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Ambulatory Anesthesiology: Special Article

Society for Ambulatory Anesthesia Consensus Statement on Preoperative Selection of Adult Patients with Obstructive Sleep Apnea Scheduled for Ambulatory Surgery

Joshi, Girish P., MBBS, MD, FFARSCI*; Ankichetty, Saravanan P., MD, DA, MBA; Gan, Tong J., MD, MHS, FRCA; Chung, Frances, MBBS, FRCPC

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doi: 10.1213/ANE.0b013e318269cfd7
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Obstructive sleep apnea (OSA) is a relatively common sleep-related breathing disorder that is associated with significant consequences such as daytime sleepiness, neurocognitive dysfunction, cardiovascular disorders (e.g., hypertension, ischemic heart disease, arrhythmia, pulmonary hypertension, and congestive heart failure), metabolic dysfunction, and impaired quality of life.1–5 The prevalence of OSA is increasing6 and is reported to be higher in the surgical population than in the general population.7 With the increase in prevalence of OSA as well as the increase in surgical procedures performed on an outpatient basis, anesthesiologists will increasingly encounter patients with OSA in the ambulatory setting. However, the suitability of ambulatory surgery in patients with OSA remains controversial because of the concerns of increased perioperative complications (Table 1). Therefore, members of the Society for Ambulatory Anesthesia requested the Task Force on Clinical Practice Guidelines to develop a consensus statement for the optimal selection of OSA patients undergoing ambulatory surgery (Appendix 1).

Table 1
Table 1:
Concerns with Obstructive Sleep Apnea Patients Undergoing Ambulatory Surgery


In 2006, the American Society of Anesthesiologists (ASA) published practice guidelines for management of surgical patients with OSA, including patient selection for ambulatory surgery.4 These guidelines recommended preoperative assessment for presence of OSA and proposed a checklist consisting of 12 items as a routine screening tool.4 In addition, the guidelines proposed a scoring system based upon the severity of OSA, the invasiveness of the surgery, the type of anesthetic technique, and the need for postoperative opioids.4 This scoring system has not yet been validated. Furthermore, the guidelines recommended that upper abdominal procedures and airway procedures are not suitable for ambulatory setting.


Since the publication of the ASA guidelines, several studies have been published that provide validated screening tools for OSA surgical patients that identify patients who are likely to develop postoperative complications.8–11 In addition, studies assessing perioperative complications after ambulatory surgery in OSA patients, including those undergoing laparoscopic bariatric surgery and upper airway surgery, have been published.12–18 Therefore, a systematic review of published literature evaluating the perioperative complications in OSA patients undergoing ambulatory surgery was performed. The preoperative factors that may influence the perioperative outcome (e.g., severity of OSA, coexisting medical conditions, and invasiveness of the surgical procedure) were assessed. On the basis of the systematic review, it was determined that the ASA guidelines were outdated and required updating.

The purpose of this consensus statement was to provide guidance for the appropriate selection of OSA patients scheduled for ambulatory surgery, with the aim of reducing perioperative complications. Of note, other sleep disorders were not evaluated. Also, intraoperative and postoperative care in OSA patients was not evaluated. In approving this consensus statement a similar process was used as previously approved by the Society for Ambulatory Anesthesia Board of Directors.19,20


A systematic review of the literature addressing the selection of adult patients with OSA scheduled for ambulatory surgery was conducted. The literature search was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using the Cochrane CENTRAL Register of Controlled Trials (first quarter 2011), Cochrane Database of Systematic Reviews (2005 through January 2011), MEDLINE (R) (1948 through February 2011), and EMBASE (1980 through February 2011).21 A reference librarian familiar with literature search protocol of the Cochrane Collaboration conducted the electronic search strategy with input from members of the consensus panel. The key words used for the literature search included “ambulatory surgery,” “ambulatory anesthesia,” “patient selection,” “obstructive sleep apnea,” “sleep apnea,” and “postoperative complications.” The medical subject heading index terms on Medline were “ambulatory surgery,” “patient selection,” “preoperative assessment,” and “postoperative complications.” We also used “obstructive sleep apnea,“ “screening,” “patient selection,” “ambulatory anesthesia,” “perioperative management,” and “anesthetics” as index terms to capture data relating to themes of “ambulatory surgery or anesthesia,” “patient selection,” “obstructive sleep apnea,” “hospital admission,” and “postoperative complications.” We hand-searched reference lists from the retrieved articles to identify further trials. The search was limited to English language and human trials in adults. Finally, duplicate records were deleted.

The search results were screened in a stepwise manner to identify eligible studies. Two reviewers independently assessed titles, abstracts, and full-text papers retrieved from the electronic database and manual searches for possible inclusion according to the predefined selection criteria. Other authors resolved any disagreements between the reviewers. In the first phase of the review, irrelevant articles were excluded by reviewing the title of the search results. In the next phase, the abstracts and full-text articles were evaluated to determine whether the eligibility criteria were met. The number and reason of excluded studies in this step were recorded.

All randomized controlled trials, prospective observational trials, and retrospective trials were eligible for inclusion if they reported intraoperative adverse events, postoperative complications, hospital admission, and mortality rates in adult OSA patients undergoing ambulatory surgery. Studies not reporting at least one of these outcomes were excluded. All included studies were graded for strength of evidence according to the Scottish Intercollegiate Guideline Networka (Table 2). Data extracted from these studies included type of study, level of evidence, demographic data, associated comorbid conditions, method of OSA diagnosis, type of procedure, type of anesthetic technique, intraoperative and postoperative events, unanticipated hospital admission, and mortality after ambulatory surgery in OSA patients.

Table 2
Table 2:
Levels of Evidence Used to Rate Individual Studies

The ensuing recommendations were formulated by a working group using the Delphi method to collate rounds of individual comments on the evidence.22 The recommendations were based on data obtained from the outpatient surgical population as well as the application of general principles of safe perioperative care. The benefits and risks of interventions and clinical practice information were considered to ensure that the recommendations preserved patient safety, clinical validity, and usefulness. We used the Grading of Recommendations, Assessment, Development, and Evaluation system for grading the recommendations.23 The strength of recommendations was graded either as “strong” or “weak.” A strong recommendation was offered when the desirable effects of an intervention either clearly did or did not outweigh the undesirable effects. A weak recommendation was offered if the overall effects were less certain, because the evidence was of low quality, or the evidence suggested that desirable and undesirable effects were closely balanced. The categories of evidence were based upon the level of evidence and agreement among the members of the consensus panel (Table 3).

Table 3
Table 3:
Level of Evidence Used to Provide Recommendations


The Quality of Reporting of Meta-Analysis (PRISMA) guidelines were followed for the description of this study. Our search strategy yielded 1905 articles. However, 1833 irrelevant studies were excluded after title review, leaving 72 studies for consideration. Subsequently, 69 studies were excluded for reasons given in Figure 1. In addition to the 3 studies identified through literature search, 4 articles were added after hand-searching and cross-referencing. Of the 7 studies included,12–18 2 were prospective cohorts13,16 and 5 were retrospective chart reviews.12,14,15,17,18 Three of the 7 studies did not have a non-OSA group for comparison.14,15,17 A total of 1491 OSA patients, 2036 low-risk OSA patients, and 2095 non-OSA patients were included in the selected studies. Data from the included studies are summarized in Tables 4 and 5.

Table 5
Table 5:
Perioperative Outcome in Obstructive Sleep Apnea (OSA) Patients Undergoing Ambulatory Surgery
Table 4
Table 4:
Demographic Data of Obstructive Sleep Apnea (OSA) Patients Undergoing Ambulatory Surgery
Figure 1
Figure 1:
Flowchart of the literature search and study selection. Numbers in boldface type are to be added up; other numbers may overlap. RCT = randomized controlled trials; CCTR = Cochrane Controlled Trials Register; OSA = obstructive sleep apnea.

A wide variety of ambulatory surgical procedures such as general surgery, orthopedic surgery, laparoscopic bariatric surgery, and upper airway surgery were included in the assessed trials. In comparison with non-OSA patients, OSA patients had a higher body mass index and more comorbidities, including diabetes, hypertension, stroke, myocardial infarction, and congestive heart failure (P < 0.05) (Table 4).

None of the included studies reported anesthesia-related mortality, as adjudicated by the research groups. There appears to be no correlation between the occurrence of these “surrogate” adverse events (e.g., desaturation, need for supplemental oxygen, need for additional monitoring, and atelectasis) and clinically significant adverse outcomes such as the need for a surgical airway, incidence of anoxic brain injury, delayed discharge, unanticipated hospital admission, and death. Although several studies reported a higher incidence of postoperative hypoxemia in the OSA population, none of the studies observed differences in the need for ventilatory assistance or reintubation.

The limitations of the trials include use of varying approaches to diagnose OSA such as polysomnography, validated screening questionnaires, presence of symptoms suggestive of OSA, and administrative data (i.e., ICD-9 codes for diagnosis of OSA). Also, the control group, when included, had not undergone a polysomnography or a validated screening questionnaire to exclude OSA. Instead the authors used the absence of clinical symptoms such as daytime hypersomnolence to assume the absence of OSA. In addition, there were significant variations in the definition of complications (e.g., hypoxemia was defined as oxygen saturation [SaO2] <95% or <90% or need for supplemental oxygen, which was provided at varying levels of desaturation). Similarly, varying definitions of difficult tracheal intubation were used (e.g., increased laryngoscopy attempts and difficult tracheal view). Despite several limitations, the included studies provide useful information that can guide clinical care.


This systematic review has resulted in several recommendations that are contradictory to the ASA OSA guidelines.4 In contrast to the ASA guidelines that recommend the use of a checklist for preoperative screening for OSA,24 the STOP–Bang screening questionnaire (Table 6) is preferred because it is simple to administer.8,9 The STOP–Bang tool has high sensitivity, and its low specificity can be improved by using a greater number of positive indicators (e.g., ≥6) rather than a cutoff ≥3 as originally suggested.10 Recent evidence suggests that the higher the cumulative score of risk factors on the STOP–Bang tool, the greater the probability of severe OSA.10,11 In addition, the STOP–Bang tool might provide some indication of the severity of OSA.

Table 6
Table 6:
STOP–Bang Questionnaire Used to Screen Patients to Determine the Risk of Obstructive Sleep Apnea (OSA)8

Similar to the ASA guidelines, we recommend that if OSA is suspected during the preoperative evaluation, one could proceed with an assumption that the patient has OSA (i.e., presumptive diagnosis of OSA) because there is no clear evidence to suggest that a sleep study and preoperative continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP) use would improve the perioperative outcome.b Also, the optimal duration of CPAP or bilevel positive airway pressure (BiPAP) therapy before proceeding with elective surgical procedures is unknown.

In outpatients with an established diagnosis of OSA (either by a sleep study or presumptive diagnosis), an adverse perioperative outcome is associated with a complex interplay of factors, particularly coexisting medical conditions and the use of opioids (Fig. 2). Patients with nonoptimized comorbid medical conditions may not be good candidates for ambulatory surgery. We agree with the ASA guidelines that opioids have a significant propensity to exacerbate OSA and prevent arousal.25 Therefore, painful ambulatory surgery may not be suitable if postoperative pain relief cannot be predominantly provided with nonopioid analgesic techniques.26 Local/regional analgesia, acetaminophen, and nonsteroidal anti-inflammatory drugs or cyclooxygenase-2 specific inhibitors should be used as primary analgesic techniques. Combinations of acetaminophen and nonsteroidal anti-inflammatory drugs or cyclooxygenase-2 specific inhibitors have been reported to offer superior analgesia in comparison with either drug alone.27,28 Also, dexamethasone has significant analgesic and opioid-sparing efficacy.29 Preoperative discussion with the surgeons regarding plans for postdischarge pain therapy should assist with this determination.

Figure 2
Figure 2:
Decision making in preoperative selection of a patient with obstructive sleep apnea scheduled for ambulatory surgery. OSA = obstructive sleep apnea; CPAP = continuous positive airway pressure.

In the included studies a majority of the OSA patients used CPAP or BiPAP postoperatively, which may have contributed to a safe perioperative course. Thus, patients’ ability to follow postdischarge instructions, particularly compliance with CPAP, appears to be critical. Therefore, patients with a known diagnosis of OSA and optimized comorbid conditions can be considered for ambulatory surgery if they are able to use a CPAP device in the postoperative period (Fig. 2). Patients who are unable or unwilling to use CPAP after discharge may not be appropriate for ambulatory surgery. Patients with a presumed diagnosis of OSA and optimized comorbid conditions can be considered for most types of ambulatory surgery, if postoperative pain relief can be provided predominantly with nonopioid analgesic techniques.4 In contrast to the ASA OSA guidelines, laparoscopic upper abdominal procedures may be safely performed on an outpatient basis provided the perioperative precautions are followed. No guidance can be provided for OSA patients undergoing upper airway surgery because of limited evidence.

It is necessary to educate surgeons, patients, and their family (or caregivers) regarding the need for increased vigilance after discharge home. Patients and their families should be informed of the potential for hospital admission, which may give them an opportunity to plan in advance and make appropriate arrangements if necessary. Patients receiving preoperative CPAP should be instructed to bring their CPAP device to the ambulatory care facility, unless one is available at the facility. Patients receiving preoperative CPAP should be advised to use their CPAP device for several days postoperatively, because the potential risks can last for several days after surgery. In addition to the usual nocturnal CPAP use, patients should be advised to use CPAP whenever sleeping, even during the daytime. Also, patients should be advised against sleeping in the supine position. Patients who are assumed to have OSA on the basis of the screening questionnaire should be advised to follow up with their primary physician for possible sleep study. Finally, the deleterious effects of opioids must be emphasized, and patients should be asked to limit opioid use.

This review has identified several areas for future research in which current data are insufficient or conflicting. There is a need for large, adequately powered, well-designed prospective trials to assess the suitability of OSA patients for ambulatory surgery. These studies must assess clinically significant outcomes (e.g., need for a surgical airway, incidence of hypoxic/anoxic brain injury, cardiovascular complications such as myocardial infarction and heart failure, delayed discharge, unanticipated hospital admission, readmission after discharge home, and death) rather than “surrogate” outcomes (e.g., desaturation, incidence of hypoxemia, need for supplemental oxygen, difficult mask ventilation or tracheal intubation, and need for additional monitoring). Future studies should assess the influence of opioids on perioperative outcomes. In addition, it is necessary to evaluate the contribution of factors that can influence perioperative outcomes such as preoperative and postoperative CPAP/BiPAP use, type of surgical procedures, anesthetic interventions, and intraoperative and postoperative opioid use. Furthermore, it would be beneficial to compare these complications with those occurring if a surgical intervention did not occur (i.e., baseline risks of OSA). Finally, the impact of the recommendations provided in this consensus statement on perioperative outcome is needed.


Members of the Society for Ambulatory Anesthesia (SAMBA) task force on clinical practice guidelines:

Girish P. Joshi, MBBS, MD, FFARCSI, Chair, Professor of Anesthesiology and Pain Management, Director of Perioperative Medicine and Ambulatory Anesthesia, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9068. Telephone: 214-590-7259. E-mail: [email protected]

Shireen Ahmad, MD, Department of Anesthesiology, Northwestern University Feinberg School of Medicine, 250 E. Huron Street, F5-704, Chicago, IL 60611. Telephone: 312-472-0550. E-mail: [email protected]

Kumar Belani, MBBS, MS, Professor, Department of Anesthesiology, Adjunct Professor, Departments of Medicine & Pediatrics, University of Minnesota, 420 Delaware Street SE, MMC 8294, Minneapolis, MN 55455. Telephone: 612-624-0180. E-mail: [email protected]

Frances Chung, BS, Professor, Department of Anesthesiology, Toronto Western Hospital, University Health Network, University of Toronto, 399 Bathurst Street, Toronto, Ontario, Canada M5T 2S8. Telephone: 416-603-5118. E-mail: [email protected]

Catherine Cooper, MD, Associate Professor of Anesthesiology, Virginia Commonwealth University Health System, P.O. Box 9806695, Richmond, VA 23298-0695. Telephone: 804-828-9160. E-mail: [email protected]

Stanley Eckert, MD, American Anesthesiology and Regional Medical Director, Hospital Corporation of America (HCA) Ambulatory Surgery Division, 7713 Sandia Loop, Austin TX 78735-1520. Telephone: 512-217-4042. E-mail: [email protected]

Tong J. Gan, MD, FRCA, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710. Telephone: 919-681-4660. E-mail: [email protected]

Douglas G. Merrill, MD, Director, Center for Perioperative Services, Medical Director, Outpatient Surgery, Dartmouth–Hitchcock Medical Center, One Medical Center Way, Lebanon, NH 03756. Telephone: 603-650-5922. E-mail: [email protected]

Ana Lucia S. Pappas, MD, Department of Anesthesiology, 835 W. Grace St., Chicago, IL 60613-3904. Telephone: 773-910-1432. E-mail: [email protected]

Bobbie Jean Sweitzer, MD, Professor, Department of Anesthesia and Critical Care, University of Chicago, 5841 South Maryland Avenue, MC4028, Chicago, IL 60637. Telephone: 773-834-8959. E-mail: [email protected]

Rebecca S. Twersky, MD, MPH, Professor, Vice-Chair for Research, Department of Anesthesiology, Medical Director, Ambulatory Surgery Unit, SUNY Downstate Medical Center, 450 Clarkson Avenue, Box 6, Brooklyn, NY 11203. Telephone: 718-613-8742. E-mail: [email protected]


Name: Girish P. Joshi, MBBS, MD, FFARSCI.

Contribution: This author helped design the study, review the data, analyze the data, and prepare the manuscript.

Conflicts of Interest: The author has no conflict of interest to declare.

Name: Saravanan P. Ankichetty, MD, DA, MBA.

Contribution: This author helped review the data, analyze the data, and review the manuscript.

Conflicts of Interest: The author has no conflict of interest to declare.

Name: Tong J. Gan, MD, MHS, FRCA.

Contribution: This author helped review the data, analyze the data, and review the manuscript.

Conflicts of Interest: The author has no conflict of interest to declare.

Name: Frances Chung, MB, BS, FRCPC.

Contribution: This author helped design the study, review the data, analyze the data, review the manuscript, and edit the manuscript.

Conflicts of Interest: Frances Chung has received research grants from ResMed Foundation.

This manuscript was handled by: Steven L. Shafer, MD.


The authors would like to thank Marina Englesakis, BA (Hons), MLIS, Information Specialist, Health Sciences Library, University Health Network, Toronto, Ontario, Canada, for her assistance with the literature search and Peter Glass, MD, for editorial guidance.

a Scottish Intercollegiate Guidelines Network. SIGN 50: a guideline developer’s handbook. Available at: Accessed August 4, 2011.
Cited Here

b Centers for Medicare and Medicaid Services. Decision memo for sleep testing for obstructive sleep apnea. Available at: Accessed August 2011.
Cited Here


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