Effect of Diffusion Respiration on Duration of Vagal Cardiac Arrest

Abstract

Conclusions

1. Sodium pentobarbital decreases the effect of vagal stimulation on the heart. Hence it is of considerable importance in experiments of this nature to maintain a constant level of barbiturate anesthesia in any one animal. 2. Progressive hypercapnia produced by diffusion respiration causes the duration of vagal cardiac arrest to increase progressively. This increase is very modest with decreases in arterial pH of the magnitude which could be expected in surgical procedures, but becomes especially marked at low pH levels. 3. The probable role of hypercapnia in surgical cardiac arrest is discussed.