A curious autopsy case of accidental carbon monoxide poisoning in a motor vehicle

A 26-year-old man was found dead in his car. All doors and windows were locked inside. The ignition key was in the "on" position; but the engine was not running and the fuel tank was empty. His post-mortem lividity was cherry-pink, and marked congestion was observed in the lungs and brain macroscopically. Massive intracardiac blood containing a small amount of cruor was found in the heart. In histological examination of the heart, partial disarrangement or necrosis was found in the myocardium. The liver cells showed derangement and degenerative changes, with focal lymphocyte infiltration in the portal regions, although they were not severe. The chemical tests showed that the blood concentration of carboxyhemoglobin was 46.6%. Stimulants were also detected from his blood and urine; the concentrations of methamphetamine and amphetamine were 3.25 and 0.84 microg/ml, respectively, for his cardiac blood. Therefore, it seemed reasonable to judge that the cause of his death was carbon monoxide poisoning; the cardiomyopathy and the presence of stimulants in blood might facilitate his death. Upon careful investigation of his car, it was disclosed that exhaust gas, leaked from small holes of the exhaust pipe due to rust-through, invaded the interior through four holes on the floor of the car during parking with the engine being on for the purpose of air-conditioning of the interior. It is very common to commit suicide by introducing exhaust gas into an interior of a closed motor car, but the present accidental case of carbon monoxide poisoning in a car seems rare and worthwhile reporting.