TCRN Practice Exam 2026 – Complete Prep for Your Test

Exhalation during cardiopulmonary resuscitation (CPR) is primarily achieved through the normal relaxation of the chest. When chest compressions are performed, they create a negative pressure in the thoracic cavity during the release phase. This negative pressure encourages air to be expelled from the lungs as the chest recoils back to its natural position after compressions are released.

In contrast, the other options do not appropriately describe the mechanism of exhalation during CPR. For instance, while the pressure from cardiac compressions contributes to airflow dynamics, it is not the primary mechanism for exhalation. Exhalation relies more on the natural elasticity of the lung tissue and the thoracic cavity's structural mechanics, rather than an active phase during compressions. Bilateral chest wall pressure or upward sub-xiphoid pressure may assist in certain situations but do not represent the standard process facilitating exhalation in CPR.