In recent years, sleep medicine has become an important medical subspecialty, with strong links to anesthesiology. The foundations of both specialties are based on an understanding of anatomic and physiologic changes that take place with loss of consciousness.1 Sleep is essential for health and resilience, and poor sleep has significant implications for perioperative management and outcomes. As a result of this common ground, the relationship between sleep medicine and anesthesiology should strengthen over the next decade as anesthesiology's role in perioperative medicine and population health expands.
Because of recent advances in our understanding of sleep, anesthesiologists and sleep medicine physicians have been able to identify new approaches to clinical care, including how to better manage patients with sleep disorders in the perioperative period. Based on advances in our understanding of sleep disorders, anesthesiologists have become more aware of risks associated with management of patients with chronic sleep disorders and their impact on perioperative outcomes, including cognitive function.
Anesthesiologists have extensive experience in managing airway obstruction in the patient with underlying airway problems as well as for those who develop obstruction when sedated or anesthetized.2 The anatomical issues underlying obstructive sleep apnea (OSA) often impact ease of intubation; intubation difficulty alone predicts substantially increased OSA risk.3 Obstruction-prone airways present particular risks in the perioperative period when protective arousal responses are depressed by residual sedation or use of opioids or other respiratory depressant drugs. “Near miss” events and fatalities have occurred when the airway problems are not recognized or managed appropriately.4
In addition to upper airway compromise, sleep-induced hypoventilation secondary to obesity is predictive of hypoventilation during anesthesia and sedation, as is likely with sleep hypoventilation secondary to neuromuscular disorders, chest wall deformity, chronic obstructive pulmonary disease, and other ventilatory disorders.5 A number of other sleep disorders often present as challenges during the perioperative period. For example, non-respiratory sleep disorders, many of which are relatively common, are readily exacerbated during hospitalization, particularly in the elderly. Many hospitalized patients experience insomnia. While the sleep medicine physician will try to identify and treat causes for insomnia in the outpatient setting, the implications for the anesthesiologist must also be considered. Insomnia is aggravated by the environmental challenges of hospitalization (noise, light, etc.), as well as by anxiety and pain, and in turn compromises recuperation. Narcolepsy can present unusual behaviours during recovery from anesthesia, such as cataplexy, which can be difficult to interpret. Patients with restless leg syndrome may manifest worsening of symptoms, particularly if medications used to treat it are withdrawn during the perioperative period. Sleep disorders also increase the risk for falls in the postoperative period. Knowledge of these and other sleep issues and consultation, when appropriate, between the sleep medicine physician and the anesthesiologist can mitigate these risks.6
Poor sleep also has negative influences on other factors affecting recovery from illness and operation. These factors, some of which may be precipitated by as little as one night of disrupted sleep, include increased pain perception; cognitive disturbance, including delirium; psychomotor impairment, including increased risk for falls; psychological disturbance, such as anxiety and irritability; cardiovascular dysfunction, including hypertension and atrial fibrillation; metabolic disturbance, including increased insulin resistance; immune dysfunction and proinflammatory changes; and catabolic propensity.6
As a result of the improved understanding of the importance of sleep and the consequences of poor sleep on perioperative outcomes, integration of “sleep health” into personalized care of the patient will become a larger part of the anesthesiologist's role as perioperative physician. Knowledge of sleep medicine represents a significant opportunity for all anesthesiologists to expand their capacity to optimize perioperative care. Anesthesiologists are well positioned to embrace this extension of their practice. Airway compromise and ventilatory and gas exchange disturbances are clinical considerations addressed by all anesthesiologists. However, other non-respiratory sleep issues also have important perioperative implications. To successfully integrate these concepts into anesthesia practice, training programs should include a comprehensive review of types and causes for sleep disorders, their potential perioperative consequences, and management strategies to address them. Extending these practices beyond the perioperative period represents an opportunity for anesthesiology to have a broader role in preoperative preparation of patients and in their care beyond surgery in the outpatient and home settings. These new opportunities can become a vital part of anesthesia practice as anesthesiologists assume a greater role in the continuum of care, including identifying ways to reduce hospital length of stay, preventing readmissions, and providing value-based care.
“Knowledge of sleep medicine represents a significant opportunity for all anesthesiologists to expand their capacity to optimize perioperative care. Anesthesiologists are well positioned to embrace this extension of their practice.”
Complementary to these changes, the practice of sleep medicine will also expand over the next 10 years with accumulation of knowledge of the complexities of sleep and its implications for overall health and well-being. “Sleep health” will be a larger part of the role of anesthesiologists as perioperative physicians. In turn, the role for the sleep medicine subspecialist will focus more on management of unusual or difficult variants of common problems and on identification and treatment of the less common among the 83 conditions listed in the 3rd edition of the International Classification of Sleep Disorders.7