Effects of Intravenous Lidocaine in Total Intravenous Anesthesia for Colonoscopy: a Double-Blind Randomized Controlled Study

Abstract

Background: Total intravenous anesthesia (TIVA) is widely used as an anesthetic technique in patients undergoing colonoscopy. Lidocaine can reduce visceral pain and potentiates the ventilatory responses to carbon dioxide. This study aimed to evaluate the efficacy and safety of lidocaine combined with propofol during a colonoscopic procedure. Methods: Sixty-one patients underwent elective colonoscopy under TIVA with IV fentanyl 0.5 mcg/kg and propofol 1 mg/kg followed by 2 mg/kg/h as a maintenance infusion with titration as needed. The patients were also randomized to receive 1.5 mg/kg of IV lidocaine followed by 2 mg/kg/h (group L) or 0.3 mL/kg of IV normal saline followed by 0.4 mL/kg/h (group N). The primary outcome was the total dose of propofol used. The secondary outcomes were complications and adverse events. Results: Data for 60 patients were available for analysis. There was no statistically significant difference in the median total dose of propofol used between the two groups or in episodes of apnea and desaturation. The mean difference in mean arterial pressure at 5 min after scope insertion was significantly smaller in group N than in group L. There was no statistically significant between groups in terms of the decrease in heart rate from baseline, or any adverse events. Conclusion: Intravenous lidocaine 1.5 mg/kg followed by lidocaine 2 mg/kg/h did not decrease the dose of IV propofol used during a colonoscopic procedure. However, it was able to reduce the risk of hypotension in the early induction phase.