Changes in pneumonectomy-space gas tensions.

The development of a simple and reliable method for measurement of the partial pressures of the atmospheric gases offers the possibility of both basic and clinical examination of the air in natural as well as pathological or iatrogenic cavities. From measurements in nine patients a plot of the changes in pO2 and pCO2 in the pneumonectomy space from the end of the thoracotomy to the establishment of equilibrium with the blood gases was made. pCO2 equilibrated faster than pO2 (6- and 50 h respectively). The equilibrium difference between arterial pO2 and pneumonectomy space pO2 was 6.5 kPa (2.5-12.3 kPa) and we propose that measuring this difference may be a sensitive method for the diagnosis of bronchopleural fistula. During the study period one of the patients developed a bronchopleural fistula. The suspicion was based on X-ray findings and was supported by gas analysis from the pneumonectomy space, and conclusively confirmed by bronchoscopy.