Obstructive sleep apnea (OSA) is a disorder characterized by repetitive episodes of apnea or reduced inspiratory airflow due to upper airway obstruction during sleep. The incidence of perioperative complications (ie, preoperative, intraoperative, and postoperative complications collectively) is increased among patients with OSA [1,2]. The Joint Commission has suggested that a National Patient Safety Goal be the reduction of perioperative complications among patients with OSA , while the American Society of Anesthesiology (ASA) and American Academy of Sleep Medicine (AASM) have developed clinical practice guidelines for the perioperative management of patients with OSA [4-6]. Common among the guidelines is an emphasis on maintaining a high index of suspicion for OSA, careful use of medications, vigilant monitoring for evidence of upper airway obstruction, an integrated team approach to perioperative management, and recognition that many recommendations are based upon clinical rationale and indirect evidence because direct evidence is scarce. Such interest in the perioperative management of patients with OSA probably reflects in part the recognition that the number of patients with OSA encountered in operating rooms is likely to increase as recognition of the disease and the prevalence of obesity increase [4,7].
Factors that contribute to the increased surgical risk of patients with OSA and the preoperative evaluation and management of patients with OSA are reviewed here. The intraoperative and postoperative management of patients with OSA are discussed elsewhere. (See "Postoperative management of adults with obstructive sleep apnea" and "Intraoperative management of adults with obstructive sleep apnea".)
SURGICAL RISK IN PATIENTS WITH OSA
Contributing factors — Patients with OSA who are undergoing procedures that require sedation, anesthesia, and/or analgesia are at higher risk for periprocedural complications than patients who do not have OSA [1,2]. This may be related to upper airway collapse and/or OSA-related comorbidities.
Upper airway collapse contributes to perioperative complications by inducing hypoxemia and other physiological perturbations. The following perioperative factors may increase the frequency and/or duration of upper airway collapse in patients with OSA (table 1):
- Perioperative medications (eg, sedatives, general anesthetic agents, narcotic analgesics) — Perioperative medications reduce upper airway dilator tone, while inhibiting protective airway reflexes, central ventilatory drive, and arousal mechanisms. These effects mimic sleep and, therefore, may exacerbate repetitive upper airway collapse in patients with OSA. (See "The effects of medications on sleep quality and sleep architecture".)
- Upper airway narrowing —A smaller amount of upper airway collapse is necessary to cause obstruction if the upper airway is narrowed by surgical factors, such as post-intubation edema, postoperative edema, nasal packing, nasal tubes, and/or hematomas [8-12].
- Supine positioning — Patients are often required to lie in the supine position perioperatively. However, this may increase the severity of the OSA, since many patients have OSA that develops or worsens in the supine position. (See "Management of obstructive sleep apnea in adults", section on 'Sleep position'.)
- Sleep deprivation — Patients often develop sleep deprivation during the perioperative period due to anxiety, the disease requiring the operation, pain, alterations in circadian rhythm, and/or nursing activity. Sleep deprivation may be associated with worsening OSA [13-16], although this is controversial.
- Cessation of continuous positive airway pressure (CPAP) therapy — Many patients with OSA temporarily discontinue their CPAP therapy perioperatively. This is often due to pain, anxiety, nausea, agitation, the presence of a nasogastric tube, failure to bring equipment to the hospital, or failure of the hospital to resume CPAP postoperatively.
- Rapid eye movement (REM) rebound – Potentially a consequence of sleep deprivation, increased REM sleep is important because OSA is typically most severe during REM sleep.