Question

-How does the body respond to blood loss? (hormones, nervous system, cardiac output and contractility, heart rate, blood vessels) What causes death from hemorrhagic shock?

Answer 1

The blood loss causes hemorrhagic shock, most common type of shock. Blood loss activate sympathetic nervous system which causes release of epinephrine and norepinephrine.

These hormones cause increase in heart rate and pulse rate which is the earliest change. These hormones also cause peripheral vasoconstriction which increases peripheral vascular Resistance such that diastolic blood pressure increases.

This causes shunt of blood from peripheral organs to vital organs. As heart is a vital organ blood and increases cardiac output and also increases systolic blood pressure due to increased venous return.

Urine output pulse and respiratory rate increases resulting Tachypnea. Mental status varies from anxious state to comatosed state depending on the amount of blood loss. Metabolic acidosis sets in. They are treated by means of IV Fluids and massive blood transfusion in dangerous cases. The death due to hemorrhagic shock is due to complications like hypothermia, hypocalcemia, hypokalemia/hyperkalemia.

Transfusion Related Acute Lung Injury (TRALI) is caused by massive blood transfusions and the patients ends up in ARDS (Acute Respiratory Distress Syndrome).

The most common cause of death coagulopathy which is caused due to hypothermia, dilution of clotting factors in stored blood and the blood poor in platelets.

It also causes many infections and septicemia.