Bright light prevents postoperative delirium in elderly tumor patients undergoing open hepatobiliary surgery

Objective To explore whether perioperative bright light therapy could inhibit the occurrence of postoperative delirium in tumor patients undergoing open hepatobiliary surgery. Methods Totally120 elderly tumor patients scheduled for open hepatobiliary surgery and postoperative ICU treatment were recruited and randomized into bright light and control group with 60 cases per group in accordance with the random number table. Bright light was delivered to the patients at an intensity of 10 000 lux from 2 days before surgery to postoperative day 7. Each intervention began at 7 am and lasted for 2 hours. Delirium was screened using the Confusion Assessment Method for Intensive Care Unit (CAM-ICU) during the first 7 days after surgery. The differences in the incidence of postoperative delirium, the duration of delirium and the length of ICU as well as postoperative hospital stay were compared. Results Demographic characteristics and surgical outcomes were similar between groups. The incidence of postoperative delirium were 46.67% (28/60) and 23.33% (14/60) for control group and bright light group respectively with a significant difference (χ2=7.179,P=0.007). The difference was seen on postoperative days 3 (χ2=5.187, P = 0.023) and 4 (χ2=8.749,P = 0.003). The incidences of delirium on postoperative days 3 for bright light and control group were 5.08% (3/59) and 18.64% (11/59) respectively. On postoperative day 4, the incidences of delirium for bright light and control group were 0 (0/58) and 14.04% (8/57) respectively. There was no difference in the duration of delirium (χ2=1.248, P=0.264), the length of ICU stay(χ2=0.036, P=0.849) or the hospital stay (χ2=1.706, P=0.192). Conclusion Bright light is useful in preventing postoperative delirium in elderly tumor patients undergoing open hepatobiliary surgery. Key words: Intensive care units; Bright light; Postoperative delirium; Confusion Assessment Method