A case of extreme carboxyhaemoglominemia due to vaping.

Acute carbon monoxide (CO) poisoning is known to cause neurological, metabolic and cardiorespiratory sequalae. However, data on chronic CO exposure are scant, particularly in the context of vaping, which recent literature suggests may be a greater source of CO than tobacco cigarette smoking. During a series of admissions at the time of vaping, our patient repeatedly presented with significant CO poisoning and developed pulmonary arterial hypertension with resultant high-output right heart failure. On each occasion, our patient's levels of carboxyhaemoglobin were both higher and took longer to resolve than 12 smokers who underwent arterial blood gas testing at two time points. Our observation may reveal an association between vaping, chronic carboxyhaemoglobinemia and the development of cardiorespiratory disease. Thus, further studies into the safety of vaping and chronic CO exposure are urged.