2006; Tarrac, 2006). In addition, surgery is controlled injury, so postoperative pain is an ever-present stressor that requires attention.

A patient's admission information will give the PACU staff the first warnings of possible complications during recovery: the operative anesthesiologist will flag patients likely to develop problems. The receiving nurse should also match the patient's profile against a checklist of some of the key risk factors for certain specific complications. (See the earlier box presenting profiles of patients at risk.)

There are a few general features that identify patients who will need close attention; these include (Freeley & Macario, 2005; Tarrac, 2006):

• Poor ASA status (see ASA Physical Status Classification System, box below)
• General (vs. regional) anesthesia
• Prolonged duration of anesthesia (>2 hours)
• Abdominal, renal, urologic, orthopedic, or emergency surgery

POSTOPERATIVE NAUSEA AND VOMITING (PONV)

Nausea and vomiting can be experienced after all types of anesthesia, but they are common side effects of inhaled anesthesia. General estimates suggest that some degree of PONV occurs in 20% to 30% of surgical cases, but various studies have reported rates from 5% to >50% of postoperative patients, with the low rates being for patients who had only regional anesthesia. Nausea or vomiting can hit a patient as late as 24 hours after surgery (Dorian, 2005; Morgan et al., 2006).

CAUSES

Many factors have been associated with an increased likelihood that a patient will develop nausea or vomiting postoperatively. The American Society of PeriAnesthesia Nurses' evidence-based guidelines (ASPAN, 2006) suggest that, at admission, the PACU nurse should count how many basic risk factors apply to each patient. These six basic risk factors are:

• Female patient
• Nonsmoker
• Long surgery (>60 minutes)
• Opioids during or after surgery
• History of PONV
• History of motion sickness

PACU patients with one or two of these factors have a mild risk of developing PONV, while patients with five or six factors have a high risk.

In addition to the ASPAN list of six factors, there are two other commonly cited and well-documented risk factors related to anesthesia

• Inhaled anesthesia, as opposed to regional anesthesia
• Sedation with nitrous oxide (Freeley & Macario, 2005)

Another predictor is the type of surgery. Certain operations are more likely to cause PONV. These operations include emergency surgery when the patient's stomach is full, intraperitoneal and gynecologic surgeries, and head and neck (especially middle ear and strabismus) surgeries.

The patient's condition in the PACU can also increase the likelihood of PONV. PACU patients are at risk for nausea and vomiting when they have

• Pain
• Opioids for pain
• Increased intracranial pressure
• Hypoglycemia
• Dehydration
• Early administration of oral liquids (Morgan et al., 2006).

RECOGNITION AND ASSESSMENT

When PACU patients emerge from anesthesia, they should be asked whether they feel nauseated. If the answer is yes, they are asked to rate the degree of nausea on a scale of 0 to 10, with 10 being the most severe. The nausea rating is then repeated after relevant events (such as the administration of opioids for pain or antiemetics for vomiting) and at discharge from the PACU (ASPAN, 2006).

MANAGEMENT

The overall plan for managing PONV is:

• On admission, determine the patient's risk level for developing PONV.
• Have patients quantify their degree of nausea (0–10) when they first awaken, during their PACU stay, and on discharge.
• Maintain adequate hydration, blood pressure, and analgesia.
• Don't push oral liquids.
• Treat vomiting and uncomfortable levels of nausea.

The main treatments for vomiting and uncomfortable degrees of nausea are medications, although a number of nonpharmacologic treatments can be added.

Medications

In the brainstem, four different neurotransmitters are involved in triggering nausea or vomiting. These neurotransmitters are dopamine, acetylcholine, histamine, and serotonin. (The brainstem trigger center also contains opioid receptors.) Most of the medications used to treat nausea and vomiting are antagonists or blockers of these four neurotransmitters. (See box below.) Adding a corticosteroid to the neurotransmitter antagonists can increase their effectiveness as anti-emetics.

NONPHARMACOLOGIC TREATMENT METHODS

Acupuncture and acupressure (eg, SeaBand, ReliefBand) have been found to prevent or reduce PONV in some adults. These techniques have been used alone or in combination with a medication, such as a serotonin antagonist (Ghods et al., 2005; Morgan et al., 2006). In addition, the deep regular breathing used during aromatherapy has been shown to reduce nausea (Spencer, 2004).

POSTOPERATIVE PAIN

Patients consider nausea, vomiting, and pain as the worst postoperative experiences (Freeley & Macario, 2005). There is no justification for hesitating to treat pain. "Postoperative pain serves no useful purpose," writes Doherty (2006), "and may cause alterations in pulmonary, circulatory, gastrointestinal, and skeletal muscle function that set the stage for postoperative complications."

Pain after thoracic or upper abdominal surgery is the most important factor responsible for impaired ventilation, ineffective cough reflexes, and decreased ability to sigh and breathe deeply, all of which can lead to atelectasis, hypoxemia, infection, and respiratory failure (Ali, 2005).

Pain is psychologically and emotionally upsetting, and it alters a patient's physiology. Pain heightens the sympathetic tone of the body; therefore, oxygen use increases, blood levels of glucose are raised, proteins are catabolized, and the kidneys retain sodium and water. Furthermore, the stress response to pain and the inflammatory response to surgical tissue damage (eg, the local production of cytokines, prostaglandins, and leukotrienes) put the circulatory system into a prothrombotic (hypercoagulable) state and make blood clots more likely (Wu, 2005).

Pain is detrimental to recovery. Nonetheless, many patients still experience postsurgical pain, because, despite the best efforts of the PACU staff, pain can be difficult to alleviate.

CAUSES

As a rule, the type of anesthesia does not predict the amount of postoperative pain. On the other hand, certain operations are associated with a higher degree of pain. For example, in comparisons of severity after surgery, thoracotomy leads to the most severe pain, upper abdominal surgery tends to produce less severe pain, while lower abdominal surgery seems to produce the least postoperative pain of the three.

There is also a strong psychological component to how much postoperative pain a patient experiences. Studies have documented that patients require less narcotic pain relief when they have had "a careful preoperative explanation about postoperative pain, including its character, intensity, and management, and [the explanation that postoperative pain is] a normal occurrence" (Freeley & Macario, 2005).

RECOGNITION AND ASSESSMENT

In the PACU, pain should be monitored frequently, as if it were a vital sign (ASPAN, 2003c). "The American Pain Society has advocated the assessment of pain as the fifth vital sign, along with temperature, pulse, blood pressure, and respiratory rate. The four vital signs provide a quick snapshot of a patient's general condition, but pain management advocates claim the picture is not complete without including pain as the fifth vital sign" (Dorian, 2005).

Even in patients who are not fully awake, pain can be recognized objectively by the physical signs it arouses. Acute pain initiates a stress response: blood pressure and heart rate increase, pupils enlarge, cortisol levels rise, and, in the painful region, muscles often contract spontaneously.

Of course, pain is also a subjective experience. Patients who are awake should be asked whether they are having any pain, and, if so, where the pain is located. The patient should also be asked to rate the pain on a 0–10 scale, with 10 denoting the most severe pain. (See the Visual Analog Scale, below.) In a conscious patient, strong pain will evoke emotions: anxiety, fear, sadness, and the urge to escape.

Visual Analog Scale (VAS) for rating pain severity.

Patients are asked to mark the severity of their pain on a plain 100-mm horizontal line labeled "no pain" at the left end and "worst pain imaginable" at the right. The VAS pain score is the distance of the patient's mark from the left end. This score is reproducible and correlates well with other accepted pain measurement techniques.

MANAGEMENT

Pain treatment relieves suffering and may improve the outcome of major surgeries (Dorian, 2005). As a rule, postoperative pain is reduced most effectively when more than one type of treatment is used concurrently. The multimodal approach includes preparing the patient beforehand, strong and complete blockade of pain during surgery, and the continuation of analgesia postoperatively (Wu, 2005).

Plans for PACU pain relief should be tailored to the specific patient, because patients differ in their response to treatments. Medication is the frontline mode of pain relief, and the two general classes of pharmacologic analgesia are systemic, such as intravenous opioids, and regional, such as local anesthetics and epidural opioids.

MEDICATIONS

Opioids (narcotics) are the most powerful analgesics available, and their intravenous administration gives pain relief in minutes. The side effects of opioids include nausea, vomiting, and sedation. The most serious problem caused by opioids is respiratory depression, ie, a reduction in the rate and the volume of the patient's spontaneous breathing. Antinarcotic drugs, such as naloxone, can reverse the side effects of most opioids.

Commonly used opioids include fentanyl, hydromorphone, meperidine, and morphine. Opioids can be given orally, parenterally, or intraspinally (intrathecally or in the epidural space), as well as subcutaneously, transcutaneously, and transmucosally.

People vary in their response to opioids; therefore, the quantity of opioid administered should be titrated to the most effective dose for each individual. One titrating system for awake and alert patients is patient-controlled analgesia (PCA), a pump and monitor that allows patients to get a controlled dose of opioid when they feel it is needed.

Nonsteroidal Anti-Inflammatory Drugs (NSAIDS) block the synthesis of prostaglandins, which are pain-enhancing molecules that are produced by the body's inflammatory response to surgery. NSAIDs cause analgesia by a different route than opioids, and by adding a NSAID to an opioid, pain relief is made more effective at lower doses of both medicines.

The most serious side effect of NSAIDs is bleeding from the gastrointestinal tract. Usually, this problem occurs only with long-term use. However, people over the age of 75 years bleed from NSAIDs more easily. Commonly used NSAIDS include acetaminophen, aspirin, ibuprofen, and ketorolac.

Oral and Intravenous Drugs

A variety of systemic analgesic drug regimens is in common use:

• For mild to moderate postoperative pain, combinations of acetaminophen and an opioid (codeine, hydrocodone, or oxycodone) are often used. Sometimes, opioid agonist-antagonists (eg, butorphanol, nalbuphine) or ketorolac are given (Morgan et al., 2006).
• For moderate to severe postoperative pain, opioids are the basis of treatment. The classic protocol for surgical pain is to begin with a small (1–3 mg) intravenous bolus of morphine at the end of the operation. In the PACU, for patients who are awake, morphine is then given intravenously in small boluses. The analgesic effect of each dose peaks in 4–5 minutes; this is usually fast enough for awake patients to endure the pain while the total morphine load is safely ramped up to effective levels without overshooting the minimum necessary level.

Aubrun (2005) discusses titrating morphine in the PACU: A typical titrating regimen begins when patients rate their pain intensity as ≥30 mm on a VAS line (See Visual Analog Scale, above.) At this point, a 1–3 mg intravenous bolus of morphine is given every 5 minutes until the patients rate their pain <30 mm on the VAS line. The patient's breathing is monitored continuously, and no further morphine is given if

• The patient falls asleep
• Respirations drop below 12 breaths/minute
• Oxygen saturation drops below 95%
• Another serious complication arises (Aubrun, 2005)

The most serious side effect of morphine and other opioids is respiratory depression, which threatens a postoperative patient with hypoventilation. Unlike its quick analgesic effect, morphine's effect on the respiratory drive does not peak for 20 to 30 minutes. Therefore, for at least a half-hour after morphine has been administered, PACU nurses must continue to monitor patients and encourage them to breathe deeply and to cough occasionally.

Epidural Drugs

Increasingly, anesthesiologists are controlling postoperative pain with epidural infusions or injections. Opioids are generally used, because, when administered into the spinal epidural space, opioids give fast, effective, and long-lasting pain relief. Often, the opioid is paired with a local anesthetic. Properly placed epidural analgesia will allow patients to retain control over most muscles and bodily functions.

The continuous epidural infusion of an opioid requires an expertly placed and carefully cared-for catheter. The alternative to an infusion is a single injection; one epidural injection of slow-release morphine can provide up to 48 hours of analgesia (Keck et al., 2007).

As always with opioids, the most serious side effect is respiratory depression, and patients' respiration must be monitored regularly; naloxone and other narcotic antagonists can reverse opioid-induced respiratory depression. Other side effects of epidural opioids are pruritus, nausea, vomiting, hypotension, and urinary retention. There is also some evidence of another side effect: concurrently given anticoagulants appear to increase the risk of a spinal hematoma when epidural catheters are removed (Wu, 2005; Miller, 2006).

Improving Pharmacologic Pain Management

As many as 86% of surgical patients report having had postoperative pain that was moderate, severe, or extreme (Keck et al., 2007). These insufficient levels of analgesia cause emotional distress, depression, and sleep disturbance. Pain makes it difficult for a person to breathe optimally, and pain delays movement and mobility. The stress response to pain also makes cardiovascular complications more likely (Aubrun, 2005).

Here are anesthesiologists' suggestions for some ways to improve postoperative analgesia (Freeley & Macario, 2005):

• Problem: Patients in pain refuse opioids for fear of becoming addicted.
• Solution: Explain that narcotics given in the hospital for postoperative pain rarely lead to addiction.
• Problem: Patients in pain wait for PACU nurses to offer analgesia.
• Solution: Quiz patients frequently about pain levels, and encourage patients to accept relief of pain that is moderate or worse.
• Problem: Some patients ask for more than the usual amount of an opioid.
• Solution: People vary widely in how much opioid is needed to produce adequate analgesia. Consider IV patient-controlled analgesia (PCA), which tends to be an improvement over more traditional, PRN regimens. (PCA patients will need the same regular monitoring as PRN patients.)
• Problem: Physicians' pain orders are too general.
• Solution: Formulate written protocols for various pain relief regimens. Each protocol should have a drug name, dosage, criteria for administration, administration interval, signs for stopping administration, and signs for calling for help. All physicians should be asked to choose which specific pain relief protocol is appropriate for a patient and then to add or change details of the protocol as needed. Nurses should not hesitate to page the physician when any questions arise.

NONPHARMACOLOGIC METHODS

Transcutaneous electrical nerve stimulation (TENS) and acupuncture have been used successfully as an adjunct to analgesic medications. These and other special techniques are often introduced by members of pain management teams available in some hospitals.

The PACU nursing staff can also institute a number of easy and practical pain-lessening practices. Simply having a calm PACU staff who acknowledge a patient's discomfort will ease patients' anxiety and diminish the impact of postoperative pain. Nurses can also teach patients simple relaxation and breathing techniques that have been shown to reduce the severity of pain (ASPAN, 2003c).

Sometimes repositioning a patient, adding a pillow, or keeping the patient warm will take the edge off the patient's pain. Normalizing a patient's sensory environment can also help: giving patients their glasses, hearing aids, or dentures often eases the feeling of pain. In addition, it is helpful to keep the PACU noise level low. Finally, when appropriate, a family member, a friend, or a religious counselor can be a soothing presence (ASPAN, 2003c).

RESPIRATORY PROBLEMS

Most medical complications that arise during a patient's postoperative recovery involve the patient's breathing, and the results of these breathing problems are blood gas abnormalities, namely, hypoxemia and hypercapnia.

The most common breathing problem is some degree of airway obstruction. Another relatively common problem is weakened ventilation, ie, a diminished ability to take breaths that are of sufficient depth and frequency. Typical causes of poor ventilation include the lingering effects of anesthesia, incomplete reversal of muscle relaxants, weakness of the diaphragm, or pain that is exacerbated by the movements of breathing.

In addition, some patients come to the PACU needing mechanical ventilation, which poses special care requirements that are otherwise usually dealt with in an ICU.

When a patient is admitted to the PACU, the anesthesiologist should warn the receiving nurse about existing or potential respiratory problems. For example, anesthesiologists will undoubtedly flag patients with obstructive sleep apnea. These people are likely to develop airway obstruction when sedated, and, as a preventive measure, patients with obstructive sleep apnea are often put on nasal continuous positive airway pressure (nasal CPAP) after they have been extubated (Freeley &3038; Macario, 2005).

PACU nurses can also use simple checklists to identify patients who are at special risk for developing postoperative breathing problems. For instance, patients with profiles similar to the following are at higher risk for respiratory complications:

• Male patient
• Elderly (>60 years) patient
• Long surgery (>4 hours)
• Emergency surgery
• Thiopental during surgery
• Diabetes or obesity

Upper Airway Obstruction

CAUSES

Patients can arrive in the PACU with or without an endotracheal tube. The common causes of airway obstruction differ somewhat in the two situations.

Patients with No Endotracheal Tube

When a patient without an endotracheal tube is sedated, airway obstruction can be caused by the tongue flopping back into the oropharynx. In patients given muscle relaxants, the oropharyneal muscles become loose and toneless and folds of wall tissue can also contribute to the obstruction.

Laryngospasm (spasm of the vocal cords) is another cause of obstruction in extubated patients. (See box below.) In a similar fashion, vocal cord paralysis and edema of the glottis can also block the upper airway.

Sometimes obstruction is caused by external compression of the patient's airways. On the outside of the neck, bandages, cervical collars, or orthopedic devices may be excessively constrictive. Within the neck, hematomas or other swellings can push on the oropharynx, making it bulge inward and become narrow.

Debris is another potential source of blockage. Anesthesia and sedation compromise a patient's protective reflexes, and blood, vomitus, mucus, or secretions can collect in the patient's airways during and after surgery. Surgical patients lying on their backs can aspirate gastric contents refluxed from the stomach, which results in gastric acid causing bronchial constriction or food clogging the airways.

Intubated Patients

Endotracheal tubes protect airways from many types of constriction, but the endotracheal tube itself can become narrowed if a patient's teeth clamp down on it. Endotracheal tubes can also become obstructed by blood, vomitus, secretions, or debris.

During the transport of a patient from the OR, or as the patient is being settled into the PACU, the tracheal end of an endotracheal tube can be dislodged. Sometimes the tube is inadvertently pulled back into the pharynx, and at other times the tube gets pushed into one of the main bronchi (Barone et al., 2004).

RECOGNITION AND ASSESSMENT

Signs of airway obstruction can usually be read directly from the patient. Obstructed patients become agitated, their nostrils flare, and they exhibit abnormal chest and neck movements, such as sternal retractions and the use of accessory respiratory muscles as they attempt to pull in air.

Listening to the patient can indicate the degree of blockage. Partial airway obstruction causes noisy breathing sounds, such as snoring, stridor, or "crowing," while complete obstruction stops breath sounds altogether. When an airway is completely obstructed, carbon dioxide accumulates quickly, leading to headaches, confusion, and then lethargy.

In the context of the continuous monitoring that should be ongoing for all PACU patients, blood oxygen saturation levels will warn of airway problems. Obstruction results in a decreasing blood oxygen saturation (SpO₂), and obstruction is one of the first causes PACU nurses should look for whenever oximetry values begin to decline (Barone et al., 2004; Sherwood et al., 2008).

MANAGEMENT

Patients with No Endotracheal Tube

The first step in treating apparent airway obstruction is to administer oxygen via a face mask and to ask the patient to take deep breaths. Simultaneously, the nurse should:

• Look for anything external that could be compressing or constricting the patient's neck
• Look in the patient's mouth and oropharynx for visible blockages

If these preliminary maneuvers do not work, the nurse should physically attempt to widen the oropharynx by tilting the patient's head backward and pulling the patient's jaw forward (head-tilt chin-lift), all the while continuing to administer oxygen.

When a head-tilt and chin-lift does not quickly ease the obstruction, a nasopharyngeal or an oropharyngeal airway should be inserted. Nasopharyngeal airways cause less gagging and vomiting in patients who are awake or semi-conscious, so oropharyngeal airways are usually recommended only for heavily sedated patients. Suctioning through these airways can sometimes help unclog the passageway.

If airway obstruction persists, the anesthesiologist should be paged, because the next treatment options include insertion of an endotracheal tube and the administration of medications to counteract possible physiologic causes of obstruction. If laryngospasm is found, 100% oxygen should be administered via a facemask using continuous positive airway pressure (CPAP) ventilation (Barone et al., 2004; Freeley & Macario, 2005).

Intubated Patients

As soon as intubated patients are admitted to a PACU, the placement and patency of their endotracheal tube is assessed. If there are uncertainties, chest films are taken and immediately interpreted by a radiologist. After ensuring that the endotracheal tube is working properly, the PACU nurse monitors the patient's breath sounds and oxygen saturation levels regularly (Barone et al., 2004).

Signs of obstruction are treated with oxygen and suctioning. The anesthesiologist should be paged if the patient does not quickly improve.

Hypoxemia and Hypercapnia

Hypoxemia is an abnormally low concentration of oxygen in the blood (PaO₂ <60 mm Hg). Hypercapnia is an abnormally high concentration of carbon dioxide in the blood (PaCO₂ >45 mm Hg).

To diagnose hypoxemia formally, arterial blood gases must be drawn and processed. Pulse oximetry is not as useful an indicator of hypoxemia; a decreased blood oxygenation value (SpO₂ <89%) usually indicates hypoxemia, but patients with higher SpO₂ values can also be hypoxemic. Hypercapnia can only be measured from arterial blood gases.

CAUSES

Here are some factors that make postsurgical blood gas abnormalities more likely:

• Older adult patient
• Thoracic or upper abdominal surgery
• Pre-existing lung problems or obesity
• Pulmonary edema

In the PACU, hypoxemia can be caused by insufficient ventilation, right-to-left shunting (significant amounts of circulating blood bypassing effective lung tissue), ventilation-perfusion mismatching (blood going to poorly ventilated lung tissue), or diffusion impairment (eg, pulmonary edema).

Hypercapnia in the PACU is caused by insufficient ventilation of the alveoli of the lungs (Stapczynski, 2004).

The stresses of surgery can lead to any of these problems:

• Pain. Pain from surgery of the thorax or upper abdomen limits a patient's ability to take full breaths, to sigh, and to cough. These limitations can cause hypoxemia and hypercapnia.
• Diaphragmatic strain. Surgery in which there is traction on or injury to the diaphragm causes the diaphragm to function poorly postoperatively. For this reason, many upper abdominal surgeries, such as open (ie, nonlaparoscopic) cholecystectomy, result in a dramatic drop in patients' vital capacity during the first 24 hours. These surgeries lead to some degree of hypoxemia in most patients. However, in patients who have little reserve lung capacity because of pre-existing lung problems, the surgically induced drop in vital capacity can cause respiratory failure (Ali, 2005).
• Airway obstruction. Airway obstruction causes hypoventilation and hypercapnia. Lower airway obstruction can be the result of bronchospasm, mucus plugs, blood, secretions, or debris. Upper airway obstruction, as discussed above, can be caused by blood vomitus, debris, secretions, or airway constriction.
• Lingering effects of anesthesia. The upper airways are normally cleared by coughing, but the cough reflex is weakened by anesthetics and by opioid analgesics. The lower airways are normally cleared by the ciliary movement of particles and mucus, but ciliary movement is by anesthetics, allowing obstructive mucus plugs to form after anesthesia (Ali, 2005). The lingering effects of anesthetics will also dampen a patient's normal respiratory drive.
• Incompletely reversed muscular relaxants. The persistence of neuromuscular blockade weakens respiratory muscles, leading to less forceful, shallow breathing (hypoventilation).
• Pulmonary edema. Pulmonary edema and increased secretions create a barrier to gas exchange and can lead to hypoxemia and hypercapnia.
• Mechanical constraints. Physical limitations can cause hypoventilation. For example, obesity, bloating, tight dressings, body casts, and other restrictive apparatus will hinder breathing. A pneumothorax will also limit a patient's ventilation capacity.
• The heart. For blood gas abnormalities, the underlying problem is not always in the respiratory system, especially in the case of hypoxemia. A reduced cardiac output can be the primary cause of a decrease in a patient's blood oxygen levels after surgery.

RECOGNITION AND ASSESSMENT

Hypoxemia

Hypoxemia is a low blood oxygen concentration, specifically, PaO₂ <60 mm Hg. An accurate blood oxygen concentration (the partial pressure of oxygen) is obtained by measuring the blood gases in an arterial sample. Determining blood oxygen saturation using a pulse oximeter is a much easier and quicker oxygen measurement, but it does not always correlate directly with the blood oxygen concentration. Nonetheless, SpO₂ <89–90% is usually considered an indication of hypoxemia.

The values 60 mm Hg and <89–90% stated above are arbitrarily chosen thresholds, and patients can be clinically hypoxemic at higher values. Clinical signs of hypoxemia are restlessness, tachycardia, and cardiac irritability (ie, a tendency to develop irregularities in rate and rhythm). Prolonged or significant hypoxemia will lead to bradycardia, hypotension, and cardiac arrest.

Hypercapnia

Hypercapnia is carbon dioxide retention that elevates the concentration of carbon dioxide in the blood to PaCO₂ >45mm Hg. There is no easy way to measure the blood concentration of carbon dioxide at the bedside; arterial blood gas measurements are needed. Clinically, mild hypercapnia may produce no visible symptoms; for example, a patient can have hypercapnia without being cyanotic. As hypercapnia increases, however, it will lead to hypoxemia and its attendant symptoms. Continuous and progressive hypercapnia will also cause headaches, confusion, lethargy, and somnolence.

Respiratory Depression and Respiratory Muscle Weakness

Residual effects of anesthetics or muscle relaxants or the effects of opioids can cause respiratory depression and respiratory muscle weakness. In turn, these breathing limitations can lead to hypoxemia and hypercapnia.

In the PACU, the degree of a patient's respiratory sedation can be monitored by noting how well the patient breathes spontaneously and how vigorously the patient responds to the request "Take a deep breath." The degree of residual neuromuscular weakness can be assessed by how well patients hold their head up from the bed for 5 seconds.

MANAGEMENT

The first step in treating hypoxemia and hypercapnia is to administer oxygen. Next, while continuing oxygen treatment, the PACU nurse should search for and treat the cause of the blood gas abnormality (Sherwood et al., 2008).

Airway obstruction is frequently the culprit; its detection and management are discussed above. Two other problems that often cause blood gas abnormalities are hypoventilation and atelectasis.

Hypoventilation

When a PACU patient suffers from hypoventilation (ie, poor movement of air into and out of alveoli) it may be a side effect of opioids. If opioid-induced hypoventilation is the cause of blood gas abnormalities, the respiratory depression can be reversed by small repeated doses of a narcotic antagonist such as naloxone.

Postoperative hypoventilation can also be the consequence of intraoperative muscle relaxants that have not been fully reversed. This can occur when muscle relaxant reversal agents have been administered but have failed to act quickly or completely. Reversal agent failures can be due to hypothermia, renal failure, or hypermagnesemia in the patient. Reversal agents can also fail because of interactions with other drugs, such as gentamicin, neomycin, clindamycin, or furosemide.

Atelectasis

Atelectasis, the incomplete expansion or the collapse of regions of the lung, will cause hypoventilation. Postoperative atelectasis is typically the result of lower airway obstruction, and its treatment includes humidifying the patient's inspired air, encouraging the patient to breathe deeply and to cough, and postural drainage.

Other Conditions

When these and other initial treatments are not sufficient to reverse blood gas abnormalities, an anesthesiologist must decide whether an external CPAP mask, intubation, or other measures are needed to sustain the patient while the search for the underlying problem continues.

CARDIOVASCULAR PROBLEMS

After respiratory problems, cardiovascular problems are the most common complications seen during postsurgical recovery. Typically, cardiovascular complications are either the result of the surgery itself or an exacerbation of the patient's pre-existing cardiovascular problems. This is in contrast to respiratory complications, which are typically the direct result medications (anesthesia, opioids, muscle relaxants).

The postoperative cardiovascular complications most commonly seen in the PACU are hypertension, hypotension, and tachycardia. Heart problems seen less often include dysrhythmias, exacerbations of heart failure, and acute myocardial infarctions.

Hypertension

Hypertension is the most common of the postoperative cardiovascular complications. When the hypertension is severe, it can cause serious problems, such as left ventricular failure, myocardial infarction, dysrhythmias, pulmonary edema, or cerebral hemorrhage. Postoperative hypertension occurs most frequently in patients who had pre-existing hypertension (Freeley & Macario, 2005).

CAUSES

Discomfort (eg, pain, anxiety, confusion, a full bladder) can raise a postoperative patient's blood pressure. Many physiologic abnormalities, such as hypoxemia, hypercapnia, or fluid overload, can also induce hypertension.

Certain surgeries have a higher risk of inducing a hypertensive response, notably:

• Abdominal aneurysm repair
• Carotid endarterectomy
• Intracranial surgery

The strongest risk factor for postoperative hypertension is a physiologic predisposition: patients' preoperative medical conditions determine their susceptibility to developing hypertension. People with atherosclerosis or pre-existing hypertension, even if it had been well controlled, are the most likely patients to develop postoperative hypertension (Tarrac, 2006).

RECOGNITION AND ASSESSMENT

Blood pressure is one of the key signs that should be continually monitored in the PACU. Postoperative hypertension tends to occur early in a patient's recovery, so blood pressures should be measured more frequently in the first 30 minutes of a patient's stay in the PACU.

MANAGEMENT

The goal in managing postoperative hypertension is to relieve the stressor. When hypertension occurs, nurses should be certain that they are providing sufficient analgesia and that the patient's bladder is not distended. Nurses should also check and, if necessary, improve the patient's ventilation, oxygen saturation, and fluid balance. Sometimes, relieving discomfort with additional sedation can lower postoperative hypertension (Barone et al., 2004; Sherwood et al., 2008).

If these measures do not reduce the patient's blood pressure, then antihypertensive drugs are probably needed. In the PACU, beta-adrenergic blockers are commonly used to reduce blood pressure. Labetalol and esmolol both work in a few minutes; labetalol is given in intravenous boluses, while esmolol, which has a shorter half-life, is given as a continuous infusion (Freeley & Macario, 2005).

Hypotension and Hypovolemia

Mild hypotension is one of the more common circulatory abnormalities seen in the PACU. Significant hypotension, however, is seen less frequently.

CAUSES

Postoperative hypotension is most often caused by hypovolemia. Cardiac dysfunction, such as heart failure, is a less common cause. The infrequent major crises (ie, severe hypoxemia, anaphylaxis, transfusion reactions, drug reactions, sepsis, cardiac tamponade, pulmonary emboli, or adrenal insufficiency) can also involve significant hypotension (Freeley & Macario, 2005).

• Hypovolemia. Causes of hypovolemia include blood loss and evaporation (fluids are lost by evaporation when an operation requires body cavities to be open for long periods). Urinary losses are sometimes not fully replaced with intravenous fluid. In addition, the body's reaction to the injury of surgery makes local blood vessels more permeable, and body fluids leave the circulation and accumulate in tissue spaces, in the peritoneal space, and even inside the intestines (Ali, 2005).
• Cardiac dysfunction. Occasionally, cardiac dysfunction is the major cause of postoperative hypotension. The cardiac dysfunction (heart failure, dysrhythmia, myocardial infarction) can be a new problem caused by the intraoperative drugs or the conditions of surgery. More often, however, postoperative heart malfunctions are exacerbations of pre-existing heart problems.
• Spinal opioids. Epidural or intrathecal anesthesia, especially with an opioid, can cause neurogenic hypotension (Tarrac, 2006; Sherwood et al., 2008).

RECOGNITION AND ASSESSMENT

Hypotension

In the PACU, patients' blood pressures should be checked regularly. Mild hypotension means a drop in blood pressure of less than 10% to 15% from the patient's baseline values. Significant hypotension means a drop of 20% to 30% in blood pressure values.

Hypovolemia

Hypovolemia in a postoperative patient can usually be recognized clinically by the occurrence of a number of these signs:

• Tachycardia
• Decreased radial pulse height
• Cool extremities
• Narrow pulse pressure (pulse pressure is the difference between the systolic and diastolic blood pressure values)
• Poor skin turgor
• Dry mucous membranes
• Scanty, concentrated urine
• Lethargy
• Sometimes, cyanosis

MANAGEMENT

Mild postoperative hypotension is a common finding, and it can usually be managed by regular monitoring. On the other hand, significant hypotension needs prompt treatment. Assuming there is a clear airway and adequate ventilation, oxygen is administered, fluids are increased, and when possible, the patient is put in the Trendelenburg position (Tarrac, 2006). Then the causes of the hypotension must be searched for and treated.

Meanwhile, if fluids do not improve the hypotension, then it may be necessary to administer vasopressors. An anesthesiologist or critical care physician must be involved in this and all further evaluations and treatments of postoperative hypotension (Walley, 2005).

Tachycardia

CAUSES

Postoperative tachycardia can be a sign of a wide range of stressors, including pain, hypoxemia, hypercapnia, anemia, hypovolemia, and fever, or it can be component of a dysrhythmia. In the PACU, pain and discomfort (eg, from an over distended bladder) are the most common causes of tachycardia.

RECOGNITION AND ASSESSMENT

Tachycardia is defined as ≥100 heartbeats/minute.

MANAGEMENT

When a PACU patient develops tachycardia, the nurse checks the patient's airway, oxygen saturation level, vital signs, volume signs (jugular venous fill level, urine output, peripheral pulses, capillary refill time), and bladder size. In addition, the nurse evaluates the patient's cardiac rhythm. Any problems are treated.

Persistent tachycardia can often be slowed with fluids, an opioid analgesic, or a beta-adrenergic blocker. All these measures need the consent of the attending physician (Tarrac, 2006).

Tachycardia may also be a component of a newly developed dysrhythmia. Most dysrhythmias that appear in the PACU are the result of an underlying metabolic or circulatory imbalance. When the physiologic imbalance is corrected, the dysrhythmia and the tachycardia will usually disappear (Freeley & Macario, 2005).

Care of Circulatory Catheters

When patients come to the PACU with venous or arterial catheters, the admitting nurse should check that all the catheters are still patent and in the correct locations. If a central venous catheter was placed during the operation without its location having been verified radiographically, the anesthesiologist will probably order a chest film in the PACU to confirm the proper placement.

Arterial pressure catheters should be calibrated against the PACU's blood pressure cuff. During the patient's stay in the PACU, measurements made via the catheters should be noted alongside the values obtained from the PACU's usual monitors (Barone et al., 2004).

BODY TEMPERATURE PROBLEMS

Hypothermia and Shivering

It is estimated that more than half of all postoperative patients have hypothermia during their stay in the PACU. Hypothermia means that the patient's central circulatory system has a core temperature of <36° C (<96.8° F). Core temperatures are most easily measured at the eardrum (Kiekkas et al., 2005d).

Hypothermia leads to shivering, which is a spontaneous and involuntary muscular tremor. The muscular effort of shivering uses energy and oxygen, increases blood levels of lactic acid and carbon dioxide, and increases cardiac output. Intense shivering will increase the body's metabolic rate 4 to 5 times, and in some cases, shivering can even produce hyperthermia of >38° C (>100.8° F).

On occasion, hypothermia and the metabolic stresses from shivering cause cardiac arrhythmias, myocardial ischemia, hypotension, coagulation problems (leading to excess blood loss), metabolic acidosis, increased rates of infection, or slowed rates of recovery. These complications are more likely in patients with pre-existing heart, lung, coagulation, or immune system problems. Previously normotensive patients can also develop hypertension from hypothermia.

These secondary complications are not common, however. In general, postoperative patients who did not have pre-existing serious medical problems will not suffer secondary complications from mild hypothermia in the PACU (Kiekkas et al., 2005d; Sherwood et al., 2008).

CAUSES

Under anesthesia, the body's temperature regulating mechanisms are less responsive than normal, and during surgery, the temperature of the central circulatory system sometimes drops inappropriately. The highly volatile anesthetics used for general anesthesia are well-known causes of hypothermia, but hypothermia can also result from regional anesthesia if the patient is not kept warm. Some situations in which patients are more likely to develop postoperative hypothermia are presented in the box below.

RECOGNITION AND ASSESSMENT

A PACU patient's core body temperature should be monitored regularly; the tympanic membrane temperature correlates well with the core body temperature.

Shivering is a good clinical indicator of hypothermia. All voluntary muscles in the body can tremble during shivering, but shivering is most easily seen in the jaw muscles and in the shoulder muscles (Barone et al., 2004).

MANAGEMENT

Even when covered by a blanket, a hypothermic person cannot quickly increase their core body temperature without using their muscles to generate heat. Shivering is the normal way that an immobile person generates muscular heat, and hypothermic patients in the PACU will involuntarily shiver to rewarm their bodies. Unfortunately, intense shivering is metabolically demanding and can cause other complications in postoperative patients. Therefore, PACU staff should remove the need for shivering by providing external heat to warm hypothermic patients.

Forced-air convection warming systems (eg, Bair Hugger systems) are preferred for heating hypothermic patients. Second choices include heated blankets, warming lights, thermal ceilings, or increased room temperature. Warm intravenous fluids (or warm transfused blood, when appropriate) will also help, as will warming the air used to ventilate intubated patients. To ease shivering in patients while awaiting the effects of external heat sources, small doses of meperidine (Demerol) can be given with caution.

Patients who are shivering should receive supplemental oxygen to compensate for the increased oxygen their muscles are using (Barone et al., 2004; Freeley & Macario, 2005; Morgan et al., 2006).

Malignant Hyperthermia

CAUSES

Malignant hyperthermia is a rare genetic disorder. Patients with this disease can develop sudden severe muscle contractures when their bodies are exposed to succinylcholine or certain anesthetic gases (fluorinated ethers—isoflurane, halothane, enflurane, sevoflurane, or desflurane). The involuntary muscle contractures generate heat, and when malignant hyperthermia is triggered, a patient's body temperature can rise to >40° C (>104° F).

RECOGNITION AND ASSESSMENT

Malignant hyperthermia usually appears in the OR, but sometimes it first shows up in the PACU. Patients with malignant hypothermia have rigid jaw muscles (spasms of the masseter muscles), metabolic acidosis, and, usually, tachycardia and tachypnea; fever develops later.

MANAGEMENT

If postoperative patients have the symptoms of malignant hyperthermia, PACU staff should administer 100% oxygen and notify the anesthesiologist immediately (Barone et al., 2004).

BLOOD SUGAR ABNORMALITIES AND DIABETES

The stresses of surgery lead to increases in blood sugar levels, and when plasma glucose concentrations remain higher than 180–200 mg/dl, patients tend to become dehydrated. Patients with diabetes are unable to reduce episodic hyperglycemia without medications; therefore, diabetics are susceptible to dehydration after surgery. Surgery can unmask type 2 diabetes in people with previously undetected disease, so all PACU patients should have their blood glucose levels checked at least once.

At the other end of the spectrum, patients with certain metabolic problems, such as liver disease, may not have sufficient stores of glycogen. For these people, the stresses of surgery can make them hypoglycemic.

Patients who are currently receiving intravenous hyperalimentation are a third population at risk for unhealthy levels of blood sugar postoperatively. For these people, anesthesiologists must carefully balance the amount of carbohydrates given during surgery; in general, normal levels of intravenous sugars in the hyperalimentation fluids can lead to postoperative hyperglycemia, while too low a level of intravenous sugar will cause postoperative hypoglycemia (Barone et al., 2004).

CAUSES

The stresses of surgery cause the body to release cortisol and glucagon. These hormones raise the level of blood glucose.

RECOGNITION AND ASSESSMENT

Patients, such as diabetics, whose metabolism is not agile at handling changes in blood sugar concentration should have their blood glucose levels monitored during their stay in the PACU. Patients who are at risk for type 2 diabetes (ie, people who are sedentary, middle-aged or older, and who are overweight, dyslipidemic, hypertensive, or with a family history of diabetes) should have their blood glucose levels checked at least once during recovery. Blood glucose levels can be measured with a simple bedside finger stick.

MANAGEMENT

Postoperative patients should maintain blood glucose levels lower than approximately 200 mg/dl. Patients with higher levels of blood glucose need insulin, the type and dose of which should be determined by the patient's physician.

When giving insulin, there is always the danger of hypoglycemia; therefore, insulin is usually given with a concurrent intravenous drip of a dextrose solution. Insulin can also cause hypokalemia, so potassium chloride is sometimes added to the intravenous dextrose drip. The patient's fluid levels and kidney functioning must be taken into account when a patient's glucose level is being adjusted externally, and all decisions must be made by an attending physician.

At the same time, the hydration status is monitored for all postoperative patients with hyperglycemia. Fluid intake and output should be recorded (urinary catheters may be needed) and serum electrolytes checked (Noble, 2005).

POSTOPERATIVE AGITATION AND DELIRIUM

As they are emerging from anesthesia, some patients become agitated, and occasionally a patient awakens confused or delirious.

CAUSES

Agitation

Restlessness or agitation in a patient who is not fully awake can be a sign of physiologic problems. Therefore, when patients seem uncomfortable, nurses should look for possible medical causes, including pain, hypoxemia, hypercapnia, acidosis, hypotension, hypoglycemia, and adverse drug reactions.

Confusion

• Confusion and delirium are most common in older adults, in patients with pre-existing cerebrovascular disease or brain dysfunctions, and in patients who were very anxious or fearful preoperatively.
• Major surgery is more likely to trigger confusion or delirium than short procedures or ones done under regional anesthesia.
• Certain medications are more likely to cause delirium; these include ketamine, anticholinergics, phenothiazines, barbiturates, and benzodiazepines.

MANAGEMENT

When mental disturbances appear, PACU staff should check vital signs, bladder distention, the state of the surgical wound, serum electrolytes, blood glucose levels, and arterial gases. Any problems should be treated.

With no evidence of pain or serious physiologic problems, restlessness, agitation, confusion, and delirium are treated empirically. An effort should be made to re-orient the patient. During this process, the staff should be patient, because it may be necessary to wait for the residual levels of intraoperative medications to decrease sufficiently so that the patient's brain can re-orient itself.

Intravenous midazolam (a benzodiazepine) can sometimes help to reduce a patient's agitation. Very agitated patients may need soft restraints to avoid injuring themselves, disrupting intravenous lines, or blocking their own airways (Barone et al., 2004; Morgan et al., 2006; Sherwood et al., 2008).

DELAYED EMERGENCE

Patients usually emerge from anesthesia within 30 minutes after surgery. On occasion, however, the return to normal consciousness is delayed.

CAUSES

Most commonly, delayed emergence is due to lingering effects of anesthetics, sedatives, analgesics, or other medicines given in the course of the surgery. One explanation for a delayed emergence is that the effects of these medicines have been potentiated by drugs or alcohol that a patient ingested before the surgery. In addition, extreme hypothermia (<33° C, <91.4° F) will slow emergence.

On the other hand, an apparent "delayed emergence" may actually be an unconscious patient. The patient may have suffered a stroke, or the unconsciousness could be the result of a metabolic problem, such as a very high or a very low blood glucose concentration.

RECOGNITION AND ASSESSMENT

When a patient has not awakened within the first half hour after surgery, there should be a thorough search for possible causes.

MANAGEMENT

Any problems in vital signs, blood electrolytes, blood glucose, or arterial blood gases should be corrected. If this does not improve the patient's level of consciousness, pharmacologic tests are tried in an attempt to counteract surgical medicines; for example:

• Naloxone usually reverses persistent effects of opioids
• Flumazenil usually reverses persistent effects of benzodiazepines
• Physostigmine partially reverses the effects of anticholinergics

The failure of these drugs to change the patient's level of consciousness should trigger a neurologic consult (Freeley & Macario, 2005; Morgan et al., 2006).

Challenges in the operation of a PACU include medication errors, accommodating non-postoperative patients, family visitation, admission delays, and discharge delays.

MEDICATION ERRORS

The fast and intense pace of a PACU during peak hours makes the staff susceptible to mistakes. The seriousness of the medication errors made in the PACU is second only to those made in the OR.

LOCATIONS OF SERIOUS MEDICATION ERRORS IN HOSPITALS

Location	% Medication errors resulting in harm
Operating room (OR)	7.2
PACU	6.0
Intensive care unit (ICU)	3.3
Hospital, overall	1.3
Source: Hicks et al., 2007.

CAUSES

Nicks and colleagues (2007) identify four types of mistakes lead to most of the medication errors in PACUs:

• Prescribing mistakes
• Physicians inaccurately filling out preprinted medication order forms
• Physicians prescribing medications contraindicated by the patient's known allergies or previous poor reactions
• Dose or quantity mistakes
• Nurses misprogramming patient-controlled analgesia (PCA) pumps
• Nurses confusing dosage weight with dosage volume (eg, giving 2 ml instead of 2 mg)
• Drug omission mistakes
• Physicians not ordering an antimicrobial when needed
• Wrong-drug mistakes
• Nurses administering similar sounding or similar looking drugs (eg, morphine solution vs. hydromorphone solution)
• Nurses retrieving the wrong drug from a common dispensing cabinet or tray (Nicks et al., 2007)

REDUCTION OF ERRORS

Here are some practical suggestions to reduce PACU drug errors (Hicks et al., 2007):

• Nurses should always do two checks of the medicine name against the prescribed name and two checks of the actual dose against the prescribed dosage.
• For PCA pumps, each programmed parameter (analgesic name, bolus dose, lockout interval, dose limit, background infusion rate) should be checked twice.
• Vials of liquid drugs should be labeled with the total weight of the drug and the total volume of liquid in the vial. In other words, a vial label should read, "100 mg drug X, total vol. = 10 ml, concentration = 10 mg/ml."
• Purchase single dose vials, ie, using vials with a premeasured single dose is better than using vials from which single doses must be extracted and measured by a nurse.
• Precalculated dose vs. weight charts should be available for medicines to avoid calculation errors.
• Pharmacists should be directly involved in stocking and organizing drugs in the PACU.
• Medication errors should be reported to the PACU director in the team spirit of helping all the staff to learn and improve.

ACCOMMODATING NON-POSTOPERATIVE PATIENTS

Like ICU nurses, PACU nurses are trained to monitor patients continuously and to be alert for developing crises. PACUs are usually adjacent to an OR, are sufficiently staffed so that nurses can devote full time to individual patients, and have the capability of managing patients on mechanical ventilation. For these reasons, PACUs are among a small group of hospital units equipped to care for and monitor patients at risk for suddenly developing life-threatening conditions.

Due to their special capabilities, PACUs are sometimes called on to care for non-postoperative patients. In some hospitals, PACUs play a broad role, being used as:

• Overflow beds for filled ICUs
• Beds for medical patients who need mechanical ventilation
• Temporary wards for patients who require preoperative stabilization
• Protected environments for anesthesiologic procedures such as the insertion of central venous catheters
• Temporary intensive care units for monitoring patients after invasive radiologic and thrombolytic procedures (Kiekkas et al., 2005b)

However, the admission of non-postoperative patients puts a strain on PACUs. These outside patients are a varied group and they come at unpredictable times. PACU staffing that had been planned for a particular postoperative schedule cannot always cover the added patients. Non-postoperative patients may need frequent lab tests, and some may need to be cared for at greater length than postoperative patients. Moreover, the flow of information—anesthesiologist to PACU nurse and PACU nurse to anesthesiologist—to which the PACU staff is accustomed, is not the way information is transmitted for most non-postoperative patients (Saastamoinen et al., 2007).

A number of specific measures have been suggested to help PACUs cope with these added responsibilities. First, it is important that the PACU director, the directors of the ICUs and the ED, and the hospital management have an explicit agreement as to the priorities and essential responsibilities of the PACU. The agreement should spell out which services (if any) can plan to use the PACU for minor procedures or for monitoring patients after nonsurgical invasive procedures (ASPAN, 2003a).

Second, PACU directors need to be aware that, occasionally, patients with complex medical problems will have to be admitted to the PACU rather than to an ICU. Therefore, some PACU nurses should regularly rotate through the ICU to increase their familiarity with the additional skills needed to care for critically ill patients. Also, the anesthesiology department should organize in-house courses to prepare PACU nurses for non-postoperative patients who may be admitted to their PACU.

Third, if it appears that a PACU will regularly be dealing with critically ill or medically complicated patients, the hospital should consider establishing an additional, somewhat differently oriented unit. Toward this end, some hospitals have created short-term or overnight ICUs that are specifically organized and staffed to cope with both postoperative or non-postoperative patients who need ICU-level care for an intermediate period of between 6 and 24 hours (Hodge, 2006). These units fill the gap between the very-short-term PACU and the longer-term ICU.

FAMILY VISITATION

The American Society of PeriAnesthesia Nurses (ASPAN) points out that allowing family members to visit patients in Level I (immediately postoperative) PACUs can benefit both the patient and the family (ASPAN, 2003b). The ASPAN recommends that PACUs try to accommodate family visits within these guidelines:

• Visits take place only when the PACU staff agrees that it is appropriate for both the patient and the nurses.
• Visitors are given guidance on safe behavior in the PACU.
• Visitors are instructed on respecting the confidentiality of all patients in the PACU.
• There is a formal visitation program that uses personnel other than the on-duty PACU staff to oversee the timing of visits and the preparatory education of visitors.

ADMISSION DELAYS

Delays in PACU admissions are inevitable. The day's surgery schedule can be squeezed by emergencies and delayed by complications. Likewise, the availability of PACU beds and nurses is limited by slow recovery times, medical complications, and bottlenecks in the discharge process. Therefore, a surgeon will occasionally complete a procedure before there is a space for the patient in the PACU.

Even with artful scheduling of surgeries and PACU nurses, it is important to have a preplanned protocol for dealing with delayed admissions to the PACU. Among all the possible solutions, the safest course is usually for the operating anesthesiologist to continue to care for the patient in the operating room until a PACU bed and nurse become available (Dexter et al., 2006).

DISCHARGE DELAYS

Patient discharges are one of the most inefficient parts of the PACU process. One large study found that the average length of a patient's stay in the PACU was 95 minutes, although patients were ready for discharge in an average of 71 minutes. These discharge delays tie up PACU beds and nurses, and the effect propagates back, causing PACU admission delays, which then slow the surgical schedule (Kiekkas et al., 2005a). Because of their additive effects, PACU discharge delays get longer as the day progresses.

Most discharge delays in the PACU are not due to medical problems. Instead, slow discharges are usually due to logistical problems in transferring PACU patients to the next stage in their care (Kiekkas et al., 2005a). The reasons for delay include many typical hospital inefficiencies and miscommunications; specifically, the following things are not always available when needed for a patient being discharged from the PACU:

• Transport assistance
• A physician to authorize or sign discharge forms
• A bed in the receiving unit
• Nurses in the receiving unit
• Test results (Freeley & Macario, 2005)

These problems are inherent in all large hospitals: hospitals are places where many complex activities are carried out simultaneously and where efficiencies must take second place to emergencies and patient care. Nonetheless, looking at the details of PACU delays, Kiekkas and colleagues (2005a) have pointed to two improvements that are feasible and that may have a significant effect.

First, they point out that little attention is usually paid to the scheduling of transporters for PACU discharges, and organizing the transport staff can reduce discharge delays. Second, Kiekkas and colleagues suggest that the PACU staff adopt a policy of notifying the receiving unit 15 to 30 minutes before the anticipated discharge of a patient; this would increase the probability that the receiving unit will be ready when the patient is discharged.

THE PACU

During their recovery from anesthesia, patients must be monitored until they are awake and their vital signs are stable. Most patients have an easy transition from the anesthetized state to stable consciousness. Nonetheless, in an era of complex major surgeries done on increasingly compromised patients, emergence from anesthesia sometimes comes with life-threatening complications. For these reasons, recovery rooms, which were once postsurgical rest stations, are now short-term ICUs called postanesthesia care units, or PACUs.

THE PACU STAFF

The PACU is a specialized division of the anesthesiology department. A PACU is directed by an anesthesiologist, and it is staffed by nurses who are skilled in recognizing and managing airway problems, hypoxemia, hypotension, hypothermia, pain, nausea, and vomiting, as well as the lingering effects of anesthesia and muscle relaxants. PACU nurses must cope with bleeding from surgical sites, hypertension, dysrhythmias, myocardial infarctions, and altered mental states. The nurses carry out these specialized medical tasks in a setting where, at the same instant, there can be patients who are unconscious, emerging from sedation, suffering from acute respiratory or circulatory complications, being admitted, and being discharged.

ADMISSION TO THE PACU

Unless the anesthesiologist specifically orders otherwise, all anesthetized patients should be sent to a PACU for recovery. After a surgical procedure has been completed, the anesthesiologist accompanies the patient to the PACU. There, the anesthesiologist gives a verbal report to a PACU nurse, rechecks the patient, and leaves contact information for the nurse. The nurse usually gives the patient oxygen and then sets up a monitoring schedule for checking the patient's vital signs, blood oxygen saturation, level of consciousness, degree of pain, and degree of nausea.

STAY IN THE PACU AND DISCHARGE

During the patient's stay in the PACU, the attending nurse manages, or gets help for, any complications that develop. Life-threatening complications in the PACU are, in general, infrequent. Nonetheless, PACU nurses regularly deal with postoperative nausea and vomiting (PONV), postoperative pain, respiratory problems, cardiovascular problems, body temperature problems, blood sugar level abnormalities, agitation, delirium, and delayed emergence.

On average, a PACU stay lasts somewhat more than an hour. The discharge process begins when the PACU nurse is convinced that the patient is alert and has vital signs that have been stable for 30 minutes or more. At this point, the nurse contacts the anesthesiologist, who then discharges the patient. Patients who are going to another care unit are turned over to a hospital nurse, who gets a report, medical orders, and further instructions. Patients who are going home are given written instructions and guidelines and must be accompanied by a responsible adult.

CHALLENGES FOR THE PACU STAFF

Running an efficient PACU is a challenge. There are inevitable medication errors, questions about family visitation, the pressure to admit non-postoperative patients, and logistical delays in patient discharges.

One of the most common difficulties is admission delays. At peak times, the patient load can fully occupy a PACU's beds and its staff, and any patients just completing surgery may have to remain in the OR temporarily. Such delays in admission to the PACU can be minimized by arranging each day's surgical schedule to make it likely that the completion times of the operations will be staggered.

Nonetheless, even elective surgery times cannot be predicted accurately, while emergency surgeries will always be unpredictable. Therefore, PACUs must build some flexibility into their staffing rosters. It is ideal, for example, to always have an extra PACU nurse on duty elsewhere in a noncritical service so that they can be paged to help if the PACU should suddenly become busy. In addition, PACUs should have a safety capacity, ie, more available beds than would be necessary for their normal level of use (Weissman, 2005).

Health professionals who advise patients over the telephone should know straightforward answers to basic questions. Here are some common questions and suggested answers about the postsurgical recovery room.

Informational Questions (ASA, 2008)