Effectiveness Of Intraoperative Intravenous Lidocaine Infusion As Part Of Postoperative Analgesia For Patients Undergoing Abdominal Surgery Under General Anesthesia Prospective Cohort Study In Jimma University Medical Center, Southwest Ethiopia, 2023.

Introduction: An increasing amount of evidence suggest that intraoperative intravenous lidocaine infusion can influence pain severity, postoperative analgesic requirement and decrease opioid side effects in a patient with abdominal surgery. Postoperative pain might be due to the damage of muscles and tissues. The importance of pain relief is well-recognized, but it is most often seen that pain control is inadequate. Results of previous study shows the opioid consumption is 70% after abdominal surgery, so that multimodal approach for managing pain will decrease opioid consumption. Objective: To assess analgesic effectiveness of intraoperative intravenous lidocaine infusion as part of postoperative analgesia for patients undergoing abdominal surgery under general anesthesia in Jimma university medical center. Methods: Institutional based prospective cohort study conducted in 38 patients with American Society of Anesthesiologist (ASA) class I and II, age ≥ 18 and elective abdominal patients in which they undergone abdominal surgery and grouped into exposed and non-exposed group based on lidocaine infusion (1mg/kg/hr.) or not. Consecutive sampling was employed to recruit study subjects. Data was entered to Epidata v 4.6 and exported to SPSS V26 for analysis. The ShapiroWilk test with a p value <0.05 for non-normally distributed data and a histogram with bellshaped were used to test for normal distributions of data. The comparison of numerical variables between study groups was done using the unpaired student t-test and Mann-Whitney U test based on normally distributed data and non-normally distributed data, respectively. Box and whisker plot were used to show a median pain score differences between groups. Result: Demographic characteristics were comparable between the groups, p>0.05. Twenty-fourhour median VAS score (0 to 10 cm) at 3rd, and 6th hour showing lower median pain score, with p<0.05. The median time to first analgesia request in minutes were longer (242.11 minutes) in exposed group compared to 91.5 minutes in non-exposed group (p= <0.001). The median tramadol consumption within 24 hour is 100mg in exposed group compared to 150 mg in nonexposed group(p<0.001). Conclusion and recommendation: Intraoperative lidocaine infusion decreases postoperative pain score, total analgesia consumption and prolongs time to first analgesia request for abdominal surgery done under general anesthesia. Based on these we recommend use of 1 mg/kg/hr of 2% lidocaine infusion is an effect postoperative analgesia.