Intraperitoneal and intravenous lidocaine for effective pain relief after laparoscopic appendectomy: a prospective, randomized, double-blind, placebo-controlled study.

BACKGROUND: The preemptive intravenous and intraperitoneal application of local anesthetics is known to improve the postoperative outcome in abdominal surgery. The aim of this study was to compare the analgesic effect of intravenous lidocaine injection to that of intraperitoneal lidocaine instillation in patients who were undergoing laparoscopic appendectomy (LA).

METHOD: Sixty-eight patients who were undergoing LA for unperforated appendicitis were randomly divided into three groups. Group IP (the intraperitoneal instillation group) received intraperitoneal instillation of lidocaine and intravenous normal saline injection. Group IV (the intravenous injection group) received intravenous lidocaine injection and intraperitoneal instillation of normal saline. In group C (the placebo control group), normal saline was given both intravenously and intraperitoneally. The visual analog scale (VAS) of pain scores was measured after surgery. The needs for additional intravenous fentanyl were evaluated and the integrated fentanyl consumption (PCA delivered + additional fentanyl) was assessed. The incidence of shoulder tip pain and postoperative nausea and vomiting (PONV) were noted.

RESULTS: Reduction of the VAS score and of fentanyl consumption was noted in the IV and IP groups and compared to that of group C (P < 0.05). The shoulder tip pain and PONV were reduced in groups IP and IV compared to that in group C (P < 0.05). However, no significant differences were found between the IP and IV groups for all the studied variables. There was no adverse effect from intravenous lidocaine throughout the study.

CONCLUSION: Intravenous lidocaine injection is as effective as intraperitoneal instillation for reducing pain and fentanyl consumption. The major benefit of intravenous injection is that this is an easily and universally applicable procedure compared to that of intraperitoneal instillation. Lidocaine intravenous administration is a better alternative for reducing the pain of patients who are undergoing laparoscopic surgery.