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Radiation 40% Heat Loss — FRCA Primary MCQ

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ModeratePhysics & Clinical MeasurementRadiation 40% Heat LossFRCA Primary

Regarding patient warming during anaesthesia forced-air warming is the most effective convective warming method. The main mechanism of perioperative heat loss is:

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Correct answer: C — Radiation from exposed skin to cooler surrounding surfaces (accounts for approximately 40% of heat loss)

Radiation (infrared emission from warm skin to cooler surroundings) accounts for approximately 40% of perioperative heat loss. Convection accounts for ~30% / evaporation ~20% / conduction ~5% / and respiration ~5%. Forced-air warming primarily addresses convective and radiative heat loss by creating a warm air barrier around the patient.

Reference: Al-Shaikh Stacey 2019 Essentials of Anaesthetic Equipment