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Background: The suitability of ambulatory surgery for patients with obstructive sleep apnea (OSA) remains controversial. This systematic review and meta-analysis aimed to evaluate the odds of perioperative adverse events in patients with OSA undergoing ambulatory surgery, compared to patients without OSA., Methods: Four electronic databases were searched for studies published between January 1, 2011 and July 11, 2023. The inclusion criteria were: adult patients with diagnosed or high-risk of OSA undergoing ambulatory surgery; perioperative adverse events; control group included; general and/or regional anesthesia; and publication on/after February 1, 2011. We calculated effect sizes as odds ratios using a random effects model, and additional sensitivity analyses were conducted., Results: Seventeen studies (375,389 patients) were included. OSA was associated with an increased odds of same-day admission amongst all surgery types (OR 1.94, 95% CI 1.46-2.59, I 2 :79%, P < 0.00001, 11 studies, n = 347,342), as well as when only orthopedic surgery was considered (OR 2.68, 95% CI 2.05-3.48, I 2 :41%, P < 0.00001, 6 studies, n = 132,473). Three studies reported that OSA was strongly associated with prolonged post anesthesia care unit (PACU) length of stay (LOS), while one study reported that the association was not statistically significant. In addition, four studies reported that OSA was associated with postoperative respiratory depression/hypoxia, with one large study on shoulder arthroscopy reporting an almost 5-fold increased odds of pulmonary compromise, 5-fold of myocardial infarction, 3-fold of acute renal failure, and 5-fold of intensive care unit (ICU) admission., Conclusions: Ambulatory surgical patients with OSA had almost two-fold higher odds of same-day admission compared to non-OSA patients. Multiple large studies also reported an association of OSA with prolonged PACU LOS, respiratory complications, and/or ICU admission. Clinicians should screen preoperatively for OSA, optimize comorbidities, adhere to clinical algorithm-based management perioperatively, and maintain a high degree of vigilance in the postoperative period., Competing Interests: Declaration of competing interest This research did not receive any grants or funding., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose of Review: The perioperative outcome in obstructive sleep apnea (OSA) patients undergoing ambulatory surgery can be potentially impacted by the type of anesthetic technique, fluid management and choice of anesthetic agents. This review highlights the best perioperative practices in the management of OSA patients undergoing ambulatory surgical procedures., Recent Findings: A recent meta-analysis found that STOP-Bang might be used as a perioperative risk stratification tool. Patients with high-risk OSA (STOP-Bang ≥3) were found to be associated with an increased risk of postoperative complications and prolonged length of hospital stay compared with low-risk OSA (STOP-Bang 0-2) patients undergoing noncardiac surgical procedures. A bidirectional relationship exists between OSA and difficult airway. Both suspected or diagnosed OSA may be associated with either difficult intubation or difficult mask ventilation or both. A recent meta-analysis identified OSA as an important risk factor for opioid-induced respiratory depression. A dose-response relationship was shown between the morphine equivalent daily dose and death or near-death events in OSA patients undergoing surgery. Postoperative continuous monitoring is recommended for high-risk OSA patients receiving opioids. Minimising the dose of muscle relaxant, neuromuscular monitoring and ensuring complete reversal of neuromuscular blockade before extubation is essential in OSA patients to avoid postoperative complications. Whenever feasible, regional anesthesia with multimodal analgesia may be considered as a better alternative to general anesthesia in OSA patients., Summary: Patients with OSA and associated comorbidities present a challenge to anesthesiologists as they are at a high risk of perioperative complications. It is important to identify patients with OSA, with the goal to raise awareness among providers, mitigate risk and improve outcomes.

Purpose: Studies comparing the recently introduced Ambu® AuraGain™ (Auragain) with the LMA® Supreme™ (Supreme) supraglottic airway (SGA) have reported conflicting results regarding differences in oropharyngeal leak pressure (OLP). This randomized-controlled trial investigated the OLP of the Auragain compared with the Supreme in patients undergoing ambulatory surgery., Methods: Adult patients with a body mass index ≤ 40 kg·m -2 presenting for ambulatory surgery and requiring an SGA were randomized to receive either the Auragain or the Supreme. Anesthesia was induced with lidocaine (1 mg·kg -1 ), fentanyl (1-2 μg·kg -1 ), and propofol (2-3 mg·kg -1 ). The SGA was inserted using a standard technique with the cuff inflated to 60 cmH 2 O. The groups were compared for the primary outcome of OLP., Results: One hundred sixty-five patients (n = 81, Auragain; n = 84, Supreme) completed the study. Demographics were similar between the groups. The mean (standard deviation [SD]) OLP was significantly higher in the Auragain than in the Supreme group [26.4 (2.8) cmH 2 O vs 21.6 (3.4) cmH 2 O, respectively; difference in means (MD), 4.8 cmH 2 O; 95% confidence interval (CI), 3.9 to 5.8; P < 0.001]. The mean (SD) insertion time was longer in the Auragain than in the Supreme group [13 (4) sec vs 11 (3) sec, respectively; MD, 2 sec; 95% CI, 1 to 3 sec; P < 0.001]., Conclusion: In patients undergoing ambulatory anesthesia, the OLP was higher but took longer to insert with the Auragain than with the Supreme. A higher OLP may allow for SGAs to be utilized in a wider range of patients and procedures., Trial Registration: www.clinicaltrials.gov (NCT02816463). Registered 28 June 2016.

Purpose of Review: Incidence of obesity continues to rise and ambulatory surgical centers will need to be prepared for the increase in the obese surgical patients. This review aims to provide recent updates in managing the obese patients in an ambulatory surgical center and to address key clinical questions, such as patient selection, assessment and optimization, as well as important perioperative consideration., Recent Findings: With low rate of major intraoperative adverse events, obesity has not been associated with unplanned admission after day surgical procedures. There is, however, a higher rate of perioperative adverse events in the super-obese patients. Recent developments in patient assessment include validation of STOP-Bang questionnaire for obstructive sleep apnea in the obese population. Nevertheless, patients with obesity hypoventilation syndrome should be identified and optimized as they are more prone to develop adverse events. The obese patients are also at a higher risk of difficult airway, and recommendations for the airway management are available., Summary: With extra considerations and meticulous perioperative management, it is well tolerated to accept obese patients for ambulatory surgery. The super-obese patients, however, are at a higher risk for perioperative adverse events.

The prevalence of obstructive sleep apnea (OSA) is increasing and a significant number of patients with OSA are undiagnosed. The suitability of ambulatory surgery in patients with OSA remains controversial, and the evidence regarding the safety of ambulatory surgery for patients with OSA is limited. Preoperative screening and careful selection of patients for ambulatory surgery is the most important step. Patients diagnosed and suspected of having OSA should be managed with a systematic algorithm to improve outcomes., (Copyright © 2014 Elsevier Inc. All rights reserved.)

With the continuous increase in the numbers and complexity of cases being done as ambulatory procedures, striking a balance between operational efficiency, patient safety, and patient satisfaction has become increasingly difficult. This article summarizes the latest evidence and consensus with regard to discharging an ambulatory patient home, the use of patient recovery scoring systems for protocol-based decision making, the concept of fast-track recovery, and requirements for patient escort. Fast-tracking (ie, bypassing the postanesthesia care unit) is an acceptable and safe pathway, provided careful patient selection and assessment are performed., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Background: The incidence of obesity has increased over the past 2 decades. In recent years, several studies have assessed perioperative outcomes in obese patients undergoing ambulatory surgery. However, this evidence has not been reviewed and evaluated systematically., Methods: We conducted a systematic review of studies published between 1948 and May 2012, assessing perioperative outcome in adult obese patients undergoing ambulatory surgery. All studies were eligible for inclusion if they reported perioperative complications including unplanned hospital admission and readmission., Results: A literature search revealed 23 studies (13 prospective and 10 retrospective), and 1 systematic review assessing laparoscopic bariatric surgery. A total of 106,119 patients were included in the analysis with 62,476 patients included in the prospective trials and 43,643 patients included in the retrospective trials (not including the systematic review of laparoscopic bariatric surgery). Of these, 39,548 patients underwent bariatric surgery. The super obese (body mass index [BMI] >50 kg/m) appear to be at higher risk of complications. Patients undergoing nonbariatric surgery had a lower degree of obesity (BMI approximately 30 kg/m). Patients undergoing bariatric surgery were morbidly obese (BMI >40 kg/m), which is associated with a higher comorbidity burden. However, the lack of increase in unanticipated admission rate in this patient population may be related to thorough preoperative assessment and avoidance of patients with comorbid conditions., Discussion: The literature lacks adequate information to make strong recommendations regarding appropriate selection of the obese patients scheduled for ambulatory surgery. The literature does indicate that the super obese (BMI >50 kg/ m) do present an increased risk for perioperative complications, while patient with lower BMIs do not seem to present any increased risk as long as any comorbidities are minimal or optimized before surgery. This review also identifies knowledge gaps and recommends future research required to guide optimal selection of obese patients scheduled for ambulatory surgery.

The suitability of ambulatory surgery for a patient with obstructive sleep apnea (OSA) remains controversial because of concerns of increased perioperative complications including postdischarge death. Therefore, a Society for Ambulatory Anesthesia task force on practice guidelines developed a consensus statement for the selection of patients with OSA scheduled for ambulatory surgery. A systematic review of the literature was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Although the studies evaluating perioperative outcome in OSA patients undergoing ambulatory surgery are sparse and of limited quality, they do provide useful information that can guide clinical practice. Patients with a known diagnosis of OSA and optimized comorbid medical conditions can be considered for ambulatory surgery, if they are able to use a continuous positive airway pressure device in the postoperative period. Patients with a presumed diagnosis of OSA, based on screening tools such as the STOP-Bang questionnaire, and with optimized comorbid conditions, can be considered for ambulatory surgery, if postoperative pain can be managed predominantly with nonopioid analgesic techniques. On the other hand, OSA patients with nonoptimized comorbid medical conditions may not be good candidates for ambulatory surgery. What other guidelines are available on this topic? The American Society of Anesthesiologists (ASA) practice guidelines for management of surgical patients with OSA published in 2006. Why was this guideline developed? The ASA guidelines are outdated because several recent studies provide new information such as validated screening tools for clinical diagnosis of OSA and safety of ambulatory laparoscopic bariatric surgery in OSA patients. Therefore, an update on the selection of patients with OSA undergoing ambulatory surgery is warranted. How does this guideline differ from existing guidelines? Unlike the ASA guidelines, this consensus statement recommends the use of the STOP-Bang criteria for preoperative OSA screening and considers patients' comorbid conditions in the patient selection process. Also, current literature does not support the ASA recommendations that upper abdominal procedures are not appropriate for ambulatory surgery. Why does this guideline differ from existing guidelines? This consensus statement differs from existing ASA guidelines because of the availability of new evidence.

Purpose of Review: The purpose of this article is to discuss the anesthetic considerations of obstructive sleep apnea (OSA) patients undergoing ambulatory surgery and the current recommendations based on recent evidence., Recent Findings: It is documented that 75% of patients with high propensity for OSA were not diagnosed prior to ambulatory surgery. An OSA screening questionnaire, the STOP-Bang questionnaire, may be useful to identify patients who have high risk of OSA. Patients with mild-to-moderate OSA with optimized comorbid condition should be able to safely undergo ambulatory surgery. However, severe OSA patients without optimized comorbid conditions are not ideal candidates for ambulatory surgery. Recently, transient oxygen desaturation in postanesthetic care unit has been described in OSA patients with no further increase in unanticipated hospital admission after ambulatory surgery. However, OSA patients undergoing ambulatory upper airway surgery often have lower threshold for hospitalization. A majority of OSA patients are undergoing ambulatory surgery safely. Careful choice of OSA patients, the use of short-acting anesthetic agents with increased perioperative vigilance helps to reduce the adverse cardiopulmonary events in the ambulatory anesthetic settings. Facilities for inpatient admission of OSA patients when necessary should be available. It may not be safe to discharge severe OSA patients who require narcotic analgesics in the postoperative period., Summary: The recent publications indicated that the majority of OSA patients may be done as ambulatory surgical patients with few adverse events. However, it may not be safe to do patients with severe OSA requiring postoperative narcotics as ambulatory surgical patients.

Optimal evidence-based perioperative blood glucose control in patients undergoing ambulatory surgical procedures remains controversial. Therefore, the Society for Ambulatory Anesthesia has developed a consensus statement on perioperative glycemic management in patients undergoing ambulatory surgery. A systematic review of the literature was conducted according the protocol recommended by the Cochrane Collaboration. The consensus panel used the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system for providing suggestions. It was revealed that there is insufficient evidence to provide strong recommendations for the posed clinical questions. In the absence of high-quality evidence, recommendations were based on general principles of blood glucose control in diabetics, drug pharmacology, and data from inpatient surgical population, as well as clinical experience and judgment. In addition, areas of further research were also identified.

Purpose of Review: There is a growing demand for greater efficiency in ambulatory surgery. The patient population is increasingly sick which is also undergoing more advanced and complex surgery. This creates a danger in discharging patients without meeting the criterion of requirement of a responsible adult as an escort to accompany the patient home. The purpose of this review is to examine the most recent findings to determine whether an escort for patient discharge is necessary., Recent Findings: Recent studies have outlined the risks of discharging patients without escort after ambulatory anesthesia. There are three aspects that deter discharge of patients without an escort: medication used in general anesthetics or sedation; regional anesthesia; and surgical factors. All these can affect the cognitive, memory and psychomotor function of the patients, deeming them unable to perform normal daily activities such as driving., Summary: Both clinicians and patients may have underestimated the risks associated with discharging patients without an escort after ambulatory anesthesia. There should be greater awareness of this problem. Patient discharge without an escort after ambulatory surgery under general anesthesia, sedation or premedication can potentially be dangerous and is not recommended.

Background: It is increasingly important to evaluate patients' recovery after ambulatory surgery. The authors developed the Functional Recovery Index (FRI) to assess postdischarge functional recovery for ambulatory surgical patients., Methods: The scale development involved four phases: item generation, item selection, reliability, and validity testing. A draft questionnaire was tested and revised. Items were selected through testing endorsement frequency, factor analysis, and testing internal consistency. The interrater reliability was calculated. Construct validity was tested by multiple hypotheses on convergent validity, extreme groups, and discriminant validity. Responsiveness was assessed by measuring the FRI postoperatively and comparing minor versus more extensive surgery. The rate of response and the time for completion of the questionnaire were recorded., Results: The final questionnaire had 14 items grouped under 3 factors. Each item was scored from 0 to 10, with 0 = no difficulty and 10 = extreme difficulty with the activity. The 3 factors were summated for a total score. Internal consistency for the 3 factors (pain and social activity, lower limb activity, and general physical activity) was as follows: Cronbach alpha = 0.90, 0.89, and 0.86, respectively. Interrater reliability was 0.99. Convergent validity for FRI versus verbal rating scale pain score was 0.76. Discriminant validity testing showed that the type of surgery was significant and that intermediate (beta = 0.138) and major surgery (beta = 0.337) were associated with higher FRI scores than minor surgery. The time to complete the questionnaires ranged between 4 min 10 s and 4 min 35 s., Conclusions: The FRI had excellent reliability, good validity, responsiveness, and acceptability, indicating that this questionnaire will be a good instrument for assessing functional recovery of ambulatory surgical patients.

Background: Preoperative testing has been criticized as having little impact on perioperative outcomes. We conducted a randomized, single-blind, prospective, controlled pilot study to determine whether indicated preoperative testing can be eliminated without increasing the perioperative incidence of adverse events in selected patients undergoing ambulatory surgery., Methods: One thousand sixty-one eligible patients were randomized either to have indicated preoperative testing or no preoperative testing. In the indicated testing group, patients received indicated preoperative testing: a complete blood count, electrolytes, blood glucose, creatinine, electrocardiogram, and chest radiograph according to the Ontario Preoperative Testing Grid as per current practice, whereas in the no testing group, no testing was ordered. The investigators, data collectors, and patient outcome reviewers were blinded to the group assignment. The primary outcome measures were the rate of perioperative adverse events and the rates of adverse events within 7 and 30 days after surgery., Results: Patients' age, gender, American Society of Anesthesiologists status, type of surgery, and anesthesia were similar between the two groups. There were no significant differences in the rates of perioperative adverse events and the rates of adverse events within 30 days after surgery between the no testing group and the indicated testing group. Hospital revisits

Background: Obstructive sleep apnea (OSA) is present in a significant proportion of the population, but the majority of patients remain undiagnosed. It is crucial that anesthesiologists and surgeons recognize the increased perioperative risks associated with undiagnosed OSA. We present a systematic review of the literature on the perioperative management of surgical patients with OSA., Methods: The scope of this review is restricted to publications in all surgical specialties and in the adult patient population. The main search key words were: "perioperative care," "sleep apnea," "obstructive sleep apnea," "perioperative risk," and "perioperative care." The databases Medline, Embase, Biological Abstract, Science Citation Index, and Healthstar were searched for relevant English language articles from 1966 to March 2007., Results: The literature supports an increased perioperative risk in OSA patients. The American Society of Anesthesiologists guidelines support the routine screening for OSA during preoperative assessment, and methods of OSA screening are discussed in this review. This review suggests a number of perioperative management strategies to reduce surgical risk in patients with OSA. However, apart from the consensus-based American Society of Anesthesiologists guidelines, it is important to note that evidence-based recommendations are lacking in the literature., Conclusions: This review suggests ways to screen for OSA in the preoperative setting and proposes perioperative management strategies. The ultimate goal is to reduce the perioperative risk of OSA patients but, to realize that goal, research will be needed to determine whether screening for OSA and/or adapting specific perioperative management approaches translates into a lessening of adverse events in surgical patients with undiagnosed OSA.

Occasionally, ambulatory surgical patients present without an escort for their procedure. This creates a dilemma for caregivers, and allowing patients to drive may have an impact on their safety. The Canadian Medical Protective Association is a mutual defense organization for 95% of Canadian physicians. The national database is a unique and extensive repository of medico-legal data. We scanned this database for malpractice patients who were discharged after an ambulatory surgery procedure and allowed to drive home with a poor outcome. From this database, two malpractice cases of patients who were discharged without an escort after an ambulatory surgical procedure were reported. Both had a car accident and sustained serious injuries. Based on this we do not recommend discharge without an escort after general anesthesia, regional anesthesia, monitored anesthesia or sedation. Driving after ambulatory surgery cannot be considered safe and caregivers need to verify a safe ride home.

The present guidelines were compiled by a multidisciplinary international panel of individuals with interest and expertise in postoperative nausea and vomiting (PONV) under the auspices of The Society of Ambulatory Anesthesia. The panel critically evaluated the current medical literature on PONV to provide an evidence-based reference tool for the management of adults and children who are undergoing surgery and are at increased risk for PONV. In brief, these guidelines identify risk factors for PONV in adults and children; recommend approaches for reducing baseline risks for PONV; identify the most effective antiemetic monotherapy and combination therapy regimens for PONV prophylaxis; recommend approaches for treatment of PONV when it occurs; and provide an algorithm for the management of individuals at increased risk for PONV.

Background: Mortality and morbidity in ambulatory surgery are rare, and thus the patient's quality of life (i.e., the ability to resume normal activities after discharge home) should be considered one of the principle end-points after ambulatory surgery and anesthesia. We conducted a systematic review of the instruments to measure the quality of recovery of ambulatory surgical patients in order to advise on the selection of appropriate measures for research and quality assurance., Methods: A systematic literature search of MEDLINE, EMBASE, CINAHL, HAPI, PsycINFO, Web of Science Search History, Biosys Previews Search, HealthStar, and ASSIA was performed to identify patient-based outcome measures to assess postoperative recovery from ambulatory anesthesia. The instruments were assessed for eight criteria: appropriateness, reliability, validity, responsiveness, precision, interpretability, acceptability, and feasibility., Results: Seven articles met the inclusion criteria set for the review. The quality of the identified instruments was variable., Conclusion: Only one instrument, 40-item Quality of recovery score, fulfilled all eight criteria, however this instrument was not specifically designed for ambulatory surgery and anesthesia.

Purpose of Review: To summarize and examine the updated published results on the outcome measures that can be used to assess the quality of ambulatory surgery and anesthesia., Recent Findings: Major morbidity and mortality following ambulatory surgery is exceedingly low. Cancellations and delays may have a negative impact on the patients, healthcare personnel and the organizations. Minor cardiovascular adverse events are the most common intraoperatively and are associated with preexisting cardiovascular diseases and elderly patients. Respiratory events postoperatively are associated with obesity, smoking and asthma. Also, pain is a common cause for longer postoperative stay, unanticipated admission and readmission. Postoperative nausea and vomiting occurs in 30% of patients and strongly affects patient satisfaction. Furthermore, prolonged stays are mainly caused by surgical factors, or minor symptoms like pain or nausea. Surgical factors are also the main causes of unanticipated hospital admission. The type of surgery and the 24 h postoperative symptoms may affect the degree of return to daily living function. Also, patient satisfaction affects the outcome of healthcare and the use of healthcare services., Summary: Ambulatory surgery, as currently practiced, provides quality care that is cost-effective. Minor adverse events such as pain and postoperative nausea and vomiting are still common, and improvement could be targeted in these areas.

Purpose: Recovery and discharge following ambulatory surgery are important components of the ambulatory surgery experience. This review provides contemporary perspectives on the issues of discharge criteria, fast-tracking, patient escort requirements, and driving after ambulatory anesthesia., Source: A search was performed in the Cochrane Central Register for Controlled Trials, MEDLINE(R), EMBASE(R), CINAHL, and PsycINFO, to review factors delaying discharge following ambulatory surgery. The following subject headings were used: "ambulatory surgery, discharge, recovery, car driving, escort, transport, fast tracking, patient discharge, recovery, transportation of patients, hospital discharge, recovery room, patient transport, hospital discharge, recovery room, anesthetic recovery, patient transport, ambulatory surgical procedures, patient discharge, recovery of function, automobile driving, patient escort service, recovery room". Using the same search engines, the following keywords were used: "fast tracking, recovery, and discharge"., Principal Findings: The current literature supports that discharge scoring systems may be useful to guide discharge following ambulatory surgery. While fast-tracking has become common in some centres, further studies are required to justify more routine implementation of this practice in the management of patients undergoing ambulatory surgery. Patients at low risk for urinary retention can be discharged home without voiding. Patients should not drive until at least 24 hr postoperatively., Conclusions: Ensuring rapid postoperative recovery and safe discharge following ambulatory surgery are important components of the ambulatory surgical program. A clearly defined process should be established for each ambulatory surgical unit to ensure the safe and timely discharge of patients after anesthesia, in accordance with current best evidence.

Purpose: A study was undertaken to identify the characteristics and outcomes of ambulatory surgical patients without an escort., Clinical Features: During a 38-month period, the incidence of patients without an escort at one tertiary care institution was 0.2% (60/28,391). Five patients had their surgery cancelled. The other 55 patients had their surgery performed. Two groups of patients without an escort were identified: patients who were known not to have an escort preoperatively, and patients with "no show" escort. The number of patients with no show escort is much higher than the number of patients who were known not to have an escort preoperatively. The outcome of the no escort patients was compared with the matched control group of patients with an escort. There were no differences in the rates of unanticipated admission, emergency visits or read-mission into the hospital within 30 days comparing the group of patients with and without an escort., Conclusions: The absence of an escort in ambulatory surgical patients occurs in 0.2% of surgeries, and varies according to the type of service. The number of patients with no show escort is higher than the number of patients with known no escort preoperatively.

Purpose: To evaluate the magnitude of subjective cognitive failure in the three days following general anesthesia (GA) for ambulatory surgery., Methods: After Research Ethics Board approval, 258 patients undergoing general anesthesia (GA) and 250 patients scheduled for local anesthesia (LA) were recruited from our ambulatory surgical unit. Following the method of Tzabar, Asbury and Millar, patients were asked to complete the cognitive failures questionnaire (CFQ) before their procedure (with respect to the previous three days) and on the third postoperative day (with respect to their recovery period)., Results: General anesthesia and LA groups were similar in demographic make-up, except that the LA group contained more patients of American Society of Anesthesiologists physical status I (64.5% vs 52.7%, P < 0.05) and had significantly shorter procedure duration (25 vs 51 min, P < 0.01) than the GA group. Median preoperative CFQ scores (interquartile range) were 26 (18) for the LA group and 26 (18) for the GA group. Postoperative CFQ scores were 25 (20) for the LA group and 28 (22) for the GA group. There was no significant difference in preoperative CFQ score between groups (Mann-Whitney U). When preoperative and postoperative CFQ scores were compared, the small increase seen in the GA group was statistically significant (P < 0.05, Wilcoxon)., Conclusion: A statistically significant impairment of cognitive function in the three days following GA, but not LA was found. However, the magnitude of this impairment was small, and is of doubtful clinical significance. Modern ambulatory anesthesia may cause less delayed cognitive impairment than was previously thought.

Background: Ambulatory surgical patients are advised to refrain from driving for 24 h postoperatively. However, currently there is no strong evidence to show that driving skills and alertness have resumed in patients by 24 h after general anesthesia. The purpose of this study was to determine whether impaired driver alertness had been restored to normal by 2 and 24 h after general anesthesia in patients who underwent ambulatory surgery., Methods: Twenty patients who underwent left knee arthroscopic surgery were studied. Their driving simulation performance, electroencephalographically verified parameters of sleepiness, subjective assessment of sleepiness, fatigue, alertness, and pain were measured preoperatively and 2 and 24 h postoperatively. The same measurements were performed in a matched control group of 20 healthy individuals., Results: Preoperatively, patients had significantly higher attention lapses and lower alertness levels versus normal controls. Significantly impaired driving skills and alertness, including longer reaction time, higher occurrence of attention lapses, and microsleep intrusions, were found 2 h postoperatively versus preoperatively. No significantly differences were found in any driving performance parameters or electroencephalographically verified parameters 24 h postoperatively versus preoperatively., Conclusions: Patients showed lower alertness levels and impaired driving skills preoperatively and 2 h postoperatively. Based on driving simulation performance and subjective assessments, patients are safe to drive 24 h after general anesthesia.

Purpose: Routine preoperative testing has been criticized as having little impact on perioperative outcomes. The purpose of this study is to identify the current practice of preoperative testing in ambulatory surgery., Methods: A standard questionnaire was sent to all active members of the Canadian Anesthesiologists' Society (CAS). The study inquired into the anesthesiologist's preoperative testing practice in healthy patients and patients with stable medical conditions undergoing ambulatory surgery., Results: Of 1,335 mailed questionnaires, a total 617 respondents who reported their participation in ambulatory surgical care were received. Eighty percent [95% confidence interval (CI) 76.5-83.2] of the respondents indicated that, if testing had to be ordered in asymptomatic patients undergoing low-risk ambulatory surgery, it would be due to the patient's clinical indications while others indicated it would be the result of following institutional guidelines (15.1%, 95% CI 12.2-17.9), and even fewer attributed it to a "routine" testing practice (0.5%, 95% CI 0-1.14). Forty-four percent (95% CI 39.8-47.8) of the anesthesiologists indicated that age alone is not a criterion when they required a preoperative electrocardiogram (ECG) while others reported various cut-points (> 65; > 55; > 45; > 40 yr) for ECG ordering for asymptomatic patients undergoing the low-risk ambulatory surgery. About 40% (95% CI 35.7-43.5) of the anesthesiologists had no specific concern about eliminating preoperative testing in ambulatory surgery., Conclusion: Our survey has documented marked disparities in the practices of preoperative testing. A large proportion of the anesthesiologists indicated that age alone is not a criterion for preoperative ordering of ECG. Many anesthesiologists had no concern about eliminating preoperative testing in low-risk ambulatory surgery.

Background: Postoperative day-case patients are usually allowed to recover from anaesthesia in a postanaesthesia care unit (PACU) before transfer back to the day surgical unit (DSU). Bypassing the PACU can decrease recovery time after day surgery. Cost savings may result from a reduced nursing workload associated with the decreased recovery time. This study was designed to evaluate the effects of bypassing the PACU on patient recovery time and nursing workload and costs., Methods: Two hundred and seven consenting outpatients undergoing day surgery procedures were enrolled. Anaesthesia was induced and maintained with a standardized technique and the electroencephalographic bispectral index was monitored and maintained at 40-60 during anaesthetic maintenance. At the end of surgery, patients were randomly assigned to either a routine or fast-tracking (FT) group. Patients in the FT group were transferred from the operating room to the DSU (i.e. bypassing the PACU) if they achieved the FT criteria. All other patients were transferred to the PACU and then to the DSU. Nursing workload was evaluated using a patient care hour chart based on the type and frequency of nursing interventions in the PACU and DSU. A cost associated with the nursing workload was calculated., Results: The overall time from end of anaesthesia to discharge home was significantly decreased in the fast-tracking group. However, overall patient care hours and costs were similar in the two recovery groups., Conclusion: Bypassing the PACU after these short outpatient procedures significantly decreases recovery time without compromising patient satisfaction. However, the overall nursing workload and the associated cost were not significantly affected.

Purpose: Postoperative pain is the commonest reason for delayed discharge and unanticipated hospital admission after ambulatory surgery. We investigated the severity of pain at 24 hr postoperatively and determined the most painful procedures. The need for further medical advice and clarity of postoperative analgesia instructions were also studied., Methods: Five thousand seven hundred and three ambulatory surgical patients were telephoned 24 hr postoperatively. Patients graded their pain using the ten-point self-assessing verbal scale (0 = no pain, 10 = worst pain). Data were analyzed in two groups, those with moderate to severe pain (pain score 4-10) and those with no or mild pain (0-3)., Results: Thirty percent of patients (1,495/5,703) had moderate to severe pain. Microdiscectomy, laparoscopic cholecystectomy, shoulder surgery, elbow/hand surgery, ankle surgery, inguinal hernia repair, and knee surgery were identified as the procedures causing most pain at 24 hr. 13.2% of patients needed medical advice by telephone, 1.4% made an unplanned visit to a doctor while the rate of readmission to the hospital was 0.08%. Ninety-eight percent found postoperative instruction sheets and advice helpful. Eighty-eight percent of patients indicated that analgesic instructions were absolutely clear., Conclusion: This study has identified the more painful common ambulatory surgical procedures which will allow take home analgesia to be tailored according to individual procedures. Further improvement in analgesic instructions may help in better pain management of ambulatory surgery patients.

Purpose: To identify and characterize the evidence supporting decisions made in the care of patients with selected medical conditions undergoing ambulatory anesthesia and surgery. Conditions highlighted in this review include: the elderly, heart transplantation, hyper-reactive airway disease, coronary artery disease, and obstructive sleep apnea., Source: A structured search of MEDLINE (1966-2003) was performed using keywords for ambulatory surgery and patient condition. Selected articles were assigned a level of evidence using Centre for Evidence Based Medicine (CEBM) criteria. Recommendations were also graded using CEBM criteria., Principal Findings: The elderly may safely undergo ambulatory surgery but are at increased risk for hemodynamic variation in the operating room. The heart transplant recipient is at increased risk of coronary artery disease and renal insufficiency and should undergo careful preoperative evaluation. The patient with reactive airway disease is at increased risk of minor respiratory complications and should be encouraged to quit smoking. The patient with coronary artery disease and recent myocardial infarction may undergo ambulatory surgery without stress testing if functional capacity is adequate. The patient with obstructive sleep apnea is at increased risk of difficult tracheal intubation but the likelihood of airway obstruction and apnea following ambulatory surgery is unknown., Conclusion: Ambulatory anesthesia is infrequently associated with adverse outcomes, however, knowledge regarding specific patient conditions is of generally low quality. Few prospective trials are available to guide management decisions.

Purpose: This is the second of two reviews evaluating the management of patients with selected medical conditions undergoing ambulatory anesthesia and surgery. Conditions highlighted in this review include: diabetes mellitus; morbid obesity; the ex-premature infant; the child with an upper respiratory infection; malignant hyperthermia; and the use of monoamine oxidase inhibitors., Source: Medline search strategies and the framework for the evaluation of clinical evidence are presented in Part I., Principal Findings: Diabetes mellitus has not been linked with adverse events following ambulatory surgery. The morbidly obese patient is at an increased risk for minor respiratory complications in the perioperative period but these events do not increase unanticipated admissions. The ex-premature infant may be considered for ambulatory surgery if post-conceptual age is > 60 weeks and hematocrit is > 30%. The child with a recent upper respiratory tract infection is at an increased risk for perioperative respiratory complications, particularly if endotracheal intubation is required. Patients with malignant hyperthermia may undergo outpatient surgery but require four hours of postoperative temperature monitoring. Sporadic cases of drug interactions have been reported when meperidine and indirect-acting catecholamines are administered in the presence of monamine oxidase inhibitors. Ambulatory anesthesia and surgery is safe if these combinations of drugs are avoided., Conclusion: Ambulatory anesthesia can be performed in, and is being offered to, a variety of patients with significant coexistent disease. In many cases there is little evidence documenting the outcomes expected in such patients. Prospective observational and interventional trials are required to better define perioperative management.

Successful ambulatory surgery is dependent on analgesia that is effective, has minimal adverse effects, and can be safely managed by the patient at home after discharge. A number of studies have identified that the provision of effective postoperative analgesia is inadequate for a significant proportion of patients. The following discussion details the current available analgesic options for ambulatory surgery patients and the rationale for their use. Preemptive analgesia should be given to all patients unless there are specific contraindications. Consideration should be given to the use of long-acting oral COX-2 selective nonsteroidal anti-inflammatory drugs (NSAIDs) and long-acting oral opioids to treat postoperative pain. A standardized multimodal postdischarge analgesic regimen tailored to the patient's expected postoperative pain levels should be prescribed. Patient follow-up by telephone questionnaire will confirm those surgical procedures that result in mild or moderate-to-severe postoperative pain and the effectiveness of treatment plans.

Aim and Background: Same-day surgeries are becoming routine for many surgical procedures. However, the degree to which patients need help with pain management at home following laparoscopic cholecystectomy (LC), shoulder, or hand ambulatory day surgery has received minimal examination. This study examined pain and related interference, analgesic use and adverse events, complications and resources utilized, and adequacy of postdischarge information at four time periods., Methods: Data were collected from 180 patients by telephone interviews at 24, 48 and 72 hours, and 7 days after discharge. Patients (n = 78 hand, 48 shoulder, 54 LC surgery) were on average 41 years old., Results: For all patients, worst 24-hour pain was reported as moderate to severe at all time periods. Using repeated measures anova demonstrated that shoulder patients had significantly more pain and overall pain-related interference, particularly in sleep and work, from 24 hours to day 7 than did hand or LC patients. The main analgesic taken was acetaminophen (paracetamol) with codeine 30 mg; 50% took no analgesia from 72 hours. About 20% experienced analgesic adverse events within 72 hours, mainly constipation and nausea. Only

Purpose: An increasing number of patients with complex medical problems are now considered suitable for ambulatory surgery. The purpose of this study was to identify the current clinical practice of ambulatory surgical patient selection., Methods: A standardized questionnaire specifying 30 clinical conditions was sent to all practicing anesthesiologists who are members of the Canadian Anesthesiologists' Society. Recipients were asked to indicate if they would provide ambulatory anesthesia (yes/no answers) for an adult patient with each of those isolated conditions. A 75% agreement was considered a majority opinion., Results: One thousand three hundred thirty-seven questionnaires were sent and 774 replies were received (57.8%). Over 75% of anesthesiologists were willing to include in their selection criteria American Society of Anesthesiologists' (ASA) physical status III, patients with low-grade angina pectoris (AP) and congestive heart failure (CHF), prior myocardial infarction, asymptomatic valvular disease, sleep apnea without use of narcotics, morbid obesity (MO) without co-morbidities, insulin dependent diabetes mellitus and malignant hyperthermia (MH) susceptible patients. Over 75% of responders found ASA IV patients, high grade AP and CHF, sleep apnea with postoperative narcotics, MO with co-morbidities and no patient escort to be unsuitable for ambulatory anesthesia., Conclusion: Our survey demonstrated that medical conditions with extreme grades of severity (mild or severe) are associated with majority opinion to proceed or not to proceed with ambulatory surgery. Issues with over 75% agreement reflect the common practice. Similar surveys may form a part of patient selection guidelines development in the future.

Unlabelled: Consent for clinical anesthesia research trials is often sought on the day of surgery when patients are most anxious and have little privacy or time for reflection. We conducted a retrospective survey of patients' perceptions and concerns regarding consent for clinical anesthesia trials on the day of surgery. Questionnaires were mailed to 175 patients who had participated in 1 of 6 negligible- or minimal-risk clinical anesthesia trials within the preceding year. Seventy-six patients responded (43%). Most patients (80%) reported that they understood the purpose of their trial, did not feel obligated (61%) or pressured (67%) to participate, and were satisfied (mean visual analog scale: 71 mm) with the recruitment and consent process on the day of surgery. Few patients (7%) believed that their well-being was put at risk because of their participation in the trial., Implications: This retrospective survey suggests that patient recruitment and consent for negligible- or minimal-risk clinical anesthesia research trials is appropriate when performed on the day of surgery.

Ambulatory surgery provides quality care that is cost-effective. The use of innovative surgical and anesthetic techniques will allow larger numbers of patients to take advantage of the benefits of undergoing an elective operation on an ambulatory basis. Anesthesiologists will be faced with more complex surgery, which will require careful selection and assessment of patients to ensure continuity of the excellent safety record of ambulatory anesthesia. Minor adverse events, such as pain and PONV, are still common. The occurrence of these minor adverse advents is now the major area of quality assessment and an area where improvement could be targeted. Fast tracking facilitates earlier discharge, but we must ensure this has benefit to the patient as speedy discharge may mask the true incidence of adverse minor symptoms. This can lead to patient dissatisfaction and a poor impression of ambulatory surgery.

Objective: Nowadays, microsurgical discectomy is being performed as an outpatient procedure. A retrospective chart review was done to document factors that delayed discharge or led to unanticipated admission., Methods: After Institutional Review Board approval, the hospital medical records of 106 patients who underwent microsurgical discectomy on an ambulatory basis were reviewed. All patients were operated upon by a single surgeon at the Toronto Western Hospital. Perioperative data were collected on specifically designed data sheets. All anesthetic and surgical factors that affected discharge were noted., Results: Of the 106 patients reviewed, only six required unanticipated admission. Two patients were admitted due to nausea and vomiting, one due to severe pain, one due to urinary retention and two were surgical causes (dural tear). Eight patients had delayed discharge. Anesthesia causes were severe nausea, severe pain, low oxygen saturation, sore throat and dry eyes. Two patients had surgical causes. The incidence of postoperative nausea was 61% and postoperative vomiting was 9.4%. Eighty patients (75.4%) complained of pain in the postanesthesia care unit. Of these, 33.9% had visual analogue pain scale scores more than 6., Conclusion: Ambulatory lumbar microdiscectomy can be carried out as an ambulatory procedure with an acceptably low unanticipated admission rate (5.7%). The percentage of patients with severe nausea (16%) and pain (33.9%) is high. Adequate perioperative pain management and effective control of nausea and vomiting may further improve the patients' experience after anesthesia for ambulatory microdiscectomy.

Background: Sore throat is a common complication of anaesthesia that affects patient satisfaction after surgery., Methods: We studied 5264 ambulatory surgical patients prospectively to determine the patient, anaesthetic, and surgical factors associated with sore throat., Results: In 5264 patients, 12.1% reported a sore throat. Patients with tracheal tube had the greatest incidence, 45.4%, followed by patients with laryngeal mask airway, 17.5%, while patients with a facemask had a lower incidence of sore throat, 3.3%. Female patients had more sore throats than male patients (13.4 vs 9.1%). Airway management had the strongest influence on the incidence of sore throat. Sore throat in ambulatory surgical patients was associated with female sex, younger patients, use of succinylcholine, and gynaecological surgery., Conclusion: Airway management, female sex, younger patients, surgery for gynaecological procedure, and succinylcholine predicts postoperative sore throat. Increased awareness of the predictive factors can help to avoid this combination and improve patient satisfaction.

Unlabelled: We designed this study to evaluate postural stability in outpatients after either desflurane or propofol anesthesia. After IRB approval, 120 consenting women undergoing gynecological laparoscopic procedures were randomly assigned to receive either desflurane or propofol-based general anesthesia. After surgery, patients' postural stability was measured as body sway velocity by using a computerized force platform in the following conditions: 1) standing on a firm surface with eyes open versus closed and 2) standing on a foam surface with eyes open versus closed. These measurements were made before anesthesia, immediately after the patient achieved a Post-Anesthesia Discharge Score of 9, and at actual discharge home. At the time patients first achieved a Post-Anesthesia Discharge Score of 9, the body sway in the Propofol group was significantly more than in the Desflurane group when patients were asked to stand on a foam surface with eyes closed (testing the ability of using vestibular information for balance control). We concluded that the desflurane-based anesthetic was associated with better postural control than the propofol-based anesthetic in the early recovery period after outpatient gynecological laparoscopic procedures., Implications: The residual effects of the short-acting general anesthetics desflurane and propofol on patient's balance function during recovery after surgery were assessed with a computerized force platform. The results showed that desflurane seemed to be associated with better postural control than propofol in the early recovery period.

Patients undergoing day surgical procedures are given postoperative instructions not to drink alcohol, drive vehicles or make important decisions for 24 h. They are also advised to have a responsible adult stay with them at home overnight. Seven hundred and fifty patients were telephoned at 24 h postoperatively to determine their compliance with these instructions. Four per cent of patients drove vehicles, 1.8% consumed alcohol, while one patient made an important decision. A higher proportion of patients (5%) drove after general anaesthesia than regional anaesthesia or intravenous sedation (2.4%). The percentage of patients consuming alcohol was similar in both groups (1.8% vs. 1.9%). Four per cent of patients had no one staying with them overnight despite being accompanied out of the hospital. Patient compliance with instructions to not drink alcohol, drive or make important decisions may be improved by physician reinforcement of instructions and patient education.

Purpose: We compared the recovery profiles, postoperative complications, perioperative OR utilization times, and times to discharge of patients undergoing ambulatory knee arthroscopy under spinal anesthesia (SA) or general anesthesia (GA)., Methods: In this randomized, prospective study, 84 ASA I-II patients were randomized to receive either SA with 50 mg of 1% lidocaine, or a standardized GA. Postoperative pain, nausea and vomiting, sedation, OR utilization, postanesthesia care unit (PACU), and ambulatory surgical unit (ASU) recovery were compared., Results: Patients in the GA group had more pain in the PACU than the SA group (61% vs 15%, P <0.01), and a higher incidence of PACU analgesic use (59% vs 7.5%, P <0.01). Patients in the SA group were able to drink and eat sooner than the GA group (83 +/- 23 vs 95 +/- 22 min, P <0.05 and 88 +/- 27 vs 105 +/- 29 min, P <0.01, respectively). The times to sit, walk, and void were similar. The length of PACU and ASU stay between the GA and SA groups were similar (67 +/- 17 vs 60 +/- 19 min, P >0.05 and 122 +/- 27 vs 127.9 +/- 31 min, P >0.05, respectively). The incidence of backache was higher in the SA group (35 vs 13.6%, P <0.05) than the GA group. However, the incidence of sore throat was higher in the GA compared to the SA group (25% vs 2.5%, P <0.01)., Conclusions: SA with 50 mg of 1% lidocaine provides an improved recovery profile for ambulatory knee arthroscopy. Discharge times were similar, and with the exception of backache and sore throat, the incidence of complications was similar.

Study Objective: To determine the optimum time of administration of diclofenac in patients undergoing ambulatory knee arthroscopy: either preoperatively or postoperatively., Design: Randomized, double-blind study., Setting: Ambulatory surgical unit in a tertiary referral hospital., Patients: 127 ASA physical status I and II patients undergoing ambulatory knee arthroscopy., Interventions: Patients were randomized into three groups. The Preop group received 50 mg of potassium diclofenac orally 1 hour preoperatively and a placebo 30 minutes postoperatively. The Pre+postop group received 25 mg of potassium diclofenac 1 hour preoperatively and 25 mg diclofenac 30 minutes postoperatively. The Postop group received a placebo 1 hour before surgery and 50 mg of potassium diclofenac 30 minutes postoperatively., Measurements and Main Results: The Postop group received a placebo 1 hour preoperatively and 50 mg of potassium diclofenac 30 min postoperatively. Postoperatively, patients used intravenous patient-controlled analgesia (PCA) with fentanyl. Total fentanyl consumption was recorded. During the recovery period, pain was assessed using a visual analog scale (VAS) at 30-minute intervals. Pain was assessed in both legs at rest, on flexion, and extension of the knee. There were no significant differences in pain scores either at rest or on movement of the operative knee among the Preop, Pre+postop, and Postop groups. The consumption of fentanyl via PCA showed no significant differences among the groups., Conclusions: There is no difference in pain relief whether diclofenac is given preoperatively or postoperatively in patients undergoing unilateral ambulatory knee arthroscopy. Preoperative and postoperative treatment with diclofenac potassium is equally effective.

Due to the growing importance of quality assurance and cost containment in healthcare, eliciting patients' preferences for post-operative outcomes may be a more economical and reliable method of assessing quality. Three hundred and fifty-five day surgery patients completed a pre-operative written questionnaire to identify patients' preferences for avoiding 10 particular post-operative symptoms: pain, nausea, vomiting, disorientation, shivering, sore throat, drowsiness, gagging on the tracheal tube, thirst and a normal outcome. The two scoring methods used to evaluate preferences were priority ranking and relative value scores. The effects of age, gender, previous health status, type of surgery and previous experience of anaesthesia on patients' preferences were also examined. Avoiding post-operative pain, gagging on the tracheal tube and nausea and vomiting are major priorities for day-case patients. Anaesthetists should take patients' preferences into consideration when developing guidelines and planning anaesthetic care.

Ambulatory surgery is growing worldwide. The challenge of providing anaesthesia for longer and more complex surgery in sicker and elderly patients is a reality. To maintain the safety and good outcomes of ambulatory anaesthesia, high-risk patients will need to be evaluated carefully. Anaesthetic techniques that use short-acting drugs and minimize postoperative morbidity and mortality should become the focus. Policies on management of postoperative pain, nausea, vomiting, voiding and discharge from hospital will maintain good outcome measures.

Purpose: To compare the timing of administration of morphine in patients undergoing painful ambulatory surgical procedures to determine whether there was a difference in postoperative nausea or vomiting (PONV), quality of analgesia, and recovery profile., Methods: In a double-blinded, placebo-controlled, prospective study, 70 ASA I-II patients were randomized to receive 0.1 mg x kg(-1) morphine intraoperatively (lop) (n=35), or postoperatively (Pop) (n=35). The severity of nausea and pain were measured using visual analog scales (VAS)., Results: There was no difference between the groups in postoperative nausea scores or the incidence of PONV. Upon awakening, patients who received Pop morphine had higher pain VAS scores with movement (7.6 +/- 2 vs 5.4 +/- 3, P < 0.003) and at rest (6.9 +/- 3 vs 5.1 +/- 3, P < 0.013) than the lop morphine group. The total number of PCA attempts and analgesic requirements were similar. Patients who received Pop morphine were able to drink sooner than the lop group (90 +/- 34 vs 111 +/- 38 min, P < 0.05). All other recovery milestones were similar. Times to discharge from hospital were similar., Conclusions: Administration of 0.1 mg x kg(-1) morphine iv intraoperatively improves postoperative analgesia upon emergence from painful ambulatory surgical procedures without increasing the incidence of PONV There was no increase in PONV when morphine was administered intraoperatively rather than postoperatively.

Purpose: To determine the ideal sedative regimen for intraocular surgery under peribulbar or retrobulbar block. The addition of alfentanil and or propofol to midazolam was evaluated with regard to hemodynamic variables, respiratory rate, pain, anxiety, sedation, postoperative recovery and patient satisfaction., Methods: Eighty two patients aged between 50 and 85 were recruited into this prospective, randomised, double blind study. Patients, in four groups, received 0.015 mg x kg(-1) midazolam, 5 microg x kg(-1) alfentanil and 0.15 mg x kg(-1) propofol; 0.015 mg x kg(-1) midazolam and 0.15 mg x kg(-1) propofol; 0.015 mg x kg(-1) midazolam and 5 microg x kg(-1) alfentanil or 0.015 mg x kg(-1) midazolam alone. Blood pressure, heart rate, respiratory rate, pain, anxiety and sedation scores were measured. Times to discharge from the Post Anesthesia Care Unit (PACU) and Day Surgery Unit (DSU) were documented. A 24 hr telephone interview was carried out to determine patient satisfaction., Result: Systolic blood pressure of patients in groups that had received alfentanil was 6% lower than that of patients who had not (P<0.05) at the time of insertion of intraocular block. Patients in the alfentanil groups also had lower respiratory rates during the first 15 min after drug administration, but all patients were given supplemental oxygen therefore oxygen saturation was unaffected. Pain scores of patients who had been given alfentanil were lower during the first postoperative hour than those who had not., Conclusion: The addition of alfentanil to midazolam is advantageous in providing sedation for insertion of intraocular block.

Unlabelled: We identified predictors for prolonged postoperative stay after ambulatory surgery using multiple logistic regression models. We collected perioperative data for 16,411 ambulatory surgical patients. A log-transformed time to discharge variable was modeled by multiple linear regression, including patient-, anesthesia-, and surgery-specific variables. The impact of hypothetical elimination of perioperative adverse events on mean length of stay was also estimated. Separate analyses were performed among patients who received general anesthesia (GA) and monitored anesthesia care (MAC). Patients receiving GA stayed 50 min longer than patients receiving MAC. Patients receiving GA and undergoing strabismus, transurethral, or otorhinolaryngological/dental procedures had the longest postoperative stay. Among patients receiving GA, smokers had a 4% shorter stay compared with nonsmokers; among patients receiving MAC, those with congestive heart failure (CHF) had a 11% longer stay compared with patients without CHF. Postoperative nausea and vomiting, dizziness, excessive pain, and cardiovascular events predicted 22%-79% increases in postoperative stay. The hypothetical elimination of all adverse events resulted in a 9.6% decrease in mean length of stay among patients receiving GA, but in only a 3.8% decrease among patients receiving MAC. The length of postoperative stay among ambulatory surgical patients is mainly determined by the type of surgery and by adverse events, such as excessive pain, postoperative nausea and vomiting, dizziness, drowsiness, and cardiovascular events. Patients with CHF and those who underwent long procedures had a higher risk of a prolonged stay. Appropriate prevention and management of postoperative symptoms could significantly decrease the length of stay among patients receiving GA., Implications: The length of postoperative stay among ambulatory surgical patients is mainly determined by the type of surgery and by adverse events, such as excessive pain, postoperative nausea and vomiting, dizziness, drowsiness, and untoward cardiovascular events. Patients with congestive heart failure and those who underwent long procedures had a higher risk of a prolonged stay. Appropriate prevention and management of postoperative symptoms could significantly decrease the length of stay among patients receiving general anesthesia.

Objective: To determine the overall and complication-related readmission rates within 30 days after ambulatory surgery at a major ambulatory surgical center., Summary Background Data: Currently in North America, 65% of the surgical procedures are carried out in ambulatory settings. The safety of ambulatory surgery is well documented, with low rates of adverse events during or immediately after surgery. The consequences of ambulatory surgery during an extended period, however, have not been studied extensively., Methods: Preoperative, intraoperative, and postoperative data were collected on 17,638 consecutive patients undergoing ambulatory surgery at a major ambulatory surgical center in Toronto, Ontario. With the use of the database of the Ontario Ministry of Health, the authors identified all return hospital visits and hospital readmissions occurring in Ontario within 30 days after the ambulatory surgery. Return visits were categorized as emergency room visits, ambulatory surgical unit admissions, or inpatient admissions. The readmissions were categorized as those resulting from surgical, medical, or anesthesia-related complications or those not related to the ambulatory surgery., Results: One hundred ninety-three readmissions occurred within 30 days after ambulatory surgery (readmission rate 1.1%). Six patients returned to the emergency room, 178 patients were readmitted to the ambulatory surgical unit, and 9 patients were readmitted as inpatients. Twenty-five readmissions were the result of surgical complications, and one resulted from a medical complication (pulmonary embolism). The complication-related readmission rate was 0.15% (1 in 678 procedures). The complication rate was significantly higher among patients undergoing transurethral resection of bladder tumor (5.7%). No anesthesia-related readmissions or deaths were identified., Conclusions: The rate of complication-related readmissions was extremely low (0.15%). This result further supports the view that ambulatory surgery is a safe practice.

We have developed mathematical models to estimate the risk of perioperative adverse events in patients with pre-existing conditions undergoing day-case surgery. We studied 17,638 consecutive day-case surgical patients in a prospective study. Preoperative, intraoperative and postoperative data were collected. Risk modelling was performed with backward stepwise multiple logistic regression and validated on a separate subset of our patients. Eighteen pre-existing conditions were entered into the model. We adjusted for age, sex, and duration and type of surgery. Seven associations between pre-existing medical conditions and perioperative adverse events were statistically significant. Hypertension predicted the occurrence of any intraoperative event and intraoperative cardiovascular events. Obesity predicted intraoperative and postoperative respiratory events, and smoking and asthma predicted postoperative respiratory events. Gastro-oesophageal reflux predicted intubation-related events. The presented models of risk estimation were validated internally and provided a useful tool for accurate risk estimation.