Primary OSCE 20

1. Examination
 You are asked to examine a patient:
- How do you locate the femoral artery?
- Where do the femoral nerve and vein lie in relation to this?
- What are the roots of the femoral nerve?
- Which nerves are blocked in a three-in-one block?
- What do these nerves supply (motor and sensory)?
- How would you go about blocking the ilioinguinal nerve?
- What other nerve is blocked when you do this?
- Between which two muscles are you infiltrating in this block?
- You are shown a diagram: which dermatomes are highlighted here? (diagram has L2 and L3 highlighted)
- Examine the third to the twelfth cranial nerves on this actor, explaining which nerves you are checking as you do so

2. Resuscitation
You are walking past a river when you come across an unconscious patient who is not breathing but has a pulse.
- Demonstrate how you would react
- Look at the ECG shown here and fill in the blanks on the algorithm to explain how you would treat the patient

3. CT
You are presented with a computer screen showing the three-dimensional CT scan of an L1 wedge fracture. This is the CT of a 27-year-old builder who has fallen from a building. He has also fractured both femurs and his left tibia. His pulse is 120 bpm and his BP is 90/60 mmHg.
Answer a series of true/false questions relating to your management of the patient and take a further history.

4. ECG
Answer a series of true/false questions relating to an ECG showing left ventricular hypertrophy and T-wave inversion in leads V3-V6.

5. Equipment
You are presented with a diagram showing a capnography trace with two normal traces followed by a sudden absent trace. This is the capnography tracing of a 26-year-old man who is undergoing a lumbar discectomy and is currently prone and ventilated.
Answer a series of true/false questions relating to the normal traces then the sudden loss of CO₂
- What are the likely causes of the sudden loss of CO₂?

6. History
A patient is about to undergo a total abdominal hysterectomy. She does not wish to receive any blood products on religious grounds. A special consent form is provided detailing that she has refused blood products and that you have discussed this with her, and that she does not hold you or the surgeon morally responsible if she suffers injury from withholding a blood transfusion. Obtain the patient’s signature for this consent form.

7. History
Obtain an anaesthetic history from a patient who is about to undergo a knee arthroscopy. The patient appears to be a fit and healthy 25-year-old male, whose only significant history is that he was involved in a road traffic accident three years previously, fracturing a femur, his pelvis and a couple of ribs and was ventilated overnight in the intensive care unit.

8. History
Obtain an anaesthetic history from a 45-year-old female who is about to undergo a hysterectomy. She is fit and healthy but has undergone a previous caesarean section under general anaesthetic and can remember the laryngoscope being passed into her mouth. She also suffered a deep vein thrombosis, which led to what may have been a pulmonary embolism, but this was not confirmed at the time and the patient maintains that she was not treated for it.

9. Equipment check
You are asked to carry out a check on anaesthetic equipment with no breathing system attached.
- What type of machine is it? (Boyles)
- What faults can you find? (e.g. vaporiser is empty, with no interlocking device between the O₂ and N₂O rotameters, preventing delivery of 100% N₂O)

10. Questions on the indications and contraindications for cricoid pressure
- How much force should be applied?
- When should the pressure be released?
- Who should perform it?
- Demonstrate on a manikin how to perform it

11. Equipment
You are shown a variety of filters.
- Describe the use of each of these filters, and answer some supplementary questions (e.g. a leucocyte filter, a filter in a standard blood giving set, an epidural catheter filter and an HME with a bacterial filter)
- What are the potential problems with using an HME in a paediatric patient?
- What does the epidural filter actually filter?
- Rank the following in order of size: a platelet, a bacterium and an erythrocyte filter

12. ECG
- What is the usual speed of an ECG recording?
- What is the calibration signal?
- How can interference be reduced?

13. Anatomy of the heart
- Where are the sinoatrial (SA) and atrioventricular (AV) nodes?
- Where are the coronary arteries and veins?
- What are the sinuses of Valsalva and what is their function?
- You are shown a coronary angiogram: what is the pathological process demonstrated at the labelled points?
- Which artery was this affecting?

14. Statistics
Answer true/false questions; for example:
- What type of data is quoted?
- Do non-parametric equations require equal numbers in each group?