[Pulmonary thromboembolism that developed during an airplane flight "economy-class syndrome"]

The occurrence of thromboembolic phenomena during long-duration airplane flights is called "economy-class syndrome". Recently it has become more popular for Japanese to go abroad by airplane, and an increase in the prevalence of pulmonary thromboembolism should be expected. However, there are few reports of the economy-class syndrome in Japan. A 52-year-old woman was admitted to our hospital because of chest discomfort and dyspnea that developed during an airplane flight. We suspected pulmonary thromboembolism, on the basis of a chest X-ray film and on electrocardiogram. A ventilation-perfusion lung scan disclosed mismatching between ventilation and perfusion in the right upper lung field. Pulmonary thromboembolism was confirmed by pulmonary arteriography. The patient was treated with heparin and urokinase. A phlebogram of the legs showed no significant findings. There was no history of thromboembolic disease or of consumption of oral contraceptives. We conclude that the pulmonary thromboembolism might have been caused by stasis of blood in the lower limb veins during the airplane flight. We emphasize the importance of including pulmonary thromboembolism in the differential diagnosis of patients with chest discomfort and dyspnea that develop during airplane flights. No noninvasive test can lead to a definitive diagnosis of pulmonary thromboembolism. Early pulmonary angiography should be recommended when pulmonary thromboembolism is suspected.