Same-Day Surgery Reports: Post Anesthesia Guidelines for Same-Day Surgery

Authors: Waseem Ashraf, MD, Clinical Fellow Department of Anesthesia, Toronto Western Hospital, Ontario, Canada; Frances Chung, MD, FRCPC, Medical Director, Ambulatory Surgical Unit and Combined Surgical Unit, Toronto Western Hospital, Professor, Department of Anesthesia, University of Toronto.

Peer Reviewer: J. Lance Lichtor, MD, Professor, Department of Anesthesia, University of Iowa, Iowa City.

Post anesthesia care is the management of a patient after the completion of surgery or a diagnostic procedure and anesthesia or sedation. The American Society of Anesthesiologists (ASA) appointed a task force of 10 members who developed the practice guidelines for post anesthesia care through the analysis of the literature, consultation with specialists in post anesthesia care, a survey of ASA members, and open discussion forums at a major meeting.1 The guidelines examine and provide recommendations for preventive strategies during the perioperative period.

Focus is placed on the prevention and treatment of common postoperative complications events with the goal of improved post anesthetic quality of life, early recovery, and timely discharge. The guidelines are intended for use by anesthesiologists and other health care professionals who direct anesthesia or sedation and analgesia care.

This article reviews these guidelines applicable to same-day surgery. The ASA Post Anesthesia Guidelines are discussed under these subheadings:

  • perioperative patient assessment and monitoring;
  • treatment during emergence and recovery;
  • antagonism of the effects of sedatives, analgesics, and neuromuscular blocking agents; and
  • protocol for discharge.

Perioperative Patient Assessment and Monitoring

The guidelines emphasize the importance of monitoring the patient’s vital signs, neuromuscular functions, mental status, nausea and vomiting, and pain during the postoperative recovery period. Patient outcome can be improved during certain surgical procedures with the monitoring of temperature, drainage and bleeding, fluid intake, and urine output.

  • Respiratory function and mental status. Recovering patients can exhibit inappropriate mental reactions ranging from confusion to extreme disorientation and physical combativeness. Hypoxia can result in altered mental status. The task force advises the use of pulse oximeter to detect hypoxia and recommends that monitoring of airway patency, respiratory rate, oxygen saturation, and mental status will reduce the risk of postoperative complications.
  • Cardiovascular and neuromuscular functions. Monitoring of vital signs, including blood pressure and pulse monitoring rate, during recovery after anesthesia is a standard practice. Electrocardiographic (ECG) monitoring during recovery may not be routine. The members of the task force agree that ECG monitoring should be done on a case-by-case basis during recovery. Physical examination should be routine for all patients with history of neuromuscular dysfunction, and the use of a neuromuscular blockade monitor is recommended especially in cases in which nondepolarizing neuromuscular blocking agents are used.1 Residual paralysis can result in hypoxia and adverse outcome. Adverse consequences may result if the train-of-four ratio is less than 0.9.2
  • Temperature. The potential for heat loss or risk of triggering malignant hyperthermia requires temperature monitoring in selected patients. Perioperative hypothermia results from anesthetic-induced inhibition of thermo regulation, the cold ambient environment in the operating room and heat loss due to surgical exposure also contributes to hypothermia.3 Effects of hypothermia can be detrimental; therefore, the guidelines recommend the patient’s body temperature should be periodically monitored intraoperatively and during early recovery period.1
  • Pain. Review of the literature shows that major morbidity and mortality after an ambulatory procedure is extremely low. However, incidence of postoperative pain is very high, which can result in delay of discharge and increases the incidence of unanticipated hospital admission.4 Furthermore, inadequate pain relief delays return to daily living functions and decreases patient satisfaction. The assessment of the pain is important during the recovery period to avoid complications and thus to ensure early patient discharge.
  • Nausea and vomiting. The incidence of postoperative nausea and vomiting (PONV) is high and often results in delay of discharge after certain types of ambulatory surgical procedures. The consultants and ASA members agree that nausea and vomiting should be assessed routinely to ensure the patient’s comfort and satisfaction to allow early treatment and timely discharge.
  • Fluid intake and urine output. Intravenous fluid therapy (20 mL/kg for eight hours NPO) will reduce the incidence of postoperative thirst, drowsiness, dizziness, and nausea and vomiting in the outpatient.5 The task force suggests agrees that a patient’s hydration status should be assessed in the post anesthesia care unit (PACU). Urine output monitoring may not be routine; it can be used to assess hydration status in some cases. Assessment of voiding may be done for patients with history of voiding difficulty or after certain types of surgical procedures particularly involving urogenital areas.
  • Drainage and bleeding. Surgical procedures that carry higher risk of bleeding require monitoring of blood loss. Fluid loss may be significant through the surgical drains. Depending on the type of procedure, assessment of bleeding and drainage should be performed. (See "Summary of Recommendations for Assessment and Monitoring.")

Treatment During Emergence and Recovery

  • Prophylaxis and treatment of nausea and vomiting. Despite pharmacological and technological advancements, nausea and vomiting remain a common problem and are present in 20% to 30% of patients in the PACU6 and 35% of patients after their discharge home.7 Risk factors for PONV include female gender, previous history of nausea and vomiting, motion sickness, nonsmokers, and use of postoperative opioids.8 Ondansetron and other 5-HT3 antagonist drugs, metoclopramide or droperidol may be used for prophylaxis or therapy. Supplemental oxygen may also decrease the incidence of PONV.9 The practice guidelines state that prophylaxis and treatment of nausea and vomiting should be done selectively. Multiple authors recommend prophylactic use multiple antiemetic drugs for high-risk patients and none for low-risk patients.10-12 Current recommendation by the ASA guidelines is that antiemetic agents should be used for the prevention and treatment of nausea and vomiting when indicated. Multiple agents may be used for the prevention or treatment of nausea and vomiting when indicated.
  • Administration of supplemental oxygen. Supplemental oxygen reduces the risk of hypoxemia in the postoperative period. The ASA guidelines recommend that patients at the risk of respiratory distress and hypoxemia should be treated by with supplemental oxygen in the PACU. Administration of oxygen also is advised for those at risk of hypoxemia during transportation from the OR to the PACU.1
  • Normothermia. The major and minor complications of hypothermia are well documented. Even a small reduction in intraoperative body temperature can produce substantial morbidity in selected patients, such as patients older than 65 years old at risk for postoperative cardiac ischemia.13

    Unless hypothermia is specifically indicated as for protection against ischemia, efforts should be made to maintain core body temperature at or more than 36° C by using devices such as a forced-air warming system.14

  • Postoperative shivering. During emergence from general anesthesia, hypothalamic regulation increases metabolic activity and generates shivering to increase endogenous heat production. As a result, myocardial ischemia or ventilatory failure can occur in patients with coronary artery disease or limited ventilatory reserve. Meperidine is recommended for the control of postoperative shivering,15 and re-warming of patients also should be strongly considered. In case meperidine is contraindicated or is not available, the ASA guidelines recommend that other opioid agonists or agonist-antagonists should be used.

Antagonism of the Effects of Sedatives, Analgesics, and Neuromuscular Blocking Agents

  • Antagonism of benzodiazepines and opioids. Residual sedation is the most frequent cause of somnolence in the PACU.16 Sedation caused by intraoperative opioids or benzodiazepines generally is dose-related. It is recommended that specific antagonists (i.e., naloxone, flumazenil) should be available whenever opioids and benzodiazepines are used. The ASA guidelines advise that the antagonists should not be administered routinely and suggest their use for selected cases of respiratory depression and prolonged sedation. The ASA guidelines also warn practitioners that the recurrence of respiratory depression after antagonism may occur. Acute antagonism of opioids may result in pain, hypertension, tachycardia, and or pulmonary edema.1
  • Reversal of neuromuscular blockade. An increased frequency of emetic episodes has been demonstrated after the use of a high dose of neostigmine (0.5 mg/kg).17 Yet, in ambulatory patients, neuromuscular recovery should be monitored and residual paralysis antagonized, unless there is strong evidence that they are not required.18 [See "Summary of Treatment Recommendations" at under "toolbox." Your user name is your subscriber number from your mailing label. Your password is sds (lowercase) plus your subscriber number.]

Protocol for Discharge

  • Requiring that patients urinate before discharge. Voiding, traditionally, has been considered a prerequisite to discharge to be assured that a patient will not later develop urinary retention. Requiring that patients urinate before discharge may unnecessarily prolong hospital stay. For example, in one study, the incidence of urinary retention after discharge was 0.8% in low-risk patients.19 The ASA guidelines recommend that the routine requirement for urination before discharge should not be part of a discharge protocol. It may be necessary only for selected patients at risk for urinary retention (hernia/anal surgery, spinal/epidural anesthesia, and those with a history of urinary retention). Patients discharged without voiding should be given clear verbal and written instructions to seek medical attention if unable to void within eight hours of discharge.
  • Requiring that patients drink clear fluids without vomiting before discharge. The requirement that oral intake be resumed prior to discharge has been challenged in children, on the grounds that mandatory drinking may in fact provoke nausea and vomiting.20 In a comparative study in adults of mandatory drinkers vs. elective drinkers, neither drinking nor nondrinking worsened the incidence of PONV.21 The requirement to drink clear liquids should not be part of a discharge protocol. Rather, the demonstration of the ability to retain orally administered fluids prior to discharge should be assessed on a case-by-case basis.1
  • Requiring that patients have a responsible individual to accompany them home after discharge. The guidelines recommend that as a part of the recovery room discharge protocol, all patients should be discharged to a responsible adult who will accompany them home and be able to continue supervision overnight and report post-procedure complications.1
  • Requiring a minimum mandatory stay in recovery. The literature is insufficient to suggest the benefits of a minimum PACU mandatory stay. In one study, when the post anesthesia discharge scoring system (PADS) was used to determine the time ambulatory patients were required to stay in the PACU, the majority of patients were discharged within one to two hours of surgery.22 Therefore, it is suggested that the length of stay in the PACU should be determined on a case-by-case basis and the minimum mandatory stay should not be a part of discharge protocol. The ASA guidelines recommend the implementation of discharge criteria to assess the suitability for the discharge. Discharge criteria or a scoring system, such as the Modified Aldrete Scoring System, which assesses activity, respiration, circulation, consciousness, and oxygen saturation, may assist in documentation of fitness for discharge to phase two recovery.23 The PADS (based upon stability of vital signs, absence of PONV, pain, and surgical bleeding) can be used to determine home readiness.3,4,22 (See "Summary of Recommendations for Discharge" and "Summary of Recovery and Discharge Criteria.")


The safe, expeditious conduct of ambulatory surgery can succeed only by appropriate intraoperative and postoperative anesthetic care and prudent, timely discharge of patients. Implementation of practical guidelines for post anesthesia care in every ambulatory surgery center can help achieve this goal. The ASA guidelines apply to patients of all ages who have just received general anesthesia, regional anesthesia, or moderate or deep sedation.

However, it is important to note that the above guidelines provide only basic recommendations and must be applied on an individual case basis with clinical judgment. The use of the preventative strategy strategies will establish high optimal postoperative patient care and avoidance of adverse outcomes. We must ensure that patients are discharged home appropriately by treating PONV and other side effects effectively, which will result in optimum patient satisfaction and early return to full daily living function.


1. Practice Guidelines for Post Anesthetic Care: A report by the American Society of Anesthesiologists Task Force on Post Anesthetic Care. Anesthesiology 2002; 96:742-752.

2. Erikkson LI, Sundman E, Olsson R, et al. Functional assessment of the pharynx at rest and during swallowing in partially paralyzed humans. Anesthesiology 1997; 87:1,035-1,043.

3. Sessler DI. Perioperative hypothermia. N Engl J Med 1997; 336:1,730-1,737.

4. Chung F, Ritchie SUJ. Post operative pain in ambulatory surgery. Anaesth Analg 1997; 85:808-816.

5. Yogendran S, Asokumar B, Cheng DCH, et al. A prospective randomized double blinded study of the effect of intravenous fluid therapy on adverse outcome on outpatient surgery. Anesth Analg 1995; 80:682-686.

6. Watcha MF. The cost effective management of post operative nausea and vomiting. Anesthesiology 2000; 92:931-933.

7. Carroll NV. Post operative nausea and vomiting after discharge from outpatient centers. Anesth Anal 1995; 80:903-909.

8. Apfel C, Laara E, Koivuranta M, et al. A simplified risk score for predicting post operative nausea and vomiting: Conclusion from cross-validations between two centers. Anesthesiology 1999; 91:963-700.

9. Greif R, Laciny S, Rapt B, et al. Supplemental oxygen also reduces the incidence of post operative nausea and vomiting. Anesthesiology 1999; 91:1,246-1,252.

10. Watcha MF, White PF. Post operative nausea and vomiting, prophylaxis versus treatment. Anesthesia Analg 1999; 89:1,337-1,339.

11. Mekenzie R, Tantisina B, Karambelkar DJ, et al. Comparison of Ondansetron with Ondansetron plus dexamethasone in the prevention of post operative nausea and vomiting. Anesth Analg 1994; 79:761-764.

12. White PF, Mehernoor F, Watcha MF. Post operative nausea and vomiting; prophylaxis vs. treatment. Anesth Analg 1999; 89:1,337-1,339.

13. Backlund M, Lepantalo M, Toivonen L. Factors associated with post operative myocardial ischemia in elderly patients undergoing major noncardiac surgery. European J Anesth 1999; 16:826-833.

14. Casati A, Fanelli G, Ricci A. Shortening the discharging time after total hip replacement under combined spinal and epidural anesthesia by actively warming the patient during the surgery. Minerva Anestesiologica 1999; 65:507-514.

15. Alfonsi P, Sessler DI. The effects of Mepridine and sufentamil on the shivering threshold in post operative patients. Anesthesiology 1998; 89:43-89.

16. Denlinger JK. "Prolonged Emergence and Failure to Regain Consciousness." In: Orkin FK, Cooperman LH. Complications in Anesthesiology. Philadelphia: JB Lippincott; 1993, p. 368.

17. Lovstad RZ, Thagaard KS, Beiner NS, et al. Neostigmine 50 mcg/kg with glycopyropate increases post operative nausea in women after laproscopic gynecological surgery. ACTA Anaesth Scand 2001; 45:495-500.

18. Fuchs-Budert T, Mencke T. Use of reversal agents in day care procedures (with special reference to post operative nausea and vomiting). Engl J of Anesth 2001; 18(sup 23):53-59.

19. Pavlin DJ, Rapp SE, Polissar NL, et al. Factors affecting discharge time in adult outpatients. Anesth Analg 1998; 87:816-826.

20. Schreiner MS, Nicholson SC, MartinT, et al. Should children drink before discharge from day surgery? Anesthesiology 1992; 76:528-533.

21. Jin F, Norris A, Chung F, et al. Should adult patients drink before discharge from ambulatory surgery? Anesth Analg 1998; 87:306-311.

22. Chung F. Recovery pattern and home readiness after ambulatory surgery. Anesth Anlag 1995; 80:896-902.

23. Aldrete JA. The post anesthesia recovery score revisited (letter). J Clin Anesth 1995; 7:89-91.

CME Objectives & Questions

After participating in this CE/CME activity, the learner will be able to:

  • Explain hypoxia during emergence and recovery.
  • List one way to address PONV.
  • List one example of a way to avoid delaying discharge.

1. Which of the following statements is false?

Hypoxia during emergence and recovery:

A. can be avoided by periodic assessment of airway patency and respiratory rate.

B. can be avoided by using supplemental oxygen.

C. can result in confusion, disorientation, and combative behavior.

D. should be treated by meperidine.

2. Which of the following statements is true?

The incidence of PONV is high and:

A. prophylactic combination therapy should be given to all patients.

B. avoidance of neostigmine for the reversal of neuromuscular blockade always will reduce PONV.

C. prophylactic administration of antiemetics can reduce PONV in high-risk patients.

D. mandatory drinking will reduce PONV by alleviating dehydration.

3. All of following are true except:

Delay in discharge can be avoided by:

A. adapting a discharge criteria or scoring system.

B. routinely antagonizing any postoperative sedation with naloxone.

C. assessing time required for minimum patient’s stay after surgery on a case-by-case basis.

D. avoiding the requirement to urinate prior to discharge in low-risk patients.