Cause of Device-Related Incident
External factors; Support system failures; User errors

Clinical Specialty or Hospital Department
Anesthesia; Clinical/Biomedical Engineering; Neurological Surgery; Ophthalmology; OR / Surgery; Otolaryngology

Device Factors
*Not stated

Document Type
Hazard Reports

External Factors
Medical gas and vacuum supplies

Mechanism of Injury or Death
Fire

Support System Failures
Failure to train and / or credential; Use of inappropriate devices

Tampering and/or Sabotage
*Not stated

User Errors
Failure to read label; Incorrect clinical use

UMDNS
Electrodes, Electrosurgical, Active [16-860]; Electrodes, Electrosurgical, Active, Foot-Controlled [16-206]; Electrodes, Electrosurgical, Active, Hand-Controlled [11-499]; Electrosurgical Units [11-490]; Electrosurgical Units, Bipolar [18-230]; Electrosurgical Units, Monopolar [18-299]; Electrosurgical Units, Monopolar/Bipolar [18-231]; Gauze [11-859]; Pledgets [13-055]; Sponges, Gauze [13-700]; Sponges, Scrub [15-281]; Tubes, Tracheal [14-085]

Electrosurgical Airway Fires Still a Hot Topic



Hazard [Health Devices Jul 1996;25(7):260-1]

Problem

ECRI continues to receive many reports of electrosurgical airway fires and to investigate a number of them. Although these fires are often mistakenly attributed to malfunction of electrosurgical units (ESUs) used during surgery, in our experience they are actually the result of other factors. Airway fires are very serious and, if not quickly extinguished, can be deadly. All surgeons, whether experienced or newly trained, need to recognize the hazards presented by using ESUs in the oxygen-enriched atmospheres (OEAs)—atmospheres containing more than 23% oxygen—that are commonly present in the oropharynx.

Discussion

ESUs provide electrical energy that is used to cut and coagulate tissue. The energy is delivered to the tissue through an active electrode controlled by the surgeon. ESUs present a fire hazard in any procedure, but their use during airway surgeries, such as tonsillectomies and tracheostomies, involves particular risks.

Too often, the ESU is initially blamed for an electrosurgical airway fire. A typical observer will attribute the flame, sparking, and arcing seen at the surgical site immediately before the fire to, for example, "some surge of electricity from the ESU." But in more than 20 years of investigating such cases, we have never found this to have occurred. The flame, sparking, and arcing are actually the accelerated burning of tissue and of gases evolved from the electrosurgery. The true cause of the fire, rather than the ESU itself, is typically the misuse of the ESU in the OEA that exists in the patient's airway.

Airway surgeries frequently use oxygen and nitrous oxide to ventilate and anesthetize patients, respectively. Both gases support combustion, and both reduce the amount of energy (e.g., current, heat, friction) needed to ignite flammable substances. Moreover, during airway surgery, these gases leak around the tracheal tube, its cuff, or packing, creating an OEA in the oropharynx. Some fuels that will not burn in the 21% concentration of oxygen found in room air will burn vigorously in an OEA.

Many flammable substances in the airway are exposed to an ESU during airway electrosurgery. For example, a portion of the tissue heated by the ESU turns to gas, some of which—especially those gases evolved from fatty tissue—will burn if made hot enough or if mixed with sufficient oxygen. Another portion of the tissue is reduced to embers, which are also flammable. Other fuels present in airway electrosurgeries include tracheal tubes, catheters, and surgical sponges. When the tip of the electrode heats tissue within this OEA, nearby flammable substances can easily catch fire. For example, a flare of evolved gases can directly ignite these substances; a spark (i.e., a tissue ember that is still incandescent) can land on and ignite a dried-out sponge; or the inactive but still hot electrode can graze the tracheal tube or sponge and ignite it.

Sudden ignition of airway fuels also presents some secondary problems: 1) The abrupt flash and sound can create a startle reflex, causing the surgeon's hand to jerk and potentially cut into unintended tissue or set other areas of the surgical site on fire. 2) This startle reflex can prevent the surgeon from accurately observing the ignition and deducing its cause.

The following are some of the specific hazards we have noted, all of which can be avoided by proper attention to technique and by taking appropriate preventive measures:

  • For tonsillectomies, some surgeons sheathe long ESU electrode probes with a section of red rubber catheter to prevent secondary mouth burns to the patient. In even a slight OEA, the heat from the probe will ignite the rubber. Long probes insulated with polytetrafluoroethylene (Teflon) and having exposed tips are commercially available and should be used instead because they offer the desired electrical protection, are difficult to ignite, and burn only in an oxygen concentration of over 95%.
  • During tracheostomies, some surgeons employ the potentially fatal practice of cutting through the tracheal rings with the ESU and entering the OEA within the trachea. If the hot electrode tip or a tissue ember contacts the tracheal tube cuff, or the tube itself, inside the trachea, a fire will erupt. To avoid this hazard, surgeons should—after dissecting down to the trachea with the ESU—use scissors or a scalpel, instead of the ESU, to cut the avascular tracheal rings.
  • Wetted sponges, gauze, or pledgets are often used to pack the trachea around the tracheal tube to prevent leaks. Over time, these materials can dry out, become saturated with oxygen, and thereby become a fire hazard. Packing should be applied wet and kept wet throughout the procedure.

Recommendations

  1. Alert surgeons and anesthesiologists to the hazards of using ESUs in the OEAs commonly present in the oropharynx and trachea. See the references below for more detailed discussions of some of the hazards described in this report, as well as discussions of some of the remedies.
  2. If long, insulated electrosurgical electrode probes are required, use only commercially available insulated probes. Do not use red rubber catheter or other materials to sheathe probes.
  3. Do not use ESUs to cut tracheal rings and enter the airway. Using scissors or a scalpel instead will avoid the risk of fire.
  4. Be sure that any sponge, gauze, or pledget used in the airway is applied wet and kept wet.

References

de Richemond AL, Bruley ME. Head and neck surgical fires. In: Eisele DW, ed. Complications in head and neck surgery. St. Louis: Mosby—Year Book, 1993. Chapter 37.

de Richemond AL, Bruley ME. Insidious iatrogenic oxygen-enriched atmospheres as a cause of surgical fires. In: Janoff DD, Stoltzfus JM, eds. Flammability and sensitivity of materials in oxygen-enriched atmospheres: Sixth volume. Philadelphia: American Society for Testing and Materials (ASTM), 1993. (ASTM Special Technical Publication 1197.)

ECRI. The patient is on fire!: A surgical fires primer [Guidance article]. Health Devices 1992 Jan;21(1):19-34.

National Fire Protection Association (NFPA). Guide on fire hazards in oxygen-enriched atmospheres. 1994 ed. Quincy (MA): NFPA, 1994; NFPA 53.

UMDNS Terms

  • Electrodes, Electrosurgical, Active [16-860]
  • Electrodes, Electrosurgical, Active, Foot-Controlled [16-206]
  • Electrodes, Electrosurgical, Active, Hand-Controlled [11-499]
  • Electrosurgical Units [11-490]
  • Electrosurgical Units, Bipolar [18-230]
  • Electrosurgical Units, Monopolar [18-299]
  • Electrosurgical Units, Monopolar/Bipolar [18-231] 
  • Gauze [11-859]
  • Pledgets [13-055]
  • Sponges, Gauze [13-700]
  • Sponges, Scrub [15-281]
  • Tubes, Tracheal [14-085]

Cause of Device-Related Incident

User errors: Failure to read label; Incorrect clinical use

External factor: Medical gas and vacuum supplies

Support system failures: Failure to train and/or credential; Use of inappropriate devices

Mechanism of Injury or Death

Fire


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