Short Answer Questions Mock Exam Answers

116 Pages·2016·1 MB·English

by  Microsoft Office User

Short Answer Questions
Mock Exam Answers
Dr Katie Ayyash and Dr Umakanth Kempanna
General Pointers
• Read the question properly and understand what is being asked
• Answer the question asked – NOT what you want to answer about the
topic
• Bullet points
• Classify/categorise
• If question asks for something “specific” – you don’t give general or
superficial answers
• Don’t write extensively for low scoring sections
• Legible and neat writing – if examiner can’t read it, you won’t get the
points!!!!
Question 1
A 56-year-old man is listed for elective surgery. He received an
orthotopic heart transplant 12 years before.
a) What key alterations in cardiac physiology and function
must be considered when planning general anaesthesia? (10
marks)
b) What are the implications of the patient’s
immunosuppressant therapy for perioperative care?
(6 marks)
c) What long-term health issues may occur in this type of
patient? (4 marks)
Pass rate 27%
“It is not uncommon to have a patient presenting for surgery that has
received a transplanted organ and is on immunosuppressive therapy. A
similar question was asked in October 2001.”
“This question proved to be the most difficult question on the paper.”
“A majority of the candidates demonstrated poor understanding of the
physiology of a transplanted heart and the side effects of
immunosuppressive therapy of relevance to the anaesthetist. “
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Number of Candidates
a) What key alterations in cardiac physiology and function must
be considered when planning general anaesthesia? (10 marks)

• Denervated heart - no autonomic function
1. High resting HR 90-100bpm (loss of vagal tone on SA Node)
2. No response to laryngoscopy, surgical stimulation, hypovolaemia, light anaesthesia.
3. Temporary bradyarrhythmia post transplantation - ? need for a pacemaker
4. Loss of baroreceptor reflex - No response to carotid sinus massage or valsalva
maneouvre
5. Tachycardia in response to physiological stress is blunted and late depending on
circulating hormones
• Cardiac output is preload dependent
• Loss of Sensory Innervation
• Silent MI, hence routine regular angiogram needed.
a) What key alterations in cardiac physiology and function must
be considered when planning general anaesthesia? (10 marks)

• Pharmacology
1. Glycopyrolate and atropine - no effect (no vagal connection), but
reversal of NMB.
2. Ephedrine – No/decreased effect (indirect symp)
3. Adrenaline, Noradrenaline – Augmented Response
4. Dobutamine, Isoprenaline – Normal Response
• Peripheral surgery under regional block well tolerated
• Neuroaxial blockade may cause marked hypotension due to absent
cardiac innervation, but has been successfully used in these patients.
b) What are the implications of the patient’s
immunosuppressant therapy for perioperative care?(6 marks)

• Normally on triple therapy azathioprine, cyclosporin, prednisolone
• General:
1. Important to maintain stable plasma levels – ensure drugs are taken
2. Preop bloods: Hematological, Renal and Elecrolyte impairment.
3. Common agents can cause a degree of nephrotoxicity, hepatotoxicity
• Malignancy – Skin, lymphoproliferative.
• NSAIDS – nephrotoxic
• Steroids:
1. supplementation to account for stress response.
2. Steroid induced osteoporosis or skin fragility necessitate careful handling and
positioning of the patient
• Increased risk of infection – signs maybe masked
• Prophylactic antibiotics
• Strict asepsis
• Hypertension, Cushingoid features, Psychosis, hyperglycaemia, hyperkalemia
b) What are the implications of the patient’s
immunosuppressant therapy for perioperative care? (6 marks)

• Monitor for classical side effects of steroids
• Steroid induced osteoporosis or skin fragility necessitate careful
handling and positioning of the patient

• Cyclosporin:
1.Nephro,
2.Neuro toxic, DM, HTN, Pancreatitis, Enhances NMBs

• Azathioprine:
1.Myelosuppression, Reduces effects of NDMRs
2.Hepatotoxic, GI side effects, Pulmonary infiltrates

• Calcium antagonists increase cyclosporine levels
c) What long-term health issues may occur in this type of
patient? (4 marks)

1. Rejection
• Acute – cellular or antibody mediated, first 3 months,
• Chronic – allograft vasculopathy, immune mediated, arrhythmias, late death.
• 40% of cardiac transplant patients develop one episode of acute rejection within the
1st year
• Features:
• Accelerated coronary artery disease
• Silent myocardial ischaemia/infarction
• Heart failure
• Arrhythmia