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James F. Morris, MD; William E. Robertson, MD; Frederick L. Glauser, MD

JAMA. 1970;211(5):802-806.

Abstract
Two hand-held respirators of differing types were evaluated in 15 patients with moderate or severe chronic obstructive pulmonary disease. One device is a manually operated venturi system and the other has an automatically cycled fluidic valve. After 20 minutes of intermittent positive pressure breathing, the group using compressed air had an average decrease of 4 mm Hg of arterial carbon dioxide pressure (Paco₂) with each respirator. This indicates a substantial increase in tidal volumes in view of an approximately 50% decrease in breathing rates. Breathing oxygen-enriched air, one of five patients had a significant increase in Paco₂, the others showing little change. Arterial pH changes corresponded to those of Paco₂. With compressed air, arterial oxygen pressure (Pao₂) did not significantly change. With oxygen-enriched air, maximum Pao₂ values were 285 mm Hg with the manual venturi system, and 195 mm Hg with the fluidic valve. No adverse effects upon heart rate and blood pressure were found.

Author Affiliations
From the University of Oregon Medical School, Portland (Dr. Morris), and Veterans Administration Hospital, Portland, Ore, (Drs. Morris, Robertson, and Glauser). Dr. Robertson is now with the Valley Medical Clinic, Portland, Ore, and Dr. Glauser is now with the University of Pittsburgh Medical School Hospital.

Footnotes
Reprint requests to Veterans Administration Hospital, Sam Jackson Park, Portland, Ore 97207 (Dr. Morris).

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