Preoperative dispositional optimism correlates with a reduced incidence of postoperative delirium and recovery of postoperative cognitive function in cardiac surgical patients

Abstract

Objective: To determine if preoperative psychosocial factors including dispositional optimism, perceived social support, and perceived stress correlate with the recovery of postoperative cognition.

Design: Observational study.

Setting: Veterans Affairs medical center.

Participants: Cardiac surgical patients.

Interventions: None.

Measurements and main results: Age- and education-balanced patients (> or =55 years of age) undergoing cardiac surgery (n = 40) and nonsurgical controls (n = 40) were recruited. A psychosocial evaluation for dispositional optimism, perceived social support, perceived stress, and depression was performed before surgery using standardized questionnaires. Delirium was assessed with the Intensive Care Delirium Screening Checklist before and for 5 consecutive days after surgery. Recent verbal and nonverbal memory and executive functions were assessed before and 1 week after cardiac surgery or at 1-week intervals in nonsurgical controls. Preoperative perceived stress significantly (p < 0.01) correlated with preoperative depression scores. Preoperative dispositional optimism significantly (p < 0.05) correlated with preoperative perceived social support. A multiple logistic regression revealed that dispositional optimism significantly (p < 0.02) predicted the absence of postoperative delirium within 5 days of surgery. Patients who showed high levels of dispositional optimism suffered a significantly (p < 0.03) lower incidence of postoperative delirium. Preoperative dispositional optimism also significantly (p < 0.001) correlated with a postoperative cognitive performance determined by composite z scores. A stepwise multiple regression analysis revealed that dispositional optimism significantly (p < 0.05, R(2) = 35%) predicted postoperative cognitive function.

Conclusions: Preoperative dispositional optimism, but not perceived social support, perceived stress, and depression positively correlated with a reduced incidence of postoperative delirium within 5 days and recovery of cognitive performance 1 week after cardiac surgery.