The early period of experimental Mendelson's syndrome in dogs with PaCO2 and pH in a normal range.

In 9 dogs the first 240 min of experimental Mendelson's syndrome were studied. To minimise hemodynamic alterations, the PaCO2 and pH were kept within the normal range. An increase in pulmonary artery pressure, Qs/Qt and a decrease in PaO2 were demonstrated. Diminution of heart rate and cardiac index were associated with the decrease of systemic oxygen transport. The first 30 min appeared as a para-sympathetic syndrome, the remainder of the experiment as a hypovolemic syndrome. Severe hypoxia was observed during the two periods.