MRCS Part B Revision · Applied surgical science and critical care
Cardiac Agents — MRCS Part B Applied surgical science and critical care
By Dr Richard Miller, MBChB FRCS · Reviewed
Cardiac Agents 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 Cardiac Agents station
Cardiac Agents
Both positive and negative inotropes are used in the management of various cardiovascular conditions. The choice of agent depends largely on specific pharmacological effects of individual agents with respect to the condition.
Both adrenergic and dopaminergic receptors increase cardiac contractility and agonistic medications aim to improve cardiac output.
Adrenergic agonists: epinephrine, norepinephrine,
isoprenaline
Dopaminergic agents: dopamine, dobutamine, dopexamine (have some adrenergic activity also)
Phosphodiesterase inhibitors: e.g. milrinone, enoximone (Decrease the rate of breakdown of cAMP by phosphodiesterase III. Primarily inotropic and vasodilator effect increasing myocardial contractility (increased CO) with reduced PAOP and SVR.
Vasodilators: e.g. nitrates (venodilators reducing preload)
What are you asked at the Cardiac Agents station?
The station runs to 18 questions over nine minutes. These are the questions as they are put to you; the model answers are in the question bank.
- The consultant anaesthetist wants to test your critical care knowledge. Applied Sciences: Cardiac Agents
- What is Metaraminol?
- Why might this gentleman have a low blood pressure?
- What is an inotrope?
- Define the term chronotrope
- What pharmacological agents do you know that can support the cardiovascular system?
- In this case the gentleman is thought to be in cardiogenic shock. What is the aim of any pharmacological agent in managing cardiogenic shock?
- An echocardiogram reveals notable left ventricular dysfunction. What inotropic agent would be best suited to treat this gentleman’s cardiogenic shock?
- Describe the effects of dobutamine
- Describe the effects of dopamine
- Describe the effects of noradrenaline
- In what situation is noradrenaline best used?
And 6 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 Cardiac Agents station ask?
It opens with "The consultant anaesthetist wants to test your critical care knowledge. Applied Sciences: Cardiac Agents" and runs to 18 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