Postoperative Delirium with Intravenous Patient-controlled Analgesia (IVPCA) Compared with Regional Analgesia for General Anesthesia: Systematic Review and Meta-analysis

Although the use of systemic narcotics has been established as the gold standard in pain control after surgery, the literature shows the possibility of a higher incidence of delirium after systemic administration of analgesics compared to regional methods, such as epidural and paravertebral analgesia.

To compare the rate of postoperative delirium when treated with systemic intravenous patient-controlled analgesia (IVPCA) with regional analgesia methods (continuous or patient-controlled).

We searched PubMed, Web of Science, Embase, and Scopus databases for relevant papers reporting delirium after surgery based on the regional analgesia methods compared with systemic IV analgesia. Risk ratios for delirium were pooled using a random effects model.

6 randomized clinical trials (RCT) with a total of 898 cases were selected in which delirium was observed 2 to 7 days after the operation. In a random-effect model of the risk ratio of delirium in patients receiving IVPCA versus patients receiving regional PCA, with 487 and 486 participants in each arm, there was a retrospective1.85 -fold higher risk of delirium with a 95% confidence interval of 1.35 to 2.53 compared with regional methods of analgesia (I2=0%; low heterogenicity). Although we attempted a comprehensive review of the literature, publication bias occurre, so we imputed the missing studies to the literature by the trim-and-fill method, which forced us to imput the missed studies of the literature by trim and fill method that showed the similar adjusted results of RR=1.75, 95% CI: 1.29 to 2.39. The RCTs assessed had relatively low quality evidence.

There appears to be a large difference in delirium risk between the methods compared, with blinded trials with larger sample sizes required Safety and cost-benefit aspects should also be considered before the clinical application of these results.