Carboxyhaemoglobin can be measured with standard blood tests

EDITOR—In their editorial about carbon monoxide poisoning, Walker and Hay note that it is tissue poisoning rather than merely the effects of carboxyhaemoglobin that contributes to its toxicity.1 We recently reported that metabolic acidosis was a better indicator of the severity of poisoning than carboxyhaemoglobin,2 as the acidosis reflects tissue poisoning.

Walker and Hay concentrate on cerebral toxicity. The heart, however, as the next most vulnerable organ may help to give a clue to the diagnosis. We reviewed 139 electrocardiograms from patients with acute severe carbon monoxide poisoning who had been referred for treatment with hyperbaric oxygen, and we found that 41% were abnormal (unpublished data). Previously, 3% of patients presenting …