IV Fluids in Head Injury — FRCA Final MCQ

Instant feedback + full explanation. One question, done properly.

EasyTrauma & Emergency AnaesthesiaIV Fluids in Head InjuryFRCA Final

A normoglycaemic adult with severe traumatic brain injury requires intravenous fluid therapy during the first 24 hours after injury. Which of the following fluids should be avoided?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: C — 5% glucose

The correct answer is C, 5% glucose. Although approximately iso-osmotic in the bag, glucose is rapidly metabolised, leaving electrolyte-free water; the solution therefore becomes physiologically hypotonic. This can reduce plasma sodium and osmolality, promoting water movement into injured brain tissue and worsening cerebral oedema. The UK SmPC specifically advises avoiding infusion during the first 24 hours after head trauma. Sodium-containing crystalloids such as 0.9% sodium chloride are used to maintain circulating volume and cerebral perfusion. Hartmann's solution is relatively hypotonic compared with plasma and may be less favoured in severe brain injury, but it is not subject to the same specific warning. Gelofusine is not first-line over crystalloid but is not uniquely contraindicated here. Hypertonic saline may be used to treat intracranial hypertension rather than as routine maintenance fluid.

Reference: Baxter Healthcare Ltd. Glucose 5% Intravenous Infusion BP, Summary of Product Characteristics, sections 4.2 and 4.4; revised June 2023, eMC updated 5 June 2024. https://www.medicines.org.uk/emc/product/1825/smpc