To the Editor:—
We would like to report an incident with a Narkomed 6000 Anesthesia System (Draeger Medical, Inc., Telford, PA). An attendant was cleaning an unoccupied operating room when she witnessed a loud “bang,” followed by sparks coming from the bottom of the anesthesia machine. At the time of the noise, the attendant had been adjusting the position of the machine, which was connected to the electrical and gas mains supply but was switched off. The charge nurse, on arrival at the scene, noted smoke in the room. The machine was immediately disconnected from the electrical and gas mains supply, and the problem subsided.
Subsequent analysis showed that a high-impedance short circuit had occurred between the metal can of a capacitor and traces on a printed circuit board in the power supply (Fig. 1). The power supply is located under the main body of the anesthesia machine, and there was minimal flammable material in the immediate area. The engineer's report concluded the incident was due to an intrinsic design fault and was not caused by cleaning solution that had been used to clean the floor prior to the incident. The manufacturer has implemented design changes and replaced the power supplies of all affected machines in Canada and the United States, and the event has been reported to the appropriate health authorities. The manufacturer noted that had the event occurred during use, the anesthesiologist could have disconnected the machine from the main supply with the operation continuing on battery backup, although we would choose to immediately replace the machine, given the unknown status of the internal components.
Until recently, reports of operating room fires and explosions caused by anesthesia equipment were usually attributable to flammable or explosive anesthetic agents 1or to contamination of pressurized gas systems with dust or oil. 2,3The development of sophisticated electronics in anesthesia machines has been associated with occasional reports of malfunctions and one previous report of an electrical fire. 4This event is an important reminder of the risks that modern anesthesia equipment may bring to the operating room. Prompt reporting of critical incidents allows the rapid investigation and implementation of design improvements to this equipment.
