Skin to Epidural Distance 4-6 cm — FRCA Primary MCQ

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EasyAnatomySkin to Epidural Distance 4-6 cmFRCA Primary

The distance from the skin to the epidural space in a midline lumbar approach in an average adult is approximately:

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Correct answer: A — 4-6 cm

The average skin-to-epidural distance in the lumbar region is approximately 4-6 cm (range 2-8+ cm). It increases with obesity. The depth is important for: selecting appropriate needle length / gauging depth of needle insertion / and detecting accidental dural puncture. Ultrasound pre-scanning can estimate the depth before needle insertion.

Reference: RCoA 2021 Primary FRCA Curriculum