Prospective, randomised comparison of two intravenous sedation methods for magnetic resonance imaging in children

BACKGROUND: Children usually need sedation or even anaesthesia for magnetic resonance imaging (MRI) studies. As there is no universally accepted method for this purpose we undertook a prospective, randomised comparison of propofol and dexmedetomidine in children aged 1 to 10 years. METHODS: After Institutional Board approval and parents’ informed consent 64 ASA status I or II children scheduled for MRI scan were enrolled. Patients were premedicated with intravenous (IV) midazolam (0.1 mg kg(–1)) and ketamine (1 mg kg(–1)) and randomised to propofol (P) or dexmedetomidine (D) group. A propofol bolus of 1 mg kg(–1) followed by infusion of 4 mg kg(–1) h(–1), or dexmedetomidine 1 µg kg(–1) followed by 2 µg kg(–1) h(–1) infusion were used. Heart rate, SpO(2) and non-invasive blood pressure were monitored and recorded at 5 min intervals. Results were compared by means of standard statistical methods. RESULTS: 62 consecutive children were analysed. ASA status and demographic variables did not differ between groups. Median MRI study time was 38 min in group D, and 43 min in P (NS), both groups had similar values of HR, NIBP and SpO(2). In group P anaes-thesiologist intervention was needed in 10 patients, in group D only in 1 (P = 0.002). In Post Anaesthesia Care Unit patients in group D had lower blood pressure and their awakening time was longer (median 48 min vs. 34 min) (P < 0.05). CONCLUSIONS: Both dexmedetomidine and propofol after premedication with ketamine and midazolam are suitable for MRI sedation, although propofol use results in shorter recovery time. Less interventions are needed when dexmedetomidine is used.