Narkomed 6400 Anesthesia Machine Failure

Abstract

To the Editor: We report a near-catastrophic failure in a Draeger Narkomed 6400 Anesthesia Machine and the operating room filling with smoke due to a failure of a capacitor in the power supply board electrical components. The Narkomed 6400 Anesthesia Machine (Draeger Medical, Inc., Telford, PA) had been in use on the day of the event. In the morning, machine power was switched on and all checkout procedures performed. Three cases were performed, anesthesia personnel were changed, and the machine ventilator test was performed. Five minutes after this last test with the Narkomed 6400 in standby mode, white smoke was observed to billow out of the bottom air vent of the Draeger Narkomed 6400 Anesthesia Machine. The room's air became very pungent, smelling of an electrical component burning. The operating room was evacuated and the fire department contacted. A respiratory technician/anesthesia tech quickly unhooked the Narkomed 6400 machine from the oxygen and nitrous oxide gas supply and disabled the power cord. The smoke from the machine decreased and then stopped. By the time the fire department arrived, the operating room's ventilation system had cleared the air and the machine was moved out of the surgical area. There were no tripped circuit breakers and no other electrical problems were observed in any other operating rooms. Subsequent analysis first noted that the power supply was a discontinued model and that the supplier of this power supply was no longer in business; therefore, the power supply was nonrepairable. The machine had undergone regular preventive maintenance through a contract with Draeger Medical Inc. Examination of the printed circuit board revealed a suspicious-looking capacitor, Capacitor C44, a can-type capacitor covered by a plastic sleeve. The plastic sleeve over the capacitor was ruptured revealing the top of the capacitor bulging upwards, which gave evidence that the capacitor venting mechanism had been actuated. This venting caused the white smoke to emanate from the anesthesia machine. This event was due to an internal failure of the capacitor. The Food and Drug Administration was not notified because Draeger stated this was caused by an internal failure of the capacitor and was an isolated event. Historically, operating room fires or explosions caused by anesthesia equipment were attributable to flammable anesthetic agents.1 Recently, contamination of pressurized gas systems with dust or oil2,3 or electrical fires from the sophisticated electronics in anesthesia monitors and machines have been reported.4,5 Although the incidence of equipment-related critical events is relatively low, morbidity associated with such events can be high.6 This event is an example of the risks that more complex and modern anesthesia machines bring to the operating rooms. Although no actual fire occurred, the operating room rapidly filled with acrid smoke. We were fortunate that this occurred between cases and patient safety was never compromised. In retrospect, the actions of operating room personnel were appropriate: notification of authorities, evacuation of all personnel from the affected area, complete gas supply disconnection, shut down and isolation of the anesthesia machine from flammable material. Had this occurred during a surgical procedure, immediate isolation of the entire surgical team from the pungent smoke and hazardous machine would have been necessary. Thomas E. Schulte, MD John H. Tinker, MD Department of Anesthesiology University of Nebraska Medical Center Omaha, Nebraska [email protected]