[Failure of the central oxygen supply to a surgical area. Analysis of a critical incident]

An incident involving central oxygen supply failure affecting 4 anesthetized patients in the operating theatre was analyzed by way of interviews with the anesthesiologists and a review of graphic records of anesthesia. The 4 ventilators involved had been checked by each anesthesiologist according to his own method. The oxygen supply failure alarm warned of the supply cutoff in 2 cases and the oxygen analyzer detected the other 2 within approximately 1 minute. After the failure, 2 patients were ventilated with ambient air through the ventilator, 1 was given medicinal air with the resuscitator. None suffered damage or recalled having awakened as a result of the incident. The cause of the failure in oxygen supply has not been determined but its duration has been estimated to be between 4 and 7 minutes. Our investigation shows that: 1) the operating rooms are not equipped with an alarm that warns of a drop in pressure within the tubes that supply central oxygen and in 2 cases the alarm warning of a cutoff in oxygen supply to the respirator did not sound correctly; 2) the ventilator equipment check did not follow a standard method and did not cover the possibility of oxygen supply failure, and 3) no alternative oxygen supply is available inside the operating theatre.(ABSTRACT TRUNCATED AT 250 WORDS)