Airway, Circulation, Head Injury, Hypothermia, Massive Haemorrhage, Respiration
Hypovolaemic Shock
The Advanced Trauma Life Support (ATLS) classification of hypovolaemic shock categorizes it into four classifications based on vital signs and the estimated percentage of blood lost.
The severity of haemorrhage begins in class I and responders should stop bleeding before the haemorrhage progresses to another class.