CHRONIC CO POISONING IN FIREFIGHTERS

BY KEVIN REILLY

“If you were able to choose the kind of brain injury you were to incur, it would be better in terms of the potential for recovery to have a stroke or a concussion in a motor vehicle accident than carbon monoxide poisoning.”-Dr. David George Penney, Ph.D., professor of physiology and adjunct professor of occupational and environmental health, Wayne State University, Detroit, Michigan

As an occupation, firefight>ing carries an extremely high exposure rate to carbon monoxide (CO), from overhaul operations to response to routine CO calls. The diligence that we firefighters routinely practice during fire suppression operations seems to fall short as soon as the flames are extinguished. As with any hazardous environment, in an area in which higher than normal CO levels are suspected, it should be standard practice during overhaul to have a multigas meter in place monitoring the atmosphere and for masks to remain on until the area CO readings fall within acceptable levels (photo 1).

Photo by James Stacy

Routine CO calls present other problems. The need to monitor symptoms of firefighters is just as important as monitoring symptoms of exposed victims. As we know, time and parts per million (ppm) exposure are key components of exposure analysis and investigation. If firefighters are repeatedly responding to CO calls, we should be keeping track of firefighters’ time and level of exposure.

Winter holidays like Thanksgiving and Christmas are the most likely times for CO calls at residences. “A properly functioning gas stove can give off as little as 35 ppm or as much as 400 ppm of CO before reaching operating temperature. A gas oven can give off as much as 800 ppm before coming up to temperature.”1

Another factor that may contribute to elevated CO calls includes the increase of fuel prices. When fuel prices increase, people tend to look for alternative sources of heat, some of which most may not be familiar with, such as wood- or coal-burning stoves and fireplaces. In one tragic story, a group of skiers died when they decided to do some laundry at their vacation house. While relaxing beside a fire they had built in their fireplace, one of them decided it would be a good time to do some laundry. The dryer, as it turned out, created a negative pressure in the house, so when the fire died down to a smoldering stage, it caused a reverse draft, killing three and permanently injuring two.

Smokers are another special category of interest. Smokers, on average, have constant levels of between three- and 13-percent blood COHb (carboxyhemoglobin, the measurable saturation of carbon monoxide in blood hemoglobin) levels. One typical scene after a fire (I call it the Marlboro Man syndrome) is of firefighters having a cigarette as a sort of ritual. Firefighters who smoke should be aware of this disadvantage when they consider prematurely removing their SCBA masks during overhaul operations. More than 45 percent of annual firefighter line-of-duty deaths are caused by heart attacks. CO toxicity in blood creates extremely stressful conditions for the heart. It essentially makes the heart pump the oxygen-deficient blood faster, while depriving the heart muscle of the oxygen needed to perform properly, potentially initiating a heart attack. COHb percentage levels as low as four percent on a consistent basis (average light smoker, typically fewer than 20 cigarettes a day) can cause permanent heart and brain damage.

Although there are many contributing factors for heart disease, CO poisoning could effectively push some high-risk firefighters “in front of the train” and be virtually undetected. I interviewed several doctors for this article and asked if a COHb test is routinely performed on heart attack victims. It is not.

SYMPTOMS

There is no rule of thumb in detecting CO exposure in a victim with symptoms of CO poisoning. The symptoms are many and varied, and such exposure affects everyone differently (Figure 1). “It has been reported by the Maryland Institute for Emergency Medical Services that its hyperbaric facility has received patients with blood carbon monoxide levels of less than 5 percent who were comatose. The same facility has admitted patients with blood CO levels of 50 percent who were both ambulatory and could speak.” (1, 176)

The currently accepted IDLH (immediately dangerous to life and health) level for CO exposure is 1,200 ppm at 30 minutes. This ratio is assumed for a healthy, resting nonsmoker who has a resting number of respirations.

The CO IDLH of 1,200 ppm should be considerably lower for a firefighter wearing 35 to 40 pounds of gear with elevated respirations.

At a Fire Department Instructors Conference I attended, I spoke to a firefighter about the arterial blood gas test he had endured several years ago. He said that it was one of the most painful things he had ever experienced. In addition to having to have his rolling artery penetrated by a needle, apparently the nurse who performed the procedure needed to puncture his arm four times before she was successful. This now-retired captain said that if it were up to him, all firefighters would be required to go through that painful test so they would think twice before removing their SCBA masks during overhaul.

THE COBTM ANALYZER

However, according to Dr. Penney, “Venous will be as good as arterial blood, and it’s a lot less painful. Also, breathalyzer equipment can be used to determine blood COHb level with great accuracy. This test does not require blood to be drawn.” One such device is the COBTM carbon monoxide breath-analyzer device made specifically for field use. From Firefighter Safety Products, the COB takes away the guesswork when assessing a patient’s symptoms on CO calls or monitoring firefighters after operations (photos 2, 3).

Photo by Marian Reilly

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Photo by Nancy Ricci

The COB monitor is used in the emergency room as a breath test for CO poisoning. When a patient is admitted to the emergency room in a dazed, incoherent, or unconscious state, this device is used to perform an immediate, noninvasive carbon monoxide test. The CO breath test will give the same results as a COHb blood test, and the device gives immediate results of CO poisoning from a single exhaled breath from the patient, without the wait for lab results. The COB was recently used in an ongoing smoke inhalation study by Yale University.

A CO test is an essential component of an emergency department test for CO poisoning. The COB monitor is an important tool in diagnosing CO levels in the blood as a result of smoke inhalation, faulty furnaces, or any other type of environmental CO poisoning. The COB device is a simple screening for carbon monoxide testing. With its single switch operation and automatic zero calibration, it instantly provides the ER physician with an indication of the level of carbon monoxide poisoning in the blood.

Major concerns that firefighters should be aware of are the short-term and long-term effects of chronic exposure to CO. It is incorrect to think that once the body has “vented” CO that one is in the clear. In fact, small-dose exposures over time cause permanent damage to both heart and brain. The heart needs to work twice as hard to pump the oxygen-lacking blood to vital organs; therefore, since the heart needs oxygen for fuel, it effectively double taxes the heart muscle and potentially initiates a heart attack.

Unfortunately, CO exposure is unavoidable in some cases, and there are no absolute standards set for individuals because exposure to CO affects everyone differently. What firefighters can do is be aware of their symptoms and, when exposed to CO, pay attention if they “don’t feel right.” They need to get checked out.

More than 45 percent of firefighter line-of-duty deaths are attributed to heart attacks. Naturally, there are several factors involved in these deaths, but some may be avoidable by lifestyle changes and more diligent safety measures in the line-of-duty and screening methods available today. What we don’t know can hurt us.

Author’s note: This article is dedicated to the memory of a fallen firefighter, Captain Dominick Buscio [Jersey City (NJ) FD], an apparently healthy 39-year-old who died of a heart attack. The results of a complete physical Buscio had had only 19 months before his death were normal, except for the presence of a moderately high cholesterol level. Since he was found to be healthy at that time, he decided not to return for his annual physical the following year. Although many people his age make the same decision not to seek regular checkups, in this case, the result was tragic.

Endnote

1. Montagna, Frank C., Responding to “Routine” Emergencies, Fire Engineering Books & Videos, 1999, 184.

KEVIN REILLY is a firefighter with the Ridgewood (NJ) Fire Department; a member of the Fire Safety Directors Association of New York City (FSDNY); an Emergency Action Plan (EAP) high-rise consultant for Diversified Security Solutions, Inc., in New York City; and founder of Firefighter Safety Products, LLC.