Module 5
Regional and Neuraxial Anesthesia
Spinals, epidurals and nerve blocks - what they are, where the medication goes, and where a student stands.
Estimated time: 5 minutes
The diagrams are detailed - fullscreen or landscape works best on a phone.
Read the transcript
Learner promise
By the end of this module you should be able to explain the difference between a spinal and an epidural, recognize what you are watching on an OB day, and know the one job a student can genuinely help with.
Who this is for: students who will watch neuraxial blocks and nerve blocks placed. Not for: performing, assisting with, or positioning a patient unsupervised.
Two families
- Neuraxial - spinal and epidural. The medication goes near the spinal cord itself.
- Peripheral nerve blocks - a specific nerve or bundle, out in an arm or a leg.
The layers, in order
A needle placed in the lower back passes through:
- Skin
- Subcutaneous fat
- Supraspinous ligament
- Interspinous ligament
- Ligamentum flavum - tough, and gives a distinct feel as it is crossed
- Epidural space ← an epidural stops here
- Dura
- Subarachnoid space (cerebrospinal fluid) ← a spinal reaches here
One path, two destinations. Which one you stop at is the whole difference.
Spinal vs epidural vs combined
| Spinal | Epidural | Combined | |
|---|---|---|---|
| Where | Subarachnoid | Epidural space | Both |
| Onset | Minutes | Slower | Fast, then sustained |
| Character | Dense, reliable | Adjustable | Dense plus adjustable |
| Duration | Single shot, finite | Catheter - hours to days | Catheter for afterwards |
On labor and delivery
A labor epidural is for pain, not for surgery - a comfortable patient who can still move and push. If that patient goes for a cesarean, the same catheter is dosed differently to make the block dense enough for an operation, reaching considerably higher. You will hear the team discuss the level of the block; it is checked, usually with something cold.
Peripheral nerve blocks
Ultrasound put the anatomy on a screen: the nerve, the needle, and the spread of medication, live. A shoulder might get a block at the base of the neck; a knee at the thigh. If you get the chance to watch the ultrasound screen while a block is placed, take it - it is the clearest anatomy lesson on the rotation.
Your job
- Ask where to stand before the procedure starts - then stay there
- Do not touch the prepped back, the drape, or the tray
- Offer to help position - it is genuinely useful
- If you feel lightheaded, say so and step back from the sterile field
Day-one pro tip
Positioning is the one job students can really help with. Patients hold still better with someone at eye level steadying their shoulders and talking to them - and holding still makes the procedure safer and faster. Ask if you can help, and ask what to say.
Why the room gets briefly busier
The nerves that carry pain also help hold blood vessels tight, so blood pressure can drop as a block sets up. It is expected, monitored, and treated - not an emergency.
Reflection prompt
What surprised you about watching a patient stay awake through an operation?
This module is for general education only. It is not medical advice, clinical credentialing, or permission to perform clinical tasks independently. Follow local institutional policy and the direction of your supervising clinicians.
Knowledge check
Enter your email to take the quiz and track completion. No account and no password - we use it only to record your progress and issue your certificate. The course is free for individual students during the founding pilot; if your program sponsored your access, it receives your completion record.