comparing the effect of dexmedetomidine versus intravenous lidocaine on colonoscopy candidates under sedation with propofol-fentanyl: a clinical trial

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.