A comparison of dexmedetomidine versus propofol on hypotension during colonoscopy under sedation

Background: Sedation for colonoscopy with propofol is often associated with decreasing in arterial blood pressure. Dexmedetomidine is a sedative drug with a highly selective alpha2 adrenoreceptor agonist. The direct action on blood vessels causes vasoconstriction and a possible increase of blood pressure. This study evaluates dexmedetomidine on suppression of decrease in blood pressure is compared with propofol for sedation during colonoscopy. Method: Seventy patients with ASA physical status I-III were randomly allocated into two groups to receive either dexmedetomidine or propofol for elective colonoscopy under sedation. Group P patient received 0.5 mcg/kg fentanyl over 5 min, followed by 1 mg/kg propofol. Group D patients was received 1 mcg/kg dexmedetomidine with 0.5 mcg/kg fentanyl over 5 min, followed by 20 mg propofol. The 20 mg propofol was titrated as required to achieve the target BIS and sedation score. Standard monitorization were provided in both groups before sedation (baseline), start of sedation (time=0) and every 5 min intervals. Result: The incidence of hypotension in Group P was significantly greater than Group D (50% vs. 20%; P=0.015). The average doses of ephedrine used in Group P was more than Group D (4.0 mg vs. 0.8 mg; P=0.011). The systolic blood pressure in Group P was significant lower than that of Group D at 5th and 20th min after start of sedation while the heart rate in Group P was higher than Group D at 10th min and from 25th min throughout the period of colonoscopy (P<0.05). There were no statistically significant differences in the induction time, intraoperative bradycardia, postoperative complications and patient satisfaction between the two groups. The patients in Group P recovered from sedation more slowly than Group D (10.2 min vs. 6 min; P=0.038) and there were fewer patients in Group P who think that they can resume normal activities on the day of colonoscopy (63.3% vs. 86.6%; P=0.018). Conclusion: Dexmedetomidine for sedation in colonoscopy reduced hypotension incidence than propofol.