The Doctor’s Advocate | Second Quarter 2015
An Ounce of Prevention
MAC/Sedation Fires Increasing
by Susan K. Palmer, MD, The Doctors Company Anesthesia Advisory Board Member
Composite case: A surgeon requested monitored anesthesia care (MAC) for a patient during excisional biopsy of a mole located on the back above the scapula. Oxygen by nasal prongs at 2 L/min resulted in a pulse oximeter reading of O2 96 percent. The anesthesia provider gave bolus of intravenous general anesthesia briefly so that the surgeon could provide wide subcutaneous and intramuscular injections of local anesthetic.
Surgery began, and the awakening patient became uncomfortable due to lateral positioning. The anesthesia provider increased the ongoing propofol infusion and oxygen flow to 6 L/min. The O2 saturation dropped to 87 percent. The anesthesia provider added a vented plastic facemask over the sleeping patient’s mouth and increased oxygen flow to 8 L/min. The surgeon began to use cautery on the patient’s skin edges. Suddenly, the drapes started to blacken and curl, the facemask ignited, and the patient’s hair began rapid incineration. The anesthesia provider quickly removed the drapes, grabbed the mask and tubing from the patient’s face, and turned off the oxygen. The nurses splashed the field and the patient’s face with saline. The patient flailed and then fell off the bed.
Events like OR fires or patient falls should, theoretically, never occur. In addition to causing patient injury, such an occurrence may lead to a malpractice claim and can preclude the involved physicians and hospital from receiving reimbursement for the patient’s ensuing care and treatment. This type of event may also trigger an inspection by the Centers for Medicare and Medicaid Services (CMS), and The Joint Commission (TJC) may determine that a sentinel event has occurred. Both organizations would then require corrections for deficiencies—which would mean that educational and correctional activities must be drafted for CMS/TJC approval. How can this chain of events be prevented?
The Fire Triad
Most anesthesia providers could correctly identify the “fire triad” shown below.
Most anesthesia providers will not, however, actually witness a sudden surgical fire that injures a patient.
Case reports fill medical literature, and fire safety guidelines in publications may result in readers—with eyes glazed over—responding, “Not another reminder about such a rare problem.” But what most anesthesia providers do not know is that OR fires during MAC cases have actually increased during the last 10 years.1,2 The rapid adjustability of sedation levels that anesthesia providers have learned to deliver with propofol infusion pumps has led to the frequent provision of brief deep sedation/general anesthesia without a secured or isolated airway circuit. Without this secured/isolated airway circuit, the fire triad becomes a reality. An open source of flowing 100 percent oxygen was found to be the cause of 95 percent of all electrocautery-induced OR fires in a 2013 American Society of Anesthesiologists (ASA) Closed Claims study.
The fire in the case outlined in the opening paragraphs would not have occurred if there had been adequate control of oxygen concentration. This single deficiency completed the fire triad. Certainly, the surgeon ignited the fire with an electrocautery device, but his testimony might be imagined as, “I’ve never seen such a thing happen before and had no idea that the anesthesia provider was using oxygen so carelessly.” The anesthesia provider chooses when and how to provide supplemental oxygen and decides whether to put combustible nasal tubing or a plastic facemask on a patient. Therefore, the patient in this case may well blame the anesthesia provider for making the decisions that resulted in the injuries caused by the fire.
A patient’s oxygen saturation during deep sedation can be expected to fall, and an anesthesia provider will usually prefer to provide more oxygen rather than allow the sedation to lighten. This is because anesthesia providers want surgeons to be assured of their ability to produce amnestic and immobile patients. A little extra propofol leads to deeper sedation with lower oxygen saturation, which leads to extra oxygen flow, which leads to an accumulation of greater than 45 percent oxygen in or under drapes, which can ultimately lead to ignition in less than one second3 with a cautery (or a laser or a drill).
Avoid Your First (and Only) OR Fire
Despite recent articles, meeting presentations, and the 2013 revision of the ASA Practice Advisory for Prevention of OR Fires,4 many anesthesia providers have not yet come to appreciate the risks of open source oxygen use in MAC cases. Because combustible materials are always present in an OR,4,5 very high fire risk cases can easily and simply be defined as any case using a source of openly flowing 100 percent oxygen. Consider fire risks before the start of any case that fits this description.
Other Special Cons
- Any airway case using greater than 30 percent oxygen.
- Any case involving surgery above the T6 dermatome, front or back.
- Any case above T6 dermatome involving an ignition source (for example, Bovie, laser, drill, or heating coil).
Patient Safety Recommendations
- Never use an open source of oxygen in greater than 30 percent concentration.
- If a concentration greater than 30 percent is required, consider using an enclosed airway circuit with a laryngeal mask airway (LMA) or endotracheal tube (ETT) for airway management.
- Use a fresh gas outlet port, attach a small ETT adaptor, attach tubing for nasal prongs or mask to the ETT adaptor, and mix air and O2 to produce a flow of less than 30 percent oxygen.
- Keep drapes open to the air in order to prevent oxygen accumulation within the drape pockets.