Multidrug intravenous anesthesia for children undergoing MRI: a comparison with general anesthesia

BACKGROUND: We used a multidrug intravenous anesthesia regimen with midazolam, ketamine, and propofol to provide anesthesia for children during magnetic resonance imaging (MRI). This regimen was compared with general anesthesia in a randomized comparative study. Outcome measures were safety, side effects and recovery variables in addition to adverse events in relation to age strata. METHODS: The children received either general anesthesia with propofol, vecuronium and isoflurane [general endotracheal anesthesia (GET) group; n=313] or intravenous anesthesia with midazolam, ketamine, and propofol [intravenous anesthesia (MKP) group; n=342]. Treatment assignment was randomized based on the date of the MRI. Physiological parameters were monitored during anesthesia and recovery. Desaturation (SpO2<93%), airway problems, and the need to repeat the scan were recorded. The discharge criteria were stable vital signs, return to baseline consciousness, absence of any side effects, and ability to ambulate. RESULTS: With the exception of two children (0.6%) in the MKP group, all enrolled children completed the scan. A significantly greater number (2.3%) required a repeat scan in the MKP group (P<0.05) and were sedated with a bolus dose of propofol. The total incidence of side effects was comparable between the MKP (7.7%) and GET groups (7.0%). Infants below the age of 1 year showed a significantly higher incidence of adverse events compared with the other age strata within each group. Within the MKP group, risk ratio was 0.40 and 0.26 when comparing infants aged below 1 year with the two older age strata, respectively. Recovery characteristics were comparable between both groups. CONCLUSIONS: Intravenous midazolam, ketamine and propofol provides safe and adequate anesthesia, comparable with that obtained from general endotracheal anesthesia, for most children during MRI.