Intraoperative management of adults with obstructive sleep apnea

INTRODUCTION — Obstructive sleep apnea (OSA) is increasing in prevalence [1,2], and the number of perioperative patients with OSA is likely to continue to rise in parallel with the increase in obesity [2-4]. Over one-half of patients with OSA who present for surgery are undiagnosed [5-7].

OSA increases the risks of perioperative complications, and should be suspected, recognized, and managed in the perioperative period to minimize postoperative morbidity and mortality.

The American Society of Anesthesiologists, the American Academy of Sleep Medicine, Society of Anesthesia and Sleep Medicine, and others have developed clinical practice guidelines and protocols for the perioperative management of patients with OSA, with the goal of reducing perioperative complications [8-13]. Recommendations are generally based upon limited evidence, clinical rationale, and expert opinion, and include maintaining a high index of suspicion for OSA, careful use of medications, vigilant monitoring for upper airway obstruction, and an integrated team approach to perioperative management (table 1).

This topic will review the intraoperative management of patients with OSA, including risk mitigation strategies and precautions. Preoperative evaluation and management, surgical risks, and postoperative management for patients with OSA are discussed separately. (See "Surgical risk and the preoperative evaluation and management of adults with obstructive sleep apnea" and "Postoperative management of adults with obstructive sleep apnea".)

CHOICE OF ANESTHETIC TECHNIQUE — In general, the choice of anesthetic technique is determined by the surgical procedure, patient factors (eg, predicted difficulty with airway management, comorbidities), and preferences of the patient, anesthesiologist, and surgeon. (See "Surgical risk and the preoperative evaluation and management of adults with obstructive sleep apnea", section on 'Associated conditions'.)

General principles include the following:

●Minimizing respiratory depressants likely to have residual effect during the postoperative period – For patients with OSA, a goal for any type of anesthesia (ie, monitored anesthesia care [MAC] with sedation, general anesthesia, or regional anesthesia) is to avoid worsened intra- and postoperative airway obstruction by minimizing the use of respiratory depressants with effects that will continue into the postoperative period. Most anesthetic techniques can be modified to conform to this goal (table 1).

●Preference for regional anesthesia – Regional anesthesia (both peripheral nerve and neuraxial blocks) techniques are preferred over general anesthesia for peripheral procedures whenever possible [13]. However, if moderate or deep sedation would be required for a patient to tolerate a procedure under regional anesthesia, general anesthesia with a secure airway may be preferred.

Regional analgesia techniques should also be used as part of multimodal, opioid-sparing postoperative analgesia when appropriate. (See "Postoperative management of adults with obstructive sleep apnea", section on 'Pain control'.)

Literature on the benefits of specific anesthesia techniques for patients with OSA is limited, and consists of mainly retrospective reviews with inherent limitations. In patients without OSA, neuraxial anesthesia may reduce the risk of postoperative pulmonary complications, though this issue is controversial. (See "Overview of neuraxial anesthesia", section on 'General versus neuraxial anesthesia'.)

Examples of studies comparing general and regional anesthesia for patients with OSA include the following:

●In a retrospective population-based study of over 30,000 patients with OSA who underwent hip or knee arthroplasty, the use of neuraxial anesthesia was associated with modestly lower overall major complications compared with combined general-neuraxial anesthesia or general anesthesia (16 versus 17 versus 18 percent, respectively) [14].

●In a retrospective single-institution case-controlled study of patients with OSA who underwent total hip or knee arthroplasty, compared with neuraxial anesthesia, general anesthesia was associated with increased risks of pulmonary and gastrointestinal complications, anemia, and mortality [15]. Conclusions are limited by lack information on the severity of OSA, criteria used for the diagnosis of OSA, compliance with OSA treatment, criteria for the choice of anesthetic technique and data regarding postoperative opioid consumption.

●In a prospective observational study of 376 OSA and non-OSA patients undergoing various surgeries with postoperative polysomnography monitoring, general anesthesia was associated with an increase in the central apnea index in all patients [16]. As in previous studies, the dose of perioperative opioids was associated with increased postoperative central apnea [17]. (See "Central sleep apnea: Risk factors, clinical presentation, and diagnosis", section on 'Diagnostic criteria'.)

ANESTHETIC MANAGEMENT — Anesthetic strategies that may mitigate perioperative risk for patients with known or suspected OSA are shown in the table (table 1). These strategies are based on known effects of anesthetic agents, with the goal of reducing postoperative respiratory adverse events, and are consistent with guidelines from the American Society of Anesthesiologists and the Society of Anesthesia and Sleep Medicine [10,13].

Sedation — Sedatives and opioids may be required for premedication, or for sedation during procedures performed with regional anesthesia or monitored anesthesia care (MAC). In patients with OSA, these medications can worsen OSA by depressing upper airway tone resulting in airway obstruction and decreased respiratory drive. Thus, we administer sedatives only as necessary, titrated to effect, in the lowest doses necessary, and choose short-acting rather than longer-acting medications.

Premedication — Sedatives and opioids should not be administered routinely as premedication for patients with OSA. If premedication is necessary, short-acting sedatives (eg, midazolam) should be administered in small doses, titrated to effect, with continuous pulse oximetry monitoring. Sedative and opioid antagonist medications (eg, flumazenil, naloxone) should be immediately available.

Multimodal opioid-sparing strategies for postoperative pain control may include premedication with alpha-2 agonists and/or acetaminophen. (See 'Sedative/analgesic agents' below.)

Procedural sedation — MAC and regional anesthesia often involve the use of sedatives and/or analgesic agents. Standard monitoring during any anesthetic includes pulse oximetry, and capnography as well for any patient who receives moderate or deep sedation or general anesthesia [18,19]. However, we use capnography to monitor ventilation whenever possible for patients with OSA who receive any sedative medications during MAC or regional anesthesia, regardless of the depth of sedation (see "Monitored anesthesia care in adults", section on 'Standard physiologic monitors'). Snoring, apnea, and/or oxyhemoglobin desaturation may indicate upper airway collapse, which can occur even if the patient is using positive airway pressure (PAP).

Strategies that may be used to minimize airway problems during and after sedation include:

●Use infusions at the lowest effective doses rather than bolus dosing of sedatives or opioids to decrease episodic respiratory depression.

●Use short-acting sedatives/opioids (eg, propofol, remifentanil) to minimize carryover into the postoperative period [20].

●Use sedatives that are least likely to induce respiratory depression (eg, dexmedetomidine, ketamine) [21].

●Position head up, if surgically acceptable.

●Use airway positioning to relieve obstruction, such as sniffing position (lower cervical flexion, upper cervical extension) (picture 1) or jaw thrust (picture 2).

●Consider the use of an oral or nasopharyngeal airway depending on the depth of sedation and the patient's tolerance.

●Consider using PAP, an oral appliance, hypoglossal nerve stimulation therapy, or high nasal flow oxygen during sedation [10]. (See "Titration of positive airway pressure therapy for adults with obstructive sleep apnea".)

●Administer oxygen therapy to avoid hypoxemia during MAC [22], recognizing that administration of supplemental oxygen delays detection of respiratory depression, particularly in the absence of any type of ventilation monitoring. (See "Carbon dioxide monitoring (capnography)", section on 'Procedural sedation'.)

Sedative/analgesic agents — The effects of sedatives and analgesics on airway patency and respiratory reflexes in patients with OSA are discussed in this section. The general considerations for the choice of sedatives and analgesics during MAC or regional anesthesia are discussed separately. (See "Monitored anesthesia care in adults", section on 'Drugs used for sedation and analgesia for monitored anesthesia care'.)

●Benzodiazepines – We avoid benzodiazepines or use reduced doses of benzodiazepines for patients with OSA. Benzodiazepines (eg, midazolam) increase supraglottic upper airway resistance, decrease arousal response to hypoxia, and may induce central apnea [13,23-25].

●Propofol – Propofol is an attractive option for sedation for patients with OSA because of its rapid onset and offset, lack of residual effect, and titratability. However, propofol causes dose-dependent relaxation of the genioglossus muscle and inhibits upper airway reflexes, both of which can cause airway collapse [26]. Thus, the lowest effective dose of propofol should be administered by bolus or infusion for sedation, titrated to effect.

●Alpha-2 agonists – Alpha-2 agonists (ie, clonidine and dexmedetomidine) have hypnotic, sedative, and analgesic effects, and may reduce requirements for other sedatives and opioids, with minimal or no respiratory depression at doses used for sedation.

•In one study involving 30 adults with OSA who were randomly assigned to receive clonidine premedication or placebo before elective ear, nose, and throat surgery, the patients who received clonidine required less intraoperative anesthetic agents and less postoperative opioids, without differences in postoperative apnea or oxygen desaturation [27].

•While studies in children suggest no difference in the changes in airway morphology that occur during deep sedation with propofol compared with dexmedetomidine, studies in adults have not yet been published.

-As an example, in one study, 60 children with OSA were randomly assigned to anesthesia with dexmedetomidine or propofol for magnetic resonance imaging airway sleep study [28]. There were insignificant changes in airway dimensions with both agents, though there was a trend towards reduced airway dimensions with propofol sedation.

-In another study, 40 children who underwent magnetic resonance imaging were randomly assigned to deep sedation with propofol or dexmedetomidine following inhalation induction of anesthesia with sevoflurane [29]. The degree of airway collapse on the images was no different during sevoflurane anesthesia and either drug during deep sedation (median degree of airway collapse 15 to 40 percent).

●Ketamine – Ketamine is an N-methyl-D-aspartate (NMDA) receptor antagonist with sedative, analgesic, and respiratory stimulant properties. Unlike most other sedatives, ketamine does not relax upper airway dilator muscles, and may theoretically avoid upper airway collapse if administered without other sedatives or opioids [30]. In an animal study, it was found to uncouple loss of consciousness and upper airway dilator muscle dysfunction [31], but data in humans are lacking.

●Opioids – Opioids should be administered cautiously and in reduced doses in patients with OSA [13]. Perioperative opioids decrease respiratory drive, suppress the arousal threshold, and may cause central apnea in susceptible OSA patients [32-35].

Use of opioids for postoperative pain control in patients with OSA is discussed separately. (See "Postoperative management of adults with obstructive sleep apnea", section on 'Pain control'.)

●Gabapentinoids – Gabapentinoids (gabapentin and pregabalin) are increasingly administered preoperatively as part of multimodal opioid-sparing analgesic regimens. These medications should be avoided or used cautiously at lowered doses in patients suspected or known to have OSA, since in non-OSA patients these drugs, when combined with opioids, have been associated with sedation, respiratory depression, and death [36,37]. (See "Nonopioid pharmacotherapy for acute pain in adults", section on 'Gabapentinoids'.)

Regional anesthesia/analgesia — Regional anesthesia techniques (ie, peripheral nerve blocks, neuraxial anesthesia) should be used rather than general anesthesia whenever possible for patients with OSA. Postoperative outcome may be improved when regional anesthesia is utilized as opposed to general anesthesia [13-15,38]. (See 'Choice of anesthetic technique' above.)

Single injection or continuous peripheral nerve blocks are effective components of multimodal opioid-sparing analgesic protocols for appropriate surgical procedures. (See "Approach to the management of acute pain in adults", section on 'Regional anesthesia techniques'.)

Patients with OSA may be more susceptible to respiratory depression associated with neuraxial analgesia with either continuous epidural lipophilic opioid solutions (eg, containing fentanyl), or single-injection hydrophilic long-acting neuraxial opioids (eg, morphine, hydromorphone). However, the data on this issue are limited and the incidence of respiratory depression is unknown. A 2013 systematic review of the literature on complications of neuraxial opioids in patients with OSA found five studies including 121 patients, with low quality evidence [39]. Five of the six reported major cardiorespiratory complications occurred during continuous epidural analgesia with fentanyl without use of concurrent PAP treatment. In a single institution retrospective study of approximately 1300 patients with OSA who underwent hip or knee arthroplasty with spinal anesthesia, low-dose intrathecal morphine, in conjunction with multimodal analgesia, was not associated with increased risk of postoperative pulmonary complications [40]. (See "Postoperative management of adults with obstructive sleep apnea", section on 'Pain control' and "Continuous epidural analgesia for postoperative pain: Technique and management", section on 'Monitoring during epidural analgesia'.)

General anesthesia — Particular concerns regarding general anesthesia in patients with OSA include the increased incidence of difficult airways [13,41,42] and the potential for postoperative respiratory compromise as a result of the residual effects of anesthetic agents. Other considerations relate to the comorbidities that may be associated with OSA. There should be a high index of suspicion for pulmonary hypertension in patients with chronic untreated severe OSA or obesity hypoventilation syndrome [43] (see "Pulmonary hypertension due to lung disease and/or hypoxemia (group 3 pulmonary hypertension): Treatment and prognosis", section on 'Sleep-disordered breathing and hypoxia').

Patients with pulmonary hypertension should generally be managed with controlled ventilation rather than allowing spontaneous respiration, as hypercarbia, hypoxemia, and acidosis are triggers for increased pulmonary artery pressures. (See "Anesthesia for adults with congenital heart disease undergoing noncardiac surgery", section on 'Pulmonary arterial hypertension' and "Anesthesia for noncardiac surgery in patients with pulmonary hypertension or right heart failure".)

Comorbidities associated with OSA are discussed separately. (See "Surgical risk and the preoperative evaluation and management of adults with obstructive sleep apnea", section on 'Associated conditions'.)

Airway management

Difficulty with airway management — OSA itself and a number of associated patient characteristics (eg, obesity, large neck circumference, snoring) are risk factors for difficulty with airway management for anesthesia (table 2 and table 3 and table 4) and for airway complications after extubation (table 5).

●In a meta-analysis of 16 observational studies of surgical patients, OSA was associated with a higher risk of difficult intubation (odds ratio 3.5) or difficult mask ventilation (odds ratio 3.4) [41].

●In a prospective international study of difficulty with airway management in 869 patients without prior diagnosis of OSA who underwent general anesthesia for noncardiac surgery, patients were assessed preoperatively with STOP-Bang scores (table 6), bedside airway examination, and portable sleep monitoring devices for OSA [44]. Based on sleep study results, moderate and severe OSA (but not mild OSA) were associated with increased incidence of difficult intubation (odds ratio 3.26 [95% CI 1.37-8.38] and 4.05 [95% CI 1.51-11.36], respectively). A STOP-Bang score of ≥3 was also associated with difficult intubation. OSA was not associated with difficult mask ventilation.

Assessment and management of the difficult airway for anesthesia (eg, mask ventilation, supraglottic airway ventilation, laryngoscopy, and intubation) and general principles of the induction and maintenance of anesthesia are discussed separately. (See "Management of the difficult airway for general anesthesia in adults" and "Induction of general anesthesia: Overview" and "Maintenance of general anesthesia: Overview".)

Preoperative screening for OSA is also discussed separately. (See "Surgical risk and the preoperative evaluation and management of adults with obstructive sleep apnea", section on 'Patients without a known diagnosis'.)

Positioning for induction and airway management — Patients should be in a head-up position for induction and airway management. This improves both lung volumes (functional residual capacity) and laryngoscopic view, particularly in obese patients [8,21,45]. Patients with obesity may require additional equipment to provide ramped positioning (figure 1). (See "Anesthesia for the patient with obesity", section on 'Preoxygenation and apneic oxygenation'.)

Preoxygenation and apneic oxygenation — Preoxygenation should be performed for all patients before induction of anesthesia. In addition, apneic oxygenation can prolong the safe apnea time for patients with OSA and obesity, any patient who is expected to desaturate rapidly during apnea, and for patients with predicted difficulty with airway management [42]. Preoxygenation and apneic oxygenation techniques are discussed separately. (See "Preoxygenation and apneic oxygenation for airway management for anesthesia" and "Anesthesia for the patient with obesity", section on 'Preoxygenation and apneic oxygenation' and "Airway management for induction of general anesthesia", section on 'Preoxygenation'.)

Choice of anesthetic agents — We prefer to use short-acting anesthetic agents that facilitate rapid emergence from anesthesia and minimal residual sedation (eg, propofol, desflurane, remifentanil). The literature on the effects of various anesthetic agents for patients with OSA is limited, and insufficient to recommend the choice of specific anesthetic agents [10,13,23]. Intravenous and inhalation anesthetics, sedatives, opioids, and neuromuscular blocking agents can all affect respiratory muscles, particularly the upper airway muscles, and effects may continue into the postoperative period. [23,26,46,47]. OSA patients are thought to be particularly susceptible to the respiratory depressant effects of these medications because of their blunted physiologic response to hypercarbia and hypoxia. Characteristics of inhaled and intravenous anesthetic agents are discussed separately. (See "Inhalation anesthetic agents: Clinical effects and uses" and "General anesthesia: Intravenous induction agents" and "Maintenance of general anesthesia: Overview", section on 'Total intravenous anesthesia'.)

Intravenous fluid management — Patients with OSA may benefit from a restrictive or goal-directed strategy for intraoperative fluid therapy, and from fluids with relatively lower salt content (ie, lactated Ringer or PlasmaLyte rather than normal saline). This strategy is based upon the biologic rationale that salt and/or fluid retention from administration of intravenous fluids and the stress response to surgery [48,49] while the patient is supine can predispose to fluid accumulation in the neck, and consequently contribute to airway narrowing [50]. When feasible, we prefer that patients with OSA be positioned head up to ameliorate this phenomenon.

Rostral fluid shift and intraoperative fluid therapy are discussed more fully separately. (See "Intraoperative fluid management", section on 'Choosing a fluid management strategy' and "Pathophysiology of upper airway obstruction in obstructive sleep apnea in adults", section on 'Rostral fluid displacement'.)

Emergence and extubation — Patients with OSA and difficult airways should be extubated at the end of anesthesia when awake, rather than when deeply anesthetized [51]. OSA and obesity are among the factors that increase the risk of extubation failure after anesthesia (see "Extubation following anesthesia", section on 'Extubation risk stratification'). Patients who are fully conscious, purposefully responding to commands, have no residual neuromuscular blockade, and have airway patency confirmed are least likely to require airway assistance after extubation. (See "Extubation following anesthesia".)

Neuromuscular blockade should be specifically assessed at the conclusion of the surgery, and reversal agents appropriately administered [42]. The risks of residual neuromuscular blockade during the early postoperative period are amplified in patients with OSA, especially in those with obesity; these include hypoxemia, airway obstruction, longer post-anesthesia care unit stays, delays in tracheal extubation, and an increased risk of postoperative pulmonary complications [21,52]. A 2018 systematic review found that OSA patients who receive intraoperative neuromuscular blockade may be at higher risk for postoperative hypoxemia, respiratory failure, and residual neuromuscular blockade compared with non-OSA patients [53]. There is limited evidence that neuromuscular blockade reversal with sugammadex may be associated with less postoperative complications than neostigmine in patients with OSA [53]. (See "Clinical use of neuromuscular blocking agents in anesthesia", section on 'Avoidance of residual neuromuscular blockade'.)

Patients should be extubated in a head-up position and remain in a non-supine position (semi-upright or lateral) during the early recovery period, if possible [10]. (See "Postoperative management of adults with obstructive sleep apnea", section on 'Positive airway pressure therapy'.)

PAP therapy should be started early in the postoperative period, preferably in the PACU, when feasible, for patients with a known diagnosis of OSA who are compliant preoperatively with PAP, and selectively for other patients with OSA. Postoperative use of PAP for OSA patients is discussed separately. (See "Postoperative management of adults with obstructive sleep apnea", section on 'Positive airway pressure therapy'.)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Sleep-related breathing disorders in adults".)

SUMMARY AND RECOMMENDATIONS

●Approach to anesthetic management – A general principle for patients with obstructive sleep apnea (OSA) is to use an anesthetic technique that minimizes the use of respiratory depressants whose effects will continue into the postoperative period. Anesthetic strategies that may mitigate perioperative risk for patients with known or suspected OSA are shown in the table (table 1). (See 'Choice of anesthetic technique' above.)

●Choice of anesthetic technique – Anesthetic technique is determined by the surgical procedure, comorbid medical conditions, and preferences of the anesthesiologist, patient, and surgeon.

Regional anesthesia techniques are preferred over general anesthesia for procedures whenever possible. However, if moderate or deep sedation would be required for a patient to tolerate a procedure under regional anesthesia, general anesthesia with a secure airway may be preferred.

Regional anesthesia should also be used whenever possible as part of a multimodal opioid-sparing strategy for postoperative pain control. (See 'Choice of anesthetic technique' above.)

●Airway management

•Optimal positioning for airway patency, airway adjuncts, and use of continuous positive airway pressure (PAP) may be helpful in minimizing airway problems during sedation for regional anesthesia and monitored anesthesia care (MAC) as well as during recovery. Oxygenation and ventilation should be continuously monitored (most often with pulse oximetry and capnography). (See 'Procedural sedation' above.)

•OSA is associated with difficulty with airway management for general anesthesia. Principles of airway management are similar to those that are used for patients without OSA with difficult airways.(See "Management of the difficult airway for general anesthesia in adults".)

•Patients with OSA should be induced and intubated in the head-up position and particular attention should be paid to preoxygenation. (See 'Positioning for induction and airway management' above and 'Preoxygenation and apneic oxygenation' above.)

●Sensitivity to sedatives and opioids – Patients with OSA are often sensitive to the respiratory-depressant effects of sedatives and opioids, which may be mitigated by lower doses and use of shorter-acting agents. Reversal agents should be available. (See 'Premedication' above.)

During general anesthesia, short-acting anesthetic agents may shorten emergence and decrease postoperative respiratory depression. (See 'Choice of anesthetic agents' above.)

●Intraoperative fluid management – Patients with OSA may benefit from a restrictive or goal-directed strategy for intraoperative fluid therapy, and from fluids with relatively lower salt content (ie, lactated Ringer or PlasmaLyte rather than normal saline). (See 'Intravenous fluid management' above.)

●Extubation – Extubation of patients with OSA should take place in a head-up position, with airway reflexes intact, neuromuscular blocking agents reversed (if needed), and the patient adequately ventilating and responsive. (See 'Emergence and extubation' above.)