Comparing the Effect of Dexmedetomidine Versus Intravenous Lidocaine on Colonoscopy Candidates Under Sedation with Propofol-Fentanyl: A Clinical Trial

Abstract

Background: Colonoscopy is an invasive and short-term diagnostic-therapeutic method that is associated with significant pain, discomfort, and anxiety in patients. Thus, various sedation and analgesia methods are used to reduce these complications. Objectives: This study compared the effect of dexmedetomidine versus intravenous lidocaine on colonoscopy candidates under sedation with propofol-fentanyl. Methods: This double-blind clinical trial was conducted on two groups of randomly divided patients (n = 60 each) referring to the colonoscopy unit of Imam Khomeini Hospital in Ahvaz, Iran. The first group was given 2% intravenous lidocaine with an initial dose of 1.5 mg/kg and a maintenance dose of 1 mg/kg/h, plus propofol 0.5 mg/kg and 1 µg/kg fentanyl. In contrast, the second group was given dexmedetomidine with an initial dose of 1 µg/kg and a maintenance dose of 0.5 µg/kg/h plus 0.5 mg/kg propofol and 1 µg/kg fentanyl. Hemodynamic changes, degree of sedation, and patients' pain were measured and recorded at certain intervals. Results: No significant differences were observed between the dexmedetomidine and lidocaine groups regarding gender, age, and weight (P > 0.05), and the two groups were homogeneous in this regard. The two groups were significantly different with respect to their heart rate after sedation (from 5 to 20 minutes) (P < 0.05), which was lower in the group receiving dexmedetomidine. In terms of mean arterial blood pressure, no significant difference was found between the dexmedetomidine and lidocaine groups (P > 0.05). With respect to the pain score at the end of the procedure, the two groups were significantly different (P < 0.05), with the group receiving dexmedetomidine obtaining a lower score. Conclusions: Although the use of lidocaine and dexmedetomidine is associated with the least hemodynamic changes, dexmedetomidine can create more suitable and favorable conditions during and after colonoscopy by inducing a higher degree of sedation and more analgesia.