Preoperative Moderate-Severe Excessive Daytime Sleepiness Is Associated With Postoperative Cognitive Dysfunction in Older Surgical Patients.

BACKGROUND

Excessive daytime sleepiness may reflect increased vulnerability to postoperative neurocognitive disorders given its association with neurodegenerative disease, cognitive decline, and dementia. However, the role of excessive daytime sleepiness in postoperative neurocognitive disorders is unknown. Here, we investigated whether preoperative moderate-severe excessive daytime sleepiness is associated with postoperative neurocognitive disorder severity.

METHODS

This prospective observational cohort study included older non-cardiac surgery patients who completed preoperative Epworth sleepiness scale questionnaires, home sleep apnea testing, and pre- and postoperative delirium assessments and cognitive testing. Cognitive scores were combined with reflective factor analysis into a global cognitive index. Moderate-severe excessive daytime sleepiness was defined as an Epworth Sleepiness Scale score greater than 12. Postoperative neurocognitive disorder severity was assessed by the global cognitive index change from before to 6-weeks and 1-year after surgery.

RESULTS

Of the 96 subjects who completed testing, 11 subjects exhibited moderate-severe excessive sleepiness. In a multivariable analysis adjusting for prespecified confounders and precision variables (age, sex, respiratory event index, baseline cognitive performance and surgery duration), moderate-severe EDS was significantly associated with 6-week postoperative change in global cognition (mean difference -0.24; 95% CI -0.48, -0.004; p = 0.046), but was not associated with peak postoperative delirium severity scores (OR 3.66; 95% CI, 0.96, 13.91; p = 0.057).

CONCLUSIONS

Preoperative moderate-severe EDS is associated with decreased 6-week postoperative global cognitive performance after adjustment for relevant confounders and precision variables. These results suggest that pre-existing moderate-severe excessive daytime sleepiness is a risk factor for increased postoperative neurocognitive disorder severity.

TRIAL REGISTRATION: clinicaltrials.gov: NCT03273335.