Virtually all operating room fires ignite on or in the patient, and about 10 surgical patient fires a year come to ECRI's attention through various medical and legal communications. These fires typically result in little damage to equipment, cause considerable injury to patients, and are a complete surprise to the staff. Some other potentially disastrous fires singe linen, hair, or instruments, but are quickly patted out and soon forgotten.

The basic elements of a fire are always present during surgery. A misstep in procedure or a momentary lapse of caution can quickly result in a catastrophe. Slow reaction or the use of improper fire-fighting techniques and tools can lead to damage, destruction, or death. Given the tremendous potential for human and economic disaster resulting from surgical patient fires, it is surprising that perioperative fire prevention receives so little attention.

Surgical fires are preventable, and their impact can be lessened through an understanding of fire and how to fight it. The following article identifies the basic elements of fire and discusses how to prevent surgical fires from starting. The surgical fire case summaries at the end of this article describe steps for putting fires out and for preventing fires from starting by using proper procedures and techniques. ECRI has also published Emergency Procedures, "Fighting Fires on the Surgical Patient" and "Extinguishing Airway Fires."

Most people have heard of the fire triangle: heat, fuel, and oxidizer. When these three components come together in the proper proportions, a fire—the rapid chemical reaction of fuel with oxygen, resulting in the release of heat and light energy—is bound to occur. Diminish or remove any element of the triangle, and a fire can be prevented or extinguished.

Each side of the triangle contains obvious (and some not-so-obvious) components that are commonly found in the OR environment. Each member of the surgical team controls a specific side of the triangle: surgeon, heat sources; nurse, fuels; anesthesiologist, oxidizers. By understanding the fire triangle and how to properly manage its components, the surgical team can prevent fires.

Heat and ignition sources. Heat input from a variety of sources increases the oxidation rate of a fuel-oxygen mixture until combustion occurs. In addition to the overhead surgical lights, some of the heat sources found in the OR are defibrillators; electrosurgical or electrocautery units (ESUs, ECUs); heated probes; drills and burs; argon beam coagulators; fiberoptic light sources and cables; and lasers used with the free-beam (bare-fiber) method or with contact tips or fibers. These sources produce temperatures from several hundred to a few thousand degrees Fahrenheit, enough to ignite most fuels, including most drapes. In addition, incandescent sparks can be produced by ESUs or high-speed drills and burs; lasers can also cause sparks when the energy hits instruments or the laser fiber becomes damaged. These sparks, or even glowing embers of charred tissue, can provide enough initial heat to ignite some fuels, especially in oxygen-enriched atmospheres (OEAs).

Also, for a few seconds after deactivation, a heated ESU or ECU probe tip, fiberoptic cable tip, or laser contact tip can retain enough heat to melt plastics or ignite some fuels. While these devices must be in contact with a material to heat it, a laser can heat a fuel from a few centimeters to several meters away. A fiberoptic light source may take a minute or so to heat a drape to the point of combustion, while a laser can cause almost instantaneous ignition. By ensuring that these heat sources are not directed toward or allowed to come in contact with fuels, OR staff can prevent fires.

Fuels. A fuel is anything that can burn, including almost everything that comes in contact with patients, as well as the patients themselves. As shown in the "Fuels Commonly Encountered in Surgery" table below, fuels abound in the OR; note that, in addition to the many items that are generally known to burn, many other items that are not generally thought of as flammable are listed.

Some prepping agents and a few ointments required during surgery are volatile and extremely flammable, more so than many other fuels. For example, liquid alcohol from a wet, dripping prep can pool under the patient and generate vapors beneath the drapes for quite some time. Concentrated alcohol vapors trapped under drapes or above areas still wet with alcohol can be easily ignited by heat or sparks (see "Proper Prepping Techniques," below). Open bottles or basins containing volatile solutions (e.g., alcohol from suture packs, acetone degreaser) should be closed or removed from the sterile area as soon as possible after use.

Under the right conditions, some surgical ointments can burn. For example, petroleum-based ointments used in an OEA will ignite when enough heat is present to cause vaporization. These materials must vaporize and mix with oxygen to allow ignition. Globs of ointment are not easy to ignite because their mass absorbs considerable heat before vaporizing. Thin layers, however, have a low mass per area and need less heat to cause vaporization; thus, they are more ignitable.

In contrast, water-based lubricants, such as K-Y Jelly, are mostly water and will not burn; heat simply vaporizes the water in the lubricant, cooling the area. In fact, water-based lubricants can be used to coat hair to make it fire resistant.

Oxidizers. Most fuels burn only in the gaseous state and ignite only when sufficient vapors have mixed with oxygen. Heat produces these vapors by evaporating liquids or vaporizing solids. Although oxygen from the air combines with fuels during a fire, the OR has other sources of oxygen. (Also see "Oxygen Supply-System Fires," below). Anesthesia often requires delivering oxygen-enriched mixtures above the 21% oxygen of room air to ensure proper oxygenation of the patient. (Whenever and wherever the oxygen concentration is above 21%, an OEA exists.) This oxygen is supplied from the anesthesia machine, ventilator, wall outlet, or gas cylinder. Because oxygen is heavier than air, it collects in low-lying areas (e.g., open chest cavity, drape folds). Some materials, such as some drape fabrics, absorb oxygen and retain it for some time (see below). With increased oxygen, a fire is easier to ignite, will burn faster and hotter, and will be more difficult to extinguish. An OEA will also allow some materials (e.g., many plastics) to burn that will not burn in room air.

Oxygen for a fire can also be supplied from the thermal decomposition of nitrous oxide. Heat from sources found in the OR or a fire liberates oxygen from nitrous oxide, allowing it to support combustion. Thus, within the context of surgical fires, any mixture of oxygen and nitrous oxide should be considered an OEA. In the event of a fire, the supply of nitrous oxide, as well as oxygen, must be shut off quickly to reduce the intensity of the fire.

Alcohol is extremely flammable and is found in many forms in the OR. An explosive fireball from alcohol vapors ignited by an ESU, laser, or other heat source has enough force to knock down the surgical team and start an extensive fire. Prevention factors include minimizing liquid alcohol solutions in pools around the patient or in open containers, allowing thorough drying of applied solutions before draping, and ensuring dissipation or dilution of alcohol vapors before using any heat source near the patient.

For example, when a patient is prepped, the prepping solution should be applied with minimal dripping to avoid forming pools of liquid on, under, or around the body. Paint-stick and gauze-prep application are typically drippy, whereas a reservoir-type applicator helps to minimize dripping. Any pools that do form, especially in the umbilicus and cricoid notch, should be blotted. Nonflammable, water-based (e.g., Soloprep, Betadine, Pharmaseal) preps should be used when appropriate. The completed prep must be visibly dry before draping; this may take 2 to 3 min, as recommended by one manufacturer, or as long as 10 min with other solutions and application techniques. A completely dry prep ensures that potentially flammable alcohol vapors will not be trapped beneath the drapes. Only then can an ESU or laser be used without fear of igniting the alcohol.

Probably the least likely but potentially most disastrous fire hazard in a medical facility is the oxygen-supply system. Such a system can be a bulk liquid-oxygen plant that supplies gaseous oxygen to the entire hospital or a simple gas cylinder with a regulator that supplies a single patient. While these systems must meet certain design, inspection, and usage requirements, fires still occur, chiefly because they have been repaired or modified in violation of the governing codes (e.g., NFPA-99; see References and Resources).

Large liquid-oxygen plants must be located outside of the hospital and away from flammable materials. However, at many sites, direct connections are made to the hospital to provide electricity or other utilities to the bulk facility. Modifications of these connections in the bulk facility with non-oxygen-approved hardware can allow liquid oxygen to enter the hospital unexpectedly. Catastrophic fires in the hospital can result, as these utilities usually terminate in machinery rooms or other low-traffic areas of the hospital.

Frequently, leaking seals in oxygen systems are really cases of adiabatic compression ignition of the seats and seals of a valve that is not designed for oxygen use. When oxygen is allowed to flow from a high-pressure into a low-pressure volume, the recompression of the gas in the piping system can cause a rapid rise in gas temperature—up to 1,700° F. Certain materials cannot withstand both 100% oxygen and high temperature and are quickly ignited and burned away. Their products of combustion are sometimes carried in the oxygen stream and can cause injury to patients some distance from the valve. If the valve body is also incompatible with oxygen use, it too can ignite and burn in a kindling chain of ignition when the burning seats and seals provide enough heat to burn the metal.

Improper assembly of high-pressure oxygen regulators has resulted in several fires. In these cases, it is thought that pieces of Teflon tape, chips from seal materials, or latent hydrocarbon contamination was present in the high-pressure section of the regulators. Rapidly opening the oxygen cylinder caused adiabatic compression ignition of this material, which, in turn, ignited O-ring seals and then the aluminum regulator body.

The fire's intensity. When a heat source, a fuel, and an oxidizer combine to produce a fire, the characteristics of the fire—such as burning rate, heat generated, and size—define the fire's intensity and depend on certain traits of the components of the fire triangle—such as heat input; fuel type, composition, geometry, and orientation; and oxygen environment. For example, a thick drape will burn a bit slower than a thin drape because it has greater mass to heat, ignite, and burn. When horizontal, a drape will burn slowly in air with the flame front spreading slowly out from the ignition point; when vertical, buoyant convection of the hot gases makes the fire spread quickly upward with large amounts of flame. If an OEA is added to the scenario, the drape will explosively burn with a large and rapidly expanding flame front. Generally, the more oxygen available, the larger, hotter, and faster a fire will burn (see "Laser Ignition of Surgical Drapes," below.

Products of combustion. If a fire burns a fuel completely, it will convert the fuel into various oxides (e.g., water, CO₂, nitrogen dioxide). However, most fires are not that simple: a complex collection of numerous molecules is produced depending on the fire's temperature; the fuel type, chemical composition, shape, and orientation; the available oxygen; and various other factors. For example, incomplete combustion will produce partially oxidized molecules such as toxic carbon monoxide, acidic free hydrogen, and unburned carbon or soot. In general, a fire will produce any and all combinations of the basic elements and molecules of the fuel with oxygen.

Few studies to determine the combustion products of specific materials have been performed, but those to date show that plastics produce the most toxic combustion products. Plastics are basically hydrocarbons with various other elements added to create special properties. These elements cause burning plastic to produce toxic chemicals such as hydrogen chloride, hydrogen fluoride, cyanide, mustard gas, phenol, aldehydes, and other complex hydrocarbons. These chemicals can cause a fire that would asphyxiate victims before burning them to death. In fact, most fire deaths in the United States are caused by asphyxiation.

The following discussion will help the surgical team learn how to prevent fires by controlling each aspect of the fire triangle; to develop a fire plan covering fire drills and fire extinguishers; and to manage fires that occur on or in the patient.

Preventing Fires: Disrupting the Fire Triangle

The most obvious and easiest method of fighting fires is to prevent them from starting, primarily by developing an understanding of the fire triangle. Staff can learn how to prevent its three elements from combining in the OR by controlling heat sources, especially by following laser and ESU safety practices; by managing fuels, particularly by allowing sufficient time for patient prep; and by minimizing oxygen concentration through judicious use of oxygen and tenting drapes. Although devices and methods exist to minimize the risk of completing the fire triangle during surgery, they have to be consistently used to be effective.

Controlling heat sources. Key to preventing fires involving surgical patients is controlling the various heat sources in the OR and preventing them from contacting fuels. Most OR fires are started because a heat source was not safely or properly used. Vigilance on the part of everyone in the OR is needed to keep this part of the triangle from creating a fire. Many heat-generating or energy-producing devices sound a tone when the device is in use; an activation tone that sounds during periods when the device is not being used should alert the surgical team to deactivate the unit and check for a fire. Laser safety protocols are designed to ensure that the laser is in Standby mode and is inactive whenever the laser tip is not within the surgical field. Removing unneeded footswitches will prevent accidental device activation and a possible fire.

Using wet, sterile towels; wet pledgets; or nonflammable drapes around the laser surgical site can prevent an errant beam from igniting the drapes near the site. Although sterile water keeps the material cool and excludes oxygen, preventing ignition, care must be taken to prevent violating sterile procedure when wetting areas near the surgical site; however, once a fire occurs, infection control takes second place to controlling the fire.

When used, an ESU holster prevents the accidental arcing of the probe tip and keeps it sterile and safe. Keeping the probe tip clean minimizes the risk of adherent tissue incandescing or flaming. Taking the time to allow a hot instrument to cool near its point of use will prevent it from igniting nearby drapes, gowns, tubing, or other fuels. The proper use of special devices, such as LRTTs or jet ventilation, will also reduce the risk of airway fires.

Managing fuels. Allotting sufficient time after patient prepping before draping allows vapors and gases to dissipate. As discussed earlier, where volatile liquid (e.g., alcohol) exists, so does the risk of fire. Volatile fuels, such as alcohol, collodion, and acetone, can take several minutes to fully vaporize and a few minutes more to become diluted in room air. Care should be taken to avoid or minimize pooling of volatile liquids, including under the patient where they may not be noticed. Taking the time to check that these volatile fuels have fully evaporated on and under the point of application will prevent them from being ignited. Also, allowing high concentrations of oxygen to dissipate will reduce the ignition risk of most fuels.

Minimizing oxygen concentration. Minimizing the concentration of oxidizers during surgery by checking for open sources of oxygen will also reduce the risk of fire. As discussed above, high oxygen concentration, including the oxygen contributed by nitrous oxide, will enhance the ignitability of most fuels; minimizing the percentage of oxygen flowing around the patient will reduce the fire risk. For many surgical patients, this can be done by using room air, oxygen diluted with an inert gas, gas scavenging, or a circle breathing system. If an open oxygen source must be used, the drapes must be tented around the patient's head to allow air circulation to dilute the additional oxygen. With an outlet, gravity will assist in pulling oxygen to the floor away from the patient.

As noted above, judicious use of oxygen can also minimize oxygen concentration. For example, not every patient needing head-and-neck surgery requires 100% oxygen; room air or a low concentration of oxygen balanced by an inert gas (e.g., nitrogen, helium) may be adequate for ventilation and thus reduce the fuel-ignition risk. Alternatively, controlled and selective use of 100% oxygen during periods of low fire risk, such as when no ignition sources are in use, will reduce the fire risk; however, time must be allotted for the OEA to return to ambient levels. These precautions are especially useful during head-and-neck surgery, where the risk of fire is increased because of the proximity of a heat source, fuels, and an oxygen source.

Conducting fire drills. Being prepared for a fire is inexpensive insurance that will minimize the cost in dollars, lost time, emotional shock, and injury or death. Preparation involves a number of steps—the most important of which is practicing fire drills that teach all staff about their responsibilities during a fire. Although many facilities, in compliance with Joint Commission on Accreditation of Healthcare Organizations (JCAHO) requirements (see References and Resources), conduct drills for evacuating the OR in the event of a major fire, drills for the surgical team for fighting fires involving the patient are rare—and should not be.

Hospitals are required to have a plan for fires and to practice this plan at regular intervals so that all staff members on all shifts are familiar with the proper response to a fire emergency. Although meeting fire-safety requirements in an effective, realistic, and capable manner is difficult because of the myriad demands on the OR staff, having a preplanned method of fighting a surgical fire so that every team member knows what to do is critically important. Practice should account for the inevitable problems that arise during emergencies, such as exits that are blocked, equipment that is not working, rooms that are crowded with people and equipment, and surgical tables that are difficult to move.

The staff must especially practice drills for fires on and in the patient (see ECRI's "Emergency Procedures: Fighting Fires on the Surgical Patient").

• keeping minor fires from getting out of control;
• managing fires that do get out of control;
• the location and proper use of fire-fighting tools; medical gas valves; heating, ventilation, and air-conditioning (HVAC) controls; and electrical supply switches; and
• the fire alarm and communication system.

All fires start small. Surgical teams should be trained in and practice drills for quickly stopping small fires that involve drapes, gauze, ointments, and liquids. But fires move quickly—slow reactions or confusion can allow a small fire to become a large, more dangerous one. Large fires especially require special drilling to develop the team effort needed to deal with sizable volumes of flame and smoke, as well as burning drapes and plastic in the small space of an OR. The use of fire-fighting equipment for rescue and escape should be explained and demonstrated. Fire extinguishers, discussed in detail below, are critical to managing fires, and staff must be trained in their proper use. Drills should also identify the location of medical gas, ventilation, and electrical systems and controls, as well as when, where, and how to shut off these systems. The fire-containment design and construction of most hospitals helps to ensure that the staff has enough time to evacuate other patients and staff. The use of the hospital's alarm system and system for contacting the local fire department should also be defined.

Fire extinguishers are classified according to National Fire Protection Association (NFPA) standards as illustrated below.

Class A: For wood, paper, cloth, and most plastics

Class B: For flammable liquids or grease

Class C: For energized electrical equipment

The various types of fire extinguishers available to fight each class of fire are described below. Knowing how these devices work and when to use them will minimize the disaster of an OR or surgical patient fire.

Carbon dioxide. A 5 lb carbon dioxide (CO₂) fire extinguisher is the best choice for putting out fires typically encountered in ORs—where the patient is the primary concern. Despite their Class BC rating, CO₂ extinguishers can be used to extinguish small masses of cloth, plastic, or paper (Class A) involved in patient fires, as well as any flammable liquid (Class B) or electrically energized (Class C) fires that could occur in the OR. Equally important, these extinguishers do not leave residue and will not harm the patient, staff, or equipment. A 5 lb capacity CO₂ extinguisher weighs approximately 7 to 9 kg (15 to 20 lb), fits in a space approximately 23 x 23 x 36 cm (9 x 9 x 14 in), and is easily handled by most people. For easy access, the extinguisher should be mounted inside the OR near the entrance.

Dry powder. Class ABC-rated fire extinguishers are not appropriate for use in the OR. These models disperse a cloud of fine, dry powder (usually ammonium phosphate) that extinguishes the fire. This cloud contaminates all surfaces in the OR, including the patient and any surgical wounds. In addition, the powder is a respiratory irritant, which could affect the staff's ability to aid the patient, is hard to remove from wounds, and requires that all contaminated equipment be thoroughly cleaned. While dry powder extinguishers should be available in the OR suite (outside individual ORs), they should be used in the OR only as a last resort.

Halon. Halon extinguishers, which are no longer available because of environmental concerns, had been a better choice for use in the OR than CO₂ extinguishers. These units have a unique fire extinguishing action and a low weight, making them easy to use. Halon extinguishers that are still in service will continue to provide protection; however, once used, they cannot be recharged.

Water. Pressurized-water (PW) fire extinguishers are available, but they are heavy and are chiefly effective against Class A fires. Using a PW extinguisher is more difficult than using a Halon or CO₂ device. To extinguish burning water-repellent drapes with a PW fire extinguisher, users must place a finger partially over the end of the nozzle to produce a fine spray. Water in a stream or tossed from a pan can fan the flames and increase a drape fire. Water from corridor-located fire hoses typically spray 50 gallons of water a minute and can be effective as a last resort when immediate rescue or evacuation is needed.

Water as a fire-extinguishing agent can be used over a wide range of fires. However, a fire involving energized electrical equipment, although rare in the OR, should not be extinguished with water, but with an extinguisher rated for Class C fires.

In order to do any job properly, the right tools—particularly, fire extinguishers—must be available and used in the correct manner. The staff should be instructed and become experienced in their use to fight fires; if improperly used, a fire extinguisher can create more problems then it solves.

Often, local fire departments can provide the staff with hands-on practice in extinguishing real fires using the equipment available in the OR. This helps build the familiarity and confidence needed to use these devices in a frightening and hectic situation. Fire extinguishers should be small enough to be easily carried and handled by the most likely users, and they should be located in plain view in positions of easy access—near escape routes, but away from fire-hazardous areas.

Most fire extinguishers are operated according to the following procedure, whose steps are abbreviated by the acronym "PASS" (however, potential users should be instructed in the proper use of each fire extinguisher because procedures other than PASS may be required):

• Pull the activation pin.
• Aim the nozzle at the base of the fire.
• Squeeze the handle to release the extinguishing agent.
• Sweep the stream over the base of the fire.

If the patient is on fire. Most fires in the OR will be either on or in the patient. In either case, quick action will avert a disaster. Smoke, the smell of fire, or a flash of heat or flame should prompt a fast response. In 30 sec or so, about the time it takes to read this and the next paragraph, a small fire can progress to a life-threatening large fire. During any fire, protecting the patient is the primary responsibility of the staff; self-protection is a secondary consideration.

To contain the flames, the fire triangle must be disrupted by diminishing or removing one or all of its sides. For example, a small area of burning drape or gown can be patted out effectively and safely by hand; larger areas can be smothered effectively with a fire blanket or towel. Fires inside the patient are typically small, but can be deadly. Practicing for an airway fire, such as from a burning tracheal tube (see the Evaluation of LRTTs (Jan 1992;21(1):4-13.), can develop the speed that will minimize the resulting injury in a real emergency.

Good communication among the surgical team can ensure fire-safe practices; stopping small fires before they become big fires or preventing them altogether requires a team effort. For example, the anesthesiologist stops the gases while the surgeon and nurses put out the fire, and then the surgical team cares for the patient. ECRI's Emergency Procedures Checklist contains three basic steps to take in the event of a fire on or in the patient that should be done in rapid succession, taking no more than a few seconds: 1) stopping the flow of breathing gases to the patient, 2) removing the burning material from on or in the patient, and 3) caring for the patient. ECRI has also prepared another Emergency Procedures Checklist, "Extinguishing Airway Fires," that outlines procedures to take if the source of the fire is the tracheal tube.

Oxidizers (i.e., oxygen and nitrous oxide) are often involved or become involved in surgical patient fires. Stopping the flow of oxidizers to the patient reduces the intensity of the fire, enabling it to be more easily controlled and extinguishing some fires. While seemingly contrary to the goal of protecting the patient, patients can usually tolerate short periods of air deprivation; a fire poses an immediate risk to the patient's life, as well as to staff and other patients in the area. Burning materials on or in the patient must be removed and extinguished immediately before they cause thermal injury to the patient and become difficult to extinguish. Removing these materials minimizes the injury and enables the fire to be put out safely and quickly. When the situation is controlled, the patient must be quickly cared for by extinguishing any residual fires, resuming ventilation, controlling bleeding, and dealing with any further injuries.

If the fire spreads beyond the patient. In addition to ensuring the patient's immediate safety, as outlined above, staff should be aware of general guidelines and procedures for containing small fires and effectively managing large fires that have somehow gotten out of control, as illustrated below. Again, fire drills should prepare staff for the worst—so that the worst won't happen.

Other staff should be alerted to the fire in case it gets out of control; then, the OR staff should act to control the flames. The oxygen and nitrous oxide flow to the patient should be interrupted, and fuels should be either removed from the fire's environment or prevented from vaporizing (e.g., by pulling apart a set of burning drapes) to separate the fuel from the fire. A nonflammable material, such as a wet towel or sterile saline, can be used to cool the fire. Water or inert gases from a fire extinguisher can be directed at the flames—a squirt of CO₂ (or Halon) will knock out a drape fire with minimal contamination of, and secondary damage to, the patient. Other tools, such as fire blankets, can be used to control some flames. Any electrical device involved in the fire should be unplugged. If the fire does start to get out of control, the fire department should be notified to give firefighters ample time to respond; firefighters would rather find that a small fire has been extinguished than see smoke billowing out of a building—especially a hospital.

If these measures are not taken or are not effective, staff must know what to do in the event of a large fire. In such cases, gases supplied to the patient can accelerate flame propagation. Toxic smoke will form a hot, dense layer near the ceiling, obliterating overhead lights. The smoke can migrate through the room ventilation system. Staff should keep low and quickly get and use fire extinguishers, perhaps the only hope at this point—although sprinklers, in ORs so equipped, may open and room ventilation may also automatically shut down to prevent smoke from entering other areas. If the fire department has not been notified, this should be done now.

The patient should be evacuated on the operating table if possible. The oxygen and nitrous oxide to the burning OR should be shut off to prevent reignition of the fire, as should electricity if equipment is involved or water is used to extinguish the flames. Electrically energized equipment doused with water can be hazardous to personnel. If the fire progresses past 1 min, the entire operating suite should be evacuated. Although the possibility of fireball explosions from bottled alcohol or gas cylinders is extremely remote, such accidents can happen. By this time, the fire department should be responding, and other surgical teams should be preparing their patients for immediate removal from the danger area. The burning OR must be closed to reduce the spread of smoke and fire. The building fire hose will apply many gallons of water per minute and can be effectively used to rescue injured or unconscious patients or staff in a major fire.

Many states and some professional organizations have regulations or standards requiring hospitals to report fires to their local fire department. For example, the Pennsylvania Department of Health, in its Rules and Regulations for Hospitals, states that "every building should have an automatic and manually activated fire alarm system installed to transmit an alarm automatically to the fire department by the most direct and reliable method approved by local regulations." Many state and local regulations refer to codes and standards written by NFPA. NFPA 101, Code for Safety to Life from Fire in Buildings and Structures, requires an alarm system that, when activated, will automatically notify the fire department. In NFPA 99, Standard for Health Care Facilities, the steps to take in the event of a fire are detailed, including notification of the fire department. Thus, if these codes are followed, an alarm set off in the hospital will automatically notify the local fire department.

Other organizations, including JCAHO and, in some states, the department of health, also require hospitals to document fires. For example, JCAHO states in its Accreditation Manual for Hospitals that, at the time of its survey, hospitals must have "records of actual fire incidents." New York regulations require hospitals to report "fires in the facility which disrupt the provision of patient care services or cause harm to patients or staff within 24 hours to the state health department." Written follow-up reports are also required. The New Jersey Department of Health, in its "Licensing Standards for Hospitals," states that "there must be a system in place for reporting and investigating fires." Thus, it is important to know the regulations.

Failure to comply with a statute or safety regulation has legal ramifications: a violation may be considered negligence per se. The standards or guidelines issued by professional or accreditation organizations, such as JCAHO, do not have the force of law. Nevertheless, they may be used as evidence of the standard of care that a hospital must meet. Thus, from a risk management point of view, the safest course is to notify the fire department and keep records of any fire in your hospital. Clinical department heads should notify the safety officer, hospital risk manager, and/or hospital administrator in the event of a fire.

Also, the event should be analyzed to determine whether it must be reported to FDA under the Safe Medical Devices Act (SMDA) of 1990. For example, in the case of a laser-related injury to a patient, a report would be required. This issue should be discussed with the hospital's risk manager.

Examples of specific cases that illustrate the variety of and ease with which surgical patient fires happen are discussed below. Tips on how these fires could have been prevented are also given. Most of these are drawn from our investigation of specific incidents. These examples are listed in groups according to the primary causative factors (aspects of the fire triangle) that were involved in each case.

• Heat source—ESU
• Fuel—Bowel gas (methane) due to improper presurgery preparation
• Oxidizer—Air

A methane-producing diet and improper cleansing of the bowel before surgery led to a bowel explosion. Without first venting the bowel, the surgeon exposed the colon and proceeded to enter it using an ESU. The hot ESU tip caused the explosive ignition of the bowel gases, which caused a 10 cm tear of the colon. The patient was otherwise uninjured and subsequently recovered.

• Heat—ESU
• Fuel—Gauze
• Oxidizer—100% O₂

The use of a dry gauze pad in an OEA led to a fire in the incision site. A gauze pad was placed in the incision site during a lung resection. The dry pad was being used to blot blood from the tissues. At the time the fire occurred, an ESU was being used to cauterize a bleeder immediately next to the gauze. The lung lobe had already been resected, and oxygen was flowing out of the resection area, enriching the operative site itself. The oxygen, in turn, enriched the gauze and allowed it to be easily ignited by the ESU. The burning gauze pad was thrown to the floor and extinguished without any apparent injury to the patient.

• Heat—ECU
• Fuel—Ointment
• Oxidizer—O₂ and N₂O

An unrecognized fuel- and oxygen-enriched atmosphere set the stage for this flash fire. Skin lesions were being removed from the patient's eyelid and neck. General anesthesia was administered by mask and was maintained with a 2:3 oxygen:nitrous oxide mixture and a small amount of halogenated anesthetic. An ophthalmic ointment was applied to the eyes. When the surgeon used an ECU to remove a mole on the eyelid, a flash fire occurred. Quick control of the fire limited the patient's injury to only minor burns. The patient recovered without incident.

• Heat—ESU
• Fuel—Drapes
• Oxidizer—Air

A straightforward breach of infection control and surgical technique led to this fire. During emergency surgery, a contaminated ESU pencil was not removed or placed in a protective holster, but was allowed to dangle over the side of the operating table. An OR nurse unknowingly leaned against the pencil, causing it to activate, arc through the drapes to an instrument table, and ignite the drapes. The flame spread rapidly up the drapes vertically from the ignition point about 2 ft off the floor and onto the patient. By this time, the fire was burning with such intensity that all other flammable materials on and around the patient were easily ignited and quickly burned. The patient died, but it is not certain whether the cause of death was the fire or the initial injuries.

• Heat—ECU
• Fuel—Gauze, drapes
• Oxidizer—Air

Use of a dry gauze pad to clean the ECU tip led to this fire. A quick response by the surgical team minimized the injury to the patient undergoing cervical cauterization. Disposable drapes were being used on the patient, who was in the lithotomy position. The surgeon routinely cleaned the ECU tip with a dry gauze pad. Frequently throughout the procedure, the dry gauze pad ignited (wet gauze would not have ignited), and the doctor threw the burning pad to the floor and stamped it out with his foot. In one instance, he threw a burning gauze pad to the floor, and it ignited the bottom edge of the vertically hanging legging drape on the left leg. Within approximately 7 sec, the fire had rapidly spread up the drape. The drapes were pulled off the patient as they were burning; however, the patient sustained severe burns on the left leg.

• Heat—ESU
• Fuel—Tracheal tube
• Oxidizer—100% O₂

Ignition of a tracheal tube during a tracheostomy resulted when a surgeon used an ESU too aggressively. With the ESU in the Coagulation mode, he attempted to cut through the cartilage rings of the trachea. In doing so, he ignited the tracheal tube cuff, which started the plastic tube burning in the presence of 100% oxygen. The surgical team, which was slow to recognize that the fire was in the airway, gave three breaths of 100% oxygen while trying to extinguish the fire. Each breath reignited the smoldering tracheal tube. The patient died several weeks later because of injures from the fire. ESUs should NOT be used to enter the airway, especially with 100% oxygen and a plastic tracheal tube present. Had the surgical team realized that there was an airway fire, reacted quickly, and not given the breaths while trying to extinguish the fire, the patient may have suffered only minor burns.

• Heat—ESU, tissue ember
• Fuel—Gauze
• Oxidizer—O₂

Gauze that was initially wet, but that dried out and became oxygen enriched during a procedure, led to this throat fire. Surgery was being performed under general anesthesia in the back of the throat of a patient with a tracheal tube. The area above the tube cuff had been packed with wet gauze. The gauze dried out during the course of surgery and became oxygen enriched because of a minor leak around the cuff. During use of an ESU, a glowing ember of charred tissue floated down into the back of the patient's throat, ignited the gauze, and caused flames to briefly erupt from the patient's mouth. The patient sustained minor burns and subsequently recovered. Had the gauze been checked and kept wet, the fire would probably not have occurred.

• Heat—ESU
• Fuel—Drape fibers or body hair
• Oxidizer—100% O₂

The creation of an OEA, caused by an open oxygen source, allowed this fire to occur. A patient was having several skin lesions removed from her right breast. She had been given a tranquilizer and was being given oxygen with a face mask at a flow rate of approximately 4 L/min. The surgeon had initially removed a lesion from her neck without incident. The drape fenestration was then slid down toward her right breast. This area was prepped in the usual fashion with povidone-iodine, and the incision site was anesthetized with a local anesthetic. During use of the ESU, the surgeon stated that a spark flew from the operative site over toward the edge of the surgical drape. This coincided with a cry from the patient.

The method of flame propagation in this case is not absolutely clear, but surface-fiber flame propagation was involved. Two possibilities are likely: 1) the nap fibers on the reusable drape burned, or 2) the patient's fine body hair burned and rapidly spread the fire under the surface of the drape up toward the patient's face. The fire then ignited the oxygen mask and resulted in some minor burns to the patient's face and neck. In either case, the presence of the open oxygen source and the oxygen wafting out of the fenestration was the predisposing factor to the fire.

• Heat—ECU
• Fuel—Drapes
• Oxidizer—100% O₂

In another drape fire involving an OEA, quick action by the surgeon and anesthesiologist resulted in minimal injury. The surgeon was operating through a microscope on a patient's eye. He asked for a disposable cautery pencil to cauterize a bleeder and was given a device with a 2-inch shaft rather than the ½ -inch shaft he was accustomed to using. He could not see that he had been given the wrong instrument because he was using the operating microscope. He turned the cauterizer on at the instant that the pencil was handed to him so that it would be hot at the time it reached the operative site seconds later.

As the device approached the operative site, the now red-hot tip of the cauterizer grazed the drapes over the patient's nose. Oxygen was being delivered through a nasal cannula at a rate of 3 L/min. When the cauterizer touched the drapes, a large ball of flame erupted on the patient's face. In a startle reaction, the surgeon scratched the patient's cornea with the red-hot cauterizing probe. The patient was also burned along the right nostril and right orbit. When the fireball occurred, the anesthesiologist immediately turned off the oxygen, and the surgeon ripped the drapes off the patient's face. Their actions minimized injuries to the patient.

In both of the following cases, the fires would not have happened if proper laser safety protocols had been practiced. Laser safety protocols require that the laser be set to the Standby or Deactivated mode whenever the handpiece is out of the surgical field. An audible activation indicator may avoid or minimize such incidents.

• Heat—Laser
• Fuel—Drapes
• Oxidizer—Air

With the patient in the lithotomy position, the surgeon used a laser to cauterize cervical polyps, then placed the laser handpiece against the patient's left thigh pointing toward her left buttock. The surgeon slid the laser footswitch out of the way with a foot just a moment before the laser nurse placed the laser in Standby mode. Unbeknownst to surgical personnel, the surgeon had accidentally activated the laser during this maneuver.

The laser penetrated the outer drapes, which did not ignite because of the flow of clearing gas from the handpiece, and ignited a dry area of the absorbent towels under the patient's left buttock. The fire burned slowly for a minute or two, concealed by the outer drapes; subsequently, flames erupted from the legging drapes. The patient suffered significant burns to her left inner thigh.

• Heat—Laser
• Fuel—Gown
• Oxidizer—Air

A similar case during abdominal surgery resulted in laser ignition of the patient's gown in the area of the left axilla and significant burns to her left arm.

• Heat—Bur spark
• Fuel—Hair
• Oxidizer—O₂ and N₂O

An OEA, created by the presence of oxygen and nitrous oxide, allowed easy ignition of facial hair. A patient was undergoing maxillofacial surgery with general anesthesia maintained through a nose mask with a concentration of 25% oxygen, 75% nitrous oxide, and a small percentage of halogenated anesthetic. The patient had a moustache. As the surgeon was grinding a filling with a tungsten-carbide bur, an incandescent spark flew from the bur and arced out of the patient's mouth, over his upper lip, and landed in his moustache. Because of the high concentration of oxygen, effectively 50% because of the nitrous oxide, the moustache immediately burst into flame and ignited the nasal mask. The fire then flashed back toward the anesthesia machine along the gas delivery hoses. As soon as the fire was noticed, the nasal mask was removed from the patient's face, but not before significant burning of his nose and upper lip had occurred. Had a water-based lubricant been used to coat the moustache hair, the spark would not have caused the fire.

In ECRI's nearly 30 years of investigating OR fires, equipment fires have been extremely rare, probably because of strict electrical safety standards, good design of equipment, and routine inspection and preventive maintenance. One fire occurred at a wall outlet and was handled by removing the plug from the socket. Another more serious fire involved a transformer bank that actually burned and required the evacuation of the patient and staff from the specialized OR.

Most "fires" in equipment are actually short circuits or electrical overloads. They create an odor, some vapors, and are controlled by stopping the flow of electricity to the device.

Surgical patient fires, while infrequent, can be disastrous. The vigilance of the surgical teams in preventing the three sides of the fire triangle—heat, fuel, and oxidizer—from combining into a fire is the best defense against a fire involving the patient. Having, understanding, and following special procedures for dealing with heat sources and flammable substances in the OR can reduce the fire risk. Having a fire plan and practicing it with fire drills and training should be part of the hospital's ongoing routine. Should a fire occur, quick and knowledgeable reaction by the staff will minimize its impact. Unfortunately, it sometimes takes a real fire to spur a hospital to become fire conscious.

It is up to the individual hospital to tailor a plan to meet its specific needs. ECRI and many other organizations and sources can help hospitals develop a fire-protection plan. State fire marshals and local fire-fighting associations are usually happy to work with hospitals on fire issues. In addition to NFPA, the the American Society for Testing and Materials (ASTM), training materials producers, and manufacturers can provide videos, films, and other teaching materials about OR fires (see References and Resources).

American Society of Testing and Materials. ASTM G4 committee on flammability of materials in oxygen enriched environments. Contact ASTM: 1916 Race St., Philadelphia, PA 19103; (215) 299-5400.

Association of Operating Room Nurses. Standard and recommended practices for perioperative nursing, 1990.

ECRI. Fighting airway fires. Health Devices 1990 Apr;19(4):111.

ECRI. Fires during surgery of the head and neck area. Health Devices 1979 Dec;9(2):50-2.

ECRI. OR fires: Preventing them and putting them out. Health Devices 1986 May;15(5):132.

Joint Commission on Accreditation of Healthcare Organizations. Accreditation manual for hospitals. Chicago: JCAHO, 1991.

Medfilms Inc. Fire safety and fire extinguishers (videos). Contact Medfilms: 6841 N. Cassim Pl., Tucson, AZ 85704-1261; (602) 575-8900.

National Fire Protection Association. NFPA 10-1988, Standard for Portable Fire Extinguishers.

National Fire Protection Association. NFPA 53M, Fire Hazards in Oxygen Enriched Atmospheres, 1990 ed.

National Fire Protection Association. NFPA 99-1990, Health Care Facilities, Section C-12.4, Suggested Procedures in the Event of a Fire or Explosion, Anesthetizing Locations.

National Fire Protection Association. NFPA 101, Life Safety Code, 1991.

National Fire Protection Association. NFPA fire protection handbook. 16th ed. Quincy, MA: NFPA, 1986.

State and local codes applicable to healthcare facilities and fire.

* * *

While many surgical drape manufacturers suggest, either in conversation or in print, that their products provide protection against fire by being flame retardant or flame resistant or that they meet this or that flammability standard, this is not necessarily so.

Fire tests using flames or ESU ignition sources cannot demonstrate the susceptibility of drapes to laser ignition. Unlike a flame or an ESU, a laser emits a concentrated beam of energy (like sunlight through a magnifying glass, but more intense) and can thus rapidly vaporize and ignite normally flame-resistant materials. Lasers also differ from ESUs in that they do not have to be in contact with a drape to ignite it; whereas an ESU heats through electrical contact, the laser irradiates and can ignite a fire with material close to the tip, at some distance from the tip, or through several layers of material. Also, drapes can trap oxygen around the patient, creating a highly oxygen-enriched environment; oxygen increases ignitability and flammability, and not all flammability or flame-spread tests are done in oxygen-enriched atmospheres (OEAs).

We have investigated a number of fires involving laser ignition of surgical drapes. In some cases, the flame was immediately seen and patted out or quickly smothered. More serious cases occurred when the laser penetrated the outer drape and ignited materials beneath it. These fires often burned for several minutes before being noticed and caused serious injury to the patients. Because we are not aware of any published scientific information regarding how a laser interacts with drape materials in the OR, we conducted the following tests to assess drape ignitability during laser use.

We tested several kinds of drape materials to learn how they interact with laser energy. Drapes are typically classified as disposable or reusable. Many disposable drapes are made of cellulose fibers and some type of fiber binder or of nonwoven polymeric fibers fused together. Reusable fabric drapes are typically cotton or cotton/polyester blends treated with a waterproofing agent or synthetics laminated to impervious material. (Most of these materials are described in our Evaluation of surgical drapes in Health Devices 15[5], May 1986.) Because they are often used on or under surgical drapes, we also tested an absorbent towel made of fluffy cotton with no waterproofing.

Test method. In our tests, we exposed small, dry pieces of each drape material to CO₂, Nd:YAG, KTP, and argon laser energy in air and 100% oxygen—the best and worst flammability conditions. The laser energy was applied at high and low power densities (e.g., 32,000 and 200 W/cm²) until a fire occurred or for 10 sec. High power densities were obtained by using small spot sizes (e.g., when the laser tip is close to the target). Low power densities were obtained by using larger spot sizes (e.g., when the laser tip is some distance from the target).

We did not use laser clearing gas (with CO₂ lasers) or cooling gas (with fiber-delivery lasers) during these tests. Gas is used, especially with older lasers, to clear smoke from the optics and surgical site or to cool the fiber. The gas can blow out a nascent fire in the outer drape on a surgical site, but it does not penetrate the drape. Laser energy will penetrate the drape and act on underlying materials, possibly causing a fire or injuring the patient.

Test results. In room air, laser energy warmed, created a hole in, or ignited the drape. High power densities typically vaporized the material, ignited the jet of vapor, and created a hole in the drape in rapid sequence. Notably, the nonwoven polymeric and synthetic laminate drapes typically melted away from the three lasers and did not burn in room air. The cellulose-based and cotton-based drapes were typically ignited and burned in room air by most of the lasers. Depending on the material, the flame either continued to burn or went out when the laser stopped. With low power densities, laser energy ignited some drapes, creating a quickly visible fire, even though with higher power the drape was not ignited. In other cases, low laser power density degraded the materials without igniting or caused a slight warming of the material. Once ignited, the orientation of the drape affected how fast the material burned; drapes burned much faster when vertical than when horizontal.

In 100% oxygen, all of these materials ignited and burned with frightening ease. High power density ignited the drapes with a loud snap. Low power density, which only degraded the materials in room air, created fires in OEAs. Even the nonwoven polymeric disposable drapes ignited rather than melted in 100% oxygen. The burning plastic was especially dangerous in that it flashed over its surface and formed individually burning beads over the area that had been covered by the drape sample. Cellulose-based drapes burned like magician's flash paper—rapidly and with much flame and little ash. The cotton-based fabrics burned with the slowest, but still rapid, flame spread.

An interesting phenomenon, called surface-fiber flame propagation (SFFP), occurred with the dry absorbent towel in oxygen. The flame started at the laser impact site and explosively spread across the surface of the towel to its edges where the flame became established. The fine nap, or surface fibers, of the towel caused this event. The nap was easily ignited because of its low mass, large surface area, and the ignition enhancement of oxygen. Similarly, any material with a coating of fine fibers, even hair on skin, can experience SFFP. Thus, frequently washed or worn drapes with raised nap can be a greater fire hazard in OEAs.

We did not test layers of drapes or special areas of drapes, such as the seams or the adhesive strip around the fenestration of some drapes. These conditions would only enhance the ignitability and/or flammability of the drape system. Most adhesives are easily vaporized and readily burn. Layers of material trap a laser beam and oxygen, retain heat and smoke, and allow fire to smolder unseen.

Our test results are presented in the "Laser Interaction with Drapes in Room Air" table, below. Results with specific drapes may vary depending on color, chemical composition, and laser wavelength.

Conclusions. All drapes ignite and rapidly burn in oxygen; thus, by minimizing the potential for an OEA near the drapes, the chance of a laser-ignited fire will be greatly reduced. Even in room air, no drape offers protection against a laser-ignited fire. Most lasers can ignite cellulose-based and cotton-based drapes in room air. Polymeric and synthetic drapes will melt away from the laser, and a high-power-density laser beam can penetrate most drapes without igniting them; in these cases, a patient injury or an unseen, smoldering fire could occur. Whenever a laser is used, the vigilance of the staff in following laser safety protocols (e.g., put laser in Standby mode as soon as it is not needed) is the best fire protection. To help minimize risk in the case of inadvertent laser activation, a clearly audible emission indicator should be present to alert OR personnel that the laser has been activated and to look for a potential fire.

In light of these conclusions, drape purchasers and users should ask questions of the drape manufacturers about the test conditions used to define the ignitability or flammability of the drapes: What was the oxygen concentration? How was the sample oriented? Does the treatment wash out, the color fade, or a nap form in reusable drapes? What was the ignition source? What type of laser was used? Have the tests been independently confirmed? Are specific test results available?

Some lasers use contact devices, which convert some of the laser energy into heat at the tip. These devices present a dual ignition challenge to drapes—heat and laser energy. Using 20 W of Nd:YAG laser energy, we pulled an active contact tip across each of the drape materials. All of the drapes, except the nonwoven plastic, were ignited by the contact tip and burned in room air. The nonwoven plastic melted away from the tip. The contact tip retained heat for several seconds and was able to hole or char all the materials after the laser was deactivated. This further points out the need for vigilance as the best fire protection during surgery.

Laser Interaction with Drapes in Room Air^*

Drape Material	CO2 Laser	Nd:YAG Laser	Argon Laser	KTP Laser
DISPOSABLE Nonwoven Polymeric	Melted	Melted	Melted	Melted
Cellulose with Plastic Binder	Burned	Burned	Charred	Burned
Cellulose with Flame-Retardant Binder	Burned	Holed	Holed	Burned
REUSABLE Waterproof Cotton	Burned	Burned	Burned	Burned
Cotton Towel	Jetted	Burned	Smoldered	Burned
Impervious Laminate	Melted	Burned	Melted	Jetted
Polyester-Cotton	Burned	Burned	Burned	Burned

Key:

Melted = Material became fluid with no ignition

Burned = Material was ignited by laser and continued to burn

Charred = Material became carbonized with no ignition

Holed = Laser energy created a void in the material

Jetted = Material erupted with column of flame only during laser impact

Smoldered = Material burned slowly with no visible flame

* Note: in 100% oxygen, all drapes burned.

UMDNS Terms

• Burs [10-519]
• Drills [11-329]
• Electrocautery Units [11-418]
• Electrosurgical Units [11-490]
• Handpieces, Surgical [17-949]
• Light Sources, Fiberoptic [12-345]
• Lights, Surgical [12-282]