Intravenous lidocaine for post-operative pain relief after hand-assisted laparoscopic colon surgery: a randomized, placebo-controlled clinical trial.

BACKGROUND: Perioperative intravenous (IV) infusion of lidocaine has been shown to decrease post-operative pain, shorten time to return of bowel function, and reduce the length of hospital stay. This randomized, prospective, double-blinded, placebo-controlled clinical trial evaluated the impact of IV lidocaine on the quality of post-operative analgesia and other outcomes after hand-assisted laparoscopic colon surgery.

METHODS: Sixty four patients with colon cancer scheduled for elective colon resection were involved in this study. Patients were randomized to receive either lidocaine infusion [lidocaine group (LG)] or normal 0.9 % saline infusion [placebo group (PG)] for a period of 24 h. Anaesthetic and surgical techniques were standardized. Twenty-four-hour post-operative analgesia in the recovery area was maintained by continuous infusion of 0.1 μg/kg/h fentanyl. The primary outcome of the study was post-operative pain control. Pain was assessed using visual analogue scale (VAS) scores at 2, 4, 8, 12, and 24 h after surgery. Patients with a VAS score >3 were treated with ketorolac 30 mg as needed. Secondary outcomes included time to resumption of bowel function and length of hospital stay. Data in the two groups were compared using the two-tailed Student's t test. All statistical tests were two-tailed at a significance level of 0.05.

RESULTS: Demographic characteristics and clinical features of both groups were similar. Intensity of pain at rest in LG compared with PG was significantly lower during the first 24 h post-operatively. LG patients reported significantly less pain during movements at 2-, 12-, and 24-h post-surgery than PG patients. The study showed that ketorolac consumption was significantly higher in PG: mean ketorolac consumption in LG was 43.77 ± 13.86 mg and in PG 51.67 ± 13.16 mg (p = 0.047). Compared with placebo, lidocaine infusion produced a 32 % reduction in time to the first drink (Cohen's d = 3.85), 16 % reduction in time to the first full diet (Cohen's d = 3.35), and 18 % reduction in time to the first bowel movement (Cohen's d = 2.30). Patients who received lidocaine stayed in hospital 1.2 days less than patients who received placebo (p < 0.01, Cohen's d = 0.72). There were no significant differences in surgery-related complications between the two groups.

CONCLUSIONS: Perioperative continuous IV lidocaine infusion has a beneficial effect as regards post-operative pain, restoration of bowel function, and length of hospital stay in patients who have undergone hand-assisted laparoscopic colon surgery.