Canadian Journal of Anesthesia, Vol 12, 531-544, Copyright © 1965 by Canadian Anesthesiologists' Society

Alveolar Collapse Induced By Denitrogenation

¹ Department of Anaesthesia and Resuscitation, Hôtel-Dieu of Quebec, Quebec, P.Q.

1. Fifty-seven determination of functional residual capacity (FRC) were performed by the closed-circuit helium dilution technique in both conscious and anaesthetized subjects breathing 100 per cent oxygen. In all these subjects we demonstrated the occurrence of military atelectasis, as indicated by a decrease in FRC and arterial oxygen tension.

2. Thirty-seven determinations were repeated in subjects breathing a 50 per cent oxygen-50 per cent nitrogen mixture. In these instances, neither FRC nor arterial oxygen tension was found to undergo significant change.

3. The importance of denitrogenation and renitrogenation as related to anaesthesia is emphasized.

4. Our study suggests that the lung manifestations of hyperoxia might not be entirely related to the toxicity of oxygen itself, but to the lack of adequate nitrogenation.

Note:

Presented at the Annual Meeting of the Canadian Anaesthetists' Society, June 21–25, 1965