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Question 1
Correct
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A patient with a history of worsening chronic breathlessness on exertion undergoes lung function testing. The results demonstrate an FEV 1 that is 58% predicted and an FEV 1 /FVC ratio less than 0.7.
Which of the following is the most likely diagnosis? Select ONE answer only.Your Answer: COPD
Explanation:Obstructive lung disorders are characterised by airway obstruction. Many obstructive diseases of the lung result from narrowing of the smaller bronchi and larger bronchioles, often because of excessive contraction of the smooth muscle itself.
In obstructive lung disease, FEV1is reduced to <80% of normal and FVC is usually reduced but to a lesser extent than FEV1. The FEV1/FVC ratio is reduced to <0.7.
Types of obstructive lung disorders include:
Chronic obstructive pulmonary disease (COPD)
Asthma
Bronchiectasis -
This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 2
Correct
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A man presents to the emergency department with an injury that has damaged the opponens pollicis muscle.
Which of the following statements regarding the opponens pollicis muscle is considered correct?Your Answer: It flexes the first metacarpal bone at the carpometacarpal joint
Explanation:Opponens pollicis is a muscle of thenar eminence, it is triangular in shape and lies deep to flexor pollicis brevis and abductor pollicis brevis. It originates from the flexor retinaculum, tubercles of scaphoid and trapezium, abductor pollicis longus tendon.
Its insertion is in the radial side of the base of proximal phalanx of thumb. It is supplied by the median nerve (C8, T1). It receives blood supply from superficial arch.
It flexes the metacarpal bone medially across the palm, also rotating it medially, causing opposition, the palmar aspect of the terminal segment of thumb contacts the flexor aspects of any other digit.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 3
Incorrect
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A 29-year-old woman presents with night sweats, fever, and haemoptysis. A diagnosis of tuberculosis was suspected.
Which of the following statements regarding the diagnosis of tuberculosis is considered correct?Your Answer: Mycobacteria tuberculosis appears blue on acid-fast staining
Correct Answer: Mycobacteria tuberculosis can be typed using a RFLP method
Explanation:Although a variety of clinical specimens may be submitted to the
laboratory to recover MTB and NTM, respiratory secretions such
as sputum and bronchial aspirates are the most common. An
early-morning specimen should be collected on three consecutive
days, although recent studies have suggested that the addition of
a third specimen does not significantly increase the sensitivity
of detecting Mycobacteria.Mycobacterium tuberculosis appear red on acid-fast staining because they take up the primary stain, which is carbolfuchsin, and is not decolorized by the acid alcohol anymore.
Culture on Lowenstein-Jensen medium should be read within 5 to 7 days after inoculation and once a week thereafter for up to 8 weeks.
Nucleic acid amplification assays designed to detect M. tuberculosis complex
bacilli directly from patient specimens can be performed in as little as 6 to 8 hours on processed specimens. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 4
Correct
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Which one of these equations best defines lung compliance?
Your Answer: Change in volume / change in pressure
Explanation:Lung compliance is defined as change in volume per unit change in distending pressure.
Lung compliance is calculated using the equation:
Lung compliance = ΔV / ΔP
Where:
ΔV is the change in volume
ΔP is the change in pleural pressure.Static compliance is lung compliance in periods without gas flow, and is calculated using the equation:
Static compliance = VT / Pplat − PEEP
Where:
VT = tidal volume
Pplat = plateau pressure
PEEP = positive end-expiratory pressure -
This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 5
Correct
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In adult basic life support, chest compressions should be performed at which of the following rates:
Your Answer: 100 - 120 per minute
Explanation:Chest compressions should be performed at a rate of 100 – 120 per minute.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 6
Correct
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Question 7
Incorrect
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In inserting a nasogastric tube, which area is least likely to be a site of resistance when the tube goes from the nose to the stomach?
Your Answer: In the posterior mediastinum where the oesophagus is crossed by the left main bronchus
Correct Answer: In the posterior mediastinum where the oesophagus is crossed by the pulmonary trunk
Explanation:In the posterior mediastinum where the oesophagus is crossed by the pulmonary trunk offers the least resistance when nasogastric tube is inserted from the nose to the stomach.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 8
Correct
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Which of the following statements accurately describes the number needed to harm?
Your 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.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 9
Correct
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A young male has presented to you with respiratory depression and small pupils on examination. You diagnose opioid overdose and immediately start therapy with Naloxone.
Which of the following statements is TRUE regarding naloxone?Your Answer: It can be given by a continuous infusion if repeated doses are required
Explanation:Naloxone is a short-acting, specific antagonist of mu(μ)-opioid receptors. It is used to reverse the effects of opioid toxicity.
It can be given by a continuous infusion if repeated doses are required and the infusion rate is adjusted according to the vital signs. Initially, the infusion rate can be set at 60% of the initial resuscitative IV dose per hour.
Naloxone has a shorter duration of action (6-24 hours) than most opioids and so close monitoring according to the respiratory rate and depth of coma and repeated injections are necessary. When repeated doses are needed in opioid addicts, naloxone administration may precipitate a withdrawal syndrome with abdominal cramps, nausea and diarrhoea, but these usually settle within 2 hours.
An initial dose of 0.4 to 2 mg can be given intravenously and can be repeated at 2 to 3-minute intervals to a maximum of 10mg.
If the intravenous route is inaccessible, naloxone can be administered via an IO line, subcutaneously (SQ), IM, or via the intranasal (IN) route.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 10
Incorrect
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Which of the following immunoglobulin molecules is the most abundant in secretions (such as saliva and breast milk):
Your Answer: IgG
Correct Answer: IgA
Explanation:IgA is the predominant antibody class in secretions and tremendous quantities are secreted into various body spaces and onto mucosal surfaces (the gut lumen, the pharynx and sinuses, the larger airways, although not the alveoli).
Because of its size, the majority of IgM is found in the circulation.Along with IgM, IgD is predominant among the surface receptors of mature B cells, where it plays a key role in B cells activation.
IgE has the lowest concentration in normal human serum. It plays a prominent role in immune responses to helminth parasites, and in allergic reactions.
IgG is the most abundant immunoglobulin and constitutes 75 percent of serum immunoglobulin in an adult human -
This question is part of the following fields:
- Immune Responses
- Pathology
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Question 11
Correct
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Typically, granulomatous inflammation is associated with one of the following infections:
Your Answer: Tuberculosis
Explanation:Granulomatous inflammation is typically seen when an infective agent with a digestion-resistance capsule (e.g. Mycobacterium tuberculosis) or a piece of inert foreign material (such as suture or glass) is introduced into the tissue. A transient acute inflammatory response occurs and when this is ineffective in eradicating the stimulus, chronic inflammation occurs.
Tuberculosis is the prototype of the granulomatous diseases, but sarcoidosis, cat-scratch disease, lymphogranuloma inguinale, leprosy, brucellosis, syphilis, some mycotic infections, berylliosis, reactions of irritant lipids, and some autoimmune diseases are also included
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 12
Correct
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While studying fluid homeostasis in the body, you encounter the term exudate. Exudate is a fluid that leaks out of the intravascular space due to changes in the permeability of the microcirculation secondary to inflammation.
Which ONE of the following conditions would not be listed among the causes of an exudate?Your Answer: Myxoedema
Explanation:An exudate is an inflammatory fluid that leaks out of the intravascular space due to increased vascular permeability and intravascular pressure. It is mostly caused by local processes and can occur in the following conditions:
1) Infection (e.g. pneumonia)
2) Malignancy
3) Pericarditis
4) Collagen vascular diseases, e.g., Rheumatoid ArthritisMyxoedema is a state of severe hypothyroidism in which deposition of mucopolysaccharides occurs in the dermis. This causes a transudative effusion, typically in the pretibial region.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 13
Incorrect
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Depolarisation of a neuron begins with which of the following:
Your Answer: Opening of voltage-gated Na + channels
Correct Answer: Opening of ligand-gated Na + channels
Explanation:Action potentials are initiated in nerves by activation of ligand-gated Na+channels by neurotransmitters. Opening of these Na+channels results in a small influx of sodium and depolarisation of the negative resting membrane potential (-70 mV). If the stimulus is sufficiently strong, the resting membrane depolarises enough to reach threshold potential (generally around -55 mV), at which point an action potential can occur. Voltage-gated Na+channels open, causing further depolarisation and activating more voltage-gated Na+channels and there is a sudden and massive sodium influx, driving the cell membrane potential to about +40 mV.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 14
Incorrect
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Which of the following anatomic structures will gallstones most likely lodge into, and cause cholestasis?
Your Answer: Common bile duct
Correct Answer: Hartmann’s pouch
Explanation:Hartmann’s pouch is a diverticulum that can occur at the neck of the gallbladder. It is one of the rarest congenital anomalies of the gallbladder. Hartmann’s gallbladder pouch is a frequent but inconsistent feature of normal and pathologic human gallbladders. It is caused by adhesions between the cystic duct and the neck of the gallbladder. As a result, it is classified as a morphologic rather than an anatomic entity.
There is a significant association between the presence of Hartmann’s pouch and gallbladder stones. It is the most common location for gallstones to become lodged and cause cholestasis.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 15
Correct
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Angiotensin II is part of the RAAS system. One of its effects is the constriction of efferent arterioles. Which of the following best describes the effect of angiotensin II- mediated constriction of efferent arterioles?
Your Answer: Decreased renal plasma flow, increased filtration fraction, increased GFR
Explanation:The Renin-Angiotensin-Aldosterone System (RAAS) is a hormone system composed of renin, angiotensin, and aldosterone. Those hormones are essential for the regulation of blood pressure and fluid balance.
Cases of hypotension, sympathetic stimulation, or hyponatremia can activate the Renin-angiotensin-aldosterone system (RAAS). The following process will then increase the blood volume and blood pressure as a response.
When renin is released it will convert the circulating angiotensinogen to angiotensin I. The ACE or angiotensin-converting enzyme will then catalyst its conversion to angiotensin II, which is a potent vasoconstrictor. Angiotensin II can constrict the vascular smooth muscles and the efferent arteriole of the glomerulus.
The efferent arteriole is a blood vessel that delivers blood away from the capillaries of the kidney. The angiotensin II-mediated constriction of efferent arterioles increases GFR, reduces renal blood flow and peritubular capillary hydrostatic pressure, and increases peritubular colloid osmotic pressure, as a response to its action of increasing the filtration fraction.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 16
Correct
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Which of the following is the primary indication for loop diuretics?
Your Answer: Acute pulmonary oedema
Explanation:Loop diuretics have long been the cornerstone of pulmonary oedema treatment, with furosemide being the most commonly used of these drugs. Premedication with drugs that decrease preload (e.g., nitro-glycerine [NTG]) and afterload (e.g., angiotensin-converting enzyme [ACE] inhibitors) before the administration of loop diuretics can prevent adverse hemodynamic changes.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 17
Incorrect
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A 70-year-old man presents with right-sided hemiplegia and loss of joint position sense, vibratory sense, and discriminatory touch. Upon further physical examination, it was observed that her tongue deviates to the left-hand side. An MRI and CT scan was ordered and results showed that he was suffering a left-sided stroke.
Branches of which of the following arteries are most likely implicated in the case?Your Answer: Posterior spinal artery
Correct Answer: Anterior spinal artery
Explanation:Medial medullary syndrome is a form of stroke that affects the medial medulla of the brain. It is caused by a lesion in the medial part of the medulla, which is due to an infraction of vertebral arteries and/or paramedian branches of the anterior spinal artery.
It is characterized by contralateral paralysis of the upper and lower limb of the body, a contralateral decrease in proprioception, vibration, and/or fine touch sensation, paresthesias or less commonly dysesthesias in the contralateral trunk and lower limb, and loss of position and vibration sense with proprioceptive dysfunction. Ipsilateral deviation of the tongue due to ipsilateral hypoglossal nerve damage can also be seen.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 18
Incorrect
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For an action potential to occur, which of the following must be true:
Your Answer: All of the above
Correct Answer: Depolarisation of the membrane must reach threshold potential
Explanation:For an action potential to occur, the membrane must become more permeable to Na+and the Na+influx must be greater than the K+efflux. An action potential occurs when depolarisation of the membrane reaches threshold potential. The membrane must be out of the absolute refractory period, however an action potential can still occur in a relative refractory period but only in response to a larger than normal stimulus.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 19
Correct
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A paediatric patient comes to the emergency room with complaints of right lower quadrant pain. The attending physician is considering appendicitis. Inside the operating room, the surgeon asks the medical student to locate the McBurney's point prior to the first incision.
Which of the following is the surface anatomy of the McBurney's point?Your Answer: One-third of the distance from the anterior superior iliac spine to the umbilicus
Explanation:Inflammation of the appendix is a significant public health problem with a lifetime incidence of 8.6% in men and 6.7% in women, with the highest incidence occurring in the second and third decade of life. While the rate of appendectomy in developed countries has decreased over the last several decades, it remains one of the most frequent emergent abdominal operations. Appendicitis can often result in anorexia, nausea, vomiting, and fever.
McBurney’s point, which is found one-third of the distance between the anterior superior iliac spine and the umbilicus, is often the point of maximal tenderness in a patient with an anatomically normal appendix. A McBurney’s incision is chiefly used for cecostomy and appendectomy. It gives a limited exposure only, and should any doubt arise about the diagnosis, an infraumbilical right paramedian incision should be used instead.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 20
Correct
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The pelvic bone is formed by which of the following:
Your Answer: Ilium, ischium and pubis
Explanation:Each pelvic bone is formed by three elements: the ilium (superiorly), the pubis (anteroinferiorly) and the ischium (posteroinferiorly).
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 21
Correct
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Which of the following statements is correct with regards to natural killer cells?
Your Answer: They are part of the innate immune system.
Explanation:Natural Killer (NK) Cells are lymphocytes in the same family as T and B cells, which come from a common progenitor. They are cytotoxic CD8 positive cells that do not have the T-cell receptor. They are very big cells with cytoplasmic granules and are designed to kill target cells with a low level of expression of HLA class I molecules.
Examples include during a viral infection or on a malignant cell. NK cells display several receptors for HLA molecules on their surface, and when HLA is expressed on the target cell, these deliver an inhibitory signal into the NK cell. Absent HLA molecules on the target cell cause this inhibitory signal to get lost and as a result, the NK cell can then kill its target. Also, NK cells display antibody-dependent cell-mediated cytotoxicity, where antibody binds to antigen on the surface of the target cell. The NK cells then bind to the Fc portion of the bound antibody and kill the target cell. -
This question is part of the following fields:
- Immune Responses
- Pathology
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Question 22
Correct
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A young female was diagnosed with a urinary tract infection and was sent home with medications. However, after 48 hours of discharge, she returned to the hospital because there had been no relief from her symptoms. The urine sensitivity test report is still unavailable. Fresh blood tests were sent, and her estimated GFR is calculated to be >60 ml/minute.
She was prescribed nitrofurantoin 100 mg modified-release orally twice a day for two days.
Out of the following, which antibiotic is most appropriate to be prescribed to this patient?Your Answer: Fosfomycin
Explanation:The NICE guidelines for women with lower UTIs who are not pregnant are:
1. Consider prescribing a different antibiotic if symptoms do not improve within 48 hours or worsen at any time
2. If the urine culture and susceptibility test results are available, review the choice of antibiotic according to the results and change the antibiotic accordingly if symptoms are not improving or bacteria is resistant to the prescribed antibioticThe first choice of antibiotics for non-pregnant women aged 16 years and over is:
1. Nitrofurantoin
100 mg modified-release PO BD for 3 days – if eGFR >45 ml/minute
2. Trimethoprim
200 mg PO BD for three daysThe second-choice (no improvement in lower UTI symptoms on first-choice for at least 48 hours, or when first-choice is not suitable) are:
1. Nitrofurantoin
100 mg modified-release PO BD for three days – if eGFR >45 ml/minute
2. Pivmecillinam
400 mg PO initial dose, then 200 mg PO TDS for three days
3. Fosfomycin 3 g single sachet dose -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 23
Correct
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At which opioid receptors do opioid analgesics act primarily?
Your Answer: Mu
Explanation:Opioid receptors are widely distributed throughout the central nervous system. Opioid analgesics mimic endogenous opioid peptides by causing prolonged activation of these receptors, mainly the mu(μ)-receptors which are the most highly concentrated in brain areas involved in nociception.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 24
Incorrect
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An analytical cohort study aimed to determine a relationship between intake of dietary calcium and incidence of hip fractures among post-menopausal women. The following are the data obtained from the study:
No. of post-menopausal women who took Calcium: 500
No. of post-menopausal women who took Calcium and suffered a hip fracture: 10
No. of post-menopausal women who took placebo: 500
No. of post-menopausal women who took placebo and suffered a hip fracture: 25
Compute for the risk ratio of a hip fracture.Your Answer: 0.03
Correct Answer: 0.4
Explanation:Relative risk (RR) is a ratio of the probability of an event occurring in the exposed group versus the probability of the event occurring in the non-exposed group.
RR can be computed as the absolute risk of events in the treatment group (ART), divided by the absolute risk of events in the control group (ARC).
RR = ART/ARC
RR = (10/500) / (25/500)
RR = 0.4Recall that:
If RR < 1, then the intervention reduces the risk of the outcome.
If RR = 1, then the treatment has no effect on the outcome.
If RR > 1, then the intervention increases the risk of the outcome. -
This question is part of the following fields:
- Evidence Based Medicine
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Question 25
Incorrect
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Which segment of the colon is most likely to be affected in diverticulitis?
Your Answer: Descending colon
Correct Answer: Sigmoid colon
Explanation:Diverticulitis refers to inflammation and infection associated with a diverticulum and is estimated to occur in 10% to 25% of people with diverticulosis. Peridiverticular and pericolic infection results from a perforation (either macroscopic or microscopic) of a diverticulum, which leads to contamination, inflammation, and infection. The spectrum of disease ranges from mild, uncomplicated diverticulitis that can be treated in the outpatient setting, to free perforation and diffuse peritonitis that requires emergency laparotomy. Most patients present with left sided abdominal pain, with or without fever, and leucocytosis. The most common location for diverticulitis is the sigmoid colon.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 26
Correct
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One of these statements about significance tests is true.
Your Answer: A p value of less than 1 in 20 is considered ‘statistically significant’
Explanation:The p value is statistically significant when it is less than 0.05 (5% or 1 in 20).
Statistical significance is not the same as clinical significance.
The null hypothesis states that there is no difference between the groups.
The power of a study is the probability of correctly rejecting the null hypothesis when it is false.
A type I error occurs when the null hypothesis has been rejected when it is true. A type II error occurs when the null hypothesis has been accepted when it is actually false.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 27
Incorrect
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An ambulance transports a 37-year-old woman who is having a seizure. She is moved to resuscitation and given a benzodiazepine dose, which quickly ends the seizure. You later learn that she has epilepsy and is usually treated with carbamazepine to control her seizures.
What is carbamazepine's main mechanism of action?Your Answer: GABA receptor agonist
Correct Answer: Sodium channel blocker
Explanation:Carbamazepine is primarily used to treat epilepsy, and it is effective for both focal and generalised seizures. It is not, however, effective in the treatment of absence or myoclonic seizures. It’s also commonly used to treat neuropathic pain, as well as a second-line treatment for bipolar disorder and as a supplement for acute alcohol withdrawal.
Carbamazepine works as a sodium channel blocker that preferentially binds to voltage-gated sodium channels in their inactive state. This prevents an action potential from firing repeatedly and continuously.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 28
Correct
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Digoxin is predominantly used for which of the following:
Your Answer: Rate control in persistent and permanent atrial fibrillation
Explanation:Digoxin is most useful for controlling the ventricular response in persistent and permanent atrial fibrillation and atrial flutter. Digoxin is usually only effective for controlling the ventricular rate at rest, and should therefore only be used as monotherapy in predominantly sedentary patients with non-paroxysmal atrial fibrillation. It is now rarely used for rapid control of heart rate, as even with intravenous administration, response may take many hours. Digoxin is reserved for patients with worsening or severe heart failure due to left ventricular systolic dysfunction refractory to combination therapy with first-line agents. Digoxin is contraindicated in supraventricular arrhythmias associated with accessory conduction pathways e.g. Wolff-Parkinson-White syndrome.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 29
Incorrect
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The neurotransmitter in the synaptic cleft is either eliminated or deactivated after the postsynaptic cell responds to the neurotransmitter.
Which of the following enzymes catalyses the breakdown of noradrenaline?Your Answer: Acetylcholinesterase (ACh)
Correct Answer: Catechol-O-methyltransferase (COMT)
Explanation:The neurotransmitter in the synaptic cleft is either eliminated or deactivated after the post-synaptic cell responds to the neurotransmitter.
This can be accomplished in a variety of ways:
Re-uptake
Breakdown
DiffusionSerotonin is an example of a neurotransmitter that is uptake. Serotonin is absorbed back into the presynaptic neuron via the serotonin transporter (SERT), which is found in the presynaptic membrane. Re-uptake neurotransmitters are either recycled by repackaging into vesicles or broken down by enzymes.
Specific enzymes found in the synaptic cleft can also break down neurotransmitters. The following enzymes are examples of these enzymes:
Acetylcholinesterase (AChE) catalyses the acetylcholine breakdown (ACh)
The enzyme catechol-O-methyltransferase (COMT) catalyses the breakdown of catecholamines like adrenaline , dopamine and noradrenaline.The breakdown of catecholamines, as well as other monoamines like serotonin, tyramine, and tryptamine, is catalysed by monoamine oxidases (MOA).
Diffusion of neurotransmitters into nearby locations can also be used to eliminate them. -
This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 30
Incorrect
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All of the following statements are considered true regarding randomized control trials, except:
Your Answer: They can overcome small sample sizes
Correct Answer: They can eliminate the need for further studies
Explanation:Meta-analysis is a quantitative, formal, epidemiological study design used to systematically assess previous research studies to derive conclusions about that body of research. Outcomes from a meta-analysis may include a more precise estimate of the effect of treatment or risk factor for disease, or other outcomes, than any individual study contributing to the pooled analysis. The examination of variability or heterogeneity in study results is also a critical outcome.
The benefits of meta-analysis include a consolidated and quantitative review of a large, and often complex, sometimes apparently conflicting, body of literature. The specification of the outcome and hypotheses that are tested is critical to the conduct of meta-analyses, as is a sensitive literature search.Important medical questions are typically studied more than once, often by different research teams in different locations. In many instances, the results of these multiple small studies of an issue are diverse and conflicting, which makes the clinical decision-making difficult. The need to arrive at decisions affecting clinical practise fostered the momentum toward evidence-based medicine. Evidence-based medicine may be defined as the systematic, quantitative, preferentially experimental approach to obtaining and using medical information. Therefore, meta-analysis, a statistical procedure that integrates the results of several independent studies, plays a central role in evidence-based medicine.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 31
Correct
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As a result of a cardiovascular drug she was prescribed, a 67-year-old woman develops corneal microdeposits.
Which of the following drugs is the MOST LIKELY cause?Your Answer: Amiodarone
Explanation:Corneal microdeposits are almost universally present (over 90%) in people who have been taking amiodarone for more than six months, especially at doses above 400 mg/day. Although these deposits usually cause no symptoms, about 10% of patients report seeing a ‘bluish halo.’ This goes away once the treatment is stopped, and it rarely causes vision problems.
Other effects of amiodarone on the eye are much rarer, occurring in only 1-2 percent of patients:
Optic neuropathy is a condition that affects the eyes.
Non-arteritic anterior ischaemic optic neuropathy (N-AION)
Swelling of the optic disc -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 32
Correct
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Regarding iron deficiency anaemia, which of the following statements is INCORRECT:
Your Answer: Dietary insufficiency is the most common cause of iron deficiency anaemia in adult men in the UK.
Explanation:Blood loss from the gastrointestinal (GI) tract is the most common cause of iron deficiency anaemia in adult men and postmenopausal women.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 33
Incorrect
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Regarding an avulsion fracture, a sudden contraction of which muscle may lead to fracture of the head of the fibula?
Your Answer: Semitendinosus
Correct Answer: Biceps femoris
Explanation:Avulsion fractures of the fibular head are rare and are so-called the arcuate signal. The “arcuate signal” is used to describe an avulsed bone fragment related to the insertion site of the tendon of the biceps femoris associated with the arcuate complex, which consists of the fabellofibular, popliteofibular, and arcuate ligaments. Such lesions are typically observed in direct trauma to the knee with excessive varus and internal rotation forces or indirect trauma with the same direction of the force.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 34
Correct
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Intrinsic factor is vital for gastrointestinal absorption of which of the following:
Your Answer: Vitamin B12
Explanation:Intrinsic factor is essential for the absorption of the small amounts of vitamin B12 normally present in the diet from the terminal ileum. The parietal cells of the stomach produce intrinsic factor, and following a gastrectomy, the absorption of vitamin B12 will be markedly reduced, and a deficiency state will exist.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 35
Correct
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A 7-days-old neonate is taken to the emergency department. She's pyretic, lethargic, and unresponsive, and her fontanelle has bulged. Antibiotics are started, and a lumbar puncture reveals Gram-negative rods. Which pathogen is most likely to be the cause:
Your Answer: Escherichia coli
Explanation:Among neonates, group B streptococci (GBS) are the most commonly identified causes of bacterial meningitis, implicated in roughly 50% of all cases. Escherichia coli(Gram-negative rods) accounts for another 20%. Thus, the identification and treatment of maternal genitourinary infections is an important prevention strategy.
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This question is part of the following fields:
- Infections
- Microbiology
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Question 36
Correct
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Which of the following cytokines is important for the maintenance of granulomatous inflammation:
Your Answer: TNF-alpha
Explanation:Granulomatous inflammation is a distinctive pattern of chronic inflammation that is encountered in a limited number of infectious and some non-infectious conditions. Briefly, a granuloma is a cellular attempt to contain an offending agent that is difficult to eradicate. In this attempt, there is often strong activation of T lymphocytes leading to macrophage activation, which can cause injury to normal tissues. IL-1 is important in initiating granuloma formation, IL-2 can cause them to enlarge and TNF-α maintains them.
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 37
Incorrect
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Fibrinoid necrosis is typically seen in which of the following:
Your Answer: Acute pancreatitis
Correct Answer: Malignant hypertension
Explanation:Fibrinoid necrosis occurs in malignant hypertension where increased arterial pressure results in necrosis of smooth muscle wall. Eosinophilic and fibrinous deposits are seen.
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 38
Correct
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Which of the following describes the pulse pressure:
Your Answer: Systolic - diastolic pressure
Explanation:During systole, the pressure in the left ventricle increases and blood is ejected into the aorta. The rise in pressure stretches the elastic walls of the aorta and large arteries and drives blood flow. Systolic pressure is the maximum arterial pressure during systole. During diastole, arterial blood flow is partly maintained by elastic recoil of the walls of large arteries. The minimum pressure reached before the next systole is the diastolic pressure. The difference between the systolic and diastolic pressure is the pulse pressure.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 39
Correct
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Regarding hepatitis A, which of the following statements is CORRECT:
Your Answer: Anti-HAV IgM antibodies are diagnostic.
Explanation:Anti-HAV IgM antibodies are diagnostic. Disease in children is more commonly asymptomatic, risk of symptomatic disease increases with age. Transmission is by the faecal-oral route. Faecal shedding has been demonstrated for 2 – 3 weeks before and about a week after, the onset of jaundice. Infection confers lifelong immunity.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 40
Correct
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A 16-year old boy is brought to the emergency room after suffering a traffic accident. Upon examination, there is noted ipsilateral loss of proprioception and vibration, ipsilateral motor loss, and contralateral loss of pain and temperature sensation. A spinal cord injury is given as a diagnosis.
Which of the following is the most probable cause of this manifestation?Your Answer: Brown-Séquard syndrome
Explanation:Brown-Sequard Hemicord Syndrome consists of ipsilateral weakness (corticospinal tract) and loss of joint position and vibratory sense (posterior column), with contralateral loss of pain and temperature sense (spinothalamic tract) one or two levels below the lesion. Segmental signs, such as radicular pain, muscle atrophy, or loss of a deep tendon reflex, are unilateral. Partial forms are more common than the fully developed syndrome.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 41
Incorrect
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Regarding ciprofloxacin, which of the following statements is INCORRECT:
Your Answer: Ciprofloxacin is particularly active against Gram-negative bacteria.
Correct Answer: Ciprofloxacin decreases plasma concentrations of theophylline.
Explanation:Ciprofloxacin increases plasma concentrations of theophylline. There is an increased risk of convulsions when quinolones are given with NSAIDs or theophylline. There is an increased risk of tendon damage when quinolones are given with corticosteroids. Quinolones are known to increase the QT-interval and should not be taken with concomitantly with other drugs that are known to cause QT-interval prolongation. There is an increased risk of myopathy when erythromycin or clarithromycin are taken with simvastatin or atorvastatin.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 42
Incorrect
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Regarding T helper cells, which of the following statements is CORRECT:
Your Answer: They are CD8 receptor positive.
Correct Answer: They form the vast majority (about 75%) of the total circulating T-cell population.
Explanation:CD4+ T-cells (Helper T cells)Recognise antigen only in association with HLA class II molecules (found on antigen presenting cells (APCs) e.g. dendritic cells, B-cells; present exogenous antigens that have been phagocytosed/endocytosed into intracellular vesicles)Form most of the circulating T-cell population (about 75%)Secrete cytokines (e.g. IFN-gamma) which are required for recruitment and activation of other immune cells such as macrophages, T cytotoxic cells and NK cells and for the activation of and production of immunoglobulin from B-cells
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 43
Incorrect
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Carbamazepine is indicated for all of the following EXCEPT for:
Your Answer: Simple focal seizures
Correct Answer: Myoclonic seizures
Explanation:Carbamazepine is a drug of choice for simple and complex focal seizures and is a first-line treatment option for generalised tonic-clonic seizures. It is also used in trigeminal neuralgia and diabetic neuropathy. Carbamazepine may exacerbate tonic, atonic, myoclonic and absence seizures and is therefore not recommended if these seizures are present.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 44
Incorrect
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Which of these is NOT a naturally occurring anticoagulant:
Your Answer: Tissue factor pathway inhibitor
Correct Answer: Factor V Leiden
Explanation:It’s crucial that thrombin’s impact is restricted to the injured site. Tissue factor pathway inhibitor (TFPI), which is produced by endothelial cells and found in plasma and platelets, is the first inhibitor to function. It accumulates near the site of harm induced by local platelet activation. Xa and VIIa, as well as tissue factor, are inhibited by TFPI. Other circulating inhibitors, the most potent of which is antithrombin, can also inactivate thrombin and other protease factors directly. Coagulation cofactors V and VIII are inhibited by protein C and protein S. Tissue plasminogen activator (TPA) from endothelial cells facilitates fibrinolysis by promoting the conversion of plasminogen to plasmin.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 45
Correct
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A 72-year-old man has a past medical history of diverticular disease. He now presents in the clinic with crampy abdominal pain. The nurse at the triage suggests prescribing hyoscine butyl bromide to help relieve the abdominal pain. However, you do not agree with this medication, as you can see on his chart that the patient has several other comorbidities.
Out of the following, what is NOT a contraindication to using hyoscine butyl bromide?Your Answer: Prostatic hyperplasia
Explanation:Hyoscine butylbromide is an antispasmodic drug that blocks muscarinic receptors and reduces intestinal motility. It is used for gastrointestinal and genitourinary smooth muscle spasms and symptomatic relief of IBS.
It has the following contraindications:
1. Closed-angle glaucoma
2. Gastrointestinal obstruction
3. Intestinal atony
4. Paralytic ileus
5. Toxic megacolon
6. Severe ulcerative colitis
7. Significant bladder outflow obstruction
8. Urinary retention
9. Myasthenia gravisUse cautiously in the following conditions:
1. Acute myocardial infarction (in adults)
2. Arrhythmias (may be worsened)
3. Autonomic neuropathy
4. Hypertension
5. Cardiac insufficiency (due to association with tachycardia)
6. Congestive cardiac failure (maybe worsened)
7. Cardiac surgery (due to association with tachycardia)
8. Gastro-oesophageal reflux disease
9. Ulcerative colitis
10. Prostatic hyperplasia
11. Use in children (increased risk of side effects) -
This question is part of the following fields:
- Gastrointestinal Pharmacology
- Pharmacology
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Question 46
Incorrect
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Which of the following corticosteroids has the most potent mineralocorticoid effect:
Your Answer: Dexamethasone
Correct Answer: Fludrocortisone
Explanation:Fludrocortisone has the most potent mineralocorticosteroid activity, making it ideal for mineralocorticoid replacement in adrenal insufficiency.
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This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 47
Correct
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Which of the following is NOT a common side effect of diazepam:
Your Answer: Bradycardia
Explanation:Adverse effects include:
Drowsiness and lightheadedness
Confusion and ataxia (especially in the elderly), amnesia, muscle weakness
Headache, vertigo, tremor, dysarthria, hypotension, decreased libido, erectile dysfunction, gynaecomastia, urinary retention
Paradoxical effects such as talkativeness, excitement, irritability, aggression, anti-social behaviour, and suicidal ideation
Withdrawal symptoms, for example anxiety, depression, anorexia, impaired concentration, insomnia, abdominal cramps, palpitations, tremor, tinnitus and perceptual disturbances
Tolerance and dependence (people who use benzodiazepines longer term can develop tolerance and eventual dependence) -
This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 48
Correct
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A 62-year-old woman presents with cold sensitivity, tiredness, and weight gain. A series of blood tests done shows a grossly elevated TSH level and a diagnosis of hypothyroidism is made.
What is the commonest cause of hypothyroidism worldwide?Your Answer: Iodine deficiency
Explanation:Hypothyroidism occurs when there is a deficiency of circulating thyroid hormones. It is commoner in women and is most frequently seen in the age over 60.
Iodine deficiency is the commonest cause of hypothyroidism worldwide.
In developed countries, iodine deficiency is not a problem and autoimmune thyroiditis is the commonest cause.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 49
Incorrect
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A study investigating the risk of suffering a stroke in patients with atrial fibrillation taking the new antiplatelet drug ticagrelor, compared with standard treatment with warfarin is done over a 2-year time period. 30 of the 300 patients taking ticagrelor and 20 of the 500 patients taking warfarin suffered a stroke over the 2-year period.
One of these statements is true regarding the outcomes of this study.
Your Answer: The absolute risk in the warfarin group is 0.1
Correct Answer: Ticagrelor increases the risk of stroke
Explanation:Absolute risk and relative risk are used to assess the strength of a relationship between a disease and a factor that may affect it.
Absolute risk (AR) is the risk of developing a disease over a time period:
AR = the number of events that occur in a group / number of people in that groupThe absolute risk reduction (ARR) is the difference between the absolute risk in the control group (ARC) and the absolute risk in the treated group (ART).
ARR = ARC – ART
The control group is the warfarin group, therefore the ARC is 20/500 (0.04).
Treatment group is the ticagrelor group and ART = 30/300 (0.1).ARR = 0.04 – 0.1 = -0.06. This shows that treatment with ticagrelor increases risk of developing stroke. This is also termed a relative risk increase.
Relative risk, or risk ratio, (RR) is used to compare the risk in the two different groups. It is the ratio of the absolute risks of the disease in the treatment group (ART) to the absolute risk of the disease in the control group (ARC):
RR=ART /ARCTherefore RR = 0.1 / 0.04 = 2.5
RR < 1 means the intervention reduces the risk of the outcome being studied
RR = 1 means the treatment has no effect on the outcome being studied
RR > 1 means the intervention increased the risk of the outcome being studied
Since RR is 2.5, ticagrelor increases the risk of stroke.SUMMARY
Absolute risk reduction is -0.06
Absolute risk in warfarin group = 0.04
Relative risk = 2.5
Ticagrelor has no effect on stroke is incorrect because RR is not =1 -
This question is part of the following fields:
- Evidence Based Medicine
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Question 50
Correct
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A 64-year-old lady attends the emergency department with a known brain tumour. Her left eye is directed outwards and downwards, she can't open it, and her pupil is fixed and dilated. The tumour is most likely compressing which of the following structures:
Your Answer: Oculomotor nerve
Explanation:The oculomotor nerve is the third cranial nerve. It is the main source of innervation to the extraocular muscles and also contains parasympathetic fibres which relay in the ciliary ganglion. Damage to the third cranial nerve may cause diplopia, pupil mydriasis, and/or upper eyelid ptosis. The clinical manifestations of third cranial nerve dysfunction reflect its constituent parts.
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This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
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SESSION STATS - PERFORMANCE PER SPECIALTY
