Table 1: Classification of haemorrhagic shock (ATLS manual American College of Surgeons).

Class of haemorrhagic shock
I II III IV

Blood loss (mL)Up to 750 750–15001500–2000>2000
Blood loss (% blood volume)Up to 1515–3030–40>40
Pulse rate (per minute)<100100–120120–140>140
Blood pressureNormal Normal Decreased Decreased
Pulse pressure (mm Hg)Normal or increased DecreasedDecreasedDecreased
Respiratory rate (per minute)14–2020–3030–40 >35
Urine output (mL/hour)>3020–305–15Negligible
Central nervous system/mental statusSlightly anxiousMildly anxious Anxious/confusedConfused/lethargic