Carbon dioxide is a colorless, odorless, nonirritating gas that has many practical uses, including as a fire extinguisher because of its ability to displace oxygen from the incendiary environment. High environmental concentrations of carbon dioxide may cause severe and even fatal poisoning in industrial (ice-making factories), occupational or recreational (diving) settings.
Although clinical reports of unintentional mass exposure to extreme concentrations of carbon dioxide are rare, a group of physicians in Israel recently reported an industrial incident that exposed a group of workers to extremely high concentrations of carbon dioxide in an ice-making factory when the discharge valve of a truck containing liquid carbon dioxide was knocked open in an enclosed environment.1 Within seconds, many of the exposed workers were incapacitated.
Twenty-five patients, including two rescue personnel who responded to the scene, were transported to an emergency department with symptoms that included dyspnea, cough, dizziness, chest pain and headache. ECGs revealed ST-segment changes in two patients, atrial fibrillation in two and non-Q wave myocardial infarction in one patient. Three patients had lost consciousness at the scene and one was observed having convulsions. Five patients had tachycardia of more than 100 beats/minute on arrival at the ED. Eleven patients were admitted to the hospital; eight were discharged 24 hours later and the others within eight days. No patients died. According to the report, swift evacuation by coworkers before the medical team arrived undoubtedly reduced the amount of exposure to carbon dioxide. Exposure of unprotected rescue teams, however, resulted in intoxication of two paramedics.
The most important action in carbon dioxide intoxication, say the authors, is removing victims from the exposed environment and providing cardiorespiratory function support until spontaneous recovery occurs. To prevent injury to themselves, it is essential for rescue personnel to protect their airways with positive pressure respirators, since filtration masks are not effective against carbon dioxide.
1. Halpern P, Raskin Y, Sorkine P, Oganezov A. Ann Emerg Med 43(2):196–199, 2004.