Effects of Oxygen Therapy on Patients with Congestive Heart Failure

Abstract

The effects of living for 2 to 5 weeks in an atmosphere containing 40 to 50% oxygen were studied in 5 patients with cardiac insufficiency. The Barach oxygen chamber, with constant temperature and humidity regulation, was used. Studies were made (a) with the patients in the ward, both before and after residence in the oxygen chamber; (b) with the patients in the oxygen chamber with normal (21%) atmospheric oxygen content; and (c) with the patients in the oxygen chamber with 40 to 50% of oxygen in the atmosphere. All other procedures, such as diet, fluid intake and the dosage of drugs, were kept sufficiently constant so that they did not modify the results. The usual clinical observations were recorded and in addition, measurements were made of the basal metabolic rate, pulmonary ventilation, vital capacity, arterial oxygen content, arterial CO₂ content, and the CO₂ dissociation curves of the arterial blood. From the latter were calculated the arterial oxygen saturation, arterial CO₂ tension and the arterial serum pH.

In one patient with mitral stenosis of long standing, great cardiac enlargement and marked chronic passive congestion but no peripheral edema, very little change occurred after a week in 45% oxygen. There was only a slight rise in the level of the CO₂ curve while he was in the chamber. No clinical improvement was noted.

Two patients with chronic valvular heart disease, marked decompensation and edema, together with fever and other evidences of active rheumatic infection, showed moderate subjective improvement. In these individuals, residence for 2 weeks in 45% oxygen was associated with a considerable rise in both the arterial CO₂ content and the level of the CO₂ curve. In one case, there was a rise in arterial oxygen saturation from 84 to 93%.