急性肺炎患者の呼吸・循環機能

Abstract

Respiratory and circulatory function tests were done on three patients with severe acute pneumonia at the height of the disease. The course of the disease was followed with these tests. From the results obtained, the occurrence of hypoxemia and electrocardiographic changes were studied.1) Pulmonary function disturbance During the height of the disease, the changes found in the pulmonary function were a decrease in lung capacity and increases in the minute ventilatory volume and oxygen consumption. The blood gas analysis during this stage showed a marked decrease in the arterial blood oxygen saturation and partial pressure with a tendency of an increase in the arterial carbon dioxide partial pressure. No remarkable difference was found in the ventilatory function distubance between a case of bronchopneumonia with widely spread pathology on X-ray and a case of lobar pneumonia with the damage limited to one lobe, but the disturbance in the blood gas was stronger in the case of bronchopneumonia.2) Electrocardiographic changes The cases of lobar pneumonia with lowered arterial blood pressure showed only low T but the two cases of bronchopneumonia had low T and marked ST depression. Sinus tachycardia was seen in all cases.3) The cause of decreased arterial blood oxygen saturation Although it is commonly thought that there should be an increase in the ineffective pulmonary blood flow in such conditions as in the present cases, it was made clear that the decrease of alveolar air oxygen partial pressure and the disturbance of alveolar diffusion are the main factors which cause the decrease in the arterial blood oxygen saturation.4) The cause of the electrocardiographic changes By referring to the results obtained by coronary catheterization studies done in our medical department, it can be considered that the cause for the electrocardiographic changes in pneumonia is a decrease in the cardiac oxygen consumption while the cardiac work increases. And, it was made clear that, although the electrocardiographic findings may be minimal especially when the arterl blood pressure is low at the same time, the state of the patient should be estimated carefully by considering the results of various other tests.