Pulmonary and Circulatory Function of the Reexpanded Pneumothorax Lung

Abstract

SUMMARY The reexpanded lung after pneumothorax was found to lose an average of 50 per cent of its vital capacity. If the collapse was not complicated by fibrothorax or empyema, it generally preserved its respiratory function. The loss of vital capacity was not compensated by the contralateral side as was oxygen uptake. The reexpanded lung is capable of considerable respiratory hyperfunction in case of disease or collapse in the contralateral side. In the rexpanded bilateral pneumothorax the loss of total vital capacity was about 50 per cent. In some cases increase of residual volume and hypoxemia due to distension emphysema was found. The main factor in the impairment of pulmonary function of the reexpanded pneumothorax lung is pulmonary pleurogenic fibrosis. Fibrothorax and empyema severely damage the pulmonary function, although in some cases respiratory function is partly preserved if the pleural fibrosis does not invade the interstitial spaces. The higher ventilatory equivalent in these group is evidence that oxygen consumption is damaged more than ventilation. The reduction of the respiratory function of the reexpanded pneumothorax lung is usually compensated for by increase in oxygen uptake of the contralateral lung, i.e., the compensation is achieved through the pulmonary artery system. Nevertheless pulmonary hypertension was found only in a few cases of long-standing bilateral collapse with effusion.