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Hyponatraemic Seizures TURP — FRCA Final MCQ

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HardGeneral AnaesthesiaHyponatraemic Seizures TURPFRCA Final

A 67-year-old man is recovering four hours after a monopolar TURP performed under spinal anaesthesia using hypotonic irrigation fluid. He becomes nauseated and increasingly drowsy before developing a generalised tonic-clonic seizure. The convulsion terminates after 90 seconds while airway support and oxygen are provided. His serum sodium is 108 mmol/L and bedside blood glucose is 6.1 mmol/L. Which single treatment should now be given immediately as the specific treatment for the life-threatening neurological complication?

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

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Correct answer: C — IV 2.7% hypertonic saline 150 mL over 20 minutes

Explanation lettering: B = shown as A · D = shown as B · A = shown as D

C is correct. This is acute severe symptomatic hyponatraemia from TURP syndrome, producing hyponatraemic encephalopathy and cerebral oedema. After immediate airway and oxygenation measures, give 150 mL of 2.7% sodium chloride over 20 minutes. Recheck sodium immediately and repeat hypertonic saline under senior and critical-care supervision if severe symptoms persist or sodium has not risen by approximately 5 mmol/L in the first hour. Limit correction to 10 mmol/L in the first 24 hours and 8 mmol/L per 24 hours thereafter. Lorazepam is appropriate if a convulsion persists or recurs, but it does not reverse the osmotic cerebral oedema. Phenytoin is not first-line treatment for this acute provoked seizure. Mannitol does not correct hypotonic hyponatraemia. Dextrose is indicated for hypoglycaemia, which has been excluded.

Reference: NHS England North West, North West Guideline: Hyponatraemia, sections 5.6.1–5.6.3, Version 4, February 2026. https://www.england.nhs.uk/north-west/wp-content/uploads/sites/48/2026/02/NW_Hyponatraemia-_Guideline_V4-.pdf