Postoperative Nausea and Vomiting – PONV

Risk Factors

  • Patient Factors
    • Female gender
    • History of PONV or motion sickness
    • Non-smoking status
    • Younger age
  • Anesthetic factors
    • Volatile anesthetics
    • Longer duration of anesthesia
    • Perioperative opioid use
    • Nitrous oxide use
  • Surgical factors
    • Abdominal procedures
    • Gynecological/breast surgery
    • ENT surgery
    • Strabismus surgery
    • Urologic surgery

Strategies to Reduce Baseline Risk

  • Avoidance of general anesthesia by the use of regional anesthesia
  • Use of propofol for induction and maintenance of anesthesia
  • Avoidance of nitrous oxide
  • Avoidance of volatile anesthetics
  • Minimization of intraoperative and postoperative opioids
  • Adequate hydration

Source: Consensus guidelines for the management of postoperative nausea and vomiting

Respiratory and Airway Problems

Common Causes of Respiratory Insufficiency in the PACU


  • Residual anesthesia
  • Residual muscle relaxant
  • Postop opioids
  • Splinting 2o to pain
  • Tight abdominal binder
  • Obstructive sleep apnea/obesity
  • Premature infants/neonates

Upper Airway Obstruction

  • Airway edema
  • Trauma
  • Vocal cord paralysis
  • Arytenoid dislocation
  • Secretions
  • Foreign body
  • Laryngospasm
  • Anxiety/Munchausen’s stridor


  • Atelectasis
  • Asthma/COPD exacerbation
  • CHF/fluid overload
  • Pulmonary embolism
  • Aspiration
  • Pneumo/hemothorax pleural effusion
  • Diaphragmatic injury/paralysis
  • Pneumonia

Respiratory Insufficiency: Diagnosis & Management

  1. Assess Airway, Breathing, Circulation
  2. ↑ delivered FiO2, ↑ flow rate and consider non-rebreather or shovel mask
  3. Consider jaw thrust/chin lift, placement of oral/nasal airway
  4. Consider positive-pressure ventilation with bag-valve mask
  5. Consider intubation vs. noninvasive ventilation (CPAP/BiPAP)
  6. Review patient history, OR and postop course, fluid status, and medications administered
  7. Consider ABG, chest X-ray (rule out pneumothorax/pulmonary edema)

Treatment of Hypoventilation

Source: D. Keith Rose, Marsha M. Cohen, Dan F. Wigglesworth, Don P. DeBoer; Critical Respiratory Events in the Postanesthesia Care Unit: Patient, Surgical, and Anesthetic FactorsAnesthesiology 1994; 81:410–418 



Common Causes of Hypertension in the PACU

  • Pain
  • Anxiety
  • Respiratory insufficiency (hypoxia, hypercarbia)
  • Hyperthermia/shivering
  • ↑ sympathetic activity
  • ↑ ICP
  • Essential hypertension/missed medications
  • Fluid overload
  • Endocrine disease (thyroid storm, pheochromocytoma)
  • Error in measurement (inappropriate cuff size, machine malfunction)


  • Treat underlying cause, resume home antihypertensives
  • For initial treatment, consider:
    • Labetalol 5-40 mg IV bolus q 10 minutes
    • Hydralazine 2.5-20 mg IV bolus q 10-20 minutes
    • Lopressor 2.5-10 mg IV bolus


Delayed Awakening

Causes of Delayed Awakening in PACU

Anesthesia related

  • Residual anesthetic
  • Residual muscle relaxant, pseudocholinesterase deficiency
  • Excessive narcotics


  • Hypothermia
  • Hypoxemia
  • Hypercarbia/hyponatremia/hypocalcemia/hypoglycemia
  • Renal/hepatic failure

Intracranial event

  • Stroke/cerebrovascular incident (CVA)
  • Seizure
  • Intracranial hypertension


  • Perform complete neuro assessment (cranial, motor, & sensory nerves)
  • Review anesthetic record for drugs/doses
  • Check for residual muscle relaxant with train-of-four/tetany
  • Send ABG, serum sodium/calcium/glucose levels, check pt temp
  • Consider application of bispectral index/EEG
    • Low bispectral index may be suggestive of residual anesthetic
    • EEG can assess for seizure activity
  • Consider neurologic imaging to assess for stroke (noncontrast CT/MRI brain)
  • Consider pseudocholinesterase deficiency (family hx, pseudocholinesterase level, dibucaine number)


  • Consider narcotic reversal if slow respiratory rate + pin point pupils
    • administer naloxone (0.04 mg IV q2min up to 0.2mg IV)
  • Consider benzo reversal with flumazenil (0.2 mg IV q2min up to 1 mg IV)
  • Reverse muscle relaxants, correct electrolyte abnl, rewarm pt as indicated

Other Specific Conditions



Tachycardia, hypotension, low CVP/PCWP, respiratory variation in arterial waveform, IVC collapse/underfilled LV on echo


Fluid resuscitation, assess for causes (ongoing bleeding, diuresis, high NG outout)



Tachycardia, anemia, hypovolemia, sanguineous drain output


Fluid resuscitation, blood transfusion, correct coagulopathy & thrombocytopenia, treat hyperthermia, consider return to OR



Fever, leukocytosis, tachycardia, hypovolemia, lactic acidosis


Fluid resuscitation, obtain blood/specific cultures, initiate broad-spectrum antibiotics

Myocardial Infarction/Ischemia


12-lead ECG, TTE/TEE, cardiac enzymes, cardiology consult


Cautious fluid resuscitation, aspirin, discuss with cardiologist & surgeon role of heparinization/cardiac cath/antiplatelet agents; consider inotropic/vasopressor/IABP support; may initiate diuresis/beta-blockade once BP stabilized



12-lead ECG, cardiac enzymes, check electrolytes, ABG


Treat the cause, follow ACLS protocol

  • Tachyarrhythmia: Electrical/chemical cardioversion, correct electrolytes, cardiology consultation, maintenance antiarrhythmics
  • Bradyarrhythmia: Atropine/epinephrine/dopamine, transcutaneous transvenous pacing, cardiology consult



Stop the drug, administer antagonist agent (e.g., naloxone for morphine)

Pulmonary Embolism


  • ECG – sinus tach/S1Q3T3; ultrasound of lower ext; D-dimer not helpful
  • TTE/TEE – rule out central pulm embolism/assess RV dysfx
  • V/Q scan/CT chest pulm angiogram when stable


  • Cautious fluid resuscitation, invasive monitoring, inotropes/pressors
  • Consider thromboembolectomy/catheter-directed thrombolysis/anticoagulation/IVC filter placement

Congestive Heart Failure


  • Bibasilar crackles, frothy sputum on examination
  • Chest x-ray – cephalization of blood vessels, pulmonary edema, ↑ cardiac shadow
  • Invasive hemodynamic monitoring shows low cardiac output, ↑ filling pressures


Supplemental O2, diuresis, digoxin/inotropic support



  • Tachycardia, vasodilatory shock (low SVR, high cardiac output)
  • Check serum tryptase & eosinophil count, consult allergy


Remove causative agent, fluid resuscitation, diphenhydramine, steroids, epinephrine



Chest x-ray may reveal foreign body, infiltrates, atelectasis or collapse


  • Supportive care for small aspirations (no respiratory compromise)
  • Large aspirations: Rapid sequence intubation, gastric decompression, mechanical ventilation with high PEEP, bronchoscopy to remove large foreign bodies; prophylactic antibiotics & steroids are ineffective; bronchoalveolar lavage & routine suctioning should not be performed
  • Prevent recurrence: Elevate head of bed, avoid sedation, place NG tube

Upper Airway Obstruction/Stridor


Airway edema/trauma, vocal cord paralysis, arytenoid dislocation, secretions, foreign body


  • Racemic epinephrine, dexamethasone, humidifies air, heliox
  • Treat secretions with suctioning & admin of glycopyrrolate (0.2 mg IV)
  • Severe edema/trauma may necessitate reintubation
  • Obtain ENT consult for vocal cord paralysis/arytenoid dislocation/removal of foreign body

Pneumothorax/Hemothorax/Pleural Effusion


Chest x-ray diagnostic most of the time


  • Needle decompression of chest (2nd intercostal space in midclavicular line), chest tube decompression (also see Chapter 11, Anesthesia Procedures)
  • Exploratory thoracotomy for large hemothorax/ongoing bleeding

PACU Discharge Criteria

Phase 1: Starts with pt entering PACU from OR till criteria are met for transfer to phase 2 in PACU/hospital room/ICU (Note: patients are not discharged home from phase 1)

Phase 2: Starts with completion of phase 1, ends with patient discharge to home

Common Discharge Issues (Anesthesiology 2002;96:742–752)

  • Passing of urine is not a mandatory requirement
  • Ability to drink and retain fluids is not mandatory
  • There is no minimum PACU stay period
  • Escort is needed if patient received any sedation