According to ATLS protocol, a patient in Class III haemorrhagic shock has estimated blood loss and clinical features. Estimated blood volume in a 70 kg adult is 5000 mL. Class III shock corresponds to blood loss of approximately:

• A 750–1500 mL (15–30% of circulating volume)
• B 1500–2000 mL (30–40% of circulating volume) ✓
• C 2000–2500 mL (40–50% of circulating volume)
• D <750 mL (<15% of circulating volume)

Explanation

ATLS classifies haemorrhagic shock into 4 classes based on estimated blood loss: Class I (<750 mL, <15%), Class II (750–1500 mL, 15–30%), Class III (1500–2000 mL, 30–40%), and Class IV (>2000 mL, >40%). Class III is characterised by marked tachycardia, hypotension, tachypnoea (30–40 breaths/min), decreased urine output, and altered mental status (anxiety/confusion), typically requiring blood transfusion. Class IV represents immediately life-threatening loss requiring emergency intervention.

Reference: Bailey & Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.