Lethal Triad Massive Haemorrhage — FRCA Final MCQ

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EasyTrauma & Emergency AnaesthesiaLethal Triad Massive HaemorrhageFRCA Final

A 65-year-old man (ASA III) is in the ICU following emergency repair of a ruptured abdominal aortic aneurysm. He received 12 units of packed red cells, 8 units FFP, and 2 pools of platelets. His temperature is 34.5°C, pH 7.18, and he has diffuse microvascular bleeding. This clinical picture is known as the:

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Correct answer: D — DIC alone

The 'lethal triad' (also called the 'triad of death' or 'bloody vicious cycle') in trauma and massive haemorrhage consists of: (1) hypothermia, (2) acidosis, and (3) coagulopathy. Each component worsens the others in a self-perpetuating cycle: hypothermia impairs enzyme function in the coagulation cascade and platelet function; acidosis inhibits thrombin generation and accelerates fibrinolysis; coagulopathy causes ongoing bleeding, which causes further hypothermia from cold blood products and acidosis from hypoperfusion. Breaking this cycle requires: active warming, damage control surgery, and early balanced blood product resuscitation (1:1:1 ratio).

Reference: ATLS – 2018 – 10th edition; NICE – 2023 – NG39 Major trauma