Changes in the Respiratory Gas Tensions of a Pneumonectomy Space and their Application to the Diagnosis of Bronchopleural Fistula

Summary

The oxygen (pO₂) and carbon dioxide (pCO₂) gas tensions of a pneumonectomy space were studied in an animal model. The 2 gases were measured in a Standard blood gas analyser. The space gas pO₂ and pCO₂ equilibrated to a steady State within 48 hours of thoracotomy (pO₂ mean 53.9 ± 9.3 SD torr; pCO₂ mean 44.8 ± 9.9 SD torr). In the presence of a bronchopleural fistula (BPF), the pO₂ rose significantly (mean pO₂ 118.4 ± 13.2 SD torr; p < 0.001). The space pCO₂ usually feil, but the response was inconsistent (mean pCO₂ 33.6 ± 16.4 SD; p = HS). A further rise in space pO₂ could sometimes be induced by allowing the animals to breathe 100% oxygen by face mask. Data from 4 clinical cases of BPF support the concept that measurement of the space gas pO₂ could be used as a bedside test for BPF.

Key words

Pneumonectomy - Bronchopleural fistula