EMT Basic Certification Complete Practice Exam 2025

A chest wound should be sealed on three sides to create a one-way valve effect that allows air to escape from the chest cavity while preventing air from entering. This is particularly important in the case of a penetrating chest injury, such as a stab or gunshot wound, which could lead to a pneumothorax (collapsed lung) if air is permitted to enter the pleural space. By leaving one side of the occlusive dressing open, air that is trapped in the pleural space can exit during exhalation, thereby reducing the pressure within the chest cavity and minimizing the risk of further complications.

In contrast, sealing the wound completely on all sides could trap air in the pleural space, worsening the pneumothorax and potentially leading to a tension pneumothorax, which is a life-threatening condition. Covering it with a damp cloth does not provide the necessary airtight seal and can allow air to enter the wound. Leaving the wound uncovered may expose it to further contamination and environmental factors, potentially leading to infection or further injury. Thus, sealing the chest wound on three sides is the most appropriate and effective method of managing it in an emergency situation.