Role of Different Volumes and Dilutions of Intraperitoneal Lignocaine Instillation on Postoperative Morbidity Following Laparoscopic Cholecystectomy

Introduction: Even though Laparoscopic Cholecystectomy (LC) is far less traumatic compared to open cholecystectomy, it is still associated with considerable postoperative pain. Apart from routine analgesics, several attempts have been made to establish intraperitoneal analgesia as a useful perioperative pain relief modality. Aim: To determine the optimal concentration (or dilution) and volume of intraperitoneal lignocaine among three preparations of 100 mg lignocaine for postoperative analgesia after LC. Materials and Methods: Study was designed as a randomised controlled, double blinded study. Patients undergoing elective LC for symptomatic cholelithiasis were included in the study. Patients (n=105) were randomised into three groups. Group A received 5 mL 2% lignocaine in 5 mL normal saline (100 mg/ 10 mL=10 mL solution of 1% lignocaine). Group B received 5 mL 2% lignocaine in 100 mL of normal saline (100 mg/ 100 mL=100 mL solution of 0.1% lignocaine). Group C received 5 mL 2% lignocaine in 500 mL normal saline (100 mg/500 mL=500 mL solution of 0.02% lignocaine). Three groups were compared for postoperative pain using Visual Analog Score (VAS), requirement of rescue analgesia, nausea and vomiting, vital parameters (heart rate, respiratory rate, mean arterial pressure, transcutaneous saturation) and hospital stay. Analysis of Variance (ANOVA) was used to compare mean and.2 test was used to compare categorical data. Results: The mean VAS of group B (100 mg lignocaine in 100 mL of normal saline) was significantly lower than the overall mean VAS at different postoperative time intervals, and consistently lower than those of groups A and C. The study found a consistent (r=0.15 to 0.33) and significant (p<0.05 at alltime intervals) positive correlation between pain and duration of surgery. Demand for rescue analgesia was significantly higher in group A. Pulse rate was least in all postoperative time and significantly lower at 4th hour. The difference in mean arterial pressures, respiratory rate, and transcutaneous saturation among the three groups was not significant statistically. Nausea and vomiting were uncommon. Conclusion: The study concluded that for a total dose of 100 mg lignocaine, 100 mL solution is more effective compared to 10 mL or 500 mL solution.