Pain relief in laparoscopic tubal ligation using intraperitoneal lignocaine: a double masked randomized controlled trial

Abstract

The intraperitoneal route of analgesia has been studied over the years for effective perioperative pain relief during minimally invasive surgery, but there were conflicting reports of the use of intraperitoneal analgesic administration and moreover there was no consensus regarding the dose and type of drugs used. We report a randomized trial to assess the safety and effectiveness of intraperitoneal lignocaine as an intraoperative and postoperative analgesic in laparoscopic tubal ligation. This is a double masked, randomized parallel group placebo-controlled trial of women seeking laparoscopic sterilization under local anaesthesia at a university hospital. The intervention group and placebo group received 20 ml of 0.5% lignocaine and 20 ml of isotonic saline intraperitoneally respectively. Allocation concealment was done by fixed block randomization. The participating women, the surgeon, anaesthetist, technician and the doctor who assessed the pain score were masked to the type of intervention. Intraoperative and postoperative pain was assessed by visual analogue pain scale and the scores are expressed as mean difference (95% confidence interval) between groups. Our trial is registered with the Clinical Trials Registry, India (http://www.ctri.nic.in/, CTRI/2009/091/000072). Out of 200 women recruited, 196 were available for final analysis with 98 women in each arm. The mean difference in the intraoperative pain score at the time of tubal ligation was 3.5 cm (95% CI 2.91-4.09). The mean difference in the postoperative pain scores at half an hour was 2.9 (95% CI 2.50-3.44), 1h was 2.5 (95% CI 2.08-3.00) and 3h was 1.2 (95% CI 0.75-1.76). There was no case of adverse reaction to lignocaine. Our findings show that intraperitoneal instillation of lignocaine is a safe and effective method for perioperative pain relief during laparoscopic tubal occlusion performed under conscious sedation.