[A case of pulmonary embolism following acute respiratory failure with hypercapnia]

A 18-year-old boy was admitted to hospital in an unconsciousness state as a result of taking a large dose of several psychotropic drugs simultaneously in an attempt to commit suicide. Blood studies revealed hypoxia (55.7 mmHg) and hypercapnia (59.7 mmHg). Hypoxia (74.3 mmHg) and hypercapnia (46.7 mmHg) were still present on the fourth day after admission, and the patient was becoming lethargic. Reduced vascular markings in the right upper lung field on chest roentgenogram in spite of hypercapnia suggested that the persistent hypoxia was the result of a pulmonary embolism. This diagnosis was supported by a perfusion defect on 99mTc-MAA scintigram and arterial obstruction in right pulmonary angiogram. Hypercapnia is an unusual finding in pulmonary embolism, and in this case was considered due to depression of respiration by psychotropic drugs.