QUANTITATIVE STUDIES OF COUGH STRENGTH IN POST-THORACOTOMY PATIENTS

Abstract

The author measured intrapleural pressure and pulmonary arterial wedge pressure simultaneously during quiet breathing and coughing in 10 post-thoracotomy patients by using a balloon-tipped catheter in the pleural space of the thoracotomy side and a Swan-Ganz flow-directed catheter in the ipsilateral or contralateral pulmonary artery. It was found that the pul-monary arterial wedge pressure during quiet breathing and coughing closely reflects the intrapleural pressure, and that the peak value of the pulmonary arterial wedge pressure at coughing reduced by the mean wedge pressure value during quiet breathing represents the intrapleural peak pressure. Therefore, it was considered that the pulmonary arterial wedge pressure tracing might be an acceptable alternative to the intrapleural balloon method or intra-esophageal balloon method for measuring intrapleural cough pressure. In the post-thoracotomy patients, the markedly decreased amplitude and peak value of the intrapleural pressure of the thoracotomy side compared to those of the non-thoracotomy side would seem to demonstrate the inefficiency of sputum expectoration from the tracheobronchial tree of the thoracotomy side.