ASA Monitor 07 2017, Vol.81, 10-12.
Frances Chung, M.B.B.S., FRCPC, is Professor of Anesthesiology, University Health Network, University of Toronto, Ontario, Canada.
The management of patients with known or suspected obstructive sleep apnea (OSA) is an evolving field. It is known that patients with OSA have a two- to three-fold increased risk of postoperative cardiopulmonary complications.1,2 In order to avoid complications, preoperative screening of patients is essential for optimal management and risk mitigation. ASA, the Society for Ambulatory Anesthesia (SAMBA) and the Society of Anesthesia and Sleep Medicine (SASM) have published recommendations in this area.3 –5 This article will highlight the essential recommendations by these groups on the specific aspect of preoperative screening and assessment of surgical patients with OSA.
ASA published updated guidelines on the perioperative management of patients with OSA in 2014.3 It is suggested that anesthesiologists should work with surgeons to develop a protocol whereby patients with suspected OSA are evaluated long before the day of surgery to allow better preparation. If OSA is suspected, the anesthesiologist and surgeon should jointly decide whether to manage the patient perioperatively based on clinical criteria alone or obtain sleep studies, conduct a more extensive airway examination and initiate indicated OSA treatment in advance of surgery. If the preoperative evaluation occurs only on the day of surgery, the surgeon and anesthesiologist may elect for presumptive management based on clinical criteria or a delay of surgery. The severity of the patient’s OSA, the invasiveness of the diagnostic or therapeutic procedure, and the requirement for postoperative analgesics should be taken into account in determining whether a patient is at increased perioperative risk from OSA.
SAMBA Consensus Statement
The suitability of ambulatory surgery in a patient with OSA remains controversial because of concerns of increased perioperative complications, including post-discharge death. In 2012, under the leadership of Dr. Joshi, SAMBA published a consensus statement for the selection of patients with OSA scheduled for ambulatory surgery.4
The recommendations include:
- Patients with known diagnosis of OSA and optimized comorbid medical conditions can be considered for ambulatory surgery if they are able to use the CPAP device in the postoperative period.
- Patients with presumed diagnosis of OSA, based on screening tools such as the STOP-Bang questionnaire,5 and optimized comorbid conditions can be considered for ambulatory surgery if postoperative pain can be managed predominantly with non-opioid analgesic techniques. It is not necessary to postpone surgery in this patient population.
- OSA patients with non-optimized comorbid conditions may not be ideal candidates for ambulatory surgery.
Recently, SASM published an evidence-based and cost-effective approach to preoperative screening and assessment of patients with known or suspected OSA.6 Dr. Chung and Dennis Auckley, M.D., Case Western Reserve University, chaired the task force, which was composed of 28 SASM members, including 12 anesthesiologists, nine sleep medicine specialists, two hospitalists, one otolaryngologist, two research assistants, a research librarian and a clinical epidemiologist. Members represented both academic and non-academic settings in various parts of the United States, Canada, Europe, Australia and South America. The task force developed recommendations with the goal of finding a practical balance between minimizing postoperative complications and the efficient use of health care resources. Essentially, the SASM guidelines support the recommendations from ASA and SAMBA. In addition, there are some new recommendations.
A summary of these recommendations follows:
- OSA surgical patients are at an increased risk for perioperative complications. Identifying patients at high risk for OSA prior to surgery for targeted perioperative precautions and interventions may reduce perioperative complications.
- Screening tools may help to risk stratify patients with suspected OSA with reasonable accuracy. Practice groups should consider making OSA screening part of standard pre-anesthetic evaluation.
- There is insufficient evidence in the current literature to support canceling or delaying surgery for a formal diagnosis (i.e., laboratory or home polysomnography) in patients with suspected OSA, unless there is evidence of uncontrolled systemic disease.
- The patient and the health care team should be aware that known, treated, partially treated and untreated OSA as well as suspected OSA may be associated with increased postoperative morbidity.
- Consideration should be given to obtaining the results of the sleep study and the recommended positive airway pressure (PAP) information before surgery.
- If resources allow, facilities should consider having PAP equipment for perioperative use or have patients bring their own PAP equipment with them to the surgical facility.
- Additional evaluation for preoperative cardiopulmonary optimization should be considered in patients with known, partially treated/untreated and suspected OSA who have uncontrolled systemic conditions (e.g., hypoventilation syndromes, severe pulmonary hypertension and resting hypoxemia in the absence of other cardiopulmonary disease).
- Patients with known OSA, partially treated/untreated and suspected OSA with optimized comorbid conditions may proceed to surgery, provided strategies for mitigation of postoperative complications are implemented.
- The risks and benefits of the decision should include consultation and discussion with the surgeon and the patient.
- The use of PAP therapy in previously undiagnosed but suspected OSA patients should be considered case by case. Due to the lack of evidence from randomized controlled trials, its routine use is not recommended.
- Continued use of PAP therapy at previously prescribed settings is recommended during periods of sleep, both preoperatively and postoperatively. Adjustments may need to be made to the settings to account for perioperative changes such as facial swelling, fluid shifts, recent pharmacotherapy and pulmonary function.
“If the preoperative evaluation occurs only on the day of surgery, the surgeon and anesthesiologist may elect for presumptive management based on clinical criteria or a delay of surgery. The severity of the patient’s OSA, the invasiveness of the diagnostic or therapeutic procedure, and the requirement for postoperative analgesics should be taken into account in determining whether a patient is at increased perioperative risk from OSA.”
In summary, the primary goal of these three guidelines is to ensure optimal preoperative evaluation of patients with known or suspected OSA in order to improve patient safety.3 –5 It is hoped that the recommendations from these guidelines will influence clinical practice as well as stimulate additional research to address the questions for which there is currently insufficient evidence to support recommendations.
Opperer M, Cozowicz C, Bugada D, et al. Does obstructive sleep apnea influence perioperative outcome? A qualitative systematic review for the Society of Anesthesia and Sleep Medicine Task Force on Preoperative Preparation of Patients with Sleep-Disordered Breathing. Anesth Analg. 2016;122(5):1321–1334.
Kaw R, Chung F, Pasupuleti V, Mehta J, Gay PC, Hernandez AV . Meta-analysis of the association between obstructive sleep apnoea and postoperative outcome. Br J Anaesth. 2012;109(6):897–906.
ASA Task Force on Perioperative Mgmt. Practice guidelines for the perioperative management of patients with obstructive sleep apnea: an updated report by the American Society of Anesthesiologists Task Force on Perioperative Management of patients with obstructive sleep apnea. Anesthesiology. 2014;120(2):268–286.
Joshi GP, Ankichetty SP, Gan TJ, Chung F . Society for Ambulatory Anesthesia consensus statement on preoperative selection of adult patients with obstructive sleep apnea scheduled for ambulatory surgery. Anesth Analg. 2012;115(5):1060–1068.
Chung F, Abdullah HR, Liao P . STOP-Bang questionnaire: a practical approach to screen for obstructive sleep apnea. Chest. 2016;149(3):631–638.
Chung F, Memtsoudis S, Krishna Ramachandran S, et al. Society of Anesthesia and Sleep Medicine guideline on preoperative screening and assessment of patients with obstructive sleep apnea. Anesth Analg. 2016;123(2):452–473.