Fatal pulmonary thromboembolism associated with excessive nitrous oxide consumption over several weeks.

A man in his early twenties had been hospitalized due to acute nitrous oxide intoxication, during which a vitamin B12 deficiency and anaemia were also diagnosed. Two weeks later he was found dead in his apartment. Twenty empty nitrous oxide cartridges were found next to the body, and according to his mother, he had been using nitrous oxide excessively for approximately two months. The autopsy revealed a fatal pulmonary embolism secondary to deep vein thrombosis, and toxicological analysis detected nitrous oxide in low concentrations in the blood. Regarding the pulmonary embolism, a coagulation disorder attributable to suspected hyperhomocysteinemia in the setting of vitamin B12 deficiency could be considered a contributory factor - this deficiency, in turn, may possibly be related to excessive nitrous oxide consumption over several weeks. Obesity and nicotine abuse were present as additional risk factors for thromboembolic events. Reapeted excessive nitrous oxide consumption can induce profound metabolic disturbances, including functional vitamin B12 deficiency and associated biochemical derangements. In cases of fatal thromboembolic events in young individuals, this possibility should be taken into account. Toxicological analysis may demonstrate recent nitrous oxide exposure and support the hypothesis, but it cannot establish the underlying biochemical pathology.