Which of the following is the most common cause of cardiac arrest in a trauma patient?

The most common cause of cardiac arrest in a trauma patient is severe hemorrhage. This is primarily due to the fact that trauma often results in significant blood loss, which can lead to hypovolemic shock and subsequent cardiac arrest if not addressed promptly.

In trauma cases, the body may not be able to compensate for the reduced blood volume, leading to inadequate tissue perfusion and oxygen delivery. As the situation worsens, the heart is unable to maintain a normal rhythm and can ultimately lead to cardiac arrest.

Hypoxemia, while certainly a serious condition that can lead to cardiac issues, is often a result of inadequate blood flow or oxygen delivery caused by things like severe hemorrhage in trauma cases. Similarly, while cardiac disease and drug overdose can cause cardiac arrest, they are less frequent in the context of acute trauma situations, where fast and massive blood loss is a more imminent threat.

Given the nature of traumatic injuries, the likelihood of severe hemorrhage as the primary cause of cardiac arrest underscores the importance of rapid assessment and intervention in trauma patients to control bleeding and restore hemodynamic stability.