“Just the Flu”

Scene

Attack One responds to a busy local foundry on a summer afternoon for a person “ill at work.” The crew is greeted by a supervisor at a large garage door, but is told the worker has been moved to the front offices. They walk through the plant area, noting several large, open garage doors and oversize racks of auto parts and paper packing materials.

Reminder to self: Let fire inspectors know about the fire load conditions in this building and the flammable packing materials.

In the office, the crew finds a worker vomiting and complaining of unusual fatigue. He has not been ill recently, and no one else in his household is ill. He ate lunch today, and has had plenty of fluids due to the warm weather. He has a mild headache, but no chest pain or other symptoms. He does not feel warm to the touch. He states that he feels too ill to drive home and requests removal to a nearby hospital.

As he’s being prepared for this, another worker enters the office, complaining of a headache and nausea and requesting to go home. A plant supervisor says, “Boy, three people with the flu in one day!” Your math skills have always been pretty good—was another person ill today?

“Yes, another worker was ill early in the afternoon,” you’re told. He was taken to the plant’s preferred occupational health clinic. In fact, he called just a few minutes ago to advise the supervisors that he “just had the flu” and was going home.

This changes your assessment. Your first thoughts are about toxic exposures, but the guard says, “Doors have been open all day, and we’ve had no material spills.”

This is not reassuring, and the crew requests a hazardous-materials response.

The patient is evaluated. No other injuries are found. His treatment includes oxygen by cannula, intravenous fluids and prochlorperazine, and placement in a position of comfort to prevent worsening the nausea. He is transported to the ED.

When the hazmat crew arrives, they initiate operations in the office area. They review the material safety data sheets for substances used at the company, and initiate a survey of the foundry work area. No material spills are evident, although closed solvent bins are scattered throughout the area. The ill workers happened to be in the same work area: between large overhead garage doors open for the entire day. There are no unusual odors or activity in the area. But as the crew finishes its surveillance, another worker in the area approaches them and says he’s feeling ill. He is taken to the office area, where the Attack One crew finds he has the same symptoms as the other ill workers. The hazmat crew takes their monitoring equipment into the work area and immediately finds the the carbon monoxide level to be significantly elevated. That information is relayed to the EMS providers in the front office. In light of this discovery, the patients are administered 100% oxygen, as well as IV fluids and antiemetic medication.

The hazmat crew begins working to identify the source of the CO and the extent of its spread. The machinery working in the area is all mechanical, but nearby workers (who are being evacuated) say a forklift had been working in the area for most of the afternoon. It is now working another area of the foundry. The initial work area shows a pocket of high carbon monoxide readings, while nearby areas are clear. When the crew follows the forklift to its current area, the readings rise again, especially around the vehicle’s exhaust. The forklift operator has gone for the day, but the floor supervisor says this propane-powered tool has recently been repaired.

The forklift is moved outside, and large fans are used to clear the air in the foundry before the workers are allowed to return.

Incident Management

The Attack One crew is now responsible for incident management—a step beyond victim management—and initiates a series of communications. They ask the foundry manager to account for each worker and contractor in the plant that day to ensure no one is lying unconscious somewhere at the worksite or on their way home. The hospital that received the first patient is notified and asked to obtain a carbon monoxide level on that patient. Within minutes blood is drawn and shows CO at 30%. The other two patients are headed to the same hospital, so the transport crews are advised and administer 100% oxygen by mask. This hospital has a set of hyperbaric chambers, so the Attack One crew discusses the incident with the emergency physician. They agree that all involved workers will be sent to this hospital, and the hospital will activate its multiple-victim incident plan and notify the hyperbaric oxygen staff. The worker seen at the occupational clinic and the forklift operator are contacted and advised to go to the same ED.

The occupational clinic is also notified of the incident and the likely cause of the symptoms in the person they saw. Staff there is also asked if any other patients from this company have been seen for the day. None have.

The plant management performs a complete accounting of personnel and discovers three additional persons who had worked in the area before going home. All are located (one, who had no phone, with the assistance of the police department) and sent to the ED.

The transporting medic crews stay with the patients until their carbon monoxide levels are tested. All results are significantly elevated (above 20%). All patients are kept on high-flow oxygen until they’re placed sequentially in the hyperbaric oxygen chambers. While at the hospital, the transport crews maintain radio contact with the Attack One crew. As the other workers are identified at the foundry office, their names are given to the ED greeting staff and emergency physician, so that upon their arrival at the ED, they can be expedited into care and lined up for hyperbaric treatment. One medic crew remains at the ED until all eight victims arrive and are processed into care. The other victims all had similar symptoms, but had attributed them to the warm conditions in the foundry.

Finally, the Attack One crew members tour the plant with the hazardous-materials team. The forklift had been working in the corner of the foundry area, between the two doors. There was little wind that afternoon, and the still air must have allowed the carbon monoxide to collect in the area between the openings, exposing the victims as they worked. After positive-pressure ventilation, all area readings drop to zero.

Hospital

The victims are treated in hyperbaric oxygen chambers and recover without complication. The first two workers (the one who left and went to the clinic and the first patient treated by Attack One) have the highest CO levels and are admitted to the hospital for fluids and repeat hyperbaric therapy. All the foundry workers receive follow-ups from the occupational health clinic (staff there were grateful to have been included in the information loop) and return to work.

Summary/Discussion

The victims all had carbon monoxide levels above 20%. This means that at least 20% of the patients’ hemoglobin was bound with carbon monoxide, not oxygen. Pulse oximetry is misleading in carbon monoxide poisoning, as oximetry measurements omit hemoglobin molecules bound with carbon monoxide.

All patients in this incident had classic symptoms of carbon monoxide poisoning, including headache, nausea, lightheadedness and fatigue. These symptoms match those of many viral syndromes. Carbon monoxide is odorless and colorless, and these workers were exposed due to a malfunctioning propane-powered machine. Propane exhaust is less noticeable than gasoline or diesel exhaust, and therefore gave less indication to the workers that a toxic exposure was occurring.

Carbon monoxide poisoning frequently occurs in groups of people (e.g., families, coworkers, those at recreational events). It is critical for emergency crews to find all potential and actual victims, accurately find the cause and area of risk, and mitigate the circumstance creating the carbon monoxide. In this incident, it was critical to identify all persons at risk, find them and have them seek care. The source of the toxin was identified, all potentially involved persons were evacuated, and the environment was cleared before the building was returned to use.

A high level of suspicion serves the emergency worker well when multiple patient incidents occur at a worksite. Common toxins should stay high on the list of potential agents, and carbon monoxide is a very common and toxic substance. Even in warm weather and with doors open at the worksite, a life-threatening concentration of the gas was present in this incident.

Once carbon monoxide is identified as the toxin, a methodical and comprehensive approach to locating and eliminating the source is mandatory.