Inpatient sleep consultation

Sleep disordered breathing (SDB) is increasingly recognized as a presenting or major comorbid diagnosis in hospitalized patients. However, there is no clear guidance on indications for inpatient sleep medicine consultation, SDB evaluation in inpatient versus outpatient setting, or optimal timing and type of positive airway pressure (PAP) treatment to be provided. Figure 8.1 gives an algorithmic approach to inpatient sleep medicine. Variations in the availability of diagnostic tests such as inpatient sleep test and pulmonary function test, and insurance coverage of PAP devices upon discharge are potential factors that limit standardized recommendations. Observational studies show that SDB is associated with increased risk for in-hospital and post-discharge adverse outcomes and compliance with PAP therapy decreases this risk. In particular, specific subgroups of patients may benefit from intervention during hospitalization, including (1) chronic respiratory failure due to severe lung disease such as chronic obstructive pulmonary disease, (2) chronic respiratory failure due to neuromuscular or thoracic cage disease, and (3) SDB in heart failure or postoperative individuals. However, the benefits of inpatient consultation on patients' outcomes are yet to be determined. Sleep disorders are common in the general population and likely even more common in the hospital setting. A systematic review of 22 studies of sleep in the ICU showed 50-67% of patients reported disturbed sleep 1-month post-discharge [53]. Neurophysiologic studies have supported these subjective reports, with studies showing that patients in the ICU have altered sleep architecture with decreased total sleep time, increased arousals, increased N1 and N2 sleep, and decreased N3 and REM sleep [54]. These changes not only lead to functional disability and increased morbidity, but can also lead to cognitive difficulty, impaired attention, and psychomotor slowing. In the acute inpatient setting, these changes can also blunt one's respiratory drive, exacerbate sleep disordered breathing, and lead to circadian desynchronization that can prolong hospital stay and impede one's functional recovery [55, 56]. There are many potential factors that contribute to poor sleep in the hospital, including unfamiliar environment, external noise (from other patients, providers, and medical devices), sleep interruption from care interactions, medications, and artificial light exposure [57]. The hospital setting also affords the unique opportunity for an individual's sleep to be actively monitored by a healthcare professional. While sleep disordered breathing may be the most observed inpatient sleep finding, other common sleep disturbances, such as insomnia and circadian rhythm abnormalities, may also be present. Less common sleep disorders such as hypersomnias, parasomnias, and sleep-related movement disorders, may also occur, especially among patients who are hospitalized for a neurologic condition.