Relation of oxygen delivery, mixed venous oxygenation, and pulmonary hemodynamics to prognosis in chronic obstructive pulmonary disease

Abstract

We studied the relation of oxygen delivery, mixed venous oxygenation, and pulmonary hemodynamics to prognosis in 50 randomly selected patients with chronic obstructive pulmonary disease. Cardiac catheterization was performed when the patients were clinically stable. Four years later, 27 patients (54 per cent) had died of respiratory failure. At the time of catheterization, patients who subsequently lived were similar to those who died in age, physical characteristics, and hematocrit. Nonsurvivors had significantly lower arterial and mixed venous oxygen tension and significantly higher arterial and mixed venous carbon dioxide tension. The mean pulmonary arterial pressure, pulmonary arteriolar resistance, right ventricular work, coefficient of oxygen delivery, and cardiac index did not differ between the two groups. After inhalation of 100 per cent oxygen for one hour, the mixed venous oxygen tension of nonsurvivors rose to a level equivalent to that of survivors, and their mean pulmonary arterial pressure fell significantly. These results indicate that, with respect to oxygen supply to the tissues, mixed venous oxygenation is one of the important prognostic factors in chronic obstructive pulmonary disease. Pulmonary and right ventricular hemodynamics measured during periods of clinical stability do not differentiate nonsurvivors from survivors.