-
Question 1
Incorrect
-
A 72-year-old man is brought to the emergency department by ambulance after collapsing at work due to dizziness. The paramedic reports that his ECG indicates hyperkalaemia. What is an ECG sign of hyperkalaemia?
Your Answer: Small or inverted T waves
Correct Answer: Sinusoidal waveform
Explanation:Hyperkalaemia can be identified on an ECG by the presence of a sinusoidal waveform, as well as small or absent P waves, tall-tented T waves, and broad bizarre QRS complexes. In severe cases, the QRS complexes may even form a sinusoidal wave pattern. Asystole can also occur as a result of hyperkalaemia.
On the other hand, ECG signs of hypokalaemia include small or inverted T waves, ST segment depression, and prominent U waves. A prolonged PR interval and long QT interval may also be present, although the latter can also be a sign of hyperkalaemia. In healthy individuals, narrow QRS complexes are typically observed, whereas hyperkalaemia can cause the QRS complexes to become wide and abnormal.
Hyperkalaemia is a condition where there is an excess of potassium in the blood. The levels of potassium in the plasma are regulated by various factors such as aldosterone, insulin levels, and acid-base balance. When there is metabolic acidosis, hyperkalaemia can occur as hydrogen and potassium ions compete with each other for exchange with sodium ions across cell membranes and in the distal tubule. The ECG changes that can be seen in hyperkalaemia include tall-tented T waves, small P waves, widened QRS leading to a sinusoidal pattern, and asystole.
There are several causes of hyperkalaemia, including acute kidney injury, drugs such as potassium sparing diuretics, ACE inhibitors, angiotensin 2 receptor blockers, spironolactone, ciclosporin, and heparin, metabolic acidosis, Addison’s disease, rhabdomyolysis, and massive blood transfusion. Foods that are high in potassium include salt substitutes, bananas, oranges, kiwi fruit, avocado, spinach, and tomatoes.
It is important to note that beta-blockers can interfere with potassium transport into cells and potentially cause hyperkalaemia in renal failure patients. In contrast, beta-agonists such as Salbutamol are sometimes used as emergency treatment. Additionally, both unfractionated and low-molecular weight heparin can cause hyperkalaemia by inhibiting aldosterone secretion.
-
This question is part of the following fields:
- Renal System
-
-
Question 2
Incorrect
-
A 49-year-old male presents to the GP for a routine blood check and follow-up. He has a medical history of angina, hypertension, asthma, and hyperlipidemia. Upon reviewing his medications, it is noted that he is taking fenofibrate, a drug that reduces triglyceride levels and increases the synthesis of high-density lipoprotein (HDL). What is the mechanism of action of this medication?
Your Answer: Reduction in the reabsorption of bile acids
Correct Answer: Activation of PPAR receptor resulting in increase lipoprotein lipase (LPL) activity
Explanation:Fibrates activate PPAR alpha receptors, which increase LPL activity and reduce triglyceride levels. These drugs are effective in lowering cholesterol.
Statins work by inhibiting HMG-CoA reductase, which reduces the mevalonate pathway and lowers cholesterol levels.
Niacin, also known as vitamin B3, inhibits hepatic diacylglycerol acyltransferase-2, which is necessary for triglyceride synthesis.
Bile acid sequestrants bind to bile salts, reducing the reabsorption of bile acids and lowering cholesterol levels.
Apolipoprotein E is a protein that plays a role in fat metabolism, specifically in removing chylomicron remnants.
Understanding Fibrates and Their Role in Managing Hyperlipidaemia
Fibrates are a class of drugs commonly used to manage hyperlipidaemia, a condition characterized by high levels of lipids in the blood. Specifically, fibrates are effective in reducing elevated triglyceride levels. This is achieved through the activation of PPAR alpha receptors, which in turn increases the activity of LPL, an enzyme responsible for breaking down triglycerides.
Despite their effectiveness, fibrates are not without side effects. Gastrointestinal side effects are common, and patients may experience symptoms such as nausea, vomiting, and diarrhea. Additionally, there is an increased risk of thromboembolism, a condition where a blood clot forms and blocks a blood vessel.
In summary, fibrates are a useful tool in managing hyperlipidaemia, particularly in cases where triglyceride levels are elevated. However, patients should be aware of the potential side effects and discuss any concerns with their healthcare provider.
-
This question is part of the following fields:
- Renal System
-
-
Question 3
Correct
-
A 50-year-old male is undergoing evaluation for persistent proteinuria. He has a medical history of relapsed multiple myeloma. A renal biopsy is performed, and the Congo red stain with light microscopy shows apple-green birefringence under polarised light.
What is the probable diagnosis?Your Answer: Amyloidosis
Explanation:Understanding Amyloidosis
Amyloidosis is a medical condition that occurs when an insoluble fibrillar protein called amyloid accumulates outside the cells. This protein is derived from various precursor proteins and contains non-fibrillary components such as amyloid-P component, apolipoprotein E, and heparan sulphate proteoglycans. The accumulation of amyloid fibrils can lead to tissue or organ dysfunction.
Amyloidosis can be classified as systemic or localized, and further characterized by the type of precursor protein involved. For instance, in myeloma, the precursor protein is immunoglobulin light chain fragments, which is abbreviated as AL (A for amyloid and L for light chain fragments).
To diagnose amyloidosis, doctors may use Congo red staining, which shows apple-green birefringence, or a serum amyloid precursor (SAP) scan. Biopsy of skin, rectal mucosa, or abdominal fat may also be necessary. Understanding amyloidosis is crucial for early detection and treatment of the condition.
-
This question is part of the following fields:
- Renal System
-
-
Question 4
Incorrect
-
A 75-year-old man presents to the emergency department with shortness of breath. He has no known medical conditions but is known to have a 80 pack-year smoking history. He reports that he has had a cough for the past six months, bringing up white sputum. An arterial blood gas reveals the following:
pH 7.30 mmol/L (7.35-7.45)
PaO2 9.1 kPa (10.5 - 13.5)
PaCO2 6.2 kPa (5.1 - 5.6)
Bicarbonate 34 mmol/L (22 - 29)
What process is likely to occur in this patient?Your Answer: Restrictive airway defect
Correct Answer: Increased secretion of erythropoietin
Explanation:Erythropoietin is produced by the kidney when there is a lack of oxygen in the body’s cells. Based on the patient’s smoking history and symptoms, it is probable that she has chronic obstructive pulmonary disorder (COPD). The type II respiratory failure and respiratory acidosis partially compensated by metabolic alkalosis suggest long-term changes. This chronic hypoxia triggers the secretion of erythropoietin, which increases the production of red blood cells, leading to polycythemia.
The accumulation of digestive enzymes in the pancreas is a characteristic of cystic fibrosis, but it is unlikely to be a new diagnosis in a 73-year-old woman. Moreover, cystic fibrosis patients typically have an isolated/compensated metabolic alkalosis on ABG, not a metabolic alkalosis attempting to correct a respiratory acidosis.
Excretion of bicarbonate is incorrect because bicarbonate would be secreted to further correct the respiratory acidosis, making this option incorrect.
Mucociliary system damage is the process that occurs in bronchiectasis, which would likely present with purulent sputum rather than white sputum. Additionally, there is no medical history to suggest the development of bronchiectasis.
Understanding Erythropoietin and its Side-Effects
Erythropoietin is a type of growth factor that stimulates the production of red blood cells. It is produced by the kidneys in response to low oxygen levels in the body. Erythropoietin is commonly used to treat anemia associated with chronic kidney disease and chemotherapy. However, it is important to note that there are potential side-effects associated with its use.
Some of the side-effects of erythropoietin include accelerated hypertension, bone aches, flu-like symptoms, skin rashes, and urticaria. In some cases, patients may develop pure red cell aplasia, which is caused by antibodies against erythropoietin. Additionally, erythropoietin can increase the risk of thrombosis due to raised PCV levels. Iron deficiency may also occur as a result of increased erythropoiesis.
There are several reasons why patients may not respond to erythropoietin therapy, including iron deficiency, inadequate dosage, concurrent infection or inflammation, hyperparathyroid bone disease, and aluminum toxicity. It is important for healthcare providers to monitor patients closely for these potential side-effects and adjust treatment as necessary.
-
This question is part of the following fields:
- Renal System
-
-
Question 5
Incorrect
-
Jill, who is in her mid-30s, has just completed a half marathon and is now dehydrated. The decreased perfusion pressure in her kidneys is detected by baroreceptors, leading to the activation of the renin-angiotensin-aldosterone system (RAAS). As a result, renin cleaves angiotensinogen to angiotensin I, which is then converted to angiotensin II by angiotensin-converting enzyme (ACE). What effect does angiotensin II have on the arteriole that branches off from the renal artery and carries blood away from the glomerulus? And how does this impact Jill's glomerular filtration rate (GFR)?
Your Answer: Vasodilation - no effect on GFR
Correct Answer: Vasoconstriction - increases GFR
Explanation:Angiotensin II causes vasoconstriction of the efferent arteriole, which increases the pressure difference between the afferent and efferent arterioles. This increase in pressure leads to an increase in filtration pressure and thus an increase in GFR. Therefore, efferent arteriole constriction increases GFR.
Reabsorption and Secretion in Renal Function
In renal function, reabsorption and secretion play important roles in maintaining homeostasis. The filtered load is the amount of a substance that is filtered by the glomerulus and is determined by the glomerular filtration rate (GFR) and the plasma concentration of the substance. The excretion rate is the amount of the substance that is eliminated in the urine and is determined by the urine flow rate and the urine concentration of the substance. Reabsorption occurs when the filtered load is greater than the excretion rate, and secretion occurs when the excretion rate is greater than the filtered load.
The reabsorption rate is the difference between the filtered load and the excretion rate, and the secretion rate is the difference between the excretion rate and the filtered load. Reabsorption and secretion can occur in different parts of the nephron, including the proximal tubule, loop of Henle, distal tubule, and collecting duct. These processes are regulated by various hormones and signaling pathways, such as aldosterone, antidiuretic hormone (ADH), and atrial natriuretic peptide (ANP).
Overall, reabsorption and secretion are important mechanisms for regulating the composition of the urine and maintaining fluid and electrolyte balance in the body. Dysfunction of these processes can lead to various renal disorders, such as diabetes insipidus, renal tubular acidosis, and Fanconi syndrome.
-
This question is part of the following fields:
- Renal System
-
-
Question 6
Incorrect
-
An 82-year-old woman with a history of chronic kidney disease presents to the general practice with a painful left foot. The pain is sharp in nature and is felt mostly towards the posterior of the sole of the foot. The pain is most severe when the patient takes her first few steps after getting out of bed in the morning. There is no history of trauma. You diagnose plantar fasciitis. The usual treatment of plantar fasciitis is with NSAIDs. However, NSAIDs are contraindicated in severe renal disease. What is the effect of NSAIDs on the glomerular filtration pressure?
Your Answer:
Correct Answer: Vasoconstriction of the afferent arteriole
Explanation:The correct answer is vasoconstriction of the afferent arteriole, as explained in the following notes.
ACE inhibitors and ARBs cause vasodilation of the efferent arteriole, which reduces glomerular filtration pressure. This effect is particularly significant in individuals with renal artery stenosis, as their kidneys receive limited perfusion, including the glomeruli.
In a healthy individual, the afferent arteriole remains dilated, while the efferent arteriole remains constricted to maintain a fine balance of glomerular pressure. Vasodilation of the afferent arteriole or vasoconstriction of the efferent arteriole would both increase glomerular filtration pressure.
The patient in the given question is experiencing symptoms that suggest plantar fasciitis, a common condition caused by inflammation of the plantar fascia in the foot.
The Impact of NSAIDs on Kidney Function
NSAIDs are commonly used anti-inflammatory drugs that work by inhibiting the enzymes COX-1 and COX-2, which are responsible for the synthesis of prostanoids such as prostaglandins and thromboxanes. In the kidneys, prostaglandins play a crucial role in vasodilating the afferent arterioles of the glomeruli, allowing for increased blood flow and a higher glomerular filtration rate (GFR).
However, when NSAIDs inhibit the COX enzymes, the levels of prostaglandins decrease, leading to a reduction in afferent arteriole vasodilation and subsequently, a decrease in renal perfusion and GFR. This can have negative consequences for kidney function, particularly in individuals with pre-existing kidney disease or those taking high doses of NSAIDs for prolonged periods of time.
It is important for healthcare providers to consider the potential impact of NSAIDs on kidney function and to monitor patients accordingly, especially those at higher risk for kidney damage. Alternative treatments or lower doses of NSAIDs may be recommended to minimize the risk of kidney injury.
-
This question is part of the following fields:
- Renal System
-
-
Question 7
Incorrect
-
A 55-year-old man with a medical history of ischaemic heart disease, gout, and diabetes presents with sudden and severe pain in his left renal angle that radiates to his groin. Upon undergoing an urgent CT KUB, it is confirmed that he has nephrolithiasis with hydronephrosis. As a result, he is admitted under the urology team for immediate intervention due to acute kidney injury.
What is the most common material that makes up these calculi in the general population?Your Answer:
Correct Answer: Calcium oxalate
Explanation:Renal stones can be classified into different types based on their composition. Calcium oxalate stones are the most common, accounting for 85% of all calculi. These stones are formed due to hypercalciuria, hyperoxaluria, and hypocitraturia. They are radio-opaque and may also bind with uric acid stones. Cystine stones are rare and occur due to an inherited recessive disorder of transmembrane cystine transport. Uric acid stones are formed due to purine metabolism and may precipitate when urinary pH is low. Calcium phosphate stones are associated with renal tubular acidosis and high urinary pH. Struvite stones are formed from magnesium, ammonium, and phosphate and are associated with chronic infections. The pH of urine can help determine the type of stone present, with calcium phosphate stones forming in normal to alkaline urine, uric acid stones forming in acidic urine, and struvate stones forming in alkaline urine. Cystine stones form in normal urine pH.
-
This question is part of the following fields:
- Renal System
-
-
Question 8
Incorrect
-
A 50-year-old man with a history of type 2 diabetes mellitus, bipolar disorder and chronic obstructive pulmonary disease presents for a preoperative assessment for an inguinal hernia repair. His bloods are taken and reveal the following results:
Na+ 125 mmol/l
K+ 3.8 mmol/l
Bicarbonate 24 mmol/l
Urea 3.7 mmol/l
Creatinine 92 µmol/l
As a result of his smoking history, a chest x-ray is ordered and reported as normal. The Consultant inquires about the most probable cause of the hyponatraemia.Your Answer:
Correct Answer: Carbamazepine
Explanation:Carbamazepine, sulfonylureas, SSRIs, and tricyclics are drugs that can cause SIADH. While lithium can lead to diabetes insipidus, it usually occurs with high sodium levels. Elevated antidiuretic hormone levels due to lithium are typically only seen in cases of severe overdose.
SIADH is a condition where the body retains too much water, leading to low sodium levels in the blood. This can be caused by various factors such as malignancy (particularly small cell lung cancer), neurological conditions like stroke or meningitis, infections like tuberculosis or pneumonia, certain drugs like sulfonylureas and SSRIs, and other factors like positive end-expiratory pressure and porphyrias. Treatment involves slowly correcting the sodium levels, restricting fluid intake, and using medications like demeclocycline or ADH receptor antagonists. It is important to correct the sodium levels slowly to avoid complications like central pontine myelinolysis.
-
This question is part of the following fields:
- Renal System
-
-
Question 9
Incorrect
-
A 37-year-old woman presents to rheumatology with complaints of fatigue and arthralgia persisting for the past 3 months. During her evaluation, a urine dipstick test reveals proteinuria, and renal biopsies reveal histological evidence of proliferative 'wire-loop' glomerulonephritis.
What is the probable diagnosis?Your Answer:
Correct Answer: Systemic lupus erythematosus (SLE)
Explanation:Renal Complications in Systemic Lupus Erythematosus
Systemic lupus erythematosus (SLE) can lead to severe renal complications, including lupus nephritis, which can result in end-stage renal disease. Regular check-ups with urinalysis are necessary to detect proteinuria in SLE patients. The WHO classification system categorizes lupus nephritis into six classes, with class IV being the most common and severe form. Renal biopsy shows characteristic findings such as endothelial and mesangial proliferation, a wire-loop appearance, and subendothelial immune complex deposits.
Management of lupus nephritis involves treating hypertension and using glucocorticoids with either mycophenolate or cyclophosphamide for initial therapy in cases of focal (class III) or diffuse (class IV) lupus nephritis. Mycophenolate is generally preferred over azathioprine for subsequent therapy to decrease the risk of developing end-stage renal disease. Early detection and proper management of renal complications in SLE patients are crucial to prevent irreversible damage to the kidneys.
-
This question is part of the following fields:
- Renal System
-
-
Question 10
Incorrect
-
A 28-year-old male patient comes to you with worries about his increasing breast size, despite not experiencing any weight gain in other areas. Upon further inquiry, he also mentions a painless lump in his right testicle. He reveals that his father had testicular cancer in the past.
What is the probable reason for gynaecomastia in this scenario?Your Answer:
Correct Answer: Increased oestrogen: androgen ratio
Explanation:Gynaecomastia is a common symptom of testicular cancer and is caused by an increased oestrogen:androgen ratio. This occurs because germ-cell tumours produce hCG, which causes Leydig cells to produce more oestradiol in relation to testosterone. Leydig cell tumours also directly secrete more oestradiol and convert additional androgen precursors to oestrogens. This results in a relative reduction in androgen concentration and an increased conversion of androgens to oestrogens.
Obesity can also cause gynaecomastia due to increased levels of aromatase, the enzyme responsible for the conversion of androgens to oestrogens. However, this is not the most likely cause in this case as the patient has not gained weight elsewhere and presents with symptoms of testicular cancer.
Undescended testis is a significant risk factor for testicular cancer, but it is not a direct cause of gynaecomastia. Similarly, a prolactinoma can cause breast enlargement in males, but it is not commonly associated with testicular cancer or gynaecomastia.
In summary, gynaecomastia in testicular cancer is caused by an increased oestrogen:androgen ratio, which can result from germ-cell or Leydig cell tumours. Other potential causes, such as obesity, undescended testis, or prolactinoma, are less likely in this clinical scenario.
Testicular cancer is a common type of cancer that affects men between the ages of 20 and 30. The majority of cases (95%) are germ-cell tumors, which can be further classified as seminomas or non-seminomas. Non-germ cell tumors, such as Leydig cell tumors and sarcomas, are less common. Risk factors for testicular cancer include infertility, cryptorchidism, family history, Klinefelter’s syndrome, and mumps orchitis. Symptoms may include a painless lump, pain, hydrocele, and gynaecomastia.
Tumour markers can be used to diagnose testicular cancer. For germ cell tumors, hCG may be elevated in seminomas, while AFP and/or beta-hCG are elevated in non-seminomas. LDH may also be elevated in germ cell tumors. Ultrasound is the first-line diagnostic tool.
Treatment for testicular cancer depends on the type and stage of the tumor. Orchidectomy, chemotherapy, and radiotherapy may be used. Prognosis is generally excellent, with a 5-year survival rate of around 95% for Stage I seminomas and 85% for Stage I teratomas.
-
This question is part of the following fields:
- Renal System
-
00
Correct
00
Incorrect
00
:
00
:
0
00
Session Time
00
:
00
Average Question Time (
Secs)