Number needed to treat (NNT)

Regarding the calculation of number needed to treat (NNT), which one of the following formulae is used?

a) 1/absolute risk reduction

b) 1/the odds ratio

c) The odds ratio/absolute risk reduction

d) Relative risk reduction/absolute risk reduction

e) 1/relative risk reduction

Transfusion immunology

A 25-year-old female presents with significant haemorrhage secondary to a ruptured

ectopic pregnancy. Which blood component transfusion practice is MOST LIKELY to

cause harm?

a) Transfusion of A +ve packed red cells to an AB –ve recipient

b) Transfusion of A –ve packed red cells to an AB +ve recipient

c) Transfusion of AB +ve fresh frozen plasma to AB –ve recipient

d) Transfusion of B +ve cryoprecipitate to an O –ve recipient

e) Transfusion of AB –ve platelets to an O +ve recipient

Acidbase physiology

A lactic acidosis will be accompanied by a normal anion gap in the presence of which one of the following circumstances?

a) Concurrent diabetic ketoacidosis

b) Hypoalbuminaemia

c) Lithium poisoning

d) Intractable vomiting

e) Hypoaldosteronism

Asthma in Pregnancy

Regarding asthma in pregnancy, which one of the following statements is TRUE?

a) Asthma attacks in brittle asthmatics are more common during labour than at any other stage of the pregnancy

b) Theophyllines are contraindicated for treating asthmatics in pregnancy

c) Oral steroid therapy should be avoided in gravid patients with acute severe asthma

d) Intravenous magnesium sulphate should not be administered to an asthmatic in labour

e) Uncontrolled asthma is associated with pre-eclampsia

Malignant carcinoid syndrome

Regarding malignant carcinoid syndrome, the following statements are true EXCEPT

which one?

a) Malignant carcinoid syndrome occurs in around 50% of those patients with a

carcinoid tumour

b) Fibrosis of heart valves is more commonly seen on the right side of the heart than

the left

c) Carcinoid tumours can produce insulin

d) For a patient to have malignant carcinoid syndrome they are likely to have liver

metastases

e) Carcinoid tumours originating in the appendix are likely to be benign

Acid–base physiology

A lactic acidosis will be accompanied by a normal anion gap in the presence of which one of the following circumstances?

a) Concurrent diabetic ketoacidosis

b) Hypoalbuminaemia

c) Lithium poisoning

d) Intractable vomiting

e) Hypoaldosteronism

Malignant carcinoid syndrome

Regarding malignant carcinoid syndrome, the following statements are true EXCEPT

which one?

a) Malignant carcinoid syndrome occurs in around 50% of those patients with a

carcinoid tumour

b) Fibrosis of heart valves is more commonly seen on the right side of the heart than

the left

c) Carcinoid tumours can produce insulin

d) For a patient to have malignant carcinoid syndrome they are likely to have liver

metastases

e) Carcinoid tumours originating in the appendix are likely to be benign

Cardiotocograph

Listed below are five descriptions of a cardiotocograph trace. With regards to signs of foetal distress, which one of the following is the SECOND most concerning trace?

a) Heart rate 90 beats/min, late decelerations, variability 5 beats/min

b) Heart rate 145 beats/min, early decelerations, variability 25 beats/min

c) Heart rate 40 beats/min, no decelerations, variability 2 beats/min

d) Heart rate 160 beats/min, variable decelerations, variability 30 beats/min

e) Heart rate 100 beats/min, early decelerations, variability 20 beats/min

Lung volumes

Of the following techniques, which one may be used to measure residual volume?

a) Carbon monoxide dilution

b) Total body plethysmography

c) Bohr’s method

d) Pendelluft analysis

e) Wet spirometry

Drug infusion rate

You are told to draw up a new inotrope for infusion to be administered to an 80 kg

patient. The drug comes as an ampoule containing 200mg in 20 mL. You are instructed

to draw the whole ampoule up with water for injection to make a final volume of

50 mL. You only have a basic syringe driver that runs in mL/h. The product information

recommends starting the infusion at 20 mcg/kg/min. How many mL/h would

you set the syringe driver to?

a) 9.6 mL/h

b) 12.0 mL/h

c) 16.7 mL/h

d) 18.0 mL/h

e) 24.0 mL/h

Korotkoff sounds

During an emergency in the hospital you are evacuated with an anaesthetised patient

into the hospital car park. You want to measure the patient’s blood pressure and are

handed a stethoscope and a sphygmomanometer. What sounds on auscultation would

you use to identify the systolic and diastolic blood pressure?

a) The peak of the first Korotkoff sound and the muffling of the fourth Korotkoff sound

b) The start of the first Korotkoff sound and the start of the fifth Korotkoff sound

c) The start of the first Korotkoff sound and the muffling of the fourth Korotkoff sound

d) The peak of the first Korotkoff sound and the peak of the fifth Korotkoff sound

e) The start of the first Korotkoff sound and the peak of the fifth Korotkoff sound

Colloids

Regarding colloid preparations for intravenous infusion, which one of the following

statements is CORRECT?

a) Gelofusine® consists of urea-linked gelatin component molecules

b) Regarding pentastarches, the ‘pent’ refers to 50% esterification with succinyl groups

c) Dextran 70 and 110 interfere with platelet aggregation and have an anticoagulant

action, whereas Dextran 40 does not

d) Gelatin used for medical colloids is derived from exposing collagen from sheep

bones to a strong alkali then boiling water

e) Hetastarch contains molecules with mean molecular weight of 450 kDa

Heart murmurs

A 57-year-old woman is listed for elective abdominal surgery. She has a history of

rheumatoid arthritis. On auscultation of her praecordium, a murmur is detected.

Regarding this patient, the following statements are true EXCEPT for which one?

a) If this murmur is related to a left-sided valve abnormality it will be heard louder

in expiration than inspiration

b) The most likely murmurs would be an apical pansystolic murmur radiating to

the axilla or a diastolic murmur heard best at the left sternal edge

c) If this murmur was secondary to aortic stenosis then a grade one sounding

murmur is of less significance than a grade five sounding murmur

d) If this murmur was secondary to mitral regurgitation, a quiet first heart sound

would be not altogether unsurprising

e) Atrial fibrillation would prompt suspicion of a mitral source of the murmur

Electrical safety

Regarding electrical equipment designed to optimise patient safety, which one of the

following statements is TRUE?

a) Under single fault conditions, type I, CF equipment should have a leakage current in

the order of 5mA

b) Type BF equipment is safe because the patient circuit is earthed

c) To promote patient safety a theatre suite should have an uninterruptible power

supply (UPS)

d) Class III equipment is defined as that which operates at ‘safety extra-low voltage’ of

less than 12V

e) A current-operated earth-leakage circuit breaker relies on an unacceptable current

causing disintegration of a fuse that then breaks the circuit

Management of pulmonary embolism

You are asked to see a 65-year-old patient on the ICU who had been admitted 24 hours

previously following emergency laparotomy for a bleeding duodenal ulcer. He had

been extubated 24 hours previously. His haematology, coagulation and biochemistry

profiles are normal and he was on 30% oxygen but has suddenly become very short of

breath with some pleuritic central chest pain. He is cardiovascularly stable. You suspect

a possible pulmonary embolism (PE) and start him on high-flow oxygen. Which of the

following statements represents your BEST immediate management plan?

a) 12-lead electrocardiogram (ECG), blood for cardiac troponin, computerised

tomography pulmonary angiogram (CTPA) and therapeutic dose unfractionated

heparin if the CTPA shows a significant PE

b) 12-lead ECG, CTPA and thrombolytic therapy if the CTPA shows a significant PE

c) 12-lead ECG, CTPA and therapeutic dose unfractionated heparin if the CTPA

shows a significant PE

d) CTPA and therapeutic dose enoxaparin sodium if the CTPA shows a significant PE

e) 12-lead ECG, D-dimer and if both are normal no further immediate interventions

Monoamine oxidase inhibitors

A 54-year-old male requires emergency laparotomy. He has long-standing depression

and is taking a monoamine oxidase inhibitor. Which one of the following monoamine

oxidase inhibitors is LEAST LIKELY to cause incident during conduct of general

anaesthesia?

a) Moclobemide

b) Phenelzine

c) Isocarboxazid

d) Tranylcypromine

e) Iproniazid

Answer: A

Explanation:

The popularity of monoamine oxidase inhibitors (MAOIs) for the treatment of depressive

disorders, obsessive syndromes and chronic back pain rose in the 1970s and 1980s

but has subsequently declined due to the emergence of superior medications with more

favourable side-effect profiles. Nevertheless, patients still taking these medications will

be encountered and awareness of the potential interactions should be maintained.

Amine neurotransmitters and neurohumoural messengers are metabolised by monoamine

oxidase (MAO) and catechol-O-methyl transferase (COMT). Inhibition of MAO

causes indiscriminate increase in concentration of amines in the central nervous system

and elsewhere. Co-administration with agents that rely on MAO for their metabolism

(e.g. indirectly acting sympathomimetics, ephedrine) or agents that also increase concentration

of amines (notably pethidine, which blocks neuronal reuptake of serotonin)

can produce dramatic clinical syndromes. The type I reaction is excitatory and involves

hypertension, hyperpyrexia, convulsions, coma and can be fatal. The type II reaction is

depressive, producing respiratory depression, hypotension and coma essentially

resembling opioid overdose. Iproniazid was the prototype MAOI, originally introduced

in the 1950s as a treatment for tuberculosis for which its efficacy was limited.

Tranylcypromine is the most hazardous as it possesses stimulant activity independent

of its enzyme inhibition properties. Moclobemide is a selective reversible inhibitor of

monoamine oxidase-A, thus is devoid of many of the side-effects and interactions of its

historical counterparts. Unlike the older agents, which form covalent bonds with the

enzyme, moclobemide’s action is reversible spontaneously with a half-life of two to

four hours. It may be continued peri-operatively but pethidine and indirectly acting

sympathomimetics should still be avoided. Carefully titrated morphine would be the

opioid of choice where regional anaesthesia cannot be employed.

Postoperative complications of trauma surgery

A horse rider falls at a jump and sustains a closed head injury without impairment of

consciousness at any stage and a femoral shaft fracture, which is internally fixated with

an intramedullary nail soon after admission. At 48 hours post-injury she becomes

confused, tachypnoeic, hypoxaemic and pyrexial (38.2 °C). An atypical rash is also

noted. Which one of the following statements is MOST APPROPRIATE?

a) Immediately alert the orthopaedic surgeons

b) Based on these features, anticoagulation is indicated

c) Transfusion of packed red cells is indicated

d) A chest X-ray will contribute to resolving the situation

e) An urgent CT head scan is highest priority

Warfarin therapy

A patient has a CT-confirmed retroperitoneal haemorrhage. He is on warfarin for

atrial fibrillation. His international normalised ratio (INR) is usually stable between

two and three. It is now eight, and this may be explained by the recent commencement

of a new drug. Of the following drugs, which is the LEAST LIKELY to be

responsible for the derangement?

a) Clopidogrel

b) Paracetamol

c) Amiodarone

d) Fluconazole

e) Metronidazole

Acute phase proteins

The following are direct or indirect measurements of acute phase proteins EXCEPT which one?

a) C-reactive protein

b) Plasma viscosity

c) Haptoglobin

d) Rheumatoid factor

e) Erythrocyte sedimentation rate

Postoperative thoracic surgery

Negative pressure may be applied to the chest drainage tube of the affected hemithorax in the following circumstances EXCEPT which one?

a) Post-pneumonectomy

b) Known bronchopleural fistula

c) Known haemothorax

d) Known empyema

e) Post-oesophagectomy

Meta-analysis

Regarding meta-analysis, which one of the following statements is TRUE?

a) Is analagous to a systematic review

b) The size of a ‘blob’ in a ‘blobbogram’ reflects the degree of significance found in the individual study

c) If the centre line is crossed by the confidence interval of the combined result,

there is no association between the variables

d) The ‘x’ axis of the results graph is usually expressed as relative risk

e) The funnel plot helps to identify selection bias

Respiratory examination

A 55-year-old male smoker presents with lethargy, cough and intermittent chest pains.  He requires assessment because of progressive respiratory failure. On examination he has a central trachea and reduced chest expansion. On the right he has a dull percussion note, easily audible breath sounds and whispering pectoriloquy. On the left his

breath sounds seem less audible but there are no added sounds and vocal resonance is normal. Which of the following is the MOST likely diagnosis?

a) Right pleural effusion

b) Left pneumothorax

c) Right pneumonic consolidation

d) Left lobar collapse with patent major bronchi

e) Right bronchial proximal obstructing lesion

Blood sampling

You are called to the resuscitation room where an unwell, 34-year-old man is undergoing

assessment. You agree to take the venous blood sample for investigations. The

bottles and syringes required are all listed below. Select the sample that you would

draw and fill THIRD.

a) Standard gold-topped sample bottle containing gel activator (SST) for urea and

electrolytes

b) Standard grey-topped sample bottle containing fluoride oxalate for glucose

c) Standard blue-topped sample bottle containing citrate coagulation screen

d) Standard purple-topped sample bottle containing EDTA for full blood count

e) Blood culture bottles

Tourniquet use for limb surgery

Regarding the use of tourniquets in the theatre environment, the following statements

are true EXCEPT which one?

a) Exsanguination and tourniquet inflation is associated with immediate rise in

central venous pressure, arterial blood pressure and heart rate

b) After two hours’ inflation time, a significant decrease in core temperature can be

expected on deflation of the tourniquet

c) Pre-inflation, ketamine 0.25 mg/kg intravenously can prevent the hypertensive

response to tourniquets

d) When using a double-cuff tourniquet for intravenous regional anaesthesia the

proximal cuff is the first to be used

e) If the continuous tourniquet inflation time exceeds two hours, the ischaemic cell

damage and lesions associated with acidosis are irreversible

Tricyclic antidepressant poisoning

Which of the following is NOT a recognised cause of the toxic effects of tricyclic

antidepressant drugs taken in overdose?

a) Inhibition of noradrenaline reuptake at nerve terminals

b) A myocardial membrane stabilising effect

c) An anticholinergic action

d) Indirect activation of GABAA receptors

e) Direct alpha adrenergic action

Crises in myasthenia gravis

A 40-year-old woman known to have myasthenia gravis presents to the emergency

department with severe global weakness. She is pale, sweaty and cyanosed. Her

partner explains that she was diagnosed some time ago and she is, to the best of his

knowledge, compliant with her oral pyridostigmine therapy. She is a smoker and has

been coughing more than usual recently. He has been worried about her low mood in

past months. In order to distinguish between an excess or inadequacy of her myasthenia

treatment, which one of the following features is likely to be the MOST HELPFUL?

a) Rapid onset of ventilatory failure

b) Response to dose of cholinesterase inhibitor

c) Flaccid muscle paralysis

d) Presence of bronchospasm

e) Loss of deep tendon reflexes

Prevention of infective endocarditis

Which of the following patient groups is NOT thought to be at increased risk of

infective endocarditis and therefore does NOT require prophylaxis against infective

endocarditis when undergoing an interventional procedure?

a) Moderate mitral regurgitation

b) A patient with a history of previous endocarditis but a structurally normal heart

c) Isolated atrial septal defect

d) Hypertrophic cardiomyopathy

e) Pulmonary stenosis

Central neuraxial block producing neurological injury

Regarding central neuraxial blocks, which one of the following is MOST likely to cause permanent neurological injury?

a) An epidural sited for obstetric indications

b) An epidural sited for adult general surgical indications

c) An epidural sited for paediatric general surgical indications

d) A spinal sited rather than an epidural

e) An epidural sited for chronic pain indications

Pulmonary vasoconstriction

Question: Pulmonary vasoconstriction may be caused by

a) Hypothermia

b) Smoking ‘Crack’ cocaine

c) Volatile anaesthetic agents

d) Calcium channel blockers

e) Positive end expiratory pressure

Sugammadex

Sugammadex

Which of the following statements regarding sugammadex is TRUE?

a) It is a modified α-cyclodextrin

b) The drug forms complexes with steroidal neuromuscular blocking drugs with a

ratio of 1:2

c) Following sugammadex administration to reverse rocuronium-induced

neuromuscular blockade the measured total plasma rocuronium concentration

will rise

d) The majority of the drug is metabolised and excreted by the kidneys

e) Sugammadex exerts its effect by binding with rocuronium at the neuromuscular

junction

Answer: c

Explanation

Sugammadex is a modified g-cyclodextrin of which there are three types (α, β and g) all

of which are doughnut shaped, have a hydrophobic, lipophilic cavity and a hydrophilic

exterior. To create sugammadex, g-cyclodextrin has been modified by the addition

of eight side-chains to extend the cavity and negatively charged carboxyl groups to

increase binding affinity. This has created a molecule that is able to bind with the

steroidal neuromuscular blocking drugs (rocuronium > vecuronium > pancuronium).

Sugammadex forms tight 1:1 complexes with these drugs in plasma, resulting in

movement of neuromuscular blocker away from the neuromuscular junction into the

plasma down a concentration gradient. Sugammadex has no effect on acetylcholinesterase

or any receptor system in the body. The majority of sugammadex is excreted

unchanged in the urine. For complete reversal of neuromuscular blockade to take place

sugammadex need only reduce post-synaptic receptor occupancy from 100% to 70%.

Several dose-finding studies have been carried out and suggested doses range between

2.0 to 4.0 mg/kg following reappearance of the second train-of-four twitch after

administration of rocuronium. There is also emerging evidence that sugammadex, at

a dose of 16 mg/kg, can promptly reverse high-dose rocuronium (1.0–1.2 mg/kg). This

may lead to the intriguing possibility of rocuronium challenging the place of suxamethonium

as the muscle relaxant of choice in rapid sequence induction.

Reference

Naguib M. Sugammadex: another milestone in clinical neuromuscular pharmacology.

Anesth Analg 2007; 104(3): 575–81.