MRCS Part B Revision · Procedural and technical skills
Spinal Anaesthetic — MRCS Part B Procedural and technical skills
By Dr Richard Miller, MBChB FRCS · Reviewed
Spinal Anaesthetic is a procedural station. Two of the seventeen examined stations in the MRCS Part B OSCE are procedural. The procedural stations ask you to perform a practical task, usually on a model, while explaining what you are doing and why.
What you need to know for the Spinal Anaesthetic station
Spinal
Preparation
Have an assistant available.
Use an Lumbar P kit in the hospital setting.
22 or 25 gauge-3 inch LP cutting needle or an atraumatic non-cutting needle.
Introduce Yourself
Wash hands
Consent
Obtain a signed informed consent from the patient or a substitute decision maker after explaining the risks and benefits of the procedure.
Site Preparation
The site is cleansed with iodinated solution, applied in a circular fashion followed by a careful application of isopropyl alcohol or a chlorhexidene based solution to wash off the iodinated solution.
Local Anaesthesia
Using a 25 gauge needle, create a skin wheal with 1% xylocaine at the insertion site. Now change to the 22 gauge needle to infiltrate the subcutaneous and interspinous areas with up to 3 cc. of 1% lidocaine solution.
Spinal needle insertion
If using the standard cutting needle, insert the needle at the identified site with the bevel facing upward (if the patient is in the left or right lateral position). The bevel should be parallel to the axis of the spine ensuring that the bevel is parallel to the dural fibres. Direct the needle at an angle of approximately 10 degrees cephalad. Advance the needle approximately 1.5 inches or until a slight "pop" is felt as the dura is penetrated. Remove the stylet and wait 2 seconds for CSF drainage. If there is no CSF return, advance the needle 1-2 mm. at a time, checking for CSF return with each advance. If the needle tip encounters bone, withdraw the needle tip to just below the skin, check your landmarks and patient positioning and advance the needle again.
Collection of CSF
Collect 2-5 ml of fluid in each of 4 to 5 sterile pots.
Removal of needle
Replace the stylet fully into the spinal needle before withdrawing the needle. Apply pressure on the site with a gauze and then apply a band-aid. Place the patient in a comfortable body position.
What are you asked at the Spinal Anaesthetic station?
The station runs to 10 questions over nine minutes. These are the questions as they are put to you; the model answers are in the question bank.
- What level of the spinal cord should lumbar puncture be performed?
- What landmark can be used to help estimate this level?
- What structures does the spinal needle pass through during a lumbar puncture?
- Are there any contraindications to performing a lumbar puncture?
- Describe how you would position a patient for a lumbar puncture
- Describe how you would perform a lumbar puncture
- Following lumbar puncture the patient develops a severe headache. What is the cause of this and how would you manage the patient?
- What tests would you send the CSF sample for?
- In a pyrexial patient with neck stiffness and photophobia what would the below CSF results suggest? Appearance Normal White Cells Raised lymphocytes Red Cells Normal Protein High Glucose Low
- What other diseases can lumbar puncture diagnose?
How is the procedural and technical skills station marked in MRCS Part B?
The two procedural stations are marked differently from each other. Procedural skills with a patient carries 8 marks for clinical and technical skill and 4 each for knowledge, communication and professionalism. Procedural skills, technical, performed on a model rather than a person, carries 12 for skill and 8 for knowledge, with no communication or professionalism marks available.
FAQ
What does the Spinal Anaesthetic station ask?
It opens with "What level of the spinal cord should lumbar puncture be performed?" and runs to 10 questions over nine minutes. The two procedural stations are marked differently from each other. Procedural skills with a patient carries 8 marks for clinical and technical skill and 4 each for knowledge, communication and professionalism. Procedural skills, technical, performed on a model rather than a person, carries 12 for skill and 8 for knowledge, with no communication or professionalism marks available.
What procedural skills are tested in MRCS Part B?
Two of the seventeen examined stations are procedural: one with a patient and one purely technical. Candidates most often report suturing, abscess incision and drainage, catheterisation and chest drain insertion.
How is a procedural station marked?
The station with a patient carries 8 of its 20 marks for clinical and technical skill and 4 each for knowledge, communication and professionalism. The technical station carries 12 for skill and 8 for knowledge, with no communication marks.
Should I talk while I perform the procedure?
At the station with a patient, yes: a third of the marks there are for communication and professionalism, and they are gone if you work in silence. At the purely technical station those marks do not exist, so the technique itself is what counts.
How many stations are in the MRCS Part B OSCE?
Seventeen examined stations of nine minutes each, with a minute to read the task before each one. Two preparation stations and at least one rest station bring the circuit to about twenty, and the exam takes about three and a half hours.
What is the pass mark for MRCS Part B?
There is no published pass mark. The cut score is set separately for Applied Knowledge and Applied Skills, for each circuit, by borderline regression. Published pass rates across the 2024/25 diets ranged from 51% to 66%.
Can I fail a station and still pass?
Yes. There is no rule about how many stations you may fail: the cut score applies to your total mark in each component, so a weak station costs the marks you lost on it and strong stations elsewhere can make them back. Applied Knowledge and Applied Skills are passed separately and must both be passed at the same sitting, so a strong anatomy performance cannot rescue a weak communication one.
Dr Richard Miller, MBChB FRCS
Station summaries are reviewed against the current intercollegiate MRCS syllabus and the published marking blueprint. Guidance changes between diets: check the royal colleges' own pages before relying on a date, a fee or a threshold.
Practise this station
The question bank carries the model answer to every question above, with the rest of the procedural and technical skills stations.
More procedural and technical skills stations