Haemorrhagic shock and massive transfusion in trauma

What it is

A trauma patient in shock is bleeding until proven otherwise. The differential for a trauma patient presenting with shock includes bleeding, bleeding and bleeding, so the first task is to rule out bleeding rather than to look for a rarer cause.

How it is diagnosed

First detect whether the patient is in shock, that is hypotensive. Then look for the blood: the floor and 5 more places, which are the chest, abdomen, pelvis, retroperitoneum and long bones. Only then consider the other causes of shock: obstructive, from tension pneumothorax or cardiac tamponade, and neurogenic, from cervical or upper spine injuries. Tension pneumothorax is identified clinically. Cardiac tamponade is identified by Becks three signs of hypotension, distended neck veins and muffled heart sound. In neurogenic shock the patient is warm and hypotensive, and the heart rate is printed as normal HR but struck through on the page and corrected in handwriting to bradycardia.

The acid-base numbers grade the shock. The most common acid-base abnormality in a patient with trauma and hemorrhage is Met acidosis due to lactic acidosis. Lactate usually takes time to increase, so the base deficit is the more useful early measure: it is the amount of base, that is bicarbonate, needed in the blood to correct the acidosis and reach a pH of 7.4. The lower the base deficit, the worse the shock and the worse the acidosis.