Duchatelet C, et al. - During cardiopulmonary resuscitation, once the patient is intubated, chest compressions in the inspiratory phase may force air out of the lungs, causing so-called “reversed airflow”, which may result in ineffective ventilation. Researchers aimed to determine the occurrence of this phenomenon and to quantify the volume of reversed airflow. In intubated patients, chest compressions during ventilation generated reversed airflow in most patients. A wide variation was noted in the number of episodes and volume of the reversed airflow between patients. The mean volume of the reversed airflow was 96 ml per episode.