EFFECTS ON INTRAOPERATIVE HEMODYNAMICS AND POST OPERATIVE PAIN AND SEDATION FOLLOWING LIDOCAINE VERSUS DEXMEDETOMIDINE INFUSION IN LAPAROSCOPIC SURGERY

Abstract

Background: Laparoscopic surgery has got tremendous popularity due to fast recovery and shortened hospital stay. The hall mark of laparoscopy, pneumoperitoneum is an additive to intubation in stimulating the neuro-humoral responses that create a pathway to hemodynamic instability which is the major hurdle faced by anaesthesiologist during laparoscopic procedure. Among the many drugs that are used to control the effects caused by pneumoperitoneum, we have used infusion of lignocaine and dexmedetomidine and compared their efficacy.

Methods: After obtaining ethical committee approval, a prospective, randomized, double blinded study was conducted on 86 patients at a tertiary care hospital in Eastern India to compare Dexmedetomidine vs Lignocaine, in laparoscopic surgery, to obtund changes in hemodynamic parameters in response to creation of capno-pneumo-peritoneum, their effect on post-operative analgesia and also their effect on recovery from anaesthesia. In Group L, immediately before induction of anaesthesia, patients received a bolus of 1.5 mg/kg lidocaine followed by an intravenous infusion of 1.5 mg/kg/h Lidocaine hydrochloride through an infusion pump. In Group D, immediately before induction of anaesthesia, patients had received a bolus of 0.5 µg/kg followed by intravenous infusion of 0.5µg/kg/hr dexmedetomidine hydrochloride through an infusion pump. In both groups, the infusion had been continued throughout the surgery and terminated after release of pneumoperitoneum. Hemodynamic parameters were recorded at predefined time interval, first at the time of intubaton, then at the time of creation of capno-pneumoperitoneum by insufflation of CO₂, then after 10, 20 and 30 minutes of creation of pneumoperitoneum, then at the time of  release of pneumoperitoneum and finally at the time of extubation. While VAS score as a measurement of post-operative analgesia was recorded at the time of arrival at PACU, then after 1 hour of stay at PACU, then finally at the time of discharge from PACU. Similarly University of Michigan Sedation Score (UMSS), as a measurement of recovery from anaesthesia was measured at the time of arrival at PACU, then after 1 hour of stay at PACU and finally at the time of discharge from PACU.

Results:  Demographic data such as age, weight, sex was comparable between the groups. At the time of intubation, there were no significant difference noted in hemodynamic parameters such as SBP, DBP, MAP and HR, when compared between dexmedetomidine and lignocaine. But parameters such as SBP, DBP, MAP and HR were better controlled with dexmedetomidine in comparison to lignocaine with respect to baseline values in subsequent time points with statistically significant p-value<0.05. Pain score which was measured as VAS on arrival at PACU, 1 hour after stay at PACU and at the time of discharge from PACU had better values in dexmedetomidine group. It was noted that, recovery from anaesthesia, which was measured as University of Michigan Sedation Score (UMSS), at the time of arrival at PACU, was delayed with dexmedetomidine in comparison to lignocaine. But 1 hour after stay at PACU was showing no significant statistical difference between lignocaine and dexmedetomidine showing no difference in recovery from anaesthesia with dexmedetomidine in comparison to lignocaine after 1 hour of stay at PACU.

Conclusion: The study has shown that dexmedetomidine infusion can obtund hemodynamic changes associated with pneumo-peritoneum creation, better than lignocaine infusion in laparoscopic surgeries, also providing better post-operative analgesia than lignocaine, but dexmedetomidine shows delayed recovery from anaesthesia at the time of arrival to PACU. Though, recovery from anaesthesia was similar after 1 hour of stay at PACU between both groups.