The accuracy of venturi masks at altitude.

The concentration of oxygen provided in the inspired gas by five samples of a venturi mask were measured at ground level and at altitudes up to 10,000 ft for each of the oxygen port settings from 24-50% oxygen. The concentration of oxygen provided at a given setting was virtually identical for each of the five masks and was unaffected by ascent to 10,000 ft. Thus, patients with chronic hypercarbia could receive "low flow oxygen therapy" while traveling on commercial airlines without danger of acute hypo-ventilation by utilizing a venturi mask.