MRCS Part B Revision · Applied surgical science and critical care
Shock 2 — MRCS Part B Applied surgical science and critical care
By Dr Richard Miller, MBChB FRCS · Reviewed
Shock 2 is an applied surgical science and critical care station. Three of the seventeen examined stations in the MRCS Part B OSCE fall in this area. These stations ask you to interpret data and manage a sick surgical patient: a chart, a blood gas, an imaging study or a deteriorating patient on the ward, and the physiology underneath the decision.
What you need to know for the Shock 2 station
Spinal and Neurogenic Shock
Neurogenic shock is a distributive type of shock resulting in low blood pressure, occasionally with a slowed heart rate, that is attributed to the disruption of the autonomic pathways within the spinal cord. Low blood pressure occurs due to decreased systemic vascular resistance resulting in pooling of blood within the extremities lacking sympathetic tone. The slowed heart rate results from unopposed vagal activity and has been found to be exacerbated by hypoxia and endobronchial suction. Neurogenic shock can be a potentially devastating complication, leading to organ dysfunction and death if not promptly recognized and treated. It is not to be confused with spinal shock, which is not circulatory in nature.
Spinal shock was first defined by Whytt in 1750 as a loss of sensation accompanied by motor paralysis with initial loss but gradual recovery of reflexes, following a spinal cord injury (SCI) – most often a complete transection. Reflexes in the spinal cord caudal to the SCI are depressed (hyporeflexia) or absent (areflexia), while those rostral to the SCI remain unaffected.
What are you asked at the Shock 2 station?
The station runs to 15 questions over nine minutes. These are the questions as they are put to you; the model answers are in the question bank.
- How would you assess this gentleman?
- The patient is haemodynamically stable but the emergency SHO is concerned about neurogenic shock. What is neurogenic shock?
- What is the classical presentation of a patient with neurogenic shock?
- Why are patients both hypotensive and bradycardic in neurogenic shock?
- Explain the differences between neurogenic shock and spinal shock?
- Describe the acute phase of spinal shock
- What is the bulbocavernosus reflex?
- What does an absent bulbocavernosus reflex indicate?
- How is the bulbocavernosus reflex performed?
- What is sacral sparing?
- What is the difference between a complete and an incomplete spinal cord injury?
- How are spinal cord injuries graded?
And 3 more at this station.
How is the applied surgical science and critical care station marked in MRCS Part B?
Each of these three stations is marked out of 20, split 12 marks for clinical knowledge and its application, 4 for clinical and technical skill and 4 for professionalism. No communication marks are available. The three cover critical care management, interpretation of clinical data, and interpretation of visual information.
FAQ
What does the Shock 2 station ask?
It opens with "How would you assess this gentleman?" and runs to 15 questions over nine minutes. Each of these three stations is marked out of 20, split 12 marks for clinical knowledge and its application, 4 for clinical and technical skill and 4 for professionalism. No communication marks are available. The three cover critical care management, interpretation of clinical data, and interpretation of visual information.
What counts as applied surgical science in MRCS Part B?
Three of the seventeen examined stations: critical care management, interpretation of clinical data such as blood results and charts, and interpretation of visual information such as imaging and traces.
How is an applied science station marked?
Out of 20, with 12 marks for clinical knowledge and its application, 4 for clinical and technical skill and 4 for professionalism. Unlike the communication stations, none of the marks are for how you say it.
How much physiology do I need?
Enough to explain the decision you are making. The station rewards applying physiology to the patient in front of you rather than reciting it, so practise talking through why a number changes your management.
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 applied surgical science and critical care stations.
More applied surgical science and critical care stations