-
Question 1
Incorrect
-
A 28-year-old female arrives after taking an unknown chemical in excess. She is tired and her speech is slurred. The following are her observations and results:HR 118,BP 92/58,SaO2 96%
HR 118, 11/15 The following are the results of his arterial blood gas (ABG):
pH: 7.24pO 2 : 9.4kPa PCO2 : 3.3kPa HCO 3 -: 22 mmol/lNa + : 143 mmol/lCl – : 99 mmol/lLactate: 5 IU/l
Which of the following statements about this patient is TRUE?Your Answer: She has respiratory acidosis
Correct Answer: Her anion gap is elevated
Explanation:The interpretation of arterial blood gas (ABG) aids in the measurement of a patient’s pulmonary gas exchange and acid-base balance.
The normal values on an ABG vary a little depending on the analyser, but they are roughly as follows:
Variable
Range
pH
7.35 – 7.45
PaO2
10 – 14 kPa
PaCO2
4.5 – 6 kPa
HCO3-
22 – 26 mmol/l
Base excess
-2 – 2 mmol/lThe patient’s history indicates that she has taken an overdose in this case. Because her GCS is 11/15 and she can communicate with slurred speech, she is clearly managing her own airway, there is no current justification for intubation.
The following are the relevant ABG findings:
Hypoxia (mild)
pH has been lowered (acidaemia)
PCO2 levels are low.
bicarbonate in its natural state
Lactate levels have increasedThe anion gap represents the concentration of all the unmeasured anions in the plasma. It is the difference between the primary measured cations and the primary measured anions in the serum. It can be calculated using the following formula:
Anion gap = [Na+] – [Cl-] – [HCO3-]The reference range varies depending on the technique of measurement, but it is usually between 8 and 16 mmol/L.
The following formula can be used to compute her anion gap:
Anion gap = [143] – [99] – [22]
Anion gap = 22As a result, it is clear that she has a metabolic acidosis with an increased anion gap.
The following are some of the causes of type A and type B lactic acidosis:
Type A lactic acidosis
Type B lactic acidosis
Shock (including septic shock)
Left ventricular failure
Severe anaemia
Asphyxia
Cardiac arrest
CO poisoning
Respiratory failure
Severe asthma and COPD
Regional hypoperfusion
Renal failure
Liver failure
Sepsis (non-hypoxic sepsis)
Thiamine deficiency
Alcoholic ketoacidosis
Diabetic ketoacidosis
Cyanide poisoning
Methanol poisoning
Biguanide poisoning -
This question is part of the following fields:
- Physiology
- Renal Physiology
-
-
Question 2
Incorrect
-
An 11-year-old girl presents with a 5-day history of persistent fever despite regular paracetamol, throbbing left ear pain, ear discharge and deafness. Her parents have observed that she is not her usual self, not eating well, and has been lethargic. On examination there is a tender swelling in the post auricular region on the left hand side.
What is the most likely causative organism?
Your Answer: Streptococcus anginosus
Correct Answer: Streptococcus pneumonia
Explanation:Acute mastoiditis is a complication (rare) of acute otitis media (AOM) and the commonest causative organism is Streptococcus pneumoniae.
Generally, acute mastoiditis presents with:
Pyrexia
Recent history of AOM
Mastoid swelling and erythema
Otalgia
Otorrhoea and perforation of tympanic membrane
Post-auricular pain
Protrusion of the ears -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 3
Correct
-
Atracurium is used as a muscle relaxant during endotracheal intubation. This drug’s mechanism of action is best described by which of the following?
Your Answer: Nicotinic acetylcholine receptor antagonist
Explanation:Atracurium is a non-depolarizing neuromuscular blocker that is used to help with intubation and controlled ventilation by causing muscle relaxation and paralysis.
At the neuromuscular junction’s post-synaptic membrane, atracurium competes with acetylcholine for nicotinic (N2) receptor binding sites. This prevents the receptors from being stimulated by acetylcholine.
Muscle paralysis occurs gradually due to the competitive blockade.
-
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 4
Incorrect
-
An ambulance transports a 23-year-old woman who has taken a witnessed overdose of her mother's diazepam tablets. She has no significant medical history and does not take any medications on a regular basis.
In this case, what is the SINGLE MOST APPROPRIATE FIRST DRUG TREATMENT?Your Answer: Flumazenil IV 0.5 mg
Correct Answer: Flumazenil IV 200 μg
Explanation:Flumazenil is a benzodiazepine antagonist that can be helpful in some overdose situations. It works quickly (in less than a minute), but the effects are fleeting, lasting less than an hour. The dose is 200 micrograms every 1-2 minutes with a maximum dose of 3 milligrams per hour.
Flumazenil should be avoided by patients who are addicted to benzodiazepines or who take tricyclic antidepressants because it can cause withdrawal symptoms. It can cause seizures or cardiac arrest in these situations.
-
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
-
-
Question 5
Incorrect
-
A 10-year-old girl presents with polyuria, polydipsia, and stomach pain. She has a history of type I diabetes mellitus. On blood gas analysis, she has metabolic acidosis. Diabetic ketoacidosis (DKA) is diagnosed, and therapy is initiated. She becomes increasingly confused when intravenous fluids and insulin are administered.
Which electrolyte imbalance is the MOSTÂ likely reason of the increased confusion
Your Answer: Hypokalaemia
Correct Answer: Hyponatraemia
Explanation:Because of the shift of water from the intracellular to the extracellular compartment as a result of hyperglycaemia and increased plasma osmolality, dilutional hyponatraemia is common in diabetic ketoacidosis (DKA).
If intravenous fluids are not delivered with caution, hyponatraemia might worsen, which can lead to increased degrees of disorientation. Hyponatraemia has also been linked to an increased risk of cerebral oedema, especially if blood glucose levels drop too quickly following treatment.
Headache, recurrence of vomiting, irritability, Glasgow Coma Scale score, inappropriate heart rate slowing, and rising blood pressure are the most common causes of death in paediatric DKA, and children should be monitored for the symptoms mentioned above. To prevent this from developing,  s low osmolarity normalization, attention to glucose and salt levels, as well as hydration over 48 hours, is necessary.Â
-
This question is part of the following fields:
- Musculoskeletal Pharmacology
- Pharmacology
-
-
Question 6
Correct
-
The least likely feature expected to be seen in a lesion of the frontal lobe is which of the following?
Your Answer: Loss of two-point discrimination
Explanation:Lesions in different areas give rise to different symptoms.
Lesions of the parietal lobe give rise to loss of two-point discrimination.
Lesions to Broca’s area give rise to expressive dysphasia results from damage
Lesions to the primary motor cortex give rise to contralateral weakness of the face and arm.
Lesions to the prefrontal cortex give rise to personality change.
Lesions to the frontal eye field give rise to conjugate eye deviation towards side of lesion. -
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 7
Incorrect
-
A 61-year-old woman returns to get the results of recent blood tests she had done for non-specific malaise, lethargy, and weight loss.
The only abnormality discovered during the blood tests was a 580 x 10 9 /l increase in platelets. Her platelets were also elevated on a blood test taken 6 months earlier, according to her previous results. You're aware of the recent emergence of elevated platelet levels as a cancer risk marker and decide to look into it.
Which of the following cancers is most likely to cause isolated thrombocytosis?Your Answer: Chronic lymphocytic leukaemia
Correct Answer: Colorectal cancer
Explanation:Raised platelet levels have emerged as a cancer risk marker, according to a large population-based study published in 2017(link is external). According to the study, 12 percent of men and 6% of women with thrombocytosis were diagnosed with cancer within a year. These figures increased to 18% in men and 10% in women if a second platelet count was taken within 6 months of the first and showed an increased or stable elevated platelet count.
The researchers discovered that thrombocytosis linked to cancer is most common in colorectal and lung cancers, and it is linked to a worse prognosis. Furthermore, one-third of the cancer patients in the study had no other symptoms that would have prompted an immediate cancer referral.
The exact mechanism by which these cancers cause thrombocytosis is unknown, but one theory proposes the existence of pathogenic feedback loops between malignant cells and platelets, with a reciprocal interaction between tumour growth and metastasis, as well as thrombocytosis and platelet activation. Another hypothesis is that thrombocytosis occurs independently of cancer but aids in its spread and progression.
The findings show that routinely testing for thrombocytosis could cut the time it takes to diagnose colorectal and lung cancer by at least two months. In the UK, this could result in around 5500 earlier cancer diagnoses per year.
Because the positive predictive value of thrombocytosis in middle age for cancer (10%) is higher than the positive predictive value for a woman in her 50s presenting with a new breast lump (8.5%), this is clearly an important research paper that should be used to adjust future clinical practise. The current NICE guidelines predate these new research findings, so we’ll have to wait and see how they affect cancer referral guidelines in the UK.
Because there are so many possible cancers associated with thrombocytosis, the treating clinician should take a thorough history and perform a thorough clinical examination if a patient is diagnosed with it. Further investigation and the most appropriate referral route should be aided by this information.
It’s worth noting that the patients in the study had their blood tests done for a medical reason rather than as a random screening test.
If there are no other symptoms to guide investigation and referral (one-third of the patients in the study had no other symptoms), keep in mind that the two most common cancers encountered were colorectal and lung cancer, so a chest X-ray and a faecal immunochemical test (FIT) for faecal blood may be reasonable initial investigations.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 8
Incorrect
-
Which of the following increases the tendency for oedema to occur?
Your Answer: Increased plasma protein concentration
Correct Answer: Increased venous pressure
Explanation:When more fluid is filtered out of the capillaries than can be returned to the circulation by the lymphatics, oedema occurs. Changes that increase capillary hydrostatic pressure or decrease plasma oncotic pressure will increase filtration.
Arteriolar constriction reduces hydrostatic capillary pressure and transiently increase absorption of fluid.
Dehydration increases plasma protein concentration and therefore increases plasma oncotic pressure and absorption. Capillary hydrostatic pressure and filtration are increased when there is increased venous pressure. -
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 9
Correct
-
Regarding diuretics, which of the following statements is CORRECT:
Your Answer: Carbonic anhydrase inhibitors have their effect by inhibiting bicarbonate reabsorption.
Explanation:Carbonic anhydrase inhibitors e.g. acetazolamide block the reaction of carbon dioxide and water and so prevent Na+/H+exchange and bicarbonate reabsorption. The increased bicarbonate levels in the filtrate oppose water reabsorption. Proximal tubule sodium reabsorption is also reduced because it is partly dependent on bicarbonate reabsorption.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 10
Incorrect
-
Which of the following is a contraindication to the use of opioid analgesics:
Your Answer: Folate deficiency
Correct Answer: Raised intracranial pressure
Explanation:Opioids should be avoided in people who have:
A risk of paralytic ileus (opioids reduce gastric motility)
Acute respiratory depressionAn acute exacerbation of asthma (opioids can aggravate bronchoconstriction as a result of histamine release)
Conditions associated with increased intracranial pressure including head injury (opioids can interfere with pupillary response making neurological assessment difficult and may cause retention of carbon dioxide aggravating the increased intracranial pressure) -
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 11
Incorrect
-
A CT pulmonary angiography of a patient with a massive pulmonary embolus will most likely show which of the following signs?
Your Answer: Decreased alveolar dead space
Correct Answer: Increased alveolar dead space
Explanation:A CT pulmonary angiogram is an angiogram of the blood vessels of the lungs. It is a diagnostic imaging test used to check for pulmonary embolism.
A pulmonary embolism is caused by a blood clot or thrombus that has become lodged in an artery in the lung and blocks blood flow to the lung. A patient with pulmonary embolism may feel an abrupt onset of pleuritic chest pain, shortness of breath, and hypoxia. Also, pulmonary embolism can result in alveolar dead space.
Dead space represents the volume of ventilated air that does not participate in gas exchange. The alveolar dead space is caused by ventilation/perfusion imbalances in the alveoli. It is defined as the sum of the volumes of alveoli that are ventilated but not perfused.
Aside from pulmonary embolism, smoking, bronchitis, emphysema, and asthma are among the other causes of alveolar dead space.
The other types of dead space are the following: Anatomical dead space is the portion of the airways that conducts gas to the alveoli. This is usually around 150 mL, and there is no possibility of gas exchange in these areas. Physiological dead space is the sum of anatomical and alveolar dead spaces.
Physiological dead space can account for up to 30% of the tidal volume.
-
This question is part of the following fields:
- Physiology
- Respiratory Physiology
-
-
Question 12
Correct
-
Atrial natriuretic peptide (ANP) is primarily produced in response to:
Your Answer: An increase in intravascular fluid volume
Explanation:Atrial natriuretic peptide (ANP) is released from cardiac atrial muscle cells in response to atrial stretch caused by an increase in intravascular fluid volume and is also produced in collecting duct cells.
Atrial natriuretic peptide acts to inhibit sodium reabsorption in the distal nephron. -
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 13
Incorrect
-
Which of the following statements accurately describes the number needed to harm?
Your Answer: A low NNH indicates a safe treatment option
Correct Answer: The NNH is the number of patients that need to be treated for one to experience the side effect
Explanation:Number needed to harm (NNH) corresponds to the number of individuals that must be treated, so that one of them presents an adverse reaction accountable to the treatment.
Hence, a NNH of 100 means that 100 individuals need to be treated in order to produce an adverse effect of the treatment in one individual.
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 14
Incorrect
-
You are planning on starting antibiotic therapy for a patient with a diagnosis of gonorrhoea.
Which of these is the MOST appropriate antibiotic combination?Your Answer: Gentamicin and metronidazole
Correct Answer: Ceftriaxone and azithromycin
Explanation:Currently, ceftriaxone in combination with azithromycin or doxycycline is the combination of antibiotics used in the treatment of gonorrhoea.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 15
Correct
-
Red cell protein expression is induced by which of the following pathogens:
Your Answer: Plasmodium falciparum
Explanation:Plasmodium falciparum induces the expression of red cell protein, making cerebral malaria more severe. Bacteria may invade a host passively through micro traumata or macro traumata in the skin or mucosa. On the other hand, bacteria that invade
through intact mucosa first, adhere to this anatomical barrier, then actively
breach it. -
This question is part of the following fields:
- Microbiology
- Principles
-
-
Question 16
Incorrect
-
A young man develops an infection spread via aerosol transmission.
Which of these organisms is commonly spread by aerosol transmission?Your Answer: Staphylococcus aureus
Correct Answer: Measles virus
Explanation:Aerosols are airborne particles less than 5 µm in size, containing infective organisms that usually cause infection of the upper or lower respiratory tract.
Examples of organisms commonly spread by aerosol transmission are:
Measles virus
Varicella zoster virus
Mycobacterium tuberculosisThe following table summarises the various routes of transmission with example organisms:
Route of transmission
Example organisms
Aerosol (airborne particle < 5 µm)
Mycobacterium tuberculosis
Varicella zoster virus
Measles virusHepatitis A and Rotavirus are spread by the faeco-oral route.
Neisseria gonorrhoea is spread by sexual route.
Staphylococcus aureus is spread by direct contact.
-
This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
-
-
Question 17
Incorrect
-
Which cervical interspace is most likely injured if a patient presents with difficulty of shoulder abduction and elbow flexion, pain in the right shoulder and lateral arm, and decreased sensation over the deltoid and lateral arm?
Your Answer: C6-C7
Correct Answer: C4-C5
Explanation:In the setting of cervical radiculopathy, because the nerve root of a spinal nerve is compressed or otherwise impaired, the pain and symptomatology can spread far from the neck and radiates to arm, neck, chest, upper back and/or shoulders. Often muscle weakness and impaired deep tendon reflexes are noted along the course of the spinal nerve.
Cervical radiculopathy is almost always unilateral, although, in rare cases, both nerves at a given level may be impacted. Those rare presentations can confound physical diagnosis and require acceleration to advanced imaging especially in cases of trauma. If there is nerve impingement, the affected side will be reduced relative to the unaffected side. Reduction in strength of muscles innervated by the affected nerve is also significant physical finding.
For a C4-C5 injury, the following symptoms may present:
Weakness in the deltoid muscle (front and side of the shoulder) and upper arm
Shoulder pain
Numbness along the outside of the upper arm -
This question is part of the following fields:
- Anatomy
- Head And Neck
-
-
Question 18
Incorrect
-
What is the effect of a positive inotrope on the Starling curve:
Your Answer: Causes a leftward shift along the curve
Correct Answer: Shifts the curve upwards
Explanation:Contractility (inotropy) is the intrinsic ability of cardiac muscle to develop force at a given muscle length. It is determined by the intracellular [Ca2+] and can be estimated by the ejection fraction. Increases in contractility cause an increase in stroke volume/cardiac output for any level of right atrial pressure or end-diastolic volume, and hence shift the Starling curve upwards. Decreases in contractility cause a decrease in stroke volume/cardiac output for any level of right atrial pressure or end-diastolic volume and hence shift the Starling curve downwards.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 19
Incorrect
-
Where is angiotensin I primarily converted to angiotensin II:
Your Answer: Liver
Correct Answer: Lungs
Explanation:Angiotensin I is converted to angiotensin II by the removal of two C-terminal residues by the enzyme angiotensin-converting enzyme (ACE). This primarily occurs in the lungs, although it does also occur to a lesser degree in endothelial cells and renal epithelial cells.
The main actions of angiotensin II are:
Vasoconstriction of vascular smooth muscle (resulting in increased blood pressure)
Vasoconstriction of the efferent arteriole of the glomerulus (resulting in an increased filtration fraction and preserved glomerular filtration rate)
Stimulation of aldosterone release from the zona glomerulosa of the adrenal cortex
Stimulation of anti-diuretic hormone (vasopressin) release from the posterior pituitary
Stimulation of thirst via the hypothalamus
Acts on the Na+/H+ exchanger in the proximal tubule of the kidney to stimulate Na+reabsorption and H+excretion -
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 20
Incorrect
-
The role of the juxtaglomerular (granular) cells of the juxtaglomerular apparatus is:
Your Answer:
Correct Answer: Production of renin
Explanation:Juxtaglomerular cells synthesise renin. These cells are specialised smooth muscle cells that are located in the walls of the afferent arterioles, and there are some in the efferent arterioles.
-
This question is part of the following fields:
- Physiology
- Renal
-
SESSION STATS - PERFORMANCE PER SPECIALTY
