Report of an incident during the use of the Servo-ventilator 900 in paediatric anesthesia.

The authors report the occurrence of an incident during the use of the Servo-ventilator 900 for paediatric anesthesia; it consisted in self-oscillation of the gas column contained in the patient respiratory circuit. After having analysed the incident and outlined the various ways of avoiding it, attention is drawn to the importance of the total circuit volume of the respirator. The respiratory circuit chosen for ventilating children, has a compliance of 1.3 ml/cm H2O.