additive effects of clonidine used in propofol sedation in colonoscopy

Background: propofol is commonly used for sedation during colonoscopy but often requires high doses. objectives: this study aimed to compare the outcomes of propofol alone versus propofol combined with clonidine for colonoscopy sedation. methods: in this randomized, double-blind controlled trial, 60 adult patients scheduled for elective colonoscopy were enrolled. patients were divided into two groups: group 1 (g1) received propofol alone, while group 2 (g2) received propofol plus 2 μg/kg clonidine intravenously over 10 minutes. propofol infusion was initiated at 25 - 75 μg/kg/min iv for the first 10 - 15 minutes, then titrated to 25 - 50 μg/kg/min based on clinical response. results: sedation onset was significantly faster in g2 than in g1 (p = 0.001). the total propofol requirement was 22% lower in g2 (p = 0.001). heart rate (hr) and mean arterial pressure (map) were significantly lower in g2 at induction and at the end of the procedure (p < 0.05). patient satisfaction scores were higher in g2 (p = 0.042). the observer's assessment of alertness/sedation (oaa/s) score after induction was lower in g2 (p = 0.015), indicating deeper sedation. however, aldrete scores in the post-anesthesia care unit (pacu) were lower in g2 (p = 0.001), suggesting a slower recovery. conclusions: the addition of clonidine to propofol for colonoscopy sedation led to faster sedation onset, reduced propofol requirements, improved patient satisfaction, and deeper sedation, but with potentially prolonged recovery times.