Propofol anaesthesia in spontaneously breathing paediatric patients during magnetic resonance imaging

Background: The aim of this study was to evaluate the use of propofol to induce and maintain anaesthesia in spontaneously breathing paediatric patients (age 2 weeks - 11 years) during Magnetic Resonance imaging (MRI) of the CNS. Methods: All patients were spontaneously breathing, without intubation, and received supplemental O-2. Pulse rate, blood pressure (BP), electrocardiogram and EtCO(2) were recorded in all patients, and in 38 subjects SpO(2) was also monitored. Patients were divided in 2 groups according to their body weights: Group A (n=34, bwt less than or equal to 10 kg) and Group B (n=48, bwt > 10 kg). Results: Dosage of propofol during the time of induction (from insertion of the i.v. cannula to positioning on the MRI table) was significantly higher in smaller children (Group A; 5.4 +/- 2.2 (SD) mg/kg) as compared to children with bwt above 10 kg (Group B; 3.7 +/- 1.6 mg/kg). Propofol dosage for maintenance of anaesthesia was significantly higher in smaller children (Group A: 10.1 +/- 5.7 vs Group B: 7.1 +/- 3.0 mgkg(-1)h(-1), P=0.003). During the time of induction, transient episodes of reduced BP (less than or equal to 20%) occurred in 6 patients in Group A and 2 patients in Group B. During anaesthesia in Group B there was 1 episode of oxygen desaturation (95%), and 3 episodes of short and mild increases of EtCO(2) (less than or equal to 52 mmHg). No other side effects occurred in any patient. MRI studies were successfully completed, only 3 sequences (Group A) had to be restarted. Conclusion: Propofol can be safely used for total intravenous anaesthesia in children undergoing MRI