[Severe bronchospasm induced by extracorporeal circulation for cardiac surgery]

Cardiac surgery was performed on a 50-yr-old man suffering from mitral valve stenosis. He has no history of allergic disease or bronchial asthma. Mitral valve was replaced uneventfully under extracorporeal circulation, and ventilation with pure oxygen was tried. But the lung was so stiff that the bag of anesthetic circuit could not be squeezed by hand. Fiberoptic bronchoscopy revealed no obstruction in endotracheal tube or bronchial tree. A presumptive diagnosis of severe bronchospasm was made, and partial extracorporeal circulation was maintained. Soon after aggressive bronchodilator therapy, there was noticeable improvement in pulmonary compliance, and the patient was removed from bypass uneventfully. No further recurrence of bronchospasm was seen in the intra- or postoperative period. Although the exact causes for bronchospasm in our case are not clear, we concluded that severe bronchospasm was induced by extracorporeal circulation. Possible etiologies and the management of patients with this problem are reviewed.