Disrupted sleep the night before breast surgery is associated with increased postoperative pain

Despite the best available clinical care, pain after surgery is a virtually universal patient experience that can have pervasive negative consequences. Given the large variability among patients in postoperative pain levels, research on novel modifiable risk factors is needed. One such factor suggested by recent experimental studies indicates that disruption of even a single night's sleep can increase subsequent pain in healthy volunteers. In this preliminary clinical study, we tested the hypothesis that poor sleep the night before surgery would predict heightened postoperative pain. Patients (n=24) scheduled for routine breast-conserving surgical procedures for the diagnosis or treatment of cancer were recruited and wore an actigraphy device providing objective, validated measures of sleep duration and disruption (low sleep efficiency). Pain severity and interference with daily activities for the week after surgery was assessed with the Brief Pain Inventory. As hypothesized, multiple regression analyses revealed that lower sleep efficiency was a significant predictor of greater pain severity and interference, controlling for age, race, and perioperative analgesics as appropriate. Sleep efficiency was not significantly related to measures of depressed mood, emotional upset, or relaxation assessed on the morning of surgery. Patients with sleep efficiency in the lowest tertile had clinically higher levels of pain (>2 points) compared with patients in the highest sleep efficiency tertile. Sleep duration had no significant effects. This preliminary clinical study supports the possibility that sleep disruption on the night before surgery may increase patients' experience of pain after surgery. Research to investigate the mechanisms underlying these effects and to explore the possible clinical benefits of interventions to improve patients' sleep before surgery is now warranted.