Sleep, Pain, and Cognition: Modifiable Targets for Optimal Perioperative Brain Health

Abstract

The prevention of perioperative neurocognitive disorders is a priority for patients, families, clinicians, and researchers. Given the multiple risk factors present throughout the perioperative period, a multicomponent preventative approach may be most effective. The objectives of this narrative review are to highlight the importance of sleep, pain, and cognition on the risk of perioperative neurocognitive disorders and to discuss the evidence behind interventions targeting these modifiable risk factors. Sleep disruption is associated with postoperative delirium, but the benefit of sleep-related interventions is uncertain. Pain is a risk factor for postoperative delirium, but its impact on other postoperative neurocognitive disorders is unknown. Multimodal analgesia and opioid avoidance are emerging as best practices, but data supporting their efficacy to prevent delirium are limited. Poor preoperative cognitive function is a strong predictor of postoperative neurocognitive disorder, and work is ongoing to determine whether it can be modified to prevent perioperative neurocognitive disorders.

Figure 1:

The impact of sleep, pain, and cognition on perioperative brain health and postoperative recovery. Here depicted is a patient presenting for orthopedic surgery. The scenarios depict how the patient’s sleep, pain, and cognition are well managed throughout the postoperative period (left side). The patient then remains delirium free in the hospital and returns to home at their cognitive and functional baseline (left-center panels). Conversely, if sleep, pain and cognition are poorly managed (right side), the same patient may experience delirium and/or inability to return to their cognitive and functional baseline (right-center).

Figure 2:

Sleep and Circadian disruption and Perioperative Neurocognitive Disorders. Preexisting sleep disorders and baseline neuropathology may contribute to sleep and circadian rhythm disruption in the perioperative period, which may then be a precipitating factor for perioperative neurocognitive disorders. OSA: Obstructive sleep apnea. PND: Perioperative neurocognitive disorders.

Figure 3:

The relationships between pain, inflammation, and analgesia on the risk for perioperative neurocognitive disorders. Red lines and (+) signs signify process that may worsen other conditions. Green arrows and (−) signs indicate processes that may ameliorate or improve other conditions. PNDs: Perioperative neurocognitive disorders.

Figure 4:

Cognitive trajectories and perioperative neurocognitive disorders. Depicted are a patient with high baseline cognitive reserve (blue line) and a patient with low baseline cognitive reserve (red line). Both patients experience an event in the perioperative period leading to a decrease in cognitive function, but only the patient with low baseline reserve may manifest symptoms. The green dashed lines represent the theoretical mechanism through which cognitive interventions in the pre – and postoperative phases may influence cognitive reserve and either prevent or aid recovery from PNDs. Adapted from Stern, Neurobiologia 2009 (reference # 128). PND: Perioperative neurocognitive disorder.