Comparison of sevoflurane administered through a face mask versus rectal thiopental sodium in children undergoing magnetic resonance imaging

Objective: Sevoflurane (S) and thiopental sodium (T) are commonly used to produce sedation for routine MRI procedures. However, to date there have been no comparative studies evaluating both techniques. We herein present the firt study comparing S and T techniques for pediatric sedation in MRI procedures. Materials and methods: 21 children, aged from 3 months to 6 years, scheduled for MRI were randomly assigned to either S or T group. Sedation performed under spontaneous respiration was induced with inspired 1-8% S in oxigen by face mask connected to a Mapleson C circuit or T (25 mg/ kg) administered in distal rectum by cannula. The observed parameters included: time for induction, MRI time, first movement activity postprocedure and recovery time; MRI pauses from patient movement; technique failure, quality of the study, emergence agitation, critical events; and parental and radiologist satisfaction. Results: S compared with T showed significantly shorter anesthesia induction time (1.93 +/- 0.7 versus 13.5 +/- 2.6 min), first movement time (3.38 +/- 1.2 versus 5.9 +/- 2.1 min), recovery time (6.8 +/- 1.6 versus 10.14 +/- 3.3 min), and discharge MRI time (27.83 +/- 5.1 versus 47.5 +/- 8.7 min). There were fewer pauses during MRI from patient movement in S versus T (0 versus 3). The radiologists reported good quality and satisfaction scores in both groups. There were less behavioral disturbances in T group compared with S group (1 versus 3). There were no critical events in either group. There were no differences in parental satisfaction in both groups. Conclusions: Sevoflurane shortens the induction and recovery time, enabling earlier discharge. Sevoflurane and rectal thiopental sodium protocols are safe and effective, providing adequate conditions for MRI in pediatric outpatients, although rectal thiopental is more unpredictable.