Prophylactic antipsychotic use for postoperative delirium: a systematic review and meta-analysis.

OBJECTIVE Although antipsychotics have been used empirically to prevent the development of postoperative delirium, there has been no confirming evidence to support their use. Thus, we conducted a systematic review and a meta-analysis to elucidate their efficacy and tolerability in surgical patients. DATA SOURCES MEDLINE, EMBASE, the Cochrane Library databases, CINAHL, and PsycINFO were searched up to February 2013 without language restrictions, using the following keywords: (antipsychotics OR [nonproprietary name of each antipsychotic medication, separated by OR]) AND delirium AND (randomized OR random OR randomly). STUDY SELECTION Randomized controlled trials comparing prophylactic use of antipsychotics with placebo in surgical patients were included. DATA EXTRACTION Two authors extracted and scrutinized the data. The risk ratio (RR), 95% confidence interval (CI), number needed to treat (NNT), and standardized mean difference were used. RESULTS Six studies (3 haloperidol, 1 olanzapine, and 2 risperidone) including 1,689 surgical patients were identified. The results showed significant efficacy in reducing the occurrence of delirium (RR = 0.50, 95% CI = 0.34 to 0.73, P = .0003; NNT = 7, P = .001, 6 studies). Sensitivity analysis showed that second-generation antipsychotics were superior to placebo (RR = 0.36, P < .00001; NNT = 4, P < .00001), whereas haloperidol failed to show superiority to placebo. There were no statistically significant differences between groups in severity of delirium, discontinuation rate, or rates of several adverse events. CONCLUSIONS Our results suggest that second-generation antipsychotics are more beneficial than placebo for preventing the incidence of delirium. Among patients who do develop delirium, the severity of delirium is not reduced in those who received prophylactic antipsychotics.