A dose-ranging pilot trial of dexmedetomidine-propofol in children undergoing magnetic resonance imaging

The optimal sedation/anesthesia technique for magnetic resonance imaging (MRI) scans has not been established. The combination of propofol with dexmedetomidine has been reported, but without systematic dosing data. Our primary aim was to determine the propofol-sparing effect of dexmedetomidine (DEX) when added to propofol for MRI scan sedation/anesthesia utilizing a dose-ranging protocol for four distinct regimens (Propofol-Only, DEX-High, DEX-Low, DEX-Bolus). Our secondary aims were to document adverse events, scan interruptions due to patient movements, and determine recovery time. Seventy-nine patients aged 1-12 years scheduled for MRIs under anesthesia were sequentially enrolled. A 60% reduction in propofol dose required was found in the dexmedetomidine cohorts. There was no difference (p = 0.161) in recovery time between Propofol-Only and DEX-Bolus groups. There were no differences in episodes of hypotension (p = 0.464), bradycardia (p = 0.558), or patient movement (p = 0.273) between the Propofol-Only and dexmedetomidine cohorts. Recovery time was prolonged for DEX-High and DEX-Low groups compared to DEX-Bolus or Propofol-Only. The addition of dexmedetomidine significantly decreased the necessary dose of propofol. Propofol combined with a single bolus of dexmedetomidine (no infusion) provided effective sedation/anesthesia without adverse events or extending recovery time.