Postanesthesia care unit (PACU)

• The location where the patient is brought for immediate recovery.
• This period is managed by a postanesthesia care nurse.
• Located adjacent to the operating room (OR)
• Three phases of postanesthesia care that provide different levels of care depending on the wide variety of patients' needs:
• Types of surgeries
• Surgical settings
• Levels of anesthesia

Phase I of postanesthsia care

• Care during the immediate postanesthesia period
• ECG and more intense monitoring
• Goal: prepare patient for transfer to Phase II or inpatient unit
• If stable and recovering well, patient may rapidly progress through Phase I to discharge to ether Phase II care or an inpatient unit.
• This accelerated progress is called rapid postanesthesia care unit progression (RPP).

Fast-tracking

• Another accelerated system of care, which involves admitting ambulatory surgery patients who have received general, regional, or local anesthesia directly to Phase II.
• Decreases overall recovery time, length of hospital stay, hospital costs and medical morbidity.

Pulse oximetry and carbon dioxide pressure monitoring

• The greatest value of pulse oximetry is to provide an early warning of hypoxemia and changes in arterial blood gases.
• Recent observational studies suggest that transcutaneous carbon dioxide pressure (PtcCO2) monitoring is a more sensitive indicator of respiratory depression.

Phase II of postanesthesia care

• Ambulatory surgery patients
• Goal: prepare patient for transfer to extended observation, home, or extended care facility

Extended observation of postanesthesia care

• Extended care/observation unit
• Goal: Prepare patient for self-care

Postanesthesia admission report

• General information
• Patient name
• Age
• Anesthesia care provider
• Surgeon
• Surgical procedure
• Patient History
• Indication for surgery
• Medical history, medications, allergies
• Intraoperative management
• Anesthesia medications
• Other medications received postoperatively or intraoperatively
• Blood loss
• Fluid replacement totals, including blood transfusions
• Urine output
• Intraoperative course
• Unexpected anesthetic events or reactions
• Unexpected surgical events
• Baseline and most recent vital signs and monitoring trends
• Results of intraoperative laboratory tests

Initial postanesthesia care unit assessment

• Airway
• Patency
• Oral or nasal airway
• Endotracheal tube
• Breathing
• Respiratory rate and quality
• Auscultated breath sounds
• Pulse oximetry
• Supplemental oxygen
• Circulation
• ECG monitoring—rate and rhythm
• Blood pressure
• Temperature
• Capillary refill
• Color of skin
• Peripheral pulses
• Neurologic
• Level of consciousness
• Orientation
• Sensory and motor status
• Pupil size and reaction
• Genitourinary
• Intake (fluids, irrigations)
• Output (urine, drains)
• Surgical site
• Dressing/drainage
• Pain
• Incision
• Other

Clinical manifestations of inadequate oxygenation

• Central nervous system
• Restlessness
• Agitation
• Muscle twitching
• Seizures
• Coma
• Cardiovascular system
• Hypertension
• Hypotension
• Tachycardia
• Bradycardia
• Dysrhythmias
• Delayed capillary refill
• Decreased oxygen saturation
• Integumentary system
• Flushed and moist skin
• Cyanosis
• Respiratory system
• Increased to absent respiratory effort
• Use of accessory muscles
• Abnormal breath sounds
• Abnormal arterial blood gases
• Renal system
• Urine output <0.5 mL/kg/hr

Potential respiratory problems in the immediate postanesthesia period

• Most common causes of airway compromise include obstruction, hypoxemia, and hypoventilation.
• Patients at high risk include those who have had general anesthesia, are older, have a smoking history, have lung disease, are obese, or have undergone airway, thoracic, or abdominal surgery.

About hypoxemia

• A partial pressure of arterial oxygen (PaO2) less than 60 mm Hg.
• Characterized by a variety of nonspecific clinical signs and symptoms, ranging from agitation to somnolence, hypertension to hypotension, and tachycardia to bradycardia.

Airway obstruction

• Tongue falling back
• Mechansims
• Muscular flaccidity associated with a decrease in consciousness and muscle relaxants
• Manifestations
• Use of accessory muscles
• Snoring respirations
• Decrease air movement
• Interventions
• Patient stimulation
• Jaw thrust
• Chin lift
• Artificial airway
• Retained thick secretions
• Mechanisms
• Secretion stimulation by anesthetic agents
• Dehydration of secretions
• Manifestations
• Noisy respirations
• Coarse crackles
• Interventions
• Suctioning
• Deep breathing and coughing
• IV hydration
• Chest physical therapy
• Laryngospasm
• Mechanisms
• Irritation from endotracheal tube or anesthetic gases
• Most likely to occur after removal of endotracheal tube
• Manifestations
• Inspiratory stridor (crowing respirations)
• Sternal retraction
• Acute respiratory distress
• Interventions
• O2
• Positive pressure ventilation
• IV muscle relaxant
• Lidocaine
• Corticosteroids
• Laryngeal edema
• Mechanisms
• Allergic drug reaction
• Mechanical irritation from intubation
• Fluid overload
• Manifestations
• Similar to laryngospasm
• Interventions
• O2
• antihistamines
• Corticosteroids
• Sedatives
• Possible intubation

Hypoxemia

• Atelectasis
• Mechanisms
• Bronchial obstruction caused by retained secretions or decreased lung volumes
• Manifestations
• Decreased breath sounds
• Decreased O2 saturation
• Interventions
• Humidified O2
• Deep breathing
• Incentive spirometry
• Early mobilization
• Pulmonary edema
• Mechanisms
• Fluid overload
• Increased hydrostatic pressure
• Decreased interstitial pressure
• Increased capillary permeability
• Manifestations
• Decreased O2 saturation
• Crackles
• Infiltrates on chest x-ray
• Interventions
• O2 therapy
• Diuretics
• Fluid restriction
• Pulmonary embolism
• Mechanisms
• Thrombus dislodged from peripheral venous system
• lodged in pulmonary arterial system
• Manifestations
• Acute tachypnea
• Dyspnea
• Tachycardia
• Hypotension
• Decreased O2 saturation
• Bronchospasm
• Interventions
• O2 therapy
• Cardiopulmonary support
• Anticoagulant therapy
• Aspiration
• Mechanisms
• Inhalation of gastric contents into lungs
• Manifestations
• Unexplained tachypnea
• Bronchospasm
• Decreased O2 saturation 
• Atelectasis
• Interstitial edema
• Alveolar hemorrhage
• Respiratory failure
• Interventions
• O2 therapy
• Cardiac support
• Antibiotics
• Bronchospasm
• Mechanisms
• Increased smooth muscle tone with closure of small airways
• Manifestations
• Wheezing
• Dyspnea
• Tachypnea
• Decreased O2 saturation
• Interventions
• O2 therapy
• Bronchodilators

Hypoventilation

• Depression of central respiratory drive
• Mechanisms
• Medullary depression from anesthetics/opioids/sedatives
• Manifestations
• Shallow respirations
• Decreased respiratory rate/apnea
• Decreased PaO2
• Increased PaCO2
• Interventions
• Stimulation
• Reversal of opioids/benzodiazepines
• Mechanical ventilation
• Poor respiratory muscle tone
• Mechanisms
• Neuromuscular blockade
• Neuromuscular disease
• Manifestations
• As above
• Interventions
• Reversal of paralysis
• Mechanical ventilation
• Mechanical restriction
• Mechanisms
• Tight casts, dressings, positioning and obesity preventing lung expansion
• Manifestations
• As above
• Interventions
• Elevate head of bed
• Repositioning
• Loosen dressings
• Pain
• Mechanisms
• Shallow breathing to prevent incisional pain
• Manifestations
• Increased respiratory rate
• Hypotension
• Hypertension
• Decreased PaCO2
• decreased PaO2
• Complaints of pain
• Guarding behavior
• Interventions
• Opioid analgesic therapy in reduced dose
• Nonsteroidal antiinflammatory drug therapy
• Adjunctive complementary and alternative therapies (e.g., music therapy, guided imagery)

Two most common causes of respiratory problems for postoperative patients

• Atelectasis
• Pneumonia

Safety alert-positioning

Most common cause of hypotension in PACU

Cauterization

Chronotropic

Inotropic

Primary cardiac dysfunction

• May occur in the case of myocardial infarction, cardiac tamponade, or pulmonary embolism.
• Results in an acute fall in cardiac output.

Secondary myocardial dysfunction

• Occurs as a result of the negative chronotropic and negative inotropic effects of drugs, such as β-adrenergic blockers, digoxin, or opioids.

Hypertension

• A common finding in the PACU, is most frequently the result of sympathetic nervous system stimulation that may be the result of pain, anxiety, bladder distension, or respiratory compromise.
• May also be the result of hypothermia and preexisting hypertension.
• May be seen after vascular and cardiac surgery as a result of revascularization.

Dysrhythmias

• Are often the result of an identifiable cause other than myocardial injury.
• The leading causes include hypoxemia, hypercapnia, alterations in electrolyte and acid-base status, circulatory instability, and preexisting heart disease.
• Hypothermia, pain, surgical stress, and many anesthetic agents are also capable of causing dysrhythmias.

Fluid and electrolytes

• Postoperative fluid and electrolyte imbalances are contributing factors to cardiovascular problems.
• Fluid retention results from the secretion and release of two hormones by the pituitary—antidiuretic hormone (ADH) and adrenocorticotropic hormone (ACTH)—and activation of the renin-angiotensin-aldosterone system.
• Fluid deficits from untreated preoperative dehyration, intraoperative blood losses, or slow or inadequate fluid replacement can lead to decreases in cardiac output and tissue perfusion.
• Hypokalemia can be a consequence of urinary and gastrointestinal (GI) tract losses, and it occurs when potassium is not replaced in IV fluids.
• Replacement of potassium is usually 40 mEq/day. However, potassium should not be given until renal function has been assessed. 
• A urine output of at least 0.5 mL/kg/hr is generally considered indicative of adequate renal function.

Pulmonary embolism

How often are vital signs mnitored in post operative patients

Emergence delirium

• "Waking up wild"
• Can include behaviors such as restlessness, agitation, disorientation, thrashing, and shouting.
• May be caused by anesthetic agents, hypoxia, bladder distension, pain, residual neuromuscular blockade, or the presence of an endotracheal tube.

Delayed emergence

• May be a problem postoperatively
• Most common cause is prolonged drug action, particularly of opioids, sedatives, and inhalation anesthetics, as opposed to neurologic injury

Postoperative cognitive impairments

1. Postoperative cognitive dysfunction (POCD)
• A decline in the patient's cognitive function (e.g., memory, ability to concentrate) for weeks or months after surgery.
• Is almost exclusively seen in the older surgical patients.
2. Postoperative delirium
• More commonly seen in the older patient, but it can occur in patients of any age.
• May be the result of a variety of psychologic and physiologic factors, including fluid and electrolyte imbalances, hypoxemia, drug effects, sleep deprivation, and sensory deprivation or overload.
• Is characterized by cognitive dysfunction, varying levels of consciousness, altered psychomotor activity, and a disturbed sleep/wake cycle.

Alcohol withdrawal delirium

• Occurs as a result of alcohol withdrawal in a postoperative patient.
• Characterized by restlessness, insomnia and nightmares, irritability, and auditory or visual hallucinations.

Most common cause of postoperative agitation in PACU

Patient controlled analgesia (PCA) and epidural analgesia

• Two alternative approaches for pain control.
• PCA
• Goals of PCA are to provide immediate analgesia and to maintain a constant, steady blood level of the analgesic agent.
• PCA involves self-administration of predetermined doses of analgesia by the patient.
• The route of delivery may be IV, oral, epidural, or transdermal.
• Transdermal route is designed for short-term pain management.
• Some advantages of PCA are early ambulation, better pain management than with PRN analgesia, and greater patient satisfaction.
• Epidural analgesia 
• The infusion of opioid analgesics through a catheter placed into the epidural space surrounding the spinal cord.
• The goal is delivery of medication directly to opiate receptors in the spinal cord.

Hypothermia

• A core temperature less than 95° F (35° C)
• Occurs when heat loss exceeds heat production.

Significance of postoperative temperature changes

• Time after surgery
• Up to 12 hr
• Temperature
• Hypothermia to 95° F (35° C)
• Possible causes
• Effects of anesthesia, body heat loss during surgical procedure
• Time after surgery
• First 48 hr. (days 1 and 2)
• Temperature
• Mild elevation: up to 100.4° F (38° C)
• Moderate elevation: above 100.4° F (38° C)
• Possible causes
• Inflammatory response to surgical stress
• Lung congestion, atelectasis, dehydration
• Time after surgery
• After first 48 hr. (day 3 and later)
• Temperature
• Elevation above 100° F (37.7°C)
• Possible causes
• Infection (e.g., wound infection, urinary infection, respiratory infection)

Passive rewarming

Active rewarming

• Involves the application of external warming devices, including warm blankets, heated aerosols, radiant warmers, forced air warmers, and heated water mattresses.
• Body temperature should be monitored at 30-minute intervals.
• The postoperative nurse should measure the patient's temperature every 4 hours for the first 48 hours post-operatively and then leff frequently if no problem develops.

Most common postoperative complications

• Nausea
• Vomiting

Singultus

Oliguria

The diminished  output of urine.

Urinary assessment

• Indwelling catheters should be assessed for patency, and urine output should be at least 0.5 mL/kg/hr.
• Most patients urinate within 6 to 8 hours after surgery.

Expected drainage from indwelling catheters

• Substance
• Urine
• Daily Amount
• 800-1500 mL for first 24 hr
• minimal expected output: 0.5 mL/kg/hr
• Color
• Clear, yellow
• Odor
• Ammonia
• Consistency
• Watery

Expected drainage from nasogastric tube/gastostomy tube

• Substance
• Gastric contents
• Daily amount
• Up to 1500 mL/day
• Color
• Pale, yellow-green
• Bloody following gastrointestinal surgery
• Odor
• Sour
• Consistency
• Watery

Expected drainage from hemovac

• Substance
• Wound drainage
• Daily Amount
• Variable with procedure
• May decrease over hours or days
• Color
• Variable with procedure
• Initially, may be sanguineous or serosanguineous, changing to serous
• Odor
• Same as wound dressing
• Consistency
• Variable

Expected drainage from T-tube

• Substance
• Bile
• Daily Amount
• 500 mL
• Color
• Bright yellow to dark green
• Odor
• Acid
• Consistency
• Thick

Postanesthesia and ambulatory surgery discharge criteria

• Postanesthesia discharge criteria (Phase I)
• Patient awake (or baseline)
• Vital signs baseline or stable
• No excess bleeding or drainage
• No respiratory depression
• Oxygen saturation >90%
• Report given
• Ambulatory surgery discharge criteria (Phase II/Extended observation)
• All PACU discharge criteria met
• no IV opioid drugs for last 30 min
• Minimal nausea and vomiting
• Voided (if appropriate to surgical procedure/orders)
• Able to ambulate if age appropriate and not contraindicated
• Responsible adult present to accompany patient
• Written discharge instructions given and understood