Prevention of and response to surgical fires

Learning objectives.

By reading this article, you should be able to:

• •Describe the elements of the fire triangle and their relation to surgical fires.
• •Distinguish those patients most likely to be involved in a surgical fire.
• •Discuss the oxidising gases used by anaesthetists and the concentrations at which the risk of surgical fires increases.
• •Explain how the surgical team can use cross-checking and how this decreases the risks of fire.
• •Identify the available organisations and resources for education and clinical guidance.

Key points.

• •Communication between members of the surgical team is an integral component of the prevention of surgical fires.
• •Open delivery of 100% oxygen should be avoided if at all possible for surgery above the xiphoid process.
• •Surgeons usually control the ignition sources, such as electrosurgical units and lasers.
• •Operating theatre nurses or practitioners usually control the fuel sources, such as alcohol-based preparations and surgical drapes.
• •The use of an ignition source in close proximity of an oxidiser-enriched environment creates a high risk for surgical fires.

Operating theatre fires remain an uncommon but real safety risk for patients undergoing nearly all types of procedures, and despite ongoing safety initiatives, occur more commonly than wrong-site surgeries.¹ One of the most compelling cases for safety improvement in the surgical setting is within this area. Combining the simple steps of operating theatre team education; improving lines of communication between surgeons, anaesthetists, and operating theatre nurses or practitioners; and the deliberate separation of the elements of the fire triangle can almost completely eliminate the incidence of surgical fires. In this brief review, we hope that readers will be able to reduce the risk of surgical fires effectively by the application of the safety principles described.

Operating theatre fires reportedly affect more than 600 patients annually or roughly 1 fire per 360,000 surgeries in the USA alone. These data are derived and extrapolated from the one US state that mandates open reporting of surgical fires.² The true incidence is likely much greater because of gaps in mandated reporting. New data show improvement, but the number of legal cases associated with surgical fires has not changed accordingly.³ Under-reporting is commonplace because of the liability implications, threat of litigation, and potential reputation damage to the personnel and institutions involved. Numerous patient safety and advocacy organisations have identified operating theatre fires as a substantive safety threat, including the ASA, The Joint Commission, the Society of American Gastrointestinal and Endoscopic Surgeons, and the Anesthesia Patient Safety Foundation (APSF).4, 5, 6, 7 Through the work of these and other organisations, increased attention and educational efforts have been implemented recently in an effort to reduce the incidence of these fires.

The science of fires

Fires require the presence of each of the three components of the fire triad to occur: a fuel source, an ignition source, and an oxidiser. In the operating theatre environment, potential fuels are ubiquitous: they can include surgical drapes and gowns, laparotomy sponges, gauze, dressings, towels, alcohol-based skin preparation solutions, tracheal tubes, and even the patient's own hair and digestive gases. Most, although not all, of these potential fuel sources are brought to the surgical field by the operating theatre circulating nurse or practitioner, and therefore, are under their control. An ignition source is required to initiate combustion. In the operating theatre, these sources are most commonly either a therapeutic laser or the monopolar electrosurgical unit (ESU). Less commonly, other ignition sources include defibrillators, light source units, heated probes, faulty electrical wiring, and sparks from drills or other surgical tools. Ignition sources are almost universally controlled and operated by the surgeon. An oxidiser is the third element of the fire triad, and most commonly is gaseous oxygen (O₂) directly from the anaesthesia machine, auxiliary oxygen port, or a stationary regulator. Nitrous oxide (N₂O) is also a strong oxidiser and can accelerate combustion. These oxidiser sources are usually administered and controlled by the anaesthetist. Only when each of these three elements—a fuel source, an ignition source, and an oxidiser—are combined in close proximity is there a risk of fire. As surgeons, anaesthetists, and operating-theatre professionals each generally controls only one leg of the fire triad, this risk is frequently forgotten and responsibility is diluted. Training, awareness, and communication may aid in the identification of risks and better prevent these fires.

Prevention strategies for surgical fires

Improvement of communication amongst operating theatre team members is the first line of defence in the prevention of surgical fires. Lawsuits brought forward in cases where harm occurred because of operating theatre fires frequently cite the lack of communication as a key factor contributing to the liability of the event.⁸ The ASA Task Force on Operating Room Fires Practice Advisory states that surgeons should inform anaesthesiologists before using a potential ignition source, whilst anaesthetists should inform surgeons if there is a potential for an ignition source to be exposed to an oxygen-enriched environment.⁴ Surgeons, theatre practitioners and anaesthesia professionals work alongside each other, but frequently experience ‘tunnel vision’ during key portions of the patient's procedure, which often renders them oblivious to the conditions that could pose great harm to the patient. Although we realise the importance of all personnel in the operating theatre in safety improvement, these three professions are the focus of this article, as each plays an important role in preventing fires in the operating theatre.

As stated previously, fires occur as a result of combining the three elements of an ignition source, a fuel, and an oxidising gas or ‘oxidisers’, and the occurrence of a reaction resulting in flame. Conversely, when one of these three components is removed from the immediate environment, the capacity of a fire breaking out is effectively reduced to zero.

Safe use of oxidisers

Anaesthetists exert the most control on oxidiser use. Oxygen and nitrous oxide are both very effective oxidisers. In concentrations above 30%, they can increase the chance of ignition of fuels; cause any fires to burn with greater intensity and speed; and, if allowed to accumulate in a closed area such as under a drape or blanket, can create the perfect environment for a flash fire. As the ambient oxygen concentration is increased, both the time for ignition and the time for fuel to burn completely decrease very rapidly.⁹ The mechanism whereby oxygen is delivered to the patient and also the clinical discretion for its use are key factors. Surgical fire risk is high when 100% oxygen is delivered in an open manner via a simple face mask or a nasal cannula. The combination of the high concentration and the accumulation of excess and exhaled oxygen result in extreme hazard, especially in cases where the anatomical location of surgery is above the T4 level or xiphoid process. If an ignition source is used in the proximity of this oxygen-enriched environment, the presence of a fuel source may result in a flash fire, and the patient may experience a severe injury that is disfiguring, debilitating, or could even result in death. These injuries are secondary to airway burns, smoke inhalation, or delayed onset infection.⁹ A closed-claim case analysis suggests that fires during sedation cases nearly always occurred on the head, neck, or chest, suggesting that proximity to an open oxygen delivery source is causative.⁸ As a result, the ASA Task Force on Operating Room Fires advises that, for patients requiring supplemental oxygen undergoing moderate or deep sedation, the anaesthetist should consider avoiding an open oxygen delivery device (such as a simple face mask or nasal cannula), and instead consider using a tracheal tube or laryngeal mask airway. These devices effectively seal the airway, thereby eliminating oxygen contamination of the surgical field.⁴

Managing fuel sources

Whether using an alcohol-based preparation solution for cleansing before a procedure, applying drapes and blankets, or controlling paper and plastic products within the surgical field, nurses and theatre practitioners are typically in charge of the sources of fuel. Given their effectiveness in infection control, alcohol-based preparation solutions are commonly used in the operating theatre. It is important that those applying these potential fuel sources heed the recommendations provided on the package insert to minimise fire risk. These recommendations include allowing adequate drying time (at least 3–5 min) before draping, the use of an appropriately sized applicator to reduce the risk of alcohol pooling, the avoidance of large-volume alcohol preparation solutions (such as the 26 ml applicator) for surgery to the head and neck, and the removal of leftover preparation solutions from the patient before starting surgery. It is noteworthy that alcohol solutions can remain in long hair for up to an hour before drying. In addition to being extremely flammable, alcohol burns with a flame that is nearly colourless and is difficult to see, especially in combination with high-intensity surgical lights.¹⁰

Clinical scenario.

A healthy patient is scheduled for removal of a pigmented naevus on her face. The patient is brought to the operating theatre and is given i.v. midazolam and propofol. A nasal cannula is selected, and 100% oxygen at 2 L min⁻¹ is administered. With the onset of sedation, her Spo₂ decreases to 92%, and the oxygen flow rate is increased to 4 L min⁻¹. The surgical site is prepared with an alcohol-based skin preparation, and the surgery begins. Bleeding is encountered, and the surgeon uses a monopolar diathermy instrument. Upon activation, a flash occurs and a fire erupts on the drapes. The fire is extinguished by pouring water on the surgical field. Upon removal of the drapes, the cannula has melted to the patient's face and second-degree burns are noted. The patient was transferred to a burn centre. The patient had to undergo reconstructive surgeries to her face. She filed a lawsuit against all involved parties, and this was settled in favour of the patient. Ideally, to decrease the risk of fire, open delivery of 100% oxygen should be avoided. An oxygen blender could have been used to maintain the Fio₂ below 30% or a supraglottic device, or tracheal tube should be placed. Alternative methods of haemostasis, such as direct pressure or haemostat, could also be used.

Controlling ignition sources

Surgeons or other proceduralists are the team members usually in control of the sources of ignition. The improper use of an ESU (or ‘Bovie’) can result in ignition, especially if used in an oxygen-enriched environment of >30% or in proximity to a flammable fuel source. Approximately 90% of operating theatre fires are triggered by the ESU.⁸ Besides the ESU, lasers are a very effective ignition source; these high-energy devices can focus on tissue or other fuels, such as dry gauze or plastics, and result in a very immediate fire. Less commonly, the heat from drills and burrs, and the heat generated from fibreoptic light sources can readily ignite fuels, especially if used in the context of an oxygen-concentrated environment. Monopolar ESU instruments are associated with a majority of reported surgical fires; other devices, such as bipolar ESU instruments and harmonic scalpels, have much less propensity to sparking a fire.⁶

Combined risks

All members of the operating theatre team can proactively reduce the risk of surgical fires. To illustrate the effectiveness of risk reduction strategies, we can examine the instance of airway fires and fires involving the open delivery of oxygen. Surgery-related fires most commonly occur in the head, neck, and upper torso. A majority of these surgical fires occur in cases of sedation without instrumentation. Both of these types of patients undergo procedures under sedation: the extremely healthy patient undergoing a cosmetic procedure who is given sedative agents along with supplemental inspired oxygen, and at the other extreme the patient with severe comorbidities, such as lung disease, obstructive sleep apnoea, or morbid obesity, presenting for a minor procedure. This latter group is frequently perceived as being a risk for general anaesthesia, and therefore, as an alternative to controlling the airway with a tracheal tube or supraglottic airway device (SAD), oxygen supplementation is provided with a mask or cannula. If a planned or, more commonly, unplanned source of ignition source is then used, a fire is possible. In both of these types of patients, the risk of fire could be significantly reduced with planning. For the healthy patient, oxygen should be used judiciously (if at all). If a precipitous reduction in saturation occurs, then sedation can be more appropriately titrated and oxygen can be supplemented using an air–oxygen blender or common gas outlet of an anaesthesia machine to dilute the oxygen to less than 30% concentration. If more oxygen is required, then tracheal intubation or placement of a SAD should be performed. Likewise, for cases of patients with co-morbid conditions, the airway should be secured if an inspired oxygen concentration >30% is required.¹⁰ The APSF algorithm offers excellent guidance for these clinical decisions (Fig. 1).

Fig 1.

Operating room (OR) fire prevention algorithm.

Another risk of fire occurs when surgery is performed within the airway. If the patient requires more than 30% oxygen to maintain oxygen saturation, then the operating-theatre team must have a strategy to mitigate the fire risk. Ideally, the high concentration of oxidisers should be isolated by the use of a cuffed tracheal tube. For cases involving lasers, a tube specific to the wavelength, optical density, and power of the laser should be used to prevent penetration of the tube by the laser (Table 1). When a laser tube is used, the cuff should be inflated with water or saline, and a small amount of dye such as methylene blue. By doing so, if the laser were to accidently penetrate the cuff, the dye serves as an indicator that the cuff is no longer intact and the risk of mixing of the higher concentrated oxidisers is more likely to occur. If a gauze or surgical sponge is used in the field where a laser is in use, it should be moistened with water or saline.⁴

Table 1.

Characteristics of common laser tracheal tubes. for KTP, potassium titanyl phosphate lasers; for Nd:YAG, neodymium-doped yttrium aluminium garnet lasers

	Laser tracheal tube brands
	Medtronic Shiley™/Laser-Flex™	Sheridan LASER-TRACH®	Rusch LaserTubus™	Medtronic Laser-Shield® II
Available sizes (mm ID)
Non-cuffed	3.0
	3.5
	4.0
Cuffed		4.0	4.0	4.0
	4.5			4.5
	5.0	5.0	5.0	5.0
	5.5			5.5
	6.0	6.0	6.0	6.0
				6.5
			7.0	7.0
				7.5
			8.0	8.0
Wavelengths			0.488–10.6 μm	10.6 μm (CO2)
				532 nm (KTP)
Type of laser protection offered
AR+	No	No	Yes	No
Nd:YAG	No	No	Yes	No
CO2	Yes	Yes	Yes	Yes
KTP	Yes	Yes	No	Yes

Other airway procedures, such as polyp removal, bronchial biopsy, and tracheostomy, should be performed with the lowest oxygen concentration feasible. If the patient requires more than 30% O₂ then at the point where an ignition source such as an ESU is used, the oxygen concentration should be reduced to <30%. Anaesthesia professionals should realise that the change in expired oxygen concentration (Feo₂) is not immediate, but is dependent upon the rate of fresh gas flows. At low flows around 2 L min⁻¹, the change in desired Feo₂ could take up to 5–6 min before decreasing to acceptable levels.11, 12

Response to surgical fires

The best way to manage a fire in the operating theatre is to take the needed steps to prevent one. Fires in oxygen-rich environments may result in a high-intensity flash fire, whereby the process of burn injury occurs in less than a second. If a fire occurs in the airway, some preplanned steps can reduce the burn injuries.⁴ Like any fire, the first priority is to stop the burning process. This is best accomplished by disconnecting the oxygen source and removing the tracheal tube. The exact sequence of these two actions is not important, but they should be carried out immediately and as close to simultaneously as possible. After the patient's trachea has been extubated, pour water or saline into the airway before re-establishing ventilation. If this is omitted, the positive pressure breaths could cause any embers to reignite into a flame in a similar manner to using bellows to establish a flame in a campfire. The patient's airway should be examined for fragments of tubes, sponges, or instruments that may have melted and are now adhering to the patient's airway. As soon as feasible, rigid bronchoscopy should be performed to examine the distal airways for thermal injury. Transfer to a burns centre should be considered and the patient assessed for carbon monoxide or cyanide exposure, as these by-products of combustion can cause systemic toxicity.

In fires occurring outside the airway, the priority for management remains to stop the process of burning. Operating theatre team members should always be alert for fire by stopping to investigate burning odours; popping noises; or, in the case of a sedated patient, unusual movement and restlessness. Upon discovery of a fire, the team member should announce the fire and the surgery should be stopped. Immediate actions should include a brief attempt to suppress the fire by dowsing the area with water or saline, or even patting out the fire with a towel. These efforts are usually effective in the first seconds of a fire. If this time period has elapsed and the fire is larger than can be safely controlled by these initial methods, then the drapes should be removed from the patient and the plans of facilities for an operating-theatre fire should be initiated. This includes the prompt use of an appropriate fire extinguisher, turning off oxidising gases, and plans for evacuation from the area. The local fire alarm should be activated, as many fire alarm systems carry out multiple tasks, such as activation of visual and audible alarms, closing of fire doors, and notification of the local fire department. As the behaviour of a fire is to spread rapidly, it is much better to activate early, rather than wait and allow a small fire to consume a large portion of a facility.

Cross-checking and communication

Reviewing the importance of communication, operating theatre team members should maintain vigilance and cross check each other's actions. When the team members are at a critical juncture in the case, they often experience tunnel vision. The nurse or theatre practitioner might become distracted or engaged in multitasking instead of watching to ensure that the flammable preparation solution is not pooling or has had adequate drying time. The surgeon or anaesthetist should be watching as well. During brisk bleeding, the surgeon might not be aware of their proximity to a fuel source or the level of oxygen in the field when using an ESU, and the other team members should be able to speak up and intervene. During an airway procedure, the anaesthesia professional could be dealing with ventilation or oxygenation difficulty, and not realise the Fio₂ has exceeded the safe threshold of 30%.13, 14 For these reasons, all in the operating theatre should participate proactively in assessing and intervening when necessary.

Developing tactics and strategies for the prevention of surgical fires and improving the culture of safety

Organisations should also take a proactive role in surgical fire prevention. By fostering a safety culture, whereby one can speak up and ‘stop the line’ without fearing retribution, an organisation can decrease the occurrence of untoward events. Also, by allowing time for education for operating-theatre-specific fire prevention education and encouraging the participation in fire drills for the operating theatre, organisations can shed light on specific methods used to mitigate the fire risk. Mandating the use of a surgical safety checklist for every case and even the consideration of formal fire risk assessment tools can increase the margin of safety in many aspects, including reducing the fire risk. One such tool is the Silverstein fire assessment tool.¹⁵ This simple tool uses a point assignment to three risk factors: the anatomical location of the procedure, the presence of an ignition source, and the open delivery of oxygen. If the location of the surgery is cephalad to the xiphoid process, then a point is assigned; if an ignition source is present, then a point is assigned; and, finally, if >30% oxygen is delivered to the patient with a cannula or mask, then another point is assigned. If the points add up to 3, then the case is deemed to be high risk, and the theatre team is assigned tasks and responsibilities to carry out in the event of a fire. The optimal management of a patient with a score of 3 is to reduce the risk; this can be achieved by the elimination of an ignition source, reducing the oxygen concentration to <30%, or using a SAD or tracheal tube. The scoring system may be integrated into an electronic health record.

Other considerations

The operating theatre team should not isolate themselves from others in the hospital that can greatly assist in the efforts to prevent surgical fires. Operating theatre staff should contact members of the local fire service, institutional safety officers, and facility engineers to help with planning and recommendations for basic fire responses, reporting, and assistance with fire drills and evacuation exercises. The time to communicate with these individuals is before an event occurs, not after. Fire officers and engineers can assist with fire code compliance and overall facility design. The facilities should have planning sessions and drills in place for assisting in the decision-making to either evacuate or defend against the fire. Should an evacuation actually be warranted, then how to evacuate anaesthetised patients both horizontally on the same floor and also vertically to a different floor should be considered. These plans should include how to ventilate patients' lungs during the transit and also the logistics of providing artificial ventilation at the final destination, how to keep the patient anaesthetised, and how to keep track of the patients. These same engineers can assist with signage to direct professionals to areas that will be segregated from smoke and fire through compartmentalising the building. Fire officers can also offer education in the operation of fire extinguishers and other life safety devices.

In conclusion, the implementation of most of the methods used to reduce the incidence of surgical fires has little or no financial burden, but just needs a change in the safety culture and realignment of priorities in an organisation. The yield of these changes approaches 100%. From a perspective of global safety, the prevention of surgical fires should be one of the leading areas targeted by clinicians for improvement, as it costs so little and can be implemented in any practice setting.

Declaration of Interest

The authors declare that they have no conflicts of interest.

MCQs

The associated MCQs (to support CME/CPD activity) will be accessible at www.bjaed.org/cme/home by subscribers to BJA Education.

Biographies

Charles E. Cowles, Jr. MD MBA FASA is an associate professor of anesthesiology at the University of Texas MD Anderson Cancer in Houston, TX, USA. Before medical training, he worked as a firefighter and paramedic. He was a coauthor of the OR Fires Practice Advisory from the ASA, and has worked extensively with the Anesthesia Patient Safety Foundation and the National Fire Protection Association.

William C. Culp, Jr. MD is a professor of anesthesiology at Texas A&M Health Science Center and Baylor Scott & White Health in Temple, TX, USA. He is a recipient of the Surgical Fire Prevention Grant from the National Science Foundation, and works in product development for surgical devices designed to reduce fire risks.

Matrix codes: 1I02, 1I03, 2A02, 2A06, 2A10, 3A01, 3A02, 3A06, 3A07