Cause of Device-Related Incident
External factors; User errors

Clinical Specialty or Hospital Department
Anesthesia; Cardiology / Cardiac Catheterization; CCU / ICU / NICU; Nursing; Pulmonary / Respiratory Therapy

Device Factors
*Not stated

Document Type
Hazard Reports

External Factors
Medical gas and vacuum supplies

Mechanism of Injury or Death
Fire

Support System Failures
*Not stated

Tampering and/or Sabotage
*Not stated

User Errors
Failure to perform pre-use inspection; Incorrect clinical use

UMDNS
Defibrillator/Monitors [11-129]; Defibrillator/Monitors, Line-Powered [15-029]; Defibrillators [11-132]; Defibrillators, Battery-Powered [11-134]; Defibrillators, Line-Powered [11-137]; Resuscitators [13-360]; Resuscitators, Pulmonary [13-364]; Ventilators [15-613]

Fires from Defibrillation during Oxygen Administration



Hazard [Health Devices Jul 1994;23(7):307-8]

Problem

ECRI continues to receive reports and investigate incidents of patients and their bedding being set on fire during defibrillation. In these cases, defibrillation was performed in the presence of oxygen administration devices, which are necessary in resuscitation attempts and which inherently spill excess oxygen. This oxygen enriches the space around the patient's head and chest and allows an electric arc sometimes produced during defibrillation discharge to ignite body hair. The fire flashes rapidly over the patient, consuming body hair and igniting nearby bedding materials and medical devices.

ECRI has discussed this problem in Health Devices twice previously; see the Hazard Report "Defibrillation in Oxygen-enriched Environments" (16[3-4]:113-4, Mar-Apr 1987) and the Consultant's Corner article "Electrical Equipment during Oxygen Administration" (9[2]:47-8, Dec 1979). Also, the medical literature includes references to this hazard as early as 1972. However, even though the problem has been recognized for a long time, incidents of fire during defibrillation in oxygen-enriched atmospheres (OEAs) continue to occur. This suggests that the ignition danger during defibrillation has been forgotten or ignored—or was never learned—and must be periodically reemphasized to minimize the incidence of this kind of fire.

Discussion

During external defibrillation, electrical energy is delivered to an erratically beating heart through paddles, or sometimes disposable defibrillation electrodes, that are placed on the surface of the skin. If a good interface between the defibrillation paddles and the patient's skin is not established, an electric arc can result. A poor interface can be caused by insufficient force during paddle application, an insufficient or excessive amount of conductive gel, use of the wrong gel (e.g., ultrasound gel), application of paddles over irregular surfaces (e.g., bony prominences, wires, ECG electrodes), or misapplication of paddles to disposable defibrillation pads (e.g., the metal surface of the paddle not completely on the pad, a fold in the pad, a pad smaller than the paddle's metal surface, a dry pad). Placing a paddle close to an ECG electrode can also cause an arc.

Although an arc may cause minor damage to the paddle surface or cause insufficient energy delivery to the heart, it will not cause a fire in room air. However, if a localized OEA is in the vicinity of the arc (e.g., on the bedding, around the patient's upper body), the energy contained in the arc can be sufficient to ignite body hair and the surface nap fibers on most fabrics. Then, in a phenomenon called "surface-fiber flame propagation (SFFP)," the fire flashes over the oxygen-enriched surface, often without burning the skin or underlying fabric, as each small hair or fiber ignites hairs or fibers nearby until the flame front meets an edge (e.g., hem or fold of cloth, area of near-ambient oxygen concentration) and either establishes a flame at the edge or burns out. In most cases, the flame front races toward the source of the oxygen enrichment and can result in ignition of the supply tubing or device. (See Bruley ME, Lavanchy C. Oxygen-enriched fires during surgery of the head and neck. In: Stoltzfus J, Benz FJ, Stradling JS, eds. Symposium on flammability and sensitivity of materials in oxygen-enriched atmospheres: Fourth volume, ASTM STP 1040. Philadelphia: American Society for Testing and Materials [ASTM], 1989.)

Defibrillation performed in the presence of oxygen does not typically result in a fire. However, if the localized oxygen concentration is significantly above ambient in the vicinity of the potential ignition point (i.e., the paddles), a flash fire may result. The oxygen concentration in this vicinity will depend on such factors as the oxygen flow rate, the position and direction of the oxygen outflow, the time oxygen has been flowing, the position of the patient, and nearby movement of people and devices. Regardless of the factors involved, the OEA will typically extend less than a foot in any direction from the outflow point and will quickly return to ambient when the source of enrichment is removed.

Recommendations

Fires during defibrillation can be prevented by 1) minimizing the presence of oxygen-enriched spaces around the patient's head, neck, and upper body and 2) reducing the chance of arcing by establishing a good interface between the defibrillator paddles and the patient's skin. To meet these requirements, do the following:

  1. Remove all sources of supplemental oxygen from the area around the patient before a defibrillation attempt to prevent zones of high oxygen concentration in the vicinity of the paddles. This includes all manual and gas-powered resuscitators, breathing circuits, masks, and nasal cannulae that provide oxygen at concentrations above 21%. Do not leave such devices near the patient or on the bed when clearing for a defibrillation discharge because the outflow of oxygen can maintain an enriched space.
  2. Reduce the risk of arcing during defibrillation by:
    • Applying the defibrillator paddles firmly with as much force as possible (the American Heart Association recommends 25 lb per paddle) while ensuring even and unobstructed contact with the patient's skin or disposable defibrillation pads.
    • Applying ECG electrodes as far from defibrillation paddle sites as possible. Do not place defibrillator paddles on an ECG electrode or wire.
    • Using pads that are larger than the metal surface of the paddle, that have not reached their expiration date, and that are wet (if using disposable defibrillator pads).
  3. Review and revise existing defibrillation protocols to include techniques, such as those above, to reduce the risk of arcing in an OEA. Preventive measures must not interfere with the resuscitation attempt or jeopardize its success.

UMDNS Terms

  • Defibrillator/Monitors [11-129]
  • Defibrillator/Monitors, Line-Powered [15-029]
  • Defibrillators [11-132]
  • Defibrillators, Battery-Powered [11-134]
  • Defibrillators, Line-Powered [11-137]
  • Resuscitators [13-360]
  • Resuscitators, Pulmonary [13-364]
  • Ventilators [15-613]

Cause of Device-Related Incident

User errors: Failure to perform pre-use inspection; Incorrect clinical use

External factor: Medical gas and vacuum supplies

Mechanism of Injury or Death

Fire


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