Question 1

Explain the JVP waveform shown

Accepted Answer

A wave is due to atrial contraction C wave produced by bulging of the tricuspid valve into the atrium at the start of ventricular systole X descent follows atrial relaxation V wave occurs as a result of venous return to the atrium. Y descent occurs during the opening of the tricuspid valve

Question 2

How does the waveform differ in cases of atrial fibrillation, complete heart block, tricuspid stenosis and incompetence?

Accepted Answer

Atrial fibrillation: absent ‘a’ wave. Timing with the carotid pulse shows that the impulses are ‘irregularly irregular’ Complete heart block: ‘cannon’ ‘a’ wave due to discordant atrial and ventricular contractions leading to the atrium intermittently contracting against a closed tricuspid valve, transmitting a large wave to the internal jugular Tricuspid stenosis: large ‘a’ wave due to obstruction at the atrio-ventricular valves and slow ‘y’ descent due to delayed atrial emptying Tricuspid incompetence: large ‘v’ wave due to surging of right ventricular blood into the atrium through an incompetent valve during ventricular systole

Question 3

What is Kussmaul’s sign?

Accepted Answer

Kussmaul’s sign is a paradoxical rise in the JVP on inspiration. It occurs in situations where the right atrium cannot accommodate the increase in its venous return caused by a fall in the intrathoracic pressure on inspiration, e.g. in right heart failure and constrictive pericarditis.

Question 4

Define cardiac output (CO)

Accepted Answer

The cardiac output is the product of the heart rate and the stroke volume. It is in the order of 5–6 l/min. The equation for cardiac output is: CO = HR x SV Therefore to calculate Q we must first establish HR and SV. An example at rest is shown below: HR (70BPM) x SV (70ml) = 4900ml/min or 4.9 litres per minute

Question 5

A young man develops facial swelling, urticaria and wheeze minutes after being stung by a bee. What type of reaction is this and what is the underlying cause?

Accepted Answer

This is a Type I hypersensitivity reaction due to overproduction of IgE on mast cells and basophils. The swelling and oedema in the face and respiratory airways is due to the release of vasoactive substances such as histamine and chemokines causing vasodilatation.

Question 6

A patient is awaiting a heart valve replacement and wants to know the difference between an autograft, allograft and xenograft?

Accepted Answer

Autograft: tissue is transferred from one area of the body to another in the same individual, e.g. skin graft. Allograft: tissue is transferred between genetically dissimilar individuals of the same species, e.g. deceased donor renal transplant. Xenograft: tissue is transferred between different species.

Question 7

What is an antigen?

Accepted Answer

An antigen is any substance capable of producing an immune response. More precisely, it is a substance binding specifically to an antibody or T-cell antigen receptor.

Question 8

What type of hypersensitivity reaction is the tuberculin test for TB?

Accepted Answer

Type 4: Cell-mediated hypersensitivity involving specifically primed T-lymphocytes. Due to the release of lymphokines. The reaction takes 2–3 days to develop.

Question 9

How would you approach this station? (opening)

Accepted Answer

Analysis This is about explaining a difficult diagnosis and end-of-life care Approach Introduce yourself Ensure she is comfortable Ask if she would like any family to be present Ensure you will not be interrupted Begin with an open question: 'what do you understand has happened?' Show empathy Gather information What are the patient’s ideas, concerns and expectations of treatment and her condition Ask if she has thought about resuscitation or discussed it with family Explain that you have been asked to discuss DNAR with her and that she is happy to proceed

Question 10

Describe how would explain DNAR and end-of-life care with the patient

Accepted Answer

Analysis Approach this as you would in work. The decision is primarily a medical one but patients and family members should be involved at every stage. Approach Check that she is happy to discuss this and whether she would like family present Be direct but sensitive Use empathy ‘I am sorry and I understand this is a difficult conversation to have’ Explain that her condition is deteriorating Explain that CPR is unlikely to be successful or restore her to good function Explain that doctors would act in her best interests Explain that should she deteriorate further we would not attempt CPR Allow her time to consider this Explain that she will be looked after and kept comfortable on the ward Explain that the palliative care team will be seeing her Check her understanding and that she is not upset by this

Question 11

How would you close the station?

Accepted Answer

Analysis Ensure that you finish in time and allow the patient/actor time to ask questions Approach Check her understanding Ask if she has any questions Answer questions to the best of your ability If you are unsure of anything be honest, say so and offer to find out and come back at a later stage Ask if there is anything else you can do Thank the patient

Question 12

Model answer & actor brief (station summary)

Accepted Answer

Analysis This is about explaining a difficult diagnosis and end-of-life care Be honest with the patient, ensure she understands what is happening and show empathy Try to approach the scenario as you would at work, this should be a common communication task The task is to discuss the DNAR and it is important you approach this sensitively but directly Approach Introduce yourself Begin with an open question: 'what do you understand has happened?' Show empathy Explain that her condition is serious and that she is deteriorating Explain that you need to have a difficult discussion with her about end-of-life care Ask if she would like any family or a nurse present Explain about the DNAR Explain that she will be kept comfortable on the ward if she continues to deteriorate Explain that invasive and aggressive resuscitation may not be in her best interests Explain that the decision can be reversed should she improve Give her time to ask questions and show empathy Explore any concerns that she may have Actor Brief You are an 85 year old lady who has recently undergone a big operation for a 'bowel tumour' You have not been seen by a doctor for two days and have been told that your blood pressure is very low and you feel washed out You are concerned as your husband passed away two months ago and had lots of tubes invasive tests in his final days You find it difficult to make decisions without first talking to your family You do not like feeling pressured by doctors and don’t like hospitals

Question 13

Please begin by describing how you would examine the cardiovascular system peripherally (from hands to face) for stigmata of CVS disease

Accepted Answer

Preparation Wash Hands Introduce Exposure CVS: Strip to the waist; 45 sitting upright Use bed sheet to maintain patient’s dignity while examining other systems. Inspection General Inspection Look around bed for: medication, oxygen, insulin, chest leads, walking aids, medical-alert bracelet. Does the patient look: well, breathless, well nourished. Any recognisable syndrome, how is the patient’s complexion? Hands Inspect dorsal and palmar aspects noting colour, skin texture, deformities and feel for temperature or sweating. Look for tar-staining, finger clubbing, lipid deposits (xanthomata), palmar erythema, Dupryten’s, Osler’s nodes and Janeway lesions (Infective endocarditis). Capillary refill (test on chest) Nails: koilonychias (spoon-shaped nail in iron deficiency), onycholysis (destruction), Beau’s lines (chronic disease), Mee’s lines (renal failure), Muehrcke’s lines (hypoalbuminaemia), pitting (psoriasis/alopecia) and capillary nailbed pulsation (Quinke’s sign of aortic regurge). JVP ‘I’m going to have a look at a vein in your neck. Can you relax your head and turn your head slightly to the left.’ With the patient slightly looking to the left observe JVP, shine light he bedside light or a pen torch to help highlight it Note cm above angle of Louis (normal =3cm) Face ‘I’m now going to look at your eyes. Could you look up to the ceiling for me.’ Eyes: Looking for anaemia, jaundice, corneal arcus, Kayser-Fleischer rings (Cu deposits, Wilson’s disease), xantholasma Cheeks: Malar flush (mitral stenosis) Mouth: Looking for central cyanosis, infection, palate for jaundice & Marfan’s. Palpation Pulse Palpate radial pulses ‘I’m now going to take your pulse.’ Rate: Count for 15 secs and x4 (60-100 is normal) Rhythm: regular, irregular Radial-radial delay ‘I’m going to raise your arm up.’ Raise arm for collapsing pulse while gripping wrist Blood Pressure Check with examiner if they would like you to check the BP ‘I’m going to take your blood pressure’ Size cuff Position relaxed arm at level of heart Palpate brachial artery Inflate cuff till brachial pulse occluded for maximum inflation pressure then deflate. Wait 15-20 seconds. Listen with diaphragm and inflate cuff then gradually deflate at rate of 2mmHg/second Note B.P. to 2mmHg Carotid pulse ‘I’m going to feel for the pulse in your neck. It may feel slightly uncomfortable’ Character & Volume: bounding pulses (CO2 retention, liver failure, sepsis), small volume (aortic stenosis, shock, pericardial effusions), collapsing (aortic incompetence, AV malformations, PDA), slow-rising (aortic stenosis), bisferiens (aortic stenosis or regurge), pulsus alternans ( strong then weak - LVF, AS, cardiomyopathy), pulsus paradoxus (systolic weakens with inspiration - severe asthma, pericardial constriction, tamponade).

Question 14

What underlying pathology might a slow-rising pulse indicate?

Accepted Answer

A slow-rising pulse is indicative of outflow obstruction through a narrowed aortic orifice. The most common causes for this are aortic stenosis or hypertrophic cardiomyopathy

Question 15

What kind of murmur would you expect to hear in a patient with aortic stenosis?

Accepted Answer

The murmur of aortic stenosis is typically a mid-systolic ejection murmur, heard best over the “aortic area” or right second intercostal space, with radiation into the right neck.

Question 16

What follow up test would you want to request prior to booking this gentleman for the inguinal hernia repair and why?

Accepted Answer

This gentleman should have a full pre-operative assessment work up including routine blood tests, group and save, ECG and most importantly an Echocardiogram should be requested as a new murmur has been diagnosed. Aortic stenosis is a high outflow state putting pressure on the heart and an Echo will tell you the ejection fraction and the severity of the aortic orifice narrowing. Aortic stenosis is important for anaesthesia as the left ventricle becomes concentrically thickened due to increased afterload, which has the dual effects of increasing myocardial demand and reducing ventricular compliance. Patients with AS are best thought of based on their hemodynamic derangements – they have increased myocardial oxygen demands, reduced left ventricular filling, and, with time, reduced contractility. This puts them at high risk as they are unable to adequately compensate for hypotensive episodes as might occur during surgery.

Question 17

What kit will you require?

Accepted Answer

Central line dressing pack with gown and drapes Sterile gloves Iodine or chlorhexidine for cleaning 1% or 2% lidocaine Central line (preferably at least a triple-lumen line) Saline or heparin saline to flush line Stitch and stitch holders Scissors Scalpel blade 21-gauge (green) and 27-gauge (orange) needles 2 × 10-ml syringes Occlusive dressing An assistant Portable US machine if trained

Question 18

Describe how you would insert a central line into the internal jugular vein

Accepted Answer

Introduction Wash your hands Introduce yourself Explain to the patient what you are about to do. Preparation Tilt the head end of the bed down by 10°–15°. Draw up 10 ml of lidocaine; raise a bleb on the skin with a blue 27-gauge needle. Infiltrate local anaesthetic all around the site, working down toward the vein. Pull back on the plunger before injecting each time to ensure that you don’t inject into the vein. Open the central line pack and take all of the items out. Ensure that the wire moves freely on its reel – you will need to advance the wire one-handed. Flush each port of the central line with saline or heparin saline, and close off each line except the distal (usually brown) line; the wire threads through this line. Attach a syringe to the large needle provided Procedure Palpate the carotid artery with your left hand, covering the artery with your fingers. Insert the needle 0.5–1 cm laterally to the artery, aiming at a 45°angle to the vertical. In men, aim for the right nipple; in women, aim for the iliac crest. Advance slowly, aspirating all the time, until you enter the vein. If you fail to aspirate blood after entering 3–4 cm, withdraw, re-enter at the same point, but aim slightly more medially Alternatively, if you have been trained, a portable US machine can be used to locate the compressible IJV When the needle is in the vein, ensure that you can reliably aspirate blood. Remove the syringe, keeping the needle very still, and immediately put your thumb over the end of the needle. Insert the wire into the end of the needle, and advance the wire until at least 30 cm are inserted. Keeping one hand on the wire at all times, remove the needle, keeping the wire in place. Make a nick in the skin where the wire enters the skin. Insert the dilator over the wire and push into the skin as far as it will go. Remove the dilator. Insert the central line over the wire. Keep one hand on the wire at all times. When the central line is 2 cm away from the skin, slowly withdraw the wire back through the central line until the wire tip appears from the line port. Hold the wire here while you insert the line. Leave a few centimetres of the line outside the skin. Withdraw the wire and immediately clip off the remaining port. Attach the line to the skin with sutures. Tie loosely so as not to pinch the skin; this causes necrosis and detachment of the line. Clean the skin around the line once more, dry, and cover with occlusive dressings. Ensure that you can aspirate blood from each lumen of the line, then flush each lumen with saline or heparin saline. Close Dispose of sharps Thank the patient Request follow up CXR

Question 19

Other than the internal jugular vein where else are central lines commonly inserted?

Accepted Answer

The subclavian vein. This is often used for tunnelled catheters in patients where it is likely to remain in for long periods of time.

Question 20

What are the benefits of using the right internal jugular vein?

Accepted Answer

Lower incidence of pneumothorax compared to subclavian vein catheterisation Right internal jugular vein takes a straight course to right atrium, easier to position at SVC-RA junction Right internal jugular vein catheterisation has lower incidence of pneumothorax compared to left due to lower dome of pleura on right side Right internal jugular vein catheterisation avoids thoracic duct injury on left

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Heart Valve Anatomy