[Propofol for sedation in pediatric magnetic resonance imaging investigations]

Magnetic Resonance Imaging requires immobilisation of the patients without excitement due to acoustic irritation. During childhood this is hardly to guarantee without anaesthesia or sedation. The problem is the magnetic field strength, which interferes with the monitoring devices and the anaesthesia machines interrupting the function and can produce thermal injury, but additionally the tools will cause image degradation.

MR Imaging was done in 46 children with a mean age of 50.9 months (0.06 to 129) in a sedation with propofol during spontaneous breathing. The induction dose of propofol was 3.0 mg/kg bodyweight and the repetition dose was 1.0 mg/kg. During the radiological examination and the time of emergence the children were monitored with a MRI-compatible fiberoptic pulseoximeter (NONIN), a capnography by naso-pharyngeal canula (OHMEDA) and a noninvasive blood pressure oscillometer (CRITICON). The monitors were located outside the 0.5 Tesla area and were connected to the patient via extension tubing. Additionally there was a clinical observation by a present anaesthesiologist.

In all children the investigation has been realized without any problem. Haemodynamics, ventilation and oxygenation have been in a normal range. Only 2 of the 186 sequences had to be repeated. After a mean time of investigation of 29 minutes (10 to 55) the emergence time until purposeful reaction was 7.7 minutes (5 to 20) and until full orientation was 13.4 minutes (5 to 30).

This regime of sedation for children undergoing Magnetic Resonance Imaging is safe and suitable independent of age: there is a good control of vital functions, a minimum of side effects and a fine recovery characteristic with short times of emergence.