Question 34

Which of the following is suggested by a history of transient episodes of vertigo, slurred speech, diplopia, and paraesthesia in a man aged 65 years?

a) Basilar artery insufficiency Correct

b) Anterior communicating artery aneurysm

c) Hypertensive encephalopathy

d) Pseudobulbar palsy

e) Occlusion of the middle cerebral artery

Episodes of vertigo, diplopia and paraesthesia indicate alteration of brainstem function caused by basilar artery insufficiency. Middle cerebral occlusions usually

presents with contralateral hemiplegia and homonymous hemianopia. Slurred speech or aphasia may occur in both conditions. Anterior communicating artery aneurysms are likely to result in emotional lability. Hypertensive encephalopathy comprises headache, confusion, stupor or convulsions. Pseudobulbar palsy presents with dysarthria, dysphagia and emotional lability.

Question 35

Mandy, a 4 year old girl, is due to accompany her parents on a flight to England in two months time. Her mother is worried about the effect of air travel on Mandy's ears. Which of the following will NOT increase the likelihood of ear pain during the flight?

a) A recent cold

b) Nasal congestion

c) Hay fever

d) Recent otitis media

e) Perforation of the ear drum Correct

Normal function of the middle ear and tympanic membrane is maintained by a patent eustachian tube which keeps the middle ear and external canal pressures equal. Blockage of the eustachian tube, e.g. with secretions as in the common cold, results in pressure imbalances between the middle and external ear. During air travel, the resulting barotrauma may cause pain, deafness, vertigo, and tinnitus. All the options

listed, except (e), can cause blockage of the eustachian tube.

* Question 36

Sue, a three year old girl, presents with shortness of breath and wheeze that have developed over the last two days. Examination reveals an afebrile, moderately

tachypnoeic child with widespread scattered wheezes on auscultation. You decide to

administer a bronchodilator (salbutamol). The recommended method of delivery of salbutamol for Sue is:

a) Syrup

b) Nebuliser

c) Breath activated inhaler

d) Metered dose inhaler with a spacer

e) Metered dose inhaler with a spacer and face mask Correct

For the treatment of acute asthma in a child <6 years of age, the recommended mode of delivery of bronchodilator (salbutamol) is via a metered dose inhaler and small volume spacer with face mask. For those >6 years of age, a large volume spacer may be substituted. Salbutamol administered via these routes has been shown to be equally effective to nebulised salbutamol. Six puffs of salbutamol via

MDI and spacer is the equivalent of a 2.5 mg nebule, while 12 puffs equals a 5mg nebule.

Question 37

Oliver, an 8 month old boy, presents with a history of anorexia and recurrent upper

respiratory tract infections. Physical examination reveals pallor and splenomegaly. His blood picture shows a hypochromic, microcytic anaemia with numerous target cells and nucleated red cells. What is the MOST LIKELY diagnosis?

a) Thalassaemia major Correct

b) Iron deficiency anaemia

c) Glucose-6-phosphate dehydrogenase deficiency

d) Sideroblastic anaemia

e) Sickle cell anaemia

Thalassaemia major (homozygous beta-thalassaemia) is a severe disease which presents during the first year of life with: failure to thrive, intermittent infection, severe hypochromic, microcytic anaemia and signs of extramedullary haemopoiesis (hepatosplenomegaly and bone expansion). It does not present at birth because the production of foetal haemoglobin is not affected.

* Question 38

In acute iritis (anterior uveitis), the pupil is:

a) Eccentric, constricted and reacts briskly to light

b) Concentric, dilated and reacts briskly to light

c) Eccentric, dilated and reacts sluggishly to light

d) Concentric, constricted and reacts sluggishly to light Correct

e) Concentric, dilated and reacts sluggishly to light

Anterior uveitis typically presents with a unilateral painful red eye, blurred vision, photophobia and tearing. There is a perilimbal flush and pupillary miosis with a sluggish response and increased pain during accommodation to light. This is due to spasm of the ciliary body and iris muscles. Slit lamp examination will demonstrate keratic precipitates on the cornea. Urgent treatment is needed to prevent

complications.

Question 39

The MOST common cause of persistent cough in children is:

a) Chronic post viral cough

b) Asthma Incorrect. The correct answer is (a).

c) Post-pertussis

d) Gastro-oesophageal reflux

e) Passive smoking

The commonest cause of persistent cough (particularly with a prominent nocturnal component) in children is post viral. It can also be associated with postnasal drip. However, care must be taken to exclude asthma which is a fairly common cause of persistent cough in children. Other less common conditions to be considered include gastrointestinal reflux, passive smoking and post pertussis.

* Question 40

Trevor is a 2.4 kg male infant with Apgars 9:10 after a normal vaginal delivery. He becomes jaundiced at 12 hours of age. Which of the following conditions would be the MOST LIKELY cause of the jaundice?

a) Gram negative septicaemia

b) Jaundice of prematurity

c) Biliary atresia

d) Physiological jaundice

e) Rh incompatibility Correct

Jaundice appearing in the first 24 hours of life is most commonly due to haemolytic disease of the newborn due to incompatibility to Rh, ABO or one of the other rare antigens. Other causes of early jaundice include transplacental infections such as

CMV, toxoplasmosis and rubella. Jaundice of prematurity, physiological jaundice and septicaemia present most commonly between days 2-5. Biliary atresia presents with jaundice after the first week of life.

Question 1

Mrs B is 55 years old and presents because of painful mouth ulcers (see figure). You diagnose aphthous ulcers. She is otherwise well. Which of the following statements about aphthous ulcers is INCORRECT?

Reproduced with permission, Hong Kong Government, Department of Health, Tooth Club, 2003.

a) The cause is rarely found

b) There is often a family history

c) The ulcers often begin in childhood

d) They are often an indicator of Behcet's syndrome

e) Aphthous ulcers may present like herpetic vesicles Incorrect. The correct answer is (d).

Behcet's syndrome is a systemic condition with recurrent multiple apthous ulcers AND two of the following: - recurrent genital ulceration, eye lesions, skin lesions or positive pathergy test (non-specific inflammatory skin reaction following intradermal saline injection). Recurrent apthous ulceration in isolation is not associated with Behcet's syndrome. The other statements concerning apthous ulcers are all true.

Question 2

The drug of choice for treatment of erysipelas is:

a) Penicillin Correct

b) Methicillin

c) Ampicillin

d) Tetracycline

e) None of the above

Erysipelas is a form of superficial cellulitis of the skin with lymphatic involvement. It

is almost always caused by Strep pyogenes and therefore the treatment of choice is penicillin (erythromycin or cephalexin can be used in penicillin allergic patients).

* Question 3

Which of the following criteria enable a clear distinction to be made between haemorrhage and thrombosis in a patient with a cerebrovascular accident?

a) The progress of the clinical features

b) The degree of loss of consciousness

c) The abruptness of onset Incorrect. The correct answer is (e).

d) The presence or absence of headache

e) None of the above

Intracerebral haemorrhages tend to be dramatic and accompanied by a severe headache. However, there really is no clinical way of reliably distinguishing between an intracerebral haemorrhage and a thromboembolic infarction, as both produce a sudden focal deficit.

PHARMACOLOGIC TREATMENT OF ANXIETY DISORDERS

Anxiety and anxiety disorders are common clinical problems. The twelve-month community prevalence rates for the major

anxiety disorders range from 0.7% for obsessive-compulsive disorder to 2.3% for panic disorder.1 Untreated anxiety may

be a significant source of distress and impairment. Anxiety disorder may be effectively managed by pharmacologic

treatment, psychotherapy, or a combination of medication and therapy. The initial selection of specific pharmacologic

treatment is often based on the anticipated duration of the anxiety. Acute (and time-limited) anxiety can often be managed

with short-term benzodiazepine therapy. Chronic anxiety is often better managed with medications in the antidepressant

class.

Treatment should be selected after a careful review of specific drug indications, adverse effects, drug-drug interactions,

cost, and clinician experience. Patients should be informed of the risks and benefits of suitable pharmacologic agents.

With all antidepressants, especially selective serotonin reuptake inhibitors (SSRIs) and venlafaxine, the clinician should

review the potential for idiosyncratic increase in anxiety and agitation. Additionally, patients should be aware of the

potential for the rare emergence of suicidal ideation.2 Since SSRIs and benzodiazepines can produce significant

withdrawal syndromes, patients should be instructed about the need to taper medications under a physician’s care, should

they decide to discontinue their medications.3

Role of benzodiazepines

Acute stress-related anxiety can result in the development of adjustment disorder with anxious mood. Physicians may

encounter patients with high anxiety related to medical illness. For example, an excessively anxious patient awaiting the

result of biopsy may meet criteria for adjustment disorder. The diagnosis of adjustment disorder requires that the patient's

anxiety level exceed that expected for the stressor. Since adjustment disorder with anxious mood often improves with

time, a limited duration of pharmacologic treatment is indicated. For milder acute anxiety, a process of observation may be

appropriate to monitor an expected resolution of symptoms over time.

Benzodiazepines produce a rapid-onset anxiolytic effect and may be the agents of choice for adjustment disorder with

anxiety with an anticipated duration of treatment of less than 6 weeks. Many benzodiazepines also have intravenous

formulations that can be used in the emergency room or preoperatively. However, clinicians should review the risk for

benzodiazepine misuse before prescribing. This risk is increased for patients with a personal history of alcohol abuse or

illicit substance dependence. Other risk factors for misuse include a family history of alcohol abuse or family history of

substance dependence. Finally, benzodiazepine therapy should be avoided in patients with antisocial personality disorder.

Since benzodiazepines have limited effect on depression, these agents should not be used as monotherapy for patients

with anxiety in the context of significant depression.

When using benzodiazepines to treat acute anxiety, dosage titration is required to limit risk of adverse effects. Higher daily

doses of benzodiazepines may raise risk of falls and other types of accidents. The ability to form memories can be

impaired during the time benzodiazepines are in the blood. Patients should not drink alcohol while taking

benzodiazepines.

Role of selective serotonin reuptake inhibitors

Chronic anxiety should produce a search for a specific anxiety disorder diagnosis. Generalized anxiety disorder, panic

disorder, social phobia, obsessive-compulsive disorder, and posttraumatic stress disorder are common causes of chronic

anxiety. SSRIs appear to be effective across many of the specific anxiety disorders. The SSRIs include fluoxetine,

sertraline, paroxetine, fluvoxamine, citalopram, and escitalopram. Some of these agents have specific indications

approved by the US Food and Drug Administration (FDA) for individual anxiety disorder diagnostic categories. However,

most head-to-head comparisons between agents in the SSRI class find similar response rates for individual anxiety

disorder categories.4

Although the SSRIs appear to have equal efficacies for anxiety disorders, a trial with a second SSRI may be indicated

after failure with the first SSRI. Some individual patients appear to respond better to one SSRI than to another. The only

valid way to determine which SSRI will produce a response in a particular patient is to perform clinical trials.

Role of other antidepressant compounds

Tricyclic antidepressants (TCAs) have been effective for the treatment of many anxiety disorders. Imipramine has been

studied and found to be effective in a variety of anxiety states. Clomipramine has an FDA indication for the treatment of

obsessive-compulsive disorder. Although TCAs have clinical effectiveness for many anxiety disorders, their limited

tolerability and toxicity in overdose make them second-line agents for many patients.

Newer antidepressants are available with good tolerability and serve as reasonable alternatives to TCAs and SSRIs.

Venlafaxine is a dual-action reuptake inhibitor that blocks the reuptake of both serotonin and norepinephrine. It has been

approved by the FDA for the treatment of generalized anxiety disorder, social phobia, and panic disorder.5 Duloxetine is

also a dual-action reuptake inhibitor; it has not yet received extensive study in the treatment of anxiety disorders.

Monoamine oxidase inhibitors (MAOIs) such as phenelzine and tranylcypromine appear to have significant anti-anxiety

properties. These agents may be considered for patients with social phobia or posttraumatic stress disorder. MAOIs can

produce hypertensive crisis in interactions with some drugs and foods with high tyramine content. This interaction limits

their usefulness except in patients whose symptoms are refractory to other treatment.

Role of other agents

A host of other pharmacologic agents from other drug classes may be helpful in the management of anxiety. Buspirone is

an agent that may prove helpful in generalized anxiety disorder. Pregabalin and gabapentin are anti-epileptic drugs with

structures similar to gamma-aminobutyric acid (GABA). These agents have limited abuse potential and may have a role in

the treatment of anxiety disorders.6 Their role in anxiety management is likely to emerge with further clinical trials.

Some clinicians have found anticholinergic agents such as diphenhydramine or hydroxyzine as helpful in managing

anxiety. Use of these drugs should be limited in geriatric populations because of the risk of memory impairment and

anticholinergic delirium.

The agents in the atypical antipsychotic class, including risperidone, olanzapine, ziprasidone, quetiapine, and aripiprazole,

may be considered for patients with treatment-resistant anxiety disorders.7 Atypical antipsychotic augmentation of an

SSRI in posttraumatic stress disorder and obsessive-compulsive disorder may provide incremental clinical improvement.

Treatment guidelines

Guidelines for treatment of anxiety disorders provide additional details about pharmacologic treatment. Available

guidelines cover all of the major anxiety disorder categories.8 Guidelines are also available for some of the individual

anxiety disorder categories and for management of anxiety in primary care populations.9,10

* Question 4

Bel is 20 years old and has had a Type I allergic reaction to a bee sting. She states that there is a family history of bee sting allergy. Which of the following is NOT useful advice for Bel?

a) Do not drink out of an open soft drink can that has been left outdoors Incorrect. The correct answer is (c).

b) Have a supply of antihistamines on hand

c) Insect repellents are useful to prevent bee stings

d) Do not walk barefoot around swimming pools

e) Always carry an adrenalin 1:1000 injection, e.g. EpiPen, and know how to use

it

Insect repellents have not been shown to be useful in preventing bites from stinging insects. Anyone with a known allergy to stinging insects should know how to administer adrenalin 1:1000 subcutaneously and have it with them at all times. EPIpen is a commercial preparation which is supplied with an auto-injection device. Avoiding behaviours likely to lead to a sting - such as those mentioned in the options and avoiding colourful clothes and perfumes which attract insects - is also important.

* Question 5

John is a 30 year old professional athlete who suddenly develops persistent dull

upper left chest pain which is not related to exertion. There are no associated cardiac or respiratory features except for a mild restriction in breathing. John is afebrile and otherwise well. Which of the following diagnoses is LEAST likely?

a) Spontaneous pneumothorax Incorrect. The correct answer is (e).

b) Functional chest pain

c) Costo-chondral syndrome

d) Muscle strain

e) Pleurodynia ( Bornholm's disease)

Bornholm's disease is due to an infection by Coxackie B virus. It is often associated with an acute upper respiratory tract infection with fever, pleuritic chest pain and upper abdominal pain. These pains can be severe and associated with tachypnoea. A spontaneous pneumothorax, functional chest pain, costochondritis or acute muscular strain would be more likely in this patient.

Question 6

Which of the following statements concerning bee sting allergy is CORRECT?

a) If a patient has had a life-threatening episode in the past, he or she is at risk of a future one Correct

b) A mild reaction in the past puts a patient at risk of a future life threatening episode

c) Wasps only sting once

d) A bee sting is smaller in volume than a wasp sting

e) A raised serum IgG persists for years in those at risk of anaphylaxis

A previous life-threatening reaction is an indicator that a similar episode may occur in the future. Reactions don't necessarily escalate. Wasps produce a smaller volume of sting, but are capable of stinging multiple times. Serum IgE levels remain elevated in those at risk of an anaphylactic reaction. IgG appears protective.

Question 7

The nephrotic syndrome can be caused by all of the following EXCEPT:

a) Minimal change disease (lipoid nephrosis)

b) Amyloidosis

c) Membranous glomerulonephropathy

d) Renal vein thrombosis Correct

e) Diabetic nephropathy

Renal vein thrombosis is more likely to be a complication of nephrotic syndrome rather than a cause. In nephrotic patients the blood is more coagulable than normal and the circulation may be sluggish owing to hypovolaemia, both of which are likely to induce thrombosis. The other options, together with focal and segmental glomerulosclerosis, are responsible for 90% of cases of nephrotic syndrome. They are all conditions which disturb the structure or function of the glomerular basement membrane.

Question 8

Bill, aged 35 years, has been unwell for 2 days with severe abdominal cramps and diarrhoea. He visited friends living on a farm during the previous week. He stated

that on inspection of his stool there appeared to be blood in it. What is the significance of blood in the stool?

a) The causative organism is more likely to be bacterial than viral

b) There is a higher risk of complications

c) This may be the first presentation of inflammatory bowel disease

d) Stool microscopy and culture to identify the organism is worthwhile

e) All of the above Correct

The presence of blood in the stool of a patient with a constitutional illness is strongly suggestive of a bacterial infection. Identification of the causal bacteria is usually desirable for clinical and public health reasons. Most of the conditions are reportable to the relevant state health department. In some cases fulminant infection can occur and treatment based on antibiotic sensitivities of the organisms will be required.

Many of these bacteria (Yersinia, Campylobacter, Shigella etc) can lead to a systemic illness with polyarthropathy.

* Question 9

Abdul is a 58 year old man who presents with transient episodes of vertigo, slurred speech, diplopia, and paraesthesia. Which of the following is the MOST likely

diagnosis?

a) Basilar artery insufficiency Correct

b) Anterior communicating artery aneurysm

c) Hypertensive encephalopathy

d) Pseudobulbar palsy

e) Occlusion of the middle cerebral artery

Transient ischaemic attacks involving the posterior brain circulation, i.e. the basilar artery, are characterised by diplopia, vertigo, vomiting, dysarthria, ataxia and hemisensory loss.

Question 10

Andrew, aged 60 years, complains of traces of blood in his stool for the past few weeks. Which of the following is the MOST likely cause?

a) Diverticulosis

b) Cancer of the rectum Incorrect. The correct answer is (c).

c) Haemorrhoids

d) Angiodysplasia

e) Colitis

Haemorrhoids and/or anal fissures are the commonest and therefore most likely causes of traces of fresh blood in the stool. These are easily identified by physical examination. However, there are a number of other more serious pathologies which

must be excluded, including colorectal cancer diverticulosis, angiodysplasia and colitic conditions. These can be diagnosed by a combination of rectal examination, sigmoidoscopy and colonoscopy plus biopsy.

Question 11

Cyanosis is LEAST likely to occur in:

a) Ebstein's anomaly (anomalous attachment of tricuspid valve)

b) Tetralogy of Fallot

c) Tricuspid atresia

d) Ventricular septal defect

e) Transposition of the great vessels Incorrect. The correct answer is (d).

Cyanotic heart disease occurs when the systemic venous return is directed backward into the systemic circulation without transitting the pulmonary vascular bed, i.e. instead of pure left to right shunting, right to left or bi-directional shunting occurs. Patients with ventricular septal defects do not usually present with cyanosis. However, if there is a particularly large defect, pulmonary vascular damage can occur leading to pulmonary hypertension and right to left shunting with cyanosis

(Eisenmenger's syndrome). The other options listed are all associated with right to left shunting and cyanosis.

Question 12

Which of the following pathogens causing gastrointestinal infection is NOT associated with bloody diarrhoea?

a) Listeria monocytogenes Correct

b) Campylobacter spp

c) Yersinia enterocolitica

d) Salmonella serovars

e) Shigella

Listeria monocytogenes usually only causes illness in immunocompromised patients and pregnant women. L. monocytogenes is quite unlike most food-borne pathogens in that it does not cause gastrointestinal symptoms but causes invasive infections like meningitis, septicaemia, and chorioamniitis leading to stillbirth. Gastrointestinal infections by all the other pathogens listed result in bloody diarrhoea to varying degrees.

Question 13

The erythrocyte sedimentation rate (ESR) is raised in all of the following EXCEPT:

a) Multiple myeloma

b) Polycythaemia rubra vera Correct

c) Macrocytic anaemia

d) Pregnancy

e) Chronic hepatitis

The ESR is a non-specific indicator of inflammatory and neoplastic disease. The ESR

increases with age and is raised in pregnancy, the puerperium and in anaemia. It is increased in acute and chronic inflammatory disease and neoplastic disease. A low ESR (<1mm/hour) may be seen in polycythaemia rubra vera and sickle cell disease. The C-reactive protein is a more sensitive early indicator of an acute phase response.

Question 14

Which of the following statements about weight loss is CORRECT?

a) Dieting reduces the basal metabolic rate (BMR)

b) Dieting increases the BMR

c) Exercise decreases appetite

d) Inactivity increases appetite

e) None of the above Incorrect. The correct answer is (a).

Changes to a person's stable weight, either an increase by forced feeding, or a

decrease by food restriction (dieting), induce compensatory physiological responses that resist these changes. Thus with low calorie regimes the BMR decreases to limit energy expenditure and appetite increases, factors which complicate the process of weight loss for the dieter. Exercise generally increases appetite in response to the fall in blood glucose caused by exercise.

Question 15

Which of the following is the MOST COMMON pathological condition associated with aortic aneurysms?

a) Atherosclerosis Correct

b) Syphilitic aortitis

c) Trauma

d) Rheumatic aortitis

e) Cystic medial necrosis

Atherosclerosis is the most common pathological condition associated with aortic aneurysms. The other options are also associated with aortic aneurysms but are less common.

Question 16

Bob has had moderately raised plasma cholesterol and triglyceride concentrations for 6 months and you have advised him to start on medication since dietary measures, including abstaining from alcohol, have had minimal effect. Investigations have shown that he has a raised plasma very low density lipoprotein (VLDL) level, i.e. he has type IV hyperlipoproteinaemia. Which of the following medications would you prescribe?

a) Cholestyramine

b) Gemfibrozil

c) Simvastatin

d) Atorvastatin Incorrect. The correct answer is (b).

e) Fish oil

Gemfibrozil is a fibrate which is the class of drugs recommended for treatment of type IV hyperlipoproteinaemia. It stimulates lipoprotein lipase activity and thereby strips triglycerides from VLDL, causing VLDL degradation and lowering of VLDL levels, with consequent lowering of plasma cholesterol and triglyceride levels. The mode of action and recommended indications for use of the other options are discussed in the references below.

Question 17

In which of the following conditions does angina pectoris occur in the absence of coronary artery disease:

a) Mitral stenosis

b) Mitral insufficiency

c) Coarctation of the aorta

d) Aortic stenosis Correct

e) Aortic insufficiency

In severe aortic stenosis when the aortic orifice is reduced to one-third or less of its normal size, angina pectoris may occur because of insufficient perfusion of the coronary arteries. This is usually associated with fainting and dyspnoea.

Question 18

Whole body zinc stores may be depleted in all of the following EXCEPT:

a) Coeliac disease

b) Diabetes mellitus Incorrect. The correct answer is (d).

c) Alcoholism

d) Vegetarianism

e) Acquired immunodeficiency syndrome (AIDS)

Zinc is an essential component of many enzyme systems including carbonic anhydrase, alcohol dehydrogenase and alkaline phosphatase. The best dietary sources are meat, shellfish and legumes; zinc in grains is less available for absorption. Zinc deficiency occurs in a variety of conditions (including all the other options listed above) but not vegetarianism. Vegetarians obtain adequate amounts of zinc from legumes, nuts and cereals.

Question 19

A man aged 55 years begins to develop progressive dementia and is admitted to hospital because of a convulsive episode. On examination the patient has weakness of the right side of his body and a positive grasp reflex on the same side. The MOST

LIKELY diagnosis is:

a) A temporal lobe tumour on the right side

b) A temporal lobe tumour on the left side

c) A pre-frontal tumour on the left side Correct

d) A pre-frontal tumour on the right side

e) A posterior fossa tumour on the left side

Involvement of the prefrontal area of the brain is often associated with impairment of executive functions (decision-making, disinhibited actions, impairment of concentration and memory). The emergence of developmentally primitive reflexes such as grasping, rooting and sucking are seen mainly in patients with large structural lesions of the frontal cortex. The right-sided hemiparesis and grasp reflex point to a left-sided lesion.

Question 20

Non haem iron absorption is promoted by all of the following EXCEPT:

a) A high phosphate content of the diet

b) Low pH in the stomach

c) Vitamin C taken with a meal

d) Iron deficiency

e) Erythroid hyperplasia Incorrect. The correct answer is (a).

A high phosphate content of the diet inhibits iron absorption by forming insoluble iron phosphates. All the other factors mentioned promote iron absorption. Acid and vitamin C keep iron in the ferrous form. Iron deficiency and erythroid hyperplasia influence iron absorption through unknown mechanisms via the gut

Question 21

Paul is a 45 year old man with an acute myocardial infarction. He develops a sinus bradycardia of 38 beats/minute with frequent ventricular extrasystoles. The IMMEDIATE treatment of choice is:

a) Intravenous propranolol

b) Immediate direct current cardioversion Incorrect. The correct answer is (d).

c) Intravenous morphine

d) Intravenous atropine sulphate

e) Intravenous lignocaine

Atropine should be the initial agent at doses of 0.5mg IV every 5 minutes until the desired response is achieved by removing vagal inhibition Transcutaneous cardiac pacing is indicated if the above is not effective (bradycardia remains <40/min), with internal pacing being the definitive treatment for progressive or persistent

bradycardias.

Question 22

All of the following features are consistent with haemolytic uraemic syndrome (HUS) EXCEPT:

a) Bloody diarrhoea

b) Thrombocytopaenia Incorrect. The correct answer is (c).

c) High fever with rigor

d) Neurological abnormalities

e) Acute renal failure

Haemolytic uraemic syndrome is most common in children following a gastrointestinal infection with a toxic strain of E.coli. Bloody diarrhoea is the usual presenting feature followed by haemolysis and renal failure. Microvascular damage

results in profound thrombocytopaenia and may involve the central nervous system.

If fever is present it is usually low-grade. Early supportive treatment allows a full recovery in 70% of children but there is a 3-5% mortality and 15-30% will have chronic renal failure.

Question 23

Which of the following triads of clinical features is found in beri beri?

a) Cardiac failure, glossitis, dermatitis

b) Cardiac failure, neuropathy, dermatitis

c) Glossitis, dermatitis, memory loss

d) Glossitis, neuropathy, memory loss Incorrect. The correct answer is (e).

e) Cardiac failure, neuropathy, memory loss

Beri beri is due to vitamin B1 (thiamin) deficiency. It is now mainly confined to the poorest areas of SE Asia. Neuropathy presents as stiffness, numbness and weakness of the legs and loss of ankle reflexes, progressing to polyneuropathy involving the trunk and arms. Thiamin deficiency impairs cardiac energy metabolism leading to cardiac failure and oedema. Chronic thiamine deficiency results in Wernicke's encephalopathy. Pellagra due to niacin deficiency results in glossitis, diarrhoea,

dermatitis, and dementia.

Question 24

Chronic inorganic lead poisoning is associated with all of the following laboratory features EXCEPT:

a) Basophilic stippling of red cells

b) Increased red cell protoporphyrin level

c) Normochromic normocytic anaemia Correct

d) Uraemia

e) Aminoaciduria

The anaemia of chronic lead poisoning is usually hypochromic microcytic. The other options are all features of lead poisoning, due to toxic effects on erythropoieses and on the kidney.

Question 25

Sheila is a 19 year old woman who presents with ascites, high venous pressure and a small quiet heart. Which of the following surgical procedures would be MOST likely to relieve her problem?

a) Mitral commissurotomy

b) Closure of the foramen ovale

c) Ligation of a patent ductus arteriosus

d) Correction of coarctation of aorta

e) Pericardiectomy Correct

Sheila has constrictive pericarditis in which the pericardial cavity is obliterated and

dense scar tissue encases and constricts the heart. Diastolic filling of the ventricles is limited resulting in a decrease in cardiac output. The right ventricular diastolic pressure is increased, leading to venous hypertension which in turn produces hepatomegaly, ascites and peripheral oedema. Prompt pericardiectomy is the treatment of choice. This corrects the hemodynamic abnormalities and patients improve rapidly with a massive diuresis.

Question 26

Tom is a 30 year old agricultural worker who works with organophosphates. He presents with acute pain in the right iliac fossa. You suspect acute appendicitis but are concerned about the risk of a laparotomy BECAUSE:

a) There is a risk of erroneous diagnosis

b) There is a tendency to prolonged bleeding post-operatively

c) There is an increased hazard in general anaesthesia

d) There is a likelihood of delayed healing of the wound Incorrect. The correct answer is (c).

e) There is a possibility of mental disorder after operation

Organophosphates irreversibly inhibit acetylcholinesterase and cause accumulation of acetylcholine at muscarinic and nicotinic receptors. In general anaesthesia, muscle relaxant drugs like prostigmine cause reversible blockade of cholinesterase. Should a patient have absorbed subclinical doses of organophosphates (e.g. in agricultural

work with pesticides), there is increased risk of excessive neuromuscular blockade with use of muscle-relaxants, and the patient may show signs of toxicity, or may continue to be paralysed beyond the duration of the anaesthetic agent given.

Question 27

Pamela is a 55 year old woman who comes to see you for dietary advice. She is an

estimated 10kg above her ideal body weight and is keen to reduce this before the summer. Which of the following strategies would NOT be appropriate in this situation?

a) Advise Pamela against the use of appetite suppressant medication

b) Encourage daily exercise of at least 30 minutes with heart rate to 70% of

maximum for her age

c) Assist Pamela to redefine her goals in terms of non-weight targets such as waist measurement and improved stamina

d) Recommend an 8 week course of a very low calorie diet (400-600kcal/day) to get started Correct

e) Warn Pamela that a diet very low in carbohydrate is less likely to result in sustained weight loss

Very low calorie diets are most appropriate when body weight is >130% of ideal. They must be supervised by a medical officer due to the potential for electrolyte imbalance. All the other options are appropriate in this situation. Behavioural modification that involves simple and sustainable changes in a person's diet, exercise and lifestyle routine is likely to be the most effective way to achieve and maintain an ideal body weight.

* Question 28

The FIRST sign of salicylate poisoning in children is usually:

a) Delirium

b) Coma

c) Hyperventilation Correct

d) Hyperpyrexia

e) Convulsions

Aspirin has a two-fold toxic effect. First, it inhibits oxidative phosphorylation leading to a metabolic acidosis. The increased hydrogen ion concentration of the extracellular fluid stimulates the respiratory centre of the brain to cause hyperventilation. This is the primary effect in children. Second, aspirin directly stimulates the respiratory centre to cause hyperventilation leading to a respiratory alkalosis. This phenomenon is seen mainly in adults

* Question 29

Charles is a 48 year old businessman who presents for a general check-up and mentions that he is experiencing occasional fluttering sensations in his chest. A routine electrocardiograph (see figure) is taken.

Your first line of management should be:

a) Reassurance

b) Referral for cardioversion

c) Begin a trial of verapamil Incorrect. The correct answer is (a).

d) Commence beta-blockade

e) Give lignocaine stat

The ECG shows Charles has premature atrial ectopic beats. Often these are asymptomatic. They may, however, be sensed as an irregularity or heaviness of the heart beat. Treatment is not normally required; reassurance is all that is needed. However, if the ectopic beats provoke more significant arrhythmias, Beta-blockade

may be effective. Charles would be given general advice regarding quitting smoking and minimising alcohol, caffeine and other stimulants such as cough medicines.

Question 30

James is a 50 year old woodcutter whom you treated for a Colles' fracture two days

ago. His wife telephones asking you to prescribe a sleeping tablet for him because James is having difficulty in sleeping. Which of the following is the MOST appropriate next step?

a) Suggest she gives James a nightcap of whisky

b) Prescribe a short-acting benzodiazepine

c) Describe some relaxation exercises for James to do immediately before bedtime

d) Prescribe an analgesic such as paracetamol and codeine combination

e) Ask James to come to the surgery so you can check the plaster Correct

The prudent action is to ask James to come to the surgery to check the plaster and the condition of his hand as soon as possible, since it may be that his problem is related to swelling around the fracture site with increased pressure inside the plaster cast. This can lead to an adverse outcome unless the pressure is relieved soon. Once this is ruled out or dealt with, the next issue to be addressed is adequate pain relief. In most cases, once adequate pain relief is ensured, insomnia will no longer be a problem. If insomnia does persist, a short-acting benzodiazepine may be prescribed

for no more than 7-10 days to avoid development of dependency. An alcoholic nightcap is not a good idea, as it usually causes the patient to wake during the night and have difficulty getting back to sleep.

Question 31

The interossei muscles of the hand are supplied by:

a) The radial nerve

b) The median nerve

c) The ulnar nerve Correct

d) All of the above

e) None of the above

The ulnar nerve (c8- T1) supplies the adductors and abductors of the fingers, the adductor of the thumb, the medial two lumbricals and the muscles of the hypothenar eminence.

* Question 32

Which of the following situations is a CONTRAINDICATION to immunisation with a live attenuated vaccine?

a) Pregnancy Correct

b) Breastfeeding

c) Mild acute febrile illness

d) Current antibiotic therapy

e) Immunodeficiency in a household contact

Pregnancy is a valid contraindication to immunisation with a live attenuated vaccine eg oral polio infection. Exposure to HIV, other immunodeficiency states and immunosuppressant treatments are also contraindications. Diarrhoea, minor acute illnesses, antibiotic therapy and breast feeding are not valid contraindications.

Question 33

Brenda brings Jake, her 2 month old son for his first Triple antigen injection. Which of the following statements is CORRECT in relation to the acellular pertussis vaccine?

a) It provokes a stronger immune reaction Incorrect. The correct response is (c).

b) The costs are the same as whole cell vaccine

c) It causes a lower incidence of fever, crying and irritability

d) It works against the bacteria rather than the toxin

e) It provides protection against P. bronchiseptica

Acellular pertussis is part of DTPa and DTPa-hepB vaccines. Triple antigen vaccine containing acellular pertussis has similar efficacy to that of whole cell pertussis-containing vaccines, but causes significantly less reaction with a much lower incidence of fever, irritability and local reactions. The cost is greater. The vaccine targets the toxin rather than the bacteria.

* Question 34

An obese man, aged 60 years, is admitted unconscious with a diagnosis of completed stroke confirmed on CT scanning as due to a cerebral thrombosis. Of the following supportive measures, the most important IMMEDIATE management is:

a) Insertion of an indwelling urinary catheter Correct

b) Commencement of anticoagulant therapy

c) Physiotherapy to prevent hypostatic pneumonia

d) Commencement of intravenous fluids to prevent dehydration

e) Positioning to prevent development of decubitus ulcers

An indwelling catheter allows monitoring of fluid status as well as allowing urinary drainage. IV fluid therapy is not urgent due to the potential to exacerbate brain swelling, in the acute phase. Anticoagulant therapy is of no value in treating a fully

developed and completed CVA. It may be used in transient ischaemic attacks, in a developing progressive thrombosis, or in prevention of DVT in a bedridden patient. The other measures of physiotherapy and nursing care should follow

* Question 35

Which of the following statements about simple febrile convulsions is CORRECT?

a) It usually occurs between 6-8 years of age

b) Prognosis depends on the precipitating illness

c) The risk of developing epilepsy is 10%

d) The convulsions last less than 15 min Correct

e) Investigation with lumbar puncture and CT is essential

Simple febrile convulsions last less than 15 minutes. They usually occur between 3 months and 5 years, with most occurring between 17 and 23 months of age. There is

no difference in IQ at age 7 years between children who have had a febrile convulsion and their seizure- free siblings. The risk of developing epilepsy following a simple febrile convulsion is 0.9% at age 7 years.

Question 36

The MOST helpful diagnostic test to evaluate a potentially enlarging pituitary neoplasm is:

a) Cerebral angiography

b) Serial serum prolactin concentration Incorrect. The correct answer is (c).

c) MRI

d) Computer assisted colour spectrum visual field plotting

e) CT scan with contrast

Once identified, pituitary neoplasms should be evaluated by an MRI scan. This gives information regarding pressure effects on surrounding structures and the need for surgical treatment. Serum prolactin estimation gives information about anterior pituitary function, but not size. Angiography is unnecessarily invasive and CT is not as sensitive as MRI. Visual field plotting will document any damage to the optic tract

- an unwanted outcome.

* Question 37

Katie, 12 years of age, collapses suddenly at school, and is transported by ambulance with dextrose drip inserted. On examination, a dolls eye reflex is present but she is not responding to painful stimuli. Her vital signs are as follows:

Resp. rate 14/min Pulse rate 50/min Sa02 100 % B/P 180/110

What is the NEXT step of management?

a) Arrange for an urgent head CT scan Incorrect. The correct answer is (c).

b) Replace the dextrose with normal saline

c) Intubate and ventilate

d) Give intravenous corticosteroids

e) Draw venous and arterial blood for urgent analysis

Katie has raised intracranial pressure as indicated by the hypertensive response in the presence of bradycardia and coma. She is at high risk of herniation and needs

urgent treatment to reduce the intracranial hypertension. The most rapid effect is

achieved by endotracheal intubation and hyperventilation to reduce arterial pCO2 to 30-35mmHg. This will be accompanied by an intravenous infusion of mannitol. Urgent assessment to determine the cause of this presentation will include blood tests and CT scan. Corticosteroids may be helpful in cases of intracranial tumour or

CNS infection. Specific treatment will be required for metabolic abnormalities eg. diabetic ketoacidosis, infection or haemorrhage.

* Question 38

The defect in visual fields MOST commonly associated with a pituitary tumour is:

a) Crossed homonymous hemianopia

b) Central scotoma

c) Bitemporal hemianopia Correct

d) Total blindness in one field

e) Peripheral concentric constriction and enlargement of the blind spot

As a pituitary tumour extends upwards from the diaphragma sellae and compresses the optic chiasm, it classically causes superior quadrantic defects followed by bitemporal hemianopia. It can however cause any variety of visual field defects,

including unilateral (or bilateral) field defects in all quadrants, due to the variable position of the chiasm above the pituitary.

Question 39

Which of the following statements about immunisation is CORRECT?

a) If a child has a cold, they can't be vaccinated

b) Fever is an uncommon adverse event after immunisation

c) If a reaction is suspected, a test dose should be used

d) Anaphylaxis to egg is not a contraindication to MMR vaccine Correct

e) Pre-term infants have an inadequate antibody response

An anaphylactic reaction to egg is not a contraindication to MMR vaccine. Infants with minor colds without high fever can be safely immunised. Vaccination should only be postponed if a child is acutely unwell or has a high fever (above 38.5 degrees Celsius). A fever (low grade temperature) is a common adverse effect after

immunisation. Test doses are not recommended, they are just as likely to produce an adverse event as the full dose. Premature infants should receive their vaccinations at the same age as term infants, ie first dose of hepatitis B vaccine at birth and then DTPa-hep B, HIB and polio vaccinations at 2 months after birth (no correction for gestation).

* Question 40

Which of the following would be MOST helpful in distinguishing cerebral infarction from cerebral neoplasm?

a) History of headache

b) Hemiplegia

c) Chronology of development Correct

d) Carotid bruit

e) Focal abnormality on electroencephalogram

Chronology of development is the most important factor in differentiating cerebral infarction from cerebral neoplasm. Cerebral infarction tends to be a simple, sudden event or a series of stepwise events within hours to days. In comparison, neoplasms tend to be preceded by symptoms such as headache, progressive cognitive decline, seizures and vomiting, and may feature steadily progressive neurological signs. The

other options are all variably present in both conditions and are not diagnostic.