Craig W. Borden

Pulmonary hypertension in chronic pulmonary emphysema

Abstract 1.1. A significant elevation of pulmonary arterial diastolic pressure was found in twenty-four patients with chronic pulmonary emphysema. Systolic pressure was also elevated in the majority of these patients. Evidence is presented which indicates that pulmonary hypertension in emphysema is related to an increased vascular resistance in the lungs. 2.2. Marked respiratory variation is the outstanding characteristic of intravascular and intracardiac pressure records in patients with emphysema. This depends upon abnormally wide fluctuations in intrathoracic pressure. 3.3. There is no correlation between the degree of pulmonary hypertension and severity of the emphysema as estimated by the altered ratio of residual air to total lung volume. 4.4. Eight of the twenty-four patients with emphysema had definite evidence of right heart failure prior to study. The pulmonary arterial pressure was significantly higher and the oxygen saturation of the arterial blood was significantly lower in this group than in the group of sixteen patients with emphysema uncomplicated by right heart failure. 5.5. The mean arteriovenous oxygen difference in twenty-three patients with pulmonary emphysema was similar to that reported for normal subjects. No evidence was found to indicate that oxygen unsaturation of the arterial blood in emphysema induces an increase in the output of the heart.

A study of hypotension (shock) produced by meningococcus toxin.

Hemodynamic alterations were produced in dogs by injecting meningococcus toxin. Hypotension and a decrease in cardiac output occurred without significant reduction in blood volume. These changes were accentuated by small hemorrhage. Increasing the blood volume above normal led to marked increase in cardiac output with slight increase in arterial pressure. The arterial pressure was markedly increased by the administration of levarterenol but large doses were required. Cortisone did not modify the effect of meningococcus toxin on the circulation. Meningococcus toxin apparently produced its effect by increasing the volume of blood in small blood vessels.