Article Abstract

Systematic review and meta-analysis of Trendelenburg position on intraocular pressure in adults undergoing surgery

Authors: Sharon Ann Van Wicklin


Background: Because of the increase in intraocular pressure (IOP) that occurs in the Trendelenburg position, patients undergoing surgery in this position may be at risk for postoperative vision loss and other ocular complications. IOPs higher than 21 millimeters of mercury (mmHg) pose a risk for glaucoma, detached retina, and postoperative vision loss. The purpose of this systematic review and meta-analysis is to estimate the magnitude of the increase in IOP in adult patients undergoing surgery in the Trendelenburg position.
Methods: Comprehensive search strategies were used to identify 18 eligible studies (n=762). Standardized mean difference effect sizes were calculated for nine intraoperative time points. Time points for meta-analysis were selected to achieve the greatest number of comparisons for analysis at each time point. Prediction intervals for each time point were also calculated.
Results: Using a random effects model, meta-analysis showed that IOP increased significantly after abdominal insufflation (T2: d=1.89, P<0.001) and during Trendelenburg position (T3: d=1.34, P<0.001; T4: d=0.91, P<0.001; T6: d=0.30, P<0.001; T8: d=0.38, P<0.001). In total, IOP increases significantly by 13.6 mmHg. Based on the upper limits of the prediction intervals, in 95% of all populations IOP could increase by as much as 28.1 mmHg.
Conclusions: IOP increases of this magnitude demonstrate the need for implementing intraoperative interventions to reduce the risk for postoperative vision loss and other ocular complications in patients undergoing surgery in the Trendelenburg position.