Anthony Del Zotto, DO, Charleston Area Medical Center and Jaryd Zummer, MD , University of Kentucky
Better late than never. It is still winter, and we are all trying to stay warm inside while awaiting warmer days to arrive! We thought this would be a fitting time to review CO toxicity, with some pearls and management tips.
Carbon monoxide (CO) is the true “silent” killer. A major contributor to indoor fire-related incidents, it is responsible for up to 500 deaths per year in the US and has both significant short and long-term morbidity. This colorless, tasteless, and odorless gas is formed via the incomplete combustion of carbon-containing fuels. Most common implicated devices include furnaces, fireplaces, space heaters, stoves, and automobile or boats, especially in poorly ventilated areas or with faulty or blocked exhaust systems. Hemoglobin’s affinity for CO is approximately 200-250 times stronger than that of oxygen. When hemoglobin binds CO to form carboxyhemoglobin, it effectively reduces hemoglobin’s O2 carrying capacity (leftward shift of the oxyhemoglobin dissociation curve) and delivery of O2 to vital tissues. This tissue hypoxia not only causes a shift to anaerobic metabolism and consequently lactate production, but also increases cerebral blood flow and capillary permeability to cause cerebral edema in the most severe cases.