Publications of the Week, February 8

Preventing postoperative delirium through exercising the brain before surgery

Postoperative delirium is a common but underappreciated clinical problem that disproportionately affects the elderly and patients with preexisting comorbidities, especially those with prior cognitive impairment. Preventing postoperative delirium is clinically important because it prolongs hospitalization, may require aggressive medical management, and is associated with increased morbidity and mortality.

This randomized trial investigated if cognitive prehabilitation, a form of brain exercise, reduces the incidence of postoperative delirium among older adults who require an elective surgery. Eligible patients were individuals aged ≥60 years undergoing major noncardiac, nonneurologic surgery under general anesthesia, with an expected hospital stay ≥72 hours. Patients in the intervention group were guided through a series of brain exercise games that focused on memory, speed, attention, flexibility, and problem-solving functions. They were asked to complete 10 hours of cognitive exercises prior to their surgery.

The primary outcome was the incidence of delirium between postoperative days 0 to 7 or hospital discharge, as measured by a brief Confusion Assessment Method (see Cognitive Assessment in Medical Settings in the McMaster Textbook of Internal Medicine), Memorial Delirium Assessment Scale, or a structured medical record review. Secondary outcomes compared delirium characteristics between patients in the intervention and control groups.

There were 251 patients in the primary outcome analysis: 125 in the intervention group and 126 controls, with 163 (64.9%) women. The median (interquartile range) age was 67 (63-71) years. In the intervention group, 97% of patients completed some brain exercise, consisting of a median of 4.6 (interquartile range, 1.31-7.4) hours of activity. In the intention-to-treat analysis there was a statistically nonsignificant but numerically large reduction in the incidence of postoperative delirium in the intervention group of 14.4% versus 23.0% (P = .08). There were no differences in the postoperative delirium onset by day, duration, or total delirium-positive days across the study groups.

This study suggests that a cognitive prehabilitation program, if adhered to, can lessen the incidence of postoperative delirium. Much thought is given to preoperative optimization of cardiorespiratory function, which may include stress testing for coronary artery disease; optimizing cardiac and respiratory medications; and lessening the risk for myocardial ischemia, stroke, and respiratory insufficiency. However, optimizing neurocognitive function also deserves our attention. Further research is needed to assess the generalizability of this intervention in different clinical settings. In the meantime, individual clinicians (or systems) involved in perioperative care of patients should consider adding this low-risk, low-cost intervention to better prepare patients for surgery and lessen the burden of disease related to postoperative delirium.