The Role of Perioperative Sleep Disturbance in Postoperative Neurocognitive Disorders

Abstract

Postoperative neurocognitive disorder (PND) increases the length of hospital stay, mortality, and risk of long-term cognitive impairment. Perioperative sleep disturbance is prevalent and commonly ignored and may increase the risk of PND. However, the role of perioperative sleep disturbances in PND remains unclear. Nocturnal sleep plays an indispensable role in learning, memory, and maintenance of cerebral microenvironmental homeostasis. Hospitalized sleep disturbances also increase the incidence of postoperative delirium and cognitive dysfunction. This review summarizes the role of perioperative sleep disturbances in PND and elucidates the potential mechanisms underlying sleep-deprivation-mediated PND. Activated neuroinflammation and oxidative stress; impaired function of the blood-brain barrier and glymphatic pathway; decreased hippocampal brain-derived neurotrophic factor, adult neurogenesis, and sirtuin1 expression; and accumulated amyloid-beta proteins are associated with PND in individuals with perioperative sleep disorders. These findings suggest that the improvement of perioperative sleep might reduce the incidence of postoperative delirium and postoperative cognitive dysfunction. Future studies should further investigate the role of perioperative sleep disturbance in PND.

Progress in Research on the Effect of Melatonin on Postoperative Cognitive Dysfunction in Older Patients

“…Melatonin is a kind of central circadian rhythm regulator, and the normal melatonin rhythm is involved in regulating the sleep-awakening cycle to some extent. All in all, there is ample evidence that melatonin production is disturbed after surgery, that perioperative sleep disorders increase the risk of POCD, and that synchronization disorders between sleep-awakening cycles and melatonin rhythms can lead to cognitive impairment ( Wright et al, 2006 ; Song et al, 2021 ; Wang X. et al, 2021 ).…”

Melatonin and Its Analogs for Prevention of Post-cardiac Surgery Delirium: A Systematic Review and Meta-Analysis

“…Although different doses of melatonin show the same preventive effect on delirium, preoperative melatonin administration appears to produce a more significant effect, possible due to the following factors: (a) Sleep disorder is associated with a high risk for delirium ( 56 ), and patients with various cardiac diseases invariably experience preoperative sleep disorders secondary to anxiety, depression, breathing disorders, or other factors ( 57 ); (b) The secretion of melatonin is delayed during anesthesia and surgery ( 58 ); (c) Postoperatively given melatonin absorption kinetics are greatly slowed, and peak plasma levels are reduced ( 59 ); and (d) Anesthesia and surgery may selectively cause functional reductions in the prefrontal cortex excitatory synaptic transmission and induce delirium ( 60 ). It is reasonable to initiate melatonin supplementation the night before cardiac surgery if conditions permit.…”

Perioperative Brain Health in the Older Adult: A Patient Safety Imperative

“…Sleep and its coupling to circadian rhythms are integral to brain health (eg, memory consolidation and metabolic waste clearance) and other systemic functions. [97][98][99][100] During normal aging, the duration of total sleep and slow-wave sleep is decreased and is associated with an increase in sleep fragmentation and difficulty falling asleep. 101 The prevalence of sleep disturbances at home can affect up to 40% of older adults and is associated with impairment of spatial memory, verbal fluency, attention, processing speed, and executive function.…”

“…101 The prevalence of sleep disturbances at home can affect up to 40% of older adults and is associated with impairment of spatial memory, verbal fluency, attention, processing speed, and executive function. 100,102 The presence of sleep disturbance before hospital admission is an independent risk factor for PND. Environmental and patient factors in the postoperative hospital setting (pain, light, environmental changes, monitoring systems, and constant interruption) can contribute to the impairment of waste clearance, especially for older patients, and could contribute to PND.…”