Influence of Added Dead Space on Pulmonary Ventilation.

Summary. Hyperventilation due to extra dead space did not cause any significant improvement in ventilatory efficiency as measured in nitrogen wash‐out experiments during oxygen breathing. In the experiments with extra dead space a significant increase in degree of uniformity of ventilation could be demonstrated. The subject's dead space increased, and the over‐all efficiency remained constant. The efficiency‐improving effect of a better distribution and the efficiency‐deteriorating effect of a larger dead space probably cancelled out. The better distribution is most probably explained by the effect of mixing of gas from different lung fractions in the large dead space. The experiments were performed with a nitrogen meter.