How is effective rescue breathing assessed during CPR?

Effective rescue breathing during CPR is assessed primarily by observing the rise and fall of the chest. This occurs because when a breath is successfully delivered into a patient's lungs, the air pushes against the diaphragm and expands the thoracic cavity, causing the chest to rise visibly. This physical movement indicates that air is entering the lungs and suggests that rescue breaths are being delivered effectively.

In contrast, simply checking for a pulse does not provide information about the effectiveness of rescue breaths. Listening for breath sounds can be helpful in a clinical setting but is not practical during CPR, where visual observations are more immediately assessable. Feeling for airflow from the mouth can indicate that air is moving but does not confirm that the breaths are adequately inflating the lungs. Thus, watching the chest rise is the most direct and reliable method to confirm that rescue breathing is performed effectively during CPR.