skip to main content

Hyperbaric Spinal Block Extension — FRCA Final MCQ

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

ModerateRegional AnaesthesiaHyperbaric Spinal Block ExtensionFRCA Final

A 48-year-old man undergoes a knee arthroscopy under spinal anaesthesia. He is given intrathecal 0.5% heavy bupivacaine 3 mL (15 mg). Immediately after injection in the sitting position, he is placed supine. His block level at 10 minutes is T12 bilaterally. The target for knee surgery is T10. What positioning manoeuvre may help extend the block?

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

Reveal the answer and explanation

Correct answer: C — Trendelenburg (head-down) tilt

Heavy (hyperbaric) bupivacaine is denser than CSF and sinks with gravity. To extend a block that is at T12 when T10 is needed, a slight Trendelenburg (head-down) tilt will encourage the hyperbaric solution to move cephalad, extending the sensory level. The tilt should be modest (5-10°) and the block level checked frequently to avoid an excessively high block. Positioning should be adjusted early (within 15-20 minutes of injection) while the solution is still mobile. After fixation (approximately 20-30 minutes), positional changes have minimal effect on block level.

Reference: RCOA – 2023 – Regional anaesthesia: spinal block positioning; Hocking G – 2004 – Intrathecal drug spread