Efficacy of dexmedetomidine as an adjuvant to propofol-based total intravenous anesthesia in children undergoing magnetic resonance imaging: A prospective randomized controlled trial
Pediatric magnetic resonance imaging (MRI) requires deep sedation to ensure immobility and optimal image quality. Propofol-based total intravenous anesthesia is effective but may cause airway depression and hemodynamic instability at higher doses. Dexmedetomidine has minimal respiratory effects but may prolong sedation. This study evaluated whether a low-dose dexmedetomidine bolus combined with propofol shortens recovery time (primary outcome); improves hemodynamic stability; reduces airway events, induction time, and total propofol dose; and minimizes scan interruptions (secondary outcomes). In this prospective, randomized controlled trial, children undergoing MRI were assigned to two groups. Group D+P received 0.5 μg/kg of dexmedetomidine over 2–3 minutes plus a 1 mg/kg bolus of propofol followed by infusion; Group P received propofol alone as bolus and infusion. Propofol infusion rate was adjusted to achieve a Ramsay Sedation Scale score of 5–6. Recovery time was analyzed using t test; scan interruptions were compared using Chi-square or Fisher’s exact tests. Group D+P had a shorter recovery time (19.4 ± 35 vs. 31.4 ± 36.1 min; P = 0.042) and faster induction (128.9 vs. 224.6 sec; P < 0.001). The propofol infusion rate was lower in Group D + P than in Group P (76.3 ± 65.6 vs 123 ± 45.5 μg/kg/min; P < 0.001). Additional boluses were more frequent in Group P ( P = 0.003). Bradycardia occurred in significantly more children in Group D + P than in Group P ( P = 0.008). Low-dose dexmedetomidine as an adjunct to propofol for pediatric MRI sedation reduces recovery time, propofol requirement, and airway-related complications, while enabling faster induction and fewer scan interruptions with increased risk of bradycardia.