What is the mental state of a casualty who has lost 2500 cc of blood?

In cases of significant blood loss, such as losing 2500 cc (which is approximately 50% of total blood volume for an average adult), the body's ability to maintain blood pressure and adequate perfusion to the brain and vital organs is severely compromised. This often leads to a drastically altered mental state due to hypoxia and insufficient blood flow, resulting in confusion, lethargy, and potentially loss of consciousness.

When a patient has lost this much blood, they typically exhibit symptoms consistent with shock, which includes altered consciousness. As blood volume decreases, the brain may not receive enough oxygen, leading to unconsciousness as a protective mechanism in response to severely low blood pressure and inadequate perfusion. Therefore, the mental state of a casualty under these circumstances is likely to be unconscious, as indicated by the correct answer.