Case
An 84-year-old woman with a history of hypertension and dyslipidemia and her husband, an 88-year-old man with a history of dementia and coronary artery disease, presented to the ED via EMS after neighbors discovered the woman lying on her living room floor, responding only to painful stimuli. Earlier in the evening, the same neighbors had helped the husband to bed after noticing that he had become lethargic. The EMS report indicated that a car had been left running in a closed garage of the patients’ home. The fire department identified an ambient carbon monoxide (CO) concentration of 88 ppm.
Upon arrival to the ED, the woman’s vital signs were: blood pressure (BP), 130/74 mm Hg; heart rate (HR), 63 beats/minute; respiratory rate (RR), 16 breaths/minute; temperature, 99°F. Oxygen saturation was 99% on room air. Her husband’s vital signs were: BP, 150/66 mm Hg; HR, 59 beats/minute; RR, 19 breaths/minute; temperature, 98°F; oxygen saturation was 98% on room air.
What is carbon monoxide poisoning?
Carbon monoxide is a colorless and odorless toxic gas produced by incomplete combustion of carbon-based fuel. Common sources in the United States include portable generators, gas-powered furnaces, cooking appliances, poorly ventilated home-heating systems, and motor vehicles (Box 1).1
Carbon monoxide is the leading cause of unintentional poisoning deaths in the United States,1 resulting in more than 20,000 ED visits and 2,000 hospital admissions. Nearly three-fourths of these deaths are due to exposures in the home, with more than half occurring during the months of November through February.2,3 The average cost of a hospital admission for confirmed CO poisoning is over $11,000, with a cumulative nationwide total cost of over $26 million per year. While the hospitalization rate for persons aged 18 to 44 years is only 6.7%, the admittance rates for persons aged 65 to 84 years and older than 85 years are 33% and 43%, respectively.3 Although there has been a slight decline in the incidence of CO poisoning over the past 10 years, it is still a public health concern (Figure 1).2
