Preoperative lidocaine infusion for the pain management in laparotomy procedures: a randomized control trial
Objectives: To evaluate the role of pre-operative lidocaine infusion for pain management in laparotomy procedures. Study Design: Prospective double blind randomized control trial. Period: 8 months duration from April 2017 to November 2017. Setting: Tertiary care hospital in Karachi, Pakistan. Method: N= 50 patients belonging to ASA Classification types I and II were selected to be part of this study. All the patients underwent major abdominal surgeries (laparotomy). The study group received lidocaine 2%, 1.5mg/kg IV bolus half an hour before induction, followed by an infusion of 1.5mg/kg/hour. The anesthesia was induced with fentanyl 3ug/kg, propofol 2mg/kg, followed by rocuronium 1mg/kg to intubate the patient. Maintenance was done with using 33% nitrous oxide in oxygen along with 0.8% of isoflurane. Fentanyl was administered as an infusion initiating prior to the procedure with a maximum dose of 1ug/kg/hour and ceasing the infusion half an hour prior to end of procedure. Visual analog scale was used to measure the pain intensity at an interval of twenty minutes during the first hour of the procedure, and at 2,4,8,12,24 and 48 hours after the end of the procedure. If the visual analog scale score was found to be more than 3, 1 to 3mg of Morphine was administered every ten minutes up to a dose of 0.1mg/kg intravenously. A proforma was used to collect data, data was analyzed using IBM SPSS version 21.0. Results: The study was conducted on n=50 patients, with a mean age of 38.35 years in the study group and 36.48 years in the control group. The intensity of pain was found to be significantly less in the case group as compared to the control group having a p value of <0.001 during the first 48 hours of the procedure. Decreased consumption of morphine was observed in patients in the study group, as compared to the control group with a statistically significant difference, having a p value of less than <0.05. In our study we did not observe any side effects related to toxicity levels of lidocaine or morphine. Conclusion: Our study confirms the results of previously done studies, and we found that in our patient population Perioperative lidocaine infusion decreased the post-operative pain experienced by the patient and decreased the need for consumption of analgesics. Thus we conclude that lidocaine infusion perioperatively is an effective pain management modality.