Oxygen turnover rate in the venous reservoir.

In a study of the oxygen stores of the body anaesthetized paralyzed dogs were hyperventilated (Pa<x), = 15 mm Hg) for 2 hours. During the final 30 minutes the inspired mixture was altered from oxygen to air. The rates at which alveolar and arterial oxygen concentrations approached their new steady-state values were represented by the halftimes (t£) 0.17 and 0.23 minutes respectively. The turnover rate in venous blood oxygen content proceeded at a considerably slower rate, t i=0.75 minutes. The data presented here will be useful in constructing models to predict changes in body oxygen content during anaesthesia with controlled breathing and hyperventilation.