Arterial Oxygen Tensions Attained in Normal Subjects Breathing Oxygen through Various Devices

Abstract

Twelve normal subjects were studied to record arterial oxygen tensions achieved during oxygen breathing via simple masks, rebreathing masks, aerosol masks in 40, 70, and 100 per cent oxygen modes, and nasal cannulas. The nasal cannula gave a mean ${\text{Pa}}_{{\text{O}}_{\text{2}}}$ of 142 mm Hg, the simple mask a mean ${\text{Pa}}_{{\text{O}}_{\text{2}}}$ of 166 mm Hg, and the partial rebreather mask a mean ${\text{Pa}}_{{\text{O}}_{\text{2}}}$ of 270 mm Hg. The aerosol mask at the 40 per cent oxygen setting produced a mean ${\text{Pa}}_{{\text{O}}_{\text{2}}}$ of 218 mm Hg, while the 70 per cent oxygen setting yielded a ${\text{Pa}}_{{\text{O}}_{\text{2}}}$ of 261 mm Hg, and at the 100 per cent oxygen setting the ${\text{Pa}}_{{\text{O}}_{\text{2}}}$ was 265 mm Hg. Females achieved higher blood values than males for given devices. Results for most devices were not surprising when compared to previous reports, but the aerosol mask data had not previously been reported. These results cannot necessarily be projected to diseased persons who receive oxygen, but they show once again that arterial blood oxygen analysis is important in guiding oxygen therapy.