Lower risk of postoperative delirium using laparoscopic approach for major abdominal surgery.

BACKGROUND: A laparoscopic approach is increasingly being used for major abdominal surgeries and is reportedly associated with a lower incidence of postoperative complications. However, the association of laparoscopic approach and postoperative delirium remains unclear. We aimed to retrospectively investigate risk factors for postoperative delirium after abdominal surgery particularly assessing the association between a laparoscopic approach and postoperative delirium. METHODS: We retrospectively studied 801 patients who underwent major abdominal surgery between April 2012 and December 2013. Among these, 181 (22.6%) patients underwent a laparoscopic and 620 (77.4%) patients underwent an open procedure. A Cox proportional hazard model analysis was used to identify risk factors for the development of postoperative delirium or overall survival within 180 days after surgery. Cumulative incidence of postoperative delirium was assessed using a propensity score-matching analysis. RESULTS: Postoperative delirium occurred in 56 patients (7.0%). A Multivariate Cox proportional hazard model analysis revealed that a laparoscopic approach reduced the risk of postoperative delirium [hazard ratio (HR) 0.30, 95% confidence interval (CI) 0.07-0.84, p = 0.019]. Postoperative delirium was associated with worse overall survival within 180 days (HR 4.91, 95% CI 1.96-12.22, p = 0.001) after adjusting for other confounders using the Cox proportional hazard model analysis. Patients who developed postoperative delirium showed worse outcomes including higher rate of morbidity except delirium (p < 0.001), longer hospitalization (p < 0.001), and post-discharge institutionalization (p < 0.001). After propensity score-matching, cumulative incidence rates of postoperative delirium were significantly lower in the laparoscopic group compared to the open group (30-day cumulative incidence rate, 1.7% vs. 7.8%, p = 0.006). CONCLUSIONS: The risk of postoperative delirium after major abdominal surgery is reduced using laparoscopic approach. Postoperative delirium should be prevented as it precipitates adverse postoperative events.