[The effectiveness of the gas-exchange function of the lungs in diffuse peritonitis]

Using a Douglas-Holden open system, gas exchange disturbances were studied and the role of gas exchange parameters in determination of gas exchange lung function was assessed in 39 patients with generalized peritonitis (GP). It has been established that in patients with GP the postoperative period is characterized by marked disturbances in ventilation/perfusion ratio (VA/QT) of the lungs. Thus, the level of arterial hypoxemia is determined both by impaired VA/QT and increased intrapulmonary shunting and by postoperative changes in the cardiac output. Consequently, arterial blood pO2 cannot serve as an absolutely objective index of the degree of gas exchange in the lungs. Alveolar-arterial difference in pO2 with 100% O2 inhalation [D(A-a)O2] will be a more accurate assessment of gas exchange in the lungs in patients with GP, as it takes into consideration the hemodynamic status. The criterion of gas exchange efficacy is [D(A-a)O2] value not exceeding 350 mmHg, with greater values being the indications for the earlier use of controlled lung ventilation.