Summary
Background. Magnetic resonance imaging is a painless procedure that requires perfect immobility for a relatively long period of time in a noisy, closed and cold setting. The vast majority of children need drug-induced sedation for this procedure. Methods. We have analyzed retrospectively data obtained from anaesthetic records of 367 children, aged from 2 months to 14 years, who were sedated intravenously with 0.1 mg kg^-1 midazolam, augmented with 4 -5 mg kg^-1 thiopental. Children were breathing spontaneously; monitoring included a continuous ECG, pulse oximetry and end-tidal CO₂ concentration. Results. Sedation was satisfactory in all cases. Heart rate ranged from 104 – 125 bpm, respiratory rate from 22 to 26 bpm, SaO₂ from 96 to 99%, and EtCO₂ from 4.42 to 4.81 kPa. Adverse events included vomiting (1), hypoxaemia (SaO₂ 89-90%) requiring supplementary oxygen (27), short episodes of apnoea (3), allergic reactions to thiopental (1) and contrast medium (1). Additional doses of thiopental (1-2 mg kg^-1) were given for procedures longer that 40 minutes. Conclusions. The protocol described is safe and effective, allowing for uninterrupted, smooth sedation without respiratory depression. Major complications were avoided.