Intraperitoneal local anesthesia for postoperative pain management in patients undergoing laparoscopic colorectal surgery: a systematic review and meta-analysis.

INTRODUCTION

Intraperitoneal instillation of local anesthetic agents has been reported as an effective adjunct to pain management and early functional recovery in colorectal surgery. Laparoscopic colorectal resection (LCR) is considered as the gold standard approach to resect benign and malignant lesions of the colon and rectum due to the advantages of reduced pain score, quicker recovery, and shorter hospitalization. The objective of this study was to systematically analyze the published RCTs evaluating the effectiveness of intraperitoneal local anesthetic (IPLA) instillation versus standard analgesia in patients undergoing LCR.

EVIDENCE ACQUISITION

Electronic databases such as Embase, Medline, PubMed, PubMed Central and the Cochrane library pertaining to the use of IPLA infiltration after LCR were systematically reviewed using the principles of meta-analysis.

EVIDENCE SYNTHESIS

Five RCTs on 292 patients undergoing LCR were either given IPLA or standard postoperative analgesia. In the random-effects model analysis using the statistical software Review Manager (Cochrane, London, UK), statistically 2-4 hours pain score (Standardized mean difference [SMD]=-1.72; 95% CI: -2.62 to -0.81; z=3.71; P=0.0002) was significantly lower in the IPLA group. The 12 hours postoperative pain score (P=0.23) was also lower in the IPLA group but failed to reach the statistical significance. Opioid analgesia requirement was lower in the IPLA group (SMD=-7.60; 95% CI: -11.21 to -3.90; z=4.12; P=0.0001) but the time to flatus, length of stay and the frequency of nausea/vomiting were statistically similar in both groups.

CONCLUSIONS

IPLA instillation is an effective modality to reduce the postoperative pain score and lower the opioid analgesic requirements in patients undergoing LCR without influencing the time to first flatus, length of stay, and postoperative nausea/vomiting.