OR Fires Caused by Fiberoptic Illumination Systems
Hazard [Health Devices May 1982;11(7):148-9]
We received two reports from member hospitals of fires ignited by fiberoptic illumination systems (which consist of the light source, or projector, and the light-transmitting cable) during arthroscopic surgery.
In one incident, the fiberoptic cable was disconnected from the arthroscope and placed on the surgical drapes with the xenon light source activated. The high-intensity output from the cable ignited the cloth drapes, causing a smoldering fire with considerable smoke. Fortunately, elevated oxygen and nitrous oxide levels were not present (as they might be near the patient's head during anesthesia). The fire was extinguished before the patient was burned. In a second incident, the disconnected fiberoptic cable ignited disposable nonwoven surgical paper drapes that had trapped a pocket of oxygen (leaked from a faulty inflation connector of a pneumatic tourniquet). The resulting flash fire severely burned the patient's leg.
Fiberoptic cables and light sources are used with many types of rigid endoscopes (e.g., laparoscopes, cystoscopes), fiberoptic surgical headlamp systems, and fiberoptic retractors, specula, and suction instruments. This hazard probably exists with most light source and cable combinations when the light source is activated and the output of the disconnected cable is directed at materials that will ignite or support combustion. Most flexible endoscopes (e.g., colonoscopes, gastroscopes) have permanently attached light cables with optical fibers that are continuous from the light source connector to the distal tip of the endoscope. Therefore, flexible endoscopy illumination systems are not likely to cause ignition.
Many users believe that fiberoptic illumination systems supply "cold" light to the visual field. This assumption is false. Actually, such light sources only reduce the amount of infrared radiation (that radiation usually associated with heat production) with respect to visible light. This is accomplished with special filters or lamp (dichroic) reflectors. Radiation in the visible and infrared wavelengths enters the fiberoptic cable and is transmitted through the cable and instruments. When the light leaves the endoscope tip, the level of infrared radiation has usually been reduced to a safe level through absorption by the optical fibers in the endoscope and substantial losses at the cable connections. However, if the cable is not connected to the endoscope, the infrared output is not reduced sufficiently and will ignite some materials. This is especially true at high light source dial settings and with xenon arc lamps that have a much higher output than conventional quartz-halogen (150-watt) lamps.
We reported the potential for fires caused by the output of fiberoptic cables in our evaluation of laparoscopes (Health Devices, Vol. 9, p. 191) and demonstrated that fires could be started with some types of disposable nonwoven surgical drapes. At that time, no such fires had been reported.
Advances in light source and fiberoptic technology may increase the radiation output of visible and infrared wavelengths at the end of the cable and at the distal tip of the endoscope. Higher outputs not only increase the risk of fire, but may introduce the risk of burns during close-range inspection of tissue with the endoscope. Since absorption of high-intensity radiation at visible light wavelengths may also cause tissue heating, additional filtering of infrared wavelengths may not eliminate this hazard. Furthermore, with the increasing use of television systems with video cameras connected to the endoscopes, many physicians operate light sources at their maximum intensities and believe they need even greater light intensities.
- Inform all operating room personnel and
endoscopists of the risk of fires from illumination systems used in
endoscopy and surgery. Instruct users to make all fiberoptic cable
connections before activating the light source and to turn off the light
source if the endoscope must be disconnected. Also instruct users not to
turn the light source higher than necessary for adequate viewing.
- Placard all fiberoptic light sources with the
Warning: High-intensity fiberoptic light sources and
cables can ignite drapes and other materials. Complete all fiberoptic cable
connections before activating the light source.
- Light Sources, Fiberoptic [12-345]
- Retractors, Fiberoptic-Illuminated
Cause of Device-Related Incident
User errors: Failure to read label; Improper connection
Mechanism of Injury or Death
Burn (thermal); Fire