Penehyclidine Hydrochloride Premedication Is Not Associated with Increased Incidence of Post-Operative Cognitive Dysfunction or Delirium:A Systemic Review and Meta-Analysis

Objective Post-operative cognitive dysfunction (POCD) and post-operative delirium (POD) are two common post-operative cerebral complications. The current meta-analysis was to systematically review the effects of penehyclidine hydrochloride (PHC) on POCD and POD in surgical patients.Methods Electronic databases were searched to identify all randomized controlled trials comparing PHC with atropine/scopolamine/placebo on POCD and POD in surgical patients. Primary outcomes of interest included the incidences of POCD and POD; the secondary outcomes of interest included peri-operative mini-mental state examination (MMSE) scores. Two authors independently extracted peri-operative data, including patients' baseline characteristics, surgical variables, and outcome data. For dichotomous data (POCD and POD occurrence), treatment effects were calculated as odds ratio (OR) and 95% confidential interval (CI). Each outcome was tested for heterogeneity, and randomized-effects or fixed-effects model was used in the presence or absence of significant heterogeneity. For continuous variables (MMSE scores), treatment effects were calculated as weighted mean difference (WMD) and 95% CI. Statistical significance was defined as P<0.05.Results Our search yielded 33 studies including 4017 patients. Meta-analysis showed that, the incidence of POCD in PHC group was comparable to that in saline group (OR=0.97; 95% CI: 0.58-1.64; P=0.92), scopolamine group (OR=0.78; 95% CI: 0.48-1.27; P=0.32) and atropine group (OR=1.20; 95% CI: 0.86-1.67; P=0.29). The incidence of POD in PHC group was comparable to that in saline group (OR=1.53; 95% CI: 0.81-2.90; P=0.19) and scopolamine group (OR=0.53; 95% CI: 0.06-4.56; P=0.56), but higher than that in atropine group (OR=4.49; 95% CI: 1.34-15.01; P=0.01).Conclusions PHC premedication was not associated with increased incidences of POCD or POD as compared to either scopolamine or placebo.