14. Mock

Question 1

1. A patient is taking 60 mg of dihydrocodeine four times per day for neuropathic leg pain. He had planned to reduce his usage but quickly
   stopped when he developed diarrhoea and shaking when he first missed a dose. He is reluctant to try again as fears his pain will become worse.
   What best describes the patients state with regard to opioids?
   A. He is addicted
   B. He is dependent
   C. He has developed tolerance
   D. He has withdrawal
   E. He has adverse reactions

Answer 1

1. B
   Dependence can be both psychological and physical.

Psychological dependence is characterized by
fear of stopping drugs and physical dependence by the appearance of withdrawal effects when the
drug is stopped.

D is correct (withdrawal), and it could also be said that he is suffering an adverse reaction (E), but B is the better, complete answer.

Addiction is characterized by compulsive drug seeking behaviour and ingestion despite clear
evidence of the substance causing ongoing harm.
Tolerance occurs when the patient requires higher
doses of opioid to achieve the same effect

Question 2

2. Which of the following operations carries the weakest indication for paravertebral block?
A. Mastectomy and axillary clearance
B. Lateral thoracotomy
C. Open cholecystectomy
D. Midline laparotomy
E. Inguinal hernia repair

Answer 2

2. D
   Paravertebral block has been described and may be indicated for unilateral surgical procedures
   in the thoracoabdominal region. All of these operations are unilateral except for the midline
   laparotomy

Question 3

3. Regarding mechanical circulatory support with an intra- aortic balloon pump. The best choice of gas for balloon inflation is:
A. Hydrogen
B. Helium
C. Oxygen
D. Nitrogen
E. Carbon dioxide

Answer 3

3. B
   Significant volumes of gas (25– 50 mL) have to be moved in and out of the aortic balloon in very
   short periods of time. Helium is therefore the best choice because its viscosity/ density is low
   compared with other gases which might be used and allows rapid passage through a narrow femoral
   catheter. Additionally, in the event of balloon rupture in situ, helium is easily absorbed and would
   therefore be removed from bubbles in the circulation faster than other more insoluble gases.

Question 4

4. Regarding the description of a skewed dataset, the most commonly quoted measure of data spread is:
A. Interquartile range
B. Standard deviation
C. Range
D. Standard error of the mean
E. Variance

Answer 4

4. A
   The interquartile range (IQR) is often quoted when referring to interval data that is not normally
   distributed.
   Additionally, it is frequently represented graphically together with the median value as a boxplot or box and whisker diagram.

Question 5

5. You anaesthetize a patient for laser vocal cord surgery. The patient is ventilated via a laser tube with an oxygen/ air/ desflurane mix. A fire is
   ignited in the airway. What should your immediate action be?
   A. Remove the endotracheal tube
   B. Flood the operative site with saline
   C. Switch off the anaesthetic machine
   D. Disconnect the breathing circuit
   E. Reduce FiO2 to 21%

Answer 5

5. B
   Fires are a very real risk during laser airway surgery since all the requirements for fire are
   present: oxygen, fuel (airway devices), and energy ignition (laser).

Should a fire ignite in the airway,
the surgeon and anaesthetist must immediately switch off the laser and flood the operation site
with saline. Following this, the anaesthetic breathing system should be disconnected temporarily.

There should be consideration of removing the endotracheal tube as even laser tubes can be
ignited. In this scenario, the patient should then be ventilated with air using a face mask and separate
breathing system.

Question 6

6. The use of mannitol as an osmotic diuretic is recommended as a standard of care by consensus guidance during management of which
   condition below?
   A. Renal protection in cardiac surgery
   B. Renal protection in non- cardiac vascular surgery
   C. Renal transplantation
   D. Intracranial pressure
   E. Rhabdomyolysis

Answer 6

D6. D
Mannitol is a standard of care for the management of intracranial hypertension and is recommended by consensus guidelines.

There is little evidence to support its continued use for
other indications, such as renal protection during cardiac and vascular surgery, or for prophylaxis
against acute renal failure in rhabdomyolysis. Following renal transplantation, adequate hydration alone appears to be effective

Question 7

7. An 82- year- old woman presents with fractured neck of femur.
   Her past medical history includes transient ischaemic attack, hypertension, and stage 4 breast cancer. Her medication includes bisoprolol, bendroflumethiazide, and clopidogrel. She lives alone and is usually able
   to climb two flights of stairs. Her blood tests are unremarkable and resting electrocardiogram (ECG) is normal. The FY1 has noted a cardiac
   murmur on examination. What is the most appropriate next step?

A. Postpone surgery pending echocardiography
B. Because of terminal diagnosis, cancel surgery, and refer to palliative care
C. Stop clopidogrel for seven days and then proceed under spinal anaesthesia
D. Arrange a platelet transfusion and proceed under general anaesthesia (GA)
E. Proceed under GA

Answer 7

7. E
   By way of formal risk assessment, this patient’s Nottingham Hip Fracture (NHF) score is 5/ 10
   which predicts mortality of around 10% at 30 days.

When a hip fracture complicates a terminal
illness, the multidisciplinary team should still consider the role of surgery as part of a palliative care
approach to minimize pain.

Surgery is the best treatment of acute pain in all hip fracture patients.

While her life expectancy is certainly limited, living at home unaided suggests death from metastases
is not imminent enough to subject her to the pain and problematic nursing involved with an unfixed
hip fracture.

Most hip fracture patients should be treated in a fast track pathway with surgery on the day of, or the day after admission.

Correctable comorbidities should be identified and treated immediately so that surgery is not delayed. Surgery should not be postponed to stop clopidogrel,
nor for platelets to be administered prophylactically.

Marginally greater blood loss should be
expected. Echocardiography is controversial in the patient with a murmur. In the context of normal
ECG, reasonable exercise tolerance and absence of significant other symptoms such as angina
or syncope in this patient, the majority of anaesthetists are likely to proceed without delay for
echocardiography.

Question 8

8. You review a 67- year- old man at the pre- assessment clinic.
   He has been smoking 20 cigarettes a day for more than 40 years.
   He has a chronic cough and is short of breath on exertion. You order pulmonary function tests to investigate further. Which of the following would best support a diagnosis of moderate chronic obstructive pulmonary disease (COPD)?

A. Forced expiratory volume in 1 second (FEV) 81% predicted
B. Increased gas transfer coefficient
C. FEV1:FVC (forced vital capacity) ratio post bronchodilator of 0.6
D. Increased vital capacity
E. Decreased carbon monoxide transfer factor

Answer 8

8. C
   The NICE guidelines exist to help the diagnosis and assessment of COPD. Anyone over
   35 who smokes and has symptoms including cough, exertional breathlessness, and excess
   sputum production should be investigated primarily using spirometry.

A FEV1/ FVC ratio post
bronchodilator of <0.7 would be diagnostic of COPD.

FEV1% predicted useful for severity grading.

FEV1/ FVC ratio <0.7 and
FEV1% predicted >80% – mild COPD or stage 1

FEV1/ FVC ratio <0.7 and FEV1% predicted 50– 79% – moderate COPD or stage 2

FEV1/ FVC ratio <0.7 and FEV1% predicted 30– 49% – severe COPD or stage 3

FEV1/ FVC ratio <0.7 and FEV1% predicted <30% – very severe COPD or stage 4

In COPD, the vital capacity, the carbon monoxide transfer factor, and the gas transfer coefficient
are all reduced.

Question 9

9. When reviewing a 57- year- old lady on the daily intensive care unit (ICU) round you notice she is grimacing, her upper limbs are fully flexed, and
   she is coughing on her ET tube after turning and dressing changes. She was admitted 24 hours ago following an emergency laparotomy for a
   perforated duodenal ulcer. She is currently on propofol and morphine infusions. What would be the best management of this patient?
   A. Add an infusion of atracurium
   B. Change to midazolam sedation
   C. Increase the morphine infusion
   D. Add a regular NSAID
   E. Increase the propofol infusion

Answer 9

9. C
   The issue here is pain rather than problems with sedation or ventilation. Grimacing, flexion of limbs,
   muscle tension, and compliance with ventilation have a high specificity and sensitivity for predicting
   significant pain in postoperative ICU patients exposed to a painful procedure.

When a patient is unable to communicate the Critical Care Pain Observation Tool or Behavioural Pain Scale scoring systems should be used which look at the factors mentioned above.

NSAIDS would be contraindicated in this case.

Treatment of pain in ICU should be multi- modal but is usually best managed by iv administration.

This associated with fast onset and is easiest to titrate to effect.

Question 10

10. You are required to anaesthetize a 29- year- old para 1 at term for category 2 caesarean section due to failure to progress in labour.
    She is using remifentanil patient- controlled analgesia (PCA) for analgesia. She had a normal vaginal delivery previously. She has congenital bicuspid aortic valve and the gradient across the valve is 25 mmHg. The best anaesthetic for caesarean section is:
    A. De novo epidural and top up
    B. Spinal
    C. Combined spinal/ epidural
    D. GA using rapid sequence induction
    E. GA using target- controlled infusion (TCI) propofol and remifentanil

Answer 10

10. C
    This represents mild to moderate aortic stenosis which is well tolerated in pregnancy. The aim of
    any intervention is to avoid reduction in systemic vascular resistance and maintain normal sinus
    rhythm.

The conduct of anaesthesia is more important than the choice of technique.

Previously GA was always advocated to avoid large drops in SVR and myocardial contractility resulting from regional sympathetic blocks to T4; however, in the last decade, reports show carefully managed and
controlled spinal and epidural anaesthesia is increasingly used.

This patient has tolerated a term
pregnancy and delivery before. There is time for a regional technique to be performed but perhaps
not for a de novo epidural to be established. A combined spinal epidural (CSE) will allow more rapid
onset of block whilst avoiding the cardiovascular changes associated with a full dose single shot
spinal.

Uterine displacement must be maintained throughout to avoid reduction in venous return and filling pressure. Heart rate should be maintained (fixed stroke volume means any reduction in HR will reduce cardiac output).

Oxytocin bolus should be avoided, an infusion is preferable to avoid tachycardia and hypotension.

Consider arterial line placement perioperatively.

Question 11

11. A 69- year- old man is scheduled for a coronary artery bypass graft.

He past medical history includes ischaemic heart disease, type 2 diabetes, and hypercholesterolaemia.

He is concerned about the risks of his surgery. What is the most common significant neurological
complication following this surgery?
A. Transient ischaemic attack
B. Raised intracranial pressure
C. Intracranial haemorrhage
D. Postoperative cognitive dysfunction (POCD)
E. Ischaemic stroke

Answer 11

11. D

POCD is the most common complication with short term cognitive decline occurring in 20– 50% of
patients. Long- term POCD lasting greater than six months occurs in 10– 30% patients

Question 12

12. A patient in the High Dependency Unit requires renal replacement therapy (RRT). The patient has no central intravenous access at present.
    What is the preferred site for a renal replacement line?
    A. Left subclavian vein
    B. Right internal jugular vein
    C. Right femoral vein
    D. Left internal jugular vein
    E. Right subclavian vein

Answer 12

12. B

KDIGO Clinical Practice guideline for acute kidney injury listed the right internal jugular site as the
first choice for vascular access catheters.

The subclavian is the least preferred because of higher
rate of stenosis formation with chronic use. The femoral vein would be the second choice.

The right internal jugular should be used in preference to the left because it allows improved delivery of
RRT with a straighter anatomical course.

Question 13

13. You have admitted a woman to ICU with a body mass index of 16 and a
    very poor nutritional state. You start controlled nasogastric feeding with a standard bag, noting that she is at high risk of refeeding syndrome.
    What is the most important additional compound to replace?
    A. Thiamine
    B. Vitamin B12
    C. Folate
    D. Vitamin D
    E. Glutamine

Answer 13

13. A
    It is extremely important to replace thiamine (as intravenous Pabrinex) when it is likely to be
    deficient in order to prevent neurological complications. Thiamine is not usually found in standard
    enteral feed.

Question 14

14. A healthy 28- year- old lady had a normal spontaneous vaginal delivery (SVD) two days ago. She had an epidural for labour which was sited without complication.
    She is now complaining of a constant band- like headache and is intolerant of noise. She has no other neurological signs or symptoms. What is the most likely cause of her headache?
    A. Pre- eclampsia
    B. Cortical vein thrombosis
    C. Post- dural puncture headache
    D. Tension headache
    E. Meningitis

Answer 14

14. D
    Tension headache is the commonest cause of post- partum headache often due to hormone level
    fluctuation, sleep deprivation, dehydration, and caffeine withdrawal. It is characterized by a bandlike
    headache and is usually self- limiting. There are no other signs or symptoms in the question to
    suggest a more sinister cause.

Question 15

15. When considering statistical test, which of the following best describes the analysis of variance (ANOVA) test?

A. A test to compare two normally distributed independent groups

B. A test to compare two normally distributed matched groups

C. A test that compares the mean of one sample group against a known value

D. A test that compares greater than three sample proportions of categorical data

E. A test that compares three or more normally distributed groups of interval data

Answer 15

15. E
    A describes the un- paired Student’s t- test
    B describes a paired Student’s t- test
    C describes a Wilcoxon rank sum test for non- normally distributed data or a one sample ttest
    for normally distributed data
    D describes a chi- squared test
    E describes ANOVA

Question 16

16. A 27- year- old woman presents with acute breathlessness and respiratory failure.

She has signs of a current chest infection. She has a
background history of worsening exercise tolerance over the previous three months.

She improves with rest and has no muscle pain. On
examination she has generalized muscle fatigability, ptosis, and diplopia.

She has normal reflexes, sensation, and coordination. An appropriate treatment includes:
A. Atropine
B. Edrophonium
C. Neostigmine
D. Hydrocotrisone
E. Pyridostigmine

Answer 16

16. B

The patient has myasthenia gravis (MG). This has a female preponderance.

MG is an autoimmune disease characterized by weakness and fatigability of skeletal muscles, with
improvement following rest.

It may be localized to specific muscle groups or more generalized.

MG is caused by a decrease in the numbers of postsynaptic acetylcholine receptors at the
neuromuscular junction, which decreases the capacity of the neuromuscular endplate to
transmit the nerve signal.

Deterioration can be precipitated by infection as in this case.

Myasthenic crisis and cholinergic crisis can present in similar ways. This patient has no diagnosis
nor medication.

The Tensilon (edrophonium) challenge test is useful in diagnosing MG and in distinguishing myasthenic crisis from cholinergic crisis.

A positive response is not completely specific for MG because several other conditions (e.g. amyotrophic lateral sclerosis) may also respond to edrophonium with increased strength. Patients who respond generally show dramatic improvement in muscle strength, regaining facial expression, posture, and respiratory function within  min.

Question 17

17. An obstetric patient with severe pre- eclampsia is managed in labour ward high dependency. You plan to site a radial arterial line for monitoring and blood sampling. The midwife asks how to prime the
    arterial line set. What is the recommended flush solution?
    A. Hartmann’s solution
    B. Glucose 5%
    C. Glucose 10%
    D. Saline 0.9%
    E. Saline 0.45%

Answer 17

17. D
    Flush solution under pressure is required to maintain patency of an arterial line.

There is no strong recommendation on the necessity of heparinized solution which can correctly be added or not depending on local protocols.

Blood sampling is common from arterial lines. When glucose is used as flush solution there may be
resultant erroneously high glucose readings in blood sampling.

There have been UK national alerts on severe hypoglycaemia from misdirected administration of insulin when glucose solutions are
used to flush arterial lines.

The Association of Anaesthetists of Great Britain and Ireland guidelines
recommend saline 0.9% safe flush solution.

Question 18

18. A male adult patient is in intensive care for 26 days and is recovering from sepsis.
    He has had multiple central lines during this admission. He has deteriorated with a new septic episode. He now requires a central
    line for vasopressor therapy. A left subclavian site is chosen as the most favourable. The most appropriate central line is:
    A. Tunnelled catheter, three lumens, 20 cm long
    B. Tunnelled catheter, three lumens, 25 cm long
    C. Non- tunnelled catheter, single lumen, 20 cm
    D. Non- tunnelled catheter, triple lumen, 20 cm
    E. Non- tunnelled catheter, triple lumen, 25 cm

Answer 18

18. E
    A tunnelled catheter requires additional expertise, is associated with reduced infection rates, and is
    more appropriate for long- term access i.e. months/ years. The indication for central line placement
    in this patient (new septic episode) is likely to be of shorter duration so a non- tunnelled catheter
    is more appropriate. Multiple lumens are indicated. A left subclavian site would indicate a 24- cm device should be chosen for an adult

Question 19

19. A 26- year- old primiparous patient requires a category one caesarean section for prolonged fetal bradycardia. Which drug combination provides the best intubating conditions, assuming appropriate doses of each are used?

A. Propofol, alfentanil, rocuronium
B. Propofol, suxamethonium
C. Thiopentone, rocuronium
D. Thiopentone, suxamethonium
E. TCI propofol and remifentanil

Answer 19

19. D
    It is important to read this question accurately. It does NOT ask for the best technique or the best
    anaesthetic or what is best for this particular patient. It asks about the best intubating conditions.

While many centres have moved away from the traditional thiopentone and suxamethonium rapid
sequence induction technique, it continues to provide the best intubating conditions with or without
the use of opioids.

Of note, suxamethonium produces better intubation conditions when used with
thiopentone when compared to its use with propofol.

Question 20

20. A 54- year- old patient has undergone brainstem death testing and is confirmed brainstem dead. He is on a voluntary organ donation register but his relatives are not willing for organ donation. How should you proceed?
    A. Check the patient’s human leukocyte antigen (HLA) status
    B. Mobilize the organ retrieval team
    C. Respect the patient’s wishes
    D. Respect the relatives’ wishes
    E. Seek the coroner’s decision over the telephone

Answer 20

20. D
    This is one of the few times where we would comply with the wishes of the relative over the
    patient.

Ideally patients should make their wishes known to relatives to allow their agreement and authorization of the organ donation process.

Despite the patient themselves having consented to
this process, relatives can, and do, refuse permission.

Various strategies are being developed to reduce the number of families preventing organ donation
in this way.

Death of a loved one is a traumatic time for relatives and no one would wish to increase their
distress.

Rather, building a relationship with relatives and explaining the process of donation and
their relatives intentions to do so before he died is a more caring approach.
It is not necessary to discuss this with the coroner as there is a robust, ethical, and professional
framework for doctors to work within.

Question 21

21. You are reviewing a 26- year- old para 1 + 0 woman on the postnatal ward.

The evening before she had delivered a live baby boy of 3.9 kg by midcavity forceps.

In labour, an epidural had been sited but had not worked well so was not topped up for delivery. Instead, in theatre a spinal was performed without complication. The woman has no complaints but
mentions she noticed the front and side of her left thigh felt numb while washing in the shower. On examination there is no motor deficit
nor any red flag signs of spinal cord injury. The most likely cause of the
numbness is:
A. Residual effect from epidural local anaesthetic
B. Pre- existing prolapsed vertebral disc at L2,3
C. Psychosomatic as does not reflect any dermatomal distribution
D. Fetal head compressing lumbosacral trunk
E. Prolonged lithotomy position

Answer 21

2. E
From the history, it can be assumed the patient spent a prolonged time in stages 2 and 3 of labour and delivery, in the lithotomy position.

Such flexion of the thigh commonly causes compression and ischaemia of the lateral cutaneous nerve of thigh.

This has no motor component and is known as
meralgia paraesthetica. It accounts for up to one third of obstetric nerve palsies.

In the history there is no dermatomal distribution of symptoms therefore the symptoms are not
due to nerve root pathology or disc prolapse. The fetal head can compress the lumbosacral trunk
causing femoral and obturator nerve palsies and their associated typical symptoms (see reference).

Postnatal obstetric palsies have an incidence of % and symptoms should be taken seriously.

Question 22

22. A 60- year- old man with obstructive sleep apnoea (OSA) and atrial fibrillation (AF) presents for elective hernia repair.
    He takes warfarin and his INR is currently 1.5. What is the best anaesthetic management?

A. Controlled ventilation, desflurane, remifentanil infusion, and an inguinal field bloc
B. Controlled ventilation sevoflurane, remifentanil, and an inguinal field block
C. Spontaneous ventilation, propofol TCI, remifentanil infusion, and inguinal field block
D. Spontaneous ventilation, sevoflurane, and inguinal field block
E. Spontaneous ventilation, propofol TCI, PCA morphine

Answer 22

22. A
    The anaesthetic principle in this case is to use short- acting agents to allow rapid emergence and
    reduce the impact of anaesthetic agents on his OSA.

Desflurane wears off most rapidly due to
its insolubility (low blood/ gas coefficient). Remifentanil has a half- life of approximately 3 min
irrespective of the duration of the infusion (context specific half- life).

Ventilation should be controlled with an endotracheal tube to maintain the airway. Spontaneous ventilation will not be adequate using a remifentanil infusion and the typical OSA patient is overweight with a large neck
and a potentially difficult airway.

The patient also requires good analgesia with minimal use of opioids. An inguinal field block will
provide this.

Regional anaesthesia would be a good option in this scenario for patients with normal INR. An INR
of 1.5 precludes spinal anaesthesia.

Sedative premedication should be avoided and any CPAP support the patient uses at home should
be available and continued in the postoperative period.
Care in a high dependency unit is usually indicated for these patients.

Question 23

23. You anaesthetize a 40- year- old 70- kg man using isoflurane to maintain anaesthesia and a circle system. The vaporizer dial setting is 2.0%,
    the end- tidal isoflurane concentration 1.2% and the fresh gas flow
    (FGF) through the vaporizer is 400 mL/ min of an oxygen/ air mixture.
    Which of the following is the fastest method of increasing the depth of anaesthesia?
    A. Increase the vaporizer setting to isoflurane 2.5%
    B. Increase the FGF to 8 L/ min
    C. Change to sevoflurane
    D. Switch to a nitrous oxide/ oxygen mix with FiO2 = 0.3
    E. Switch to a nitrous oxide/ oxygen mix with FiO2 = 0.5

Answer 23

23. B
    Changing only the composition of the inspired gas mixture will take a long time at such a low FGF
    rate due to the inertia of the circle system. The quickest option to increase the end- tidal isoflurane
    concentration is to increase the FGF rate.

Question 24

24. A 7- year- old boy with significant snoring attends for day case tonsillectomy. He is otherwise well. Which of the following would preclude him being discharged home postoperatively?
    A. Having NSAIDs in theatre
    B. Having 7 mg of morphine perioperatively
    C. His parents are both heavy smokers
    D. His parents do not have a car
    E. He has spat out a few blood streaked secretions postoperatively

Answer 24

24. B
    The child’s weight can be estimated to 22 or 23 kg with various commonly used formulae. The
    dose of morphine is 0.1– 0.2 mg/ kg which equates to a maximum of 4.6 mg morphine.

Opioid related complications are the commonest cause of postoperative problems following tonsillectomy,
particularly when sleep apnoea may be suspected.

Though difficult to diagnose in children, a
careful history must be taken as a diagnosis of OSA increases the rate of all cause post- operative
complications from % up to 6– 27%.

NSAIDs are routinely given. It is normal to have blood stained secretions post tonsillectomy and
any problems the parents have are no contraindications to discharging the child.

Question 25

25. You prescribe a fentanyl patch for a patient in the chronic pain clinic. ``` Which physicochemical feature of drugs most improves their efficacy via the transdermal route? A. Low molecular weight B. Low lipid solubility C. Low pKa D. Melting point above 37°C E. Active metabolites ```

Answer 25

25. A Transdermal drug delivery occurs by diffusion down a concentration gradient from the patch to the skin. Low molecular weight, high potency, and high lipid solubility promote transdermal transfer of a drug. A low melting point is desirable to promote release of the drug. The thickness of skin and fat is important as is the peripheral blood flow to the area. Metabolites have no effect on transdermal delivery of drug

Question 26

26. According to accepted receptor theory, a partial agonist A. Has reduced receptor affinity when compared with a full agonist B. Produces a concentration– effect curve similar to a full agonist but will take longer to attain maximum activity levels C. Produces the same level of response as that achieved by a full agonist in the presence of a competitive antagonist D. Is less potent than a full agonist E. Can bind to both agonist and antagonist binding sites

Answer 26

26. C A partial agonist binds to and activates a specific receptor, but has only partial efficacy when compared to a full agonist. Therefore the effect it can produce will always be sub- maximal, and less than a full agonist. Potency is the dose range over which a drug is active and partial agonists can higher or lower potency than the corresponding full agonist. A partial agonist, by definition, only binds to agonist receptors but can have antagonist effects, by occupying a proportion of receptors and preventing the full agonist reaching them, and so causes a net reduction in the response. Competitive antagonists compete for the same binding sites as the corresponding agonist whereas non- competitive antagonists have a separate binding site meaning their action cannot be overcome by increasing the dose of agonist.

Question 27

27. Regarding pharmacokinetics in the elderly A. Bioavailability of many drugs is increased B. Phase 2 metabolic reactions in liver are significantly reduced C. The volume of distribution for water soluble drugs is increased D. The duration of action of fat soluble drugs is reduced E. eGFR is unchanged

Answer 27

27. A Bioavailability is increased as hepatic blood flow is reduced by up to 35% and less drug is extracted and lost to first pass metabolism. Phase I reactions (reduction and oxidation) in the liver are greatly reduced, while phase 2 reactions (conjugation) are largely maintained. Cytochrome p450 genetic polymorphisms remain by far the most important cause of metabolic variability than aging. Drug metabolism by the liver may be flow dependent (most common) with a high extraction ratio or capacity dependent with a lower extraction ratio. Hepatic blood flow is reduced in the elderly and membrane transport mechanisms less efficient. With increasing age the proportion of body fat increases relative to that of water and muscle mass which decrease. This means water soluble drugs will have a lower volume of distribution (VoD) and increased concentration in the extra cellular fluid. Fat soluble drugs have a higher VoD and a prolonged half life.

Question 28

28. You assess a 23- year- old woman for consideration of labour epidural analgesia. She is a 40/ 52 gestation primigravida in established labour with no significant medical history. While in the room the midwife expresses concerns regarding the cardiotocograph (CTG) and asks the senior midwife to attend. Which of the following is most indicative of a pathological CTG? A. Baseline rate of 140 bpm with early decelerations B. Baseline rate of 135 bpm with late decelerations C. Baseline rate of 135 bpm with persistently absent variability D. Baseline rate of 20 bpm with normal variability E. Baseline rate of 40 bpm with transient accelerations

Answer 28

28. C Normal fetal heart rate at term is 110– 160 bpm and is frequently monitored on a CTG. The baseline is recorded as the mean heart rate over 0 min. A rate >160 bpm is classified as a fetal tachycardia and a rate <0 bpm is a fetal bradycardia. Variability refers to normal fluctuations in heart rate with normal variability being 5– 25 bpm and is reassuring. It is measured from the peak to the trough heart rate of a CTG recording over a period of 1 min. A persistent absence of variability is considered a pre- terminal feature and carries with it a high probability of a hypoxic fetus. Decelerations are transient reductions in fetal heart rate >15 bpm for at least 15 seconds. They can be early or late when observed against the timing of uterine contractions: • Early decelerations are uniform in shape, mirror the contraction, and are a normal finding in labour. They are thought to be a result of fetal head compression during a contraction and should recover with relaxation of the uterus. • Late decelerations are uniform and gradual in shape but they have a trough that occurs after the peak of a contraction. These are a possible sign of reduced fetal oxygenation Accelerations are defined as a transient increase in fetal heart rate (>15 bpm for at least 15 seconds) and these tend to be associated with fetal activity. Although their presence is reassuring, absence in an otherwise normal CTG should not cause concern. All the answers describe normal fetal heart rate. Both answers B and C show a concerning feature but the absence of variability indicates a higher concern for fetal hypoxia.

Question 29

29. A 69- year- old woman was admitted to ICU 24 hours ago following a catastrophic intracerebral bleed. There was no possible neurosurgical intervention. Her past medical history includes hypertension and hypothyroidism. She is a non- smoker. She remains GCS 3 and you and your consultant are about to perform brainstem death testing to diagnose death using neurological criteria. Which of the following most correctly describes the PaCO2 criteria necessary for apnoea testing? A. PaCO2 of 4– 5.3 kPa prior to commencing test and then a rise of ≥1 kPa at end of test B. PaCO2 of 4– 4.5 kPa prior to commencing apnoea test and then a rise of ≥0.5 kPa at end of test C. PaCO2 of ≥6 kPa prior to testing with a rise of ≥0.5 kPa at end of test D. PaCO2 of 4.5– 5.3 kPa prior to commencing test with a rise of ≥2 kPa E. PaCO2 of ≥6.5 kPa prior to commencing test with a rise of ≥0.5 kPa at end of test

Answer 29

29. C There are many specific criteria to be met for brainstem death testing or the diagnosis of death by neurological criteria. Although normocapnia is recommended in the general management of these patients in the Intensive Care Unit, in the specific incidence of performing apnoea testing the minute ventilation should be reduced to allow the PaCO2 to rise to ≥6.0 kPa before commencing the test. At the end of the 5 min apnoea the recorded PaCO2 should have risen ≥0.5 kPa. This is the case in both sets of tests. It has also been suggested that if the patient is a chronic retainer of CO2 due to heavy smoking or chronic obstructive airway disease then it would be prudent to allow PaCO2 to rise to ≥6.5 kPa prior to testing.

Question 30

30. A 54- year- old man is listed for an amputation of his left big toe. He has chronic renal impairment, stable angina, heart failure (NYHA grade 2) and type 2 diabetes. On reviewing his blood results and ECG from this morning you discover his potassium is 7.3 mmol/ L and his ECG shows 52 bpm sinus rhythm with flattening of P waves and tall T waves. What would be the best initial treatment? A. 10 units of Actrapid in 50 mL 50% dextrose over 5 minutes intravenously B. Nebulized salbutamol 5 mg C. Oral calcium resonium D. Bolus of calcium gluconate 0% 0 mL intravenously E. Commence haemodialysis

Answer 30

30. D This patient has several risk factors for the development of hyperkalaemia including cardiac failure and likely use of angiotensin- converting enzyme inhibitors and diuretics, diabetes, and chronic renal impairment. A potassium level >7 mmol/ L is classified as severe especially with ECG changes and urgent treatment is required. The priority is to give calcium gluconate to stabilize the myocardium and then institute treatment to lower the serum potassium concentration such as insulin/ dextrose infusion and nebulized salbutamol. You would stop drugs or infusions containing potassium. Haemodialysis may also be a definitive treatment. The ECG changes associated with hyperkalaemia are tall tented T wave, flattening and loss of p waves, prolonged P- R interval, and widening of the QRS complex. Bradycardia and AV block are also common. These changes are progressive with increasing potassium concentrations and can eventually there will be ventricular fibrillation and cardiac arrest.