The Effects of Intra-Operative Lidocaine Infusion on Post Operative Pain and Morphine Consumption Following Major Gynaecological Surgeries Under General Anaesthesia

<i>Introduction</i>: Major gynaecological surgeries are associated with considerable postoperative pain, which remains a challenge for many practitioners. Multimodal forms of analgesia significantly reduce the requirement of opioids for pain management. Despite its local anaesthetic effects, lidocaine infusion improves postoperative pain and morphine consumption following gynaecological surgeries. <i>Materials and methods</i>: Sixty patients were assigned randomly into 2 groups (A and B) with 30 patients per group. Group A received intravenous lidocaine 1.5 mg/kg at induction via a bolus injection and 1.5 mg/kg/hr in normal saline infusion from onset of surgery to the end of surgery, while the control group (Group B) received equal volume of normal saline at the same timelines. Pain scores were assessed postoperatively using the numerical rating scale and the cumulative morphine consumed postoperatively were also measured. <i>Results</i>: The mean pain scores were significantly higher in the Saline Group than in the Lidocaine group. The cumulative morphine consumption after 48 hours was significantly reduced in the study group 4.87 ± 1.80 mg vs 14.13 ± 4.10 mg (P<0.0001). Conclusion: The administration of a bolus dose (1.5 mg/kg) of intravenous lidocaine at induction and a continuous intravenous infusion of 1.5 mg/kg/hr from onset of surgery till skin closure reduced the postoperative pain intensity and morphine consumption in patients undergoing major gynaecological surgeries under general anaesthesia.