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Question 1
Correct
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A 56-year-old teacher presents to the Emergency Department with nausea and vomiting, with associated lethargy. She has mild asthma which is well controlled with a steroid inhaler but has no other medical history of note. She does not smoke but drinks up to 20 units of alcohol a week, mostly on the weekends. Observations are as follows:
Temperature is 37.2 oC, blood pressure is 110/70 mmHg, heart rate is 90 bpm and regular.
On examination, the patient appears to be clinically dehydrated, but there are no other abnormalities noted.
Blood tests reveal:
Investigation Result Normal Values
Haemoglobin (Hb) 140 g/l 135–175 g/l
White cell count (WCC) 7.8 × 109/l 4–11 × 109/l
Urea 8.5 mmol/l 2.5–6.5 mmol/l
Creatinine 190 µmol/l
(bloods carried out one year
previously showed a creatinine
of 80) 50–120 µmol/l
Potassium (K+) 4.7 mmol/l 3.5–5.0 mmol/l
Sodium (Na+) 133 mmol/l 135–145 mmol/l
Which of the following is most suggestive of acute kidney injury rather than chronic renal failure?Your Answer: Oliguria
Explanation:Signs and Symptoms of Acute and Chronic Renal Failure
Renal failure can be acute or chronic, and it is important to differentiate between the two. Acute renal failure may present with symptoms such as acute lethargy, dehydration, shortness of breath, nausea and vomiting, oliguria, acute onset peripheral edema, confusion, seizures, and coma. On the other hand, chronic renal failure may present with symptoms such as anemia, pruritus, long-standing fatigue, weight loss, and reduced appetite. A history of underlying medical conditions such as diabetes or hypertension is also a risk factor for chronic kidney disease.
Oliguria is a clinical hallmark of renal failure and can be one of the early signs of acute renal injury. Raised parathyroid hormone levels are more commonly found in chronic renal failure, while peripheral neuropathy is likely to be present in patients with chronic renal failure due to an underlying history of diabetes. Nocturia or nocturnal polyuria is often found in patients with chronic kidney disease, while in acute injury, urine output tends to be reduced rather than increased. Small kidneys are seen in chronic renal failure, while the kidneys are more likely to be of normal size in acute injury.
Understanding the Signs and Symptoms of Acute and Chronic Renal Failure
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This question is part of the following fields:
- Renal
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Question 2
Correct
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A 60-year-old man has been asked to visit his GP because of abnormal renal function tests for the past two months. His GFR reading has been consistently 35 ml/min. What stage of CKD is this patient exhibiting?
Your Answer: This patient does not meet the criteria for CKD
Explanation:Understanding Chronic Kidney Disease Stages
Chronic Kidney Disease (CKD) is a condition that affects the kidneys and their ability to filter waste from the blood. To diagnose CKD, a patient must have a GFR (glomerular filtration rate) of less than 60 ml/min for at least three months. This is the primary criteria for CKD diagnosis.
There are five stages of CKD, each with different GFR values and symptoms. Stage 1 CKD presents with a GFR greater than 90 ml/min and some signs of kidney damage. Stage 3a CKD presents with a GFR of 45-59 ml/min, while stage 3b CKD patients have a GFR of 30-44 ml/min. However, both stage 3a and 3b require the GFR to be present for at least three months.
There is no stage 4a CKD. Instead, stage 4 CKD patients have a GFR of 15-29 ml/min. It is important to understand the different stages of CKD to properly diagnose and treat patients with this condition.
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This question is part of the following fields:
- Renal
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Question 3
Correct
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A 45-year-old writer presents to his routine follow up at the Nephrology Clinic complaining of numbness and tingling sensation of his right fingers. This worsens when he types for more than an hour and slightly improves when he stops typing. He suffers from diabetes mellitus and end-stage kidney disease and has been on regular haemodialysis via brachiocephalic fistula on his right antecubital fossa. On examination, his right radial artery is palpable and he has reduced sensation in all his right fingers, predominantly affecting the fingertips. The numbness does not worsen with tapping over the wrist nor with forced flexion of his wrists. His capillary refill time over his right fingers is prolonged to three seconds.
Which of the following is the most likely diagnosis?Your Answer: Fistula steal syndrome
Explanation:Differential Diagnosis for Numbness in a Patient with Arteriovenous Fistula
Fistula Steal Syndrome, Carpal Tunnel Syndrome, and Diabetic Neuropathy are Possible Causes of Numbness in a Patient with Arteriovenous Fistula
Arteriovenous fistula is a common procedure for patients undergoing hemodialysis. However, up to 20% of patients may develop complications such as fistula steal syndrome, which occurs when the segment of artery distal to the fistula is narrowed, leading to reduced arterial blood flow to the limb extremities. This can cause numbness and worsening of symptoms on usage of the hands.
Other possible causes of numbness in this patient include carpal tunnel syndrome, which is a common complication among patients on long-term renal replacement therapy due to protein deposition in the carpal tunnel, and diabetic neuropathy, which is a common complication of chronic diabetes mellitus. However, the loss of sensation in peripheral neuropathy in diabetic patients is symmetrical in nature, commonly following a glove and stocking pattern.
Radial nerve palsy and ulnar styloid fracture are less likely causes of numbness in this patient, as they typically present with muscle weakness and a history of trauma, respectively. A thorough differential diagnosis is necessary to determine the underlying cause of numbness in patients with arteriovenous fistula.
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This question is part of the following fields:
- Renal
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Question 4
Correct
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A 43-year-old man is suspected of having a renal calculus. He has some investigations carried out by the general practitioner to monitor the effects of his medication. The following results are obtained:
Plasma
Na+ 138 mmol/l (135–145 mmol/l)
K+ 3.1 mmol/l (3.5–5 mmol/l)
24-hour urine sample:
Ca2+ 40 mg/day (100–300 mg/day)
Given the results above, which one of the following is the patient most likely taking?Your Answer: Bendroflumethiazide
Explanation:Overview of Different Types of Diuretics and Their Effects on Electrolytes and Renal Calculi Formation
Diuretics are medications that increase urine output and are commonly used to treat conditions such as hypertension and edema. However, different types of diuretics have varying effects on electrolyte balance and renal calculi formation.
Thiazide diuretics, such as bendroflumethiazide, work in the distal tubule of the nephron and result in sodium and potassium loss in urine, with calcium resorption. This makes them useful in controlling chronic renal calculi formation. However, they can also cause hypokalemia and hypercalcemia.
Loop diuretics, such as furosemide, work in the thick ascending limb of the loop of Henle and result in sodium, potassium, and calcium loss in urine. This can increase the risk of renal calculi formation.
Carbonic anhydrase inhibitors, such as acetazolamide, work in the proximal convoluted tubule and produce alkaline urine rich in bicarbonate. Continued use can lead to metabolic acidosis and an increased risk of renal calculi formation.
Aldosterone antagonists, such as spironolactone, work in the distal part of the distal tubule and collecting tubules and inhibit aldosterone-mediated sodium absorption and potassium excretion. This can result in hyperkalemia.
Mannitol, a osmotic diuretic, may cause hyponatremia but does not usually affect plasma potassium or urinary calcium excretion.
Overall, understanding the different types of diuretics and their effects on electrolyte balance and renal calculi formation is important in selecting the appropriate medication for a patient’s specific needs.
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This question is part of the following fields:
- Renal
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Question 5
Correct
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A 52-year-old man with an acute kidney injury has developed fluid overload and treatment has been initiated. An ABCDE assessment is performed, and the findings are below:
Airway Patent, speaking but confused in conversation
Breathing Respiratory rate (RR) 24/min, SaO2 96% on 4 litres of O2/min, bibasal crackles heard on auscultation in the lower zones (up to mid-zones on admission)
Circulation Heart rate (HR) 112 bpm, blood pressure (BP) 107/68 mmHg, heart sounds disturbed by a friction rub, ECG shows sinus tachycardia
Disability Pupils equal and reactive to light, normal upper and lower limb neurology, Glasgow Coma Scale (GCS) 14 (E4 V4 M6)
Exposure Temperature 36.8°C
On initial bloods, the C-reactive protein (CRP) is within normal limits.
The results of initial arterial blood gas and serum urea and electrolytes are shown below:
Investigation Result Normal value
pH 7.28 7.35–7.45
pO2 10.7 kPa > 11 kPa
pCO2 5.7 kPa 4.5–6.0 kPa
Bicarbonate 20 mmol/l 22–26 mmol/l
Lactate 1.8 mmol/l < 2 mmol/l
Urea 53 mmol/l 2.5–7.8 mmol/l
Creatinine 729 µmol/l 50–120 µmol/l
Which one of the following is an indication for urgent dialysis in this patient?Your Answer: Urea of 53 mmol/l
Explanation:A raised urea level of 53 mmol/l, along with an audible friction rub on heart auscultation and reduced Glasgow Coma Scale (GCS), suggests uraemic pericarditis and uraemic encephalopathy respectively. Urgent dialysis is necessary if symptoms or complications occur due to uraemia. Hyperkalaemia with a K+ level >6.5, refractory to medical therapies, or associated with ECG changes, requires urgent dialysis. Life-threatening hyperkalaemia should be treated with medical therapies such as calcium gluconate, insulin-dextrose, and salbutamol. Metabolic acidaemia with a pH <7.1, refractory to medical therapies, is an indication for dialysis. Creatinine levels do not indicate when dialysis is required. Bibasal crackles may represent pulmonary oedema due to fluid overload, but if they respond to medical treatment, urgent dialysis is not necessary. However, if they are refractory to medical therapy, dialysis may be warranted.
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This question is part of the following fields:
- Renal
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Question 6
Correct
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A 6-year-old boy presents to the Emergency Department with periorbital pain, ascites, and oedema. He has no past medical history and is typically healthy, without recent illnesses. Upon examination, his serum urea is elevated and protein in his urine is ++++. What is the probable cause of his symptoms?
Your Answer: Minimal change glomerulonephritis
Explanation:Overview of Different Types of Glomerulonephritis
Glomerulonephritis is a group of kidney diseases that affect the glomeruli, the tiny blood vessels in the kidneys that filter waste and excess fluids from the blood. Here are some of the different types of glomerulonephritis:
1. Minimal Change Glomerulonephritis: This is the most common cause of nephrotic syndrome in children. It is caused by T-cell-mediated injury to the podocytes of the epithelial cells. The diagnosis is made by electron microscopy, and treatment is with steroids.
2. Membranous Glomerulonephritis: This is the second most common cause of nephrotic syndrome in adults. It can be primary or secondary, and some causes of secondary membranous glomerulonephritis include autoimmune conditions, malignancy, viral infections, and drugs. On light microscopy, the basement membrane has characteristic spikes.
3. Mesangiocapillary Glomerulonephritis: This is associated with immune deposition in the glomerulus, thickening of the basement membrane, and activation of complement pathways leading to glomerular damage. It presents with nephrotic syndrome and is seen in both the pediatric and adult population. It is the most common glomerulonephritis associated with hepatitis C.
4. Post-Streptococcal Glomerulonephritis: This presents with haematuria, oedema, hypertension, fever, or acute kidney failure following an upper respiratory tract infection or pharyngitis from Streptococcus spp.
5. IgA Nephropathy Glomerulonephritis: This is a condition associated with IgA deposition within the glomerulus, presenting with haematuria following an upper respiratory tract infection. It is the most common cause of glomerulonephritis in adults.
Understanding the Different Types of Glomerulonephritis
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This question is part of the following fields:
- Renal
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Question 7
Incorrect
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A middle-aged woman with a history of renal cell carcinoma complains of swelling in both legs extending from the groin area and dilated veins around the belly button. What is the underlying mechanism responsible for these symptoms?
Your Answer: Hypoalbuminaemia
Correct Answer: Inferior vena cava obstruction
Explanation:Causes of Bilateral Lower Limb Edema: Differential Diagnosis
Bilateral lower limb edema can have various causes, and a thorough differential diagnosis is necessary to determine the underlying condition. In this case, the patient presents with inferior vena cava obstruction, which is caused by extrinsic compression from a renal mass. This obstruction prevents venous drainage of the lower limbs and leads to bilateral edema and distended superficial abdominal veins. Other causes of bilateral lower limb edema include hyponatremia, hypoalbuminemia, deep venous thrombosis, and heart failure. However, each of these conditions presents with distinct symptoms and signs. Hyponatremia and hypoalbuminemia cause generalized edema, while deep venous thrombosis presents with painful swelling and erythema in the affected limb. Heart failure also causes bilateral dependent edema but does not lead to venous engorgement and dilated veins around the umbilicus. Therefore, a careful evaluation of the patient’s history, physical examination, and laboratory tests is crucial to establish the correct diagnosis and initiate appropriate treatment.
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This question is part of the following fields:
- Renal
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Question 8
Incorrect
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A 20-year-old man visits his GP clinic with a chief complaint of headaches. During the physical examination, no abnormalities are detected, but his blood pressure is found to be 178/90 mmHg. The doctor suspects a renal origin for the hypertension and wants to perform an initial screening test for renovascular causes. What is the most appropriate investigation for this purpose?
Your Answer: Magnetic resonance angiography of abdomen
Correct Answer: Abdominal duplex ultrasound
Explanation:Diagnostic Tests for Renal Hypertension
Renal hypertension, or high blood pressure caused by kidney disease, can be diagnosed through various diagnostic tests. The appropriate initial screening investigation is an abdominal duplex ultrasound, which can detect renal vascular or anatomical pathologies such as renal artery stenosis or polycystic kidney disease. If abnormalities are found, more advanced testing such as a CTA, magnetic resonance angiography, or nuclear medicine testing may be necessary. However, an ultrasound is the best initial screening investigation for renal hypertension.
A CTA is a follow-up test that may be performed if an initial abdominal duplex ultrasound suggests a renal cause for the hypertension. It is an advanced, specialist test that would not be appropriate as an initial screening investigation. On the other hand, a magnetic resonance angiography is an advanced, gold-standard test that can be performed if an initial abdominal duplex ultrasound suggests a renal cause for the hypertension.
HbA1c is a blood test that tests your average blood glucose levels over the last 2–3 months. It can indicate if diabetes may have contributed to the hypertension, but will not clarify whether there is a renal cause. Lastly, a urine albumin: creatinine ratio tests for the presence of protein in the urine, which is a reflection of kidney disease, but does not give us any indication of the cause.
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This question is part of the following fields:
- Renal
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Question 9
Correct
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A 35-year-old woman presents with an incidental finding of a blood pressure of 180/130 mmHg on three separate occasions. Her cardiovascular examination is unremarkable, but further investigation reveals a significantly smaller left kidney with a 'string of beads' appearance in the left renal artery. What is the most appropriate management option for this patient?
Your Answer: Balloon angioplasty
Explanation:Management of Renal Artery Stenosis: Fibromuscular Dysplasia
Fibromuscular dysplasia is a rare cause of renal artery stenosis, typically affecting young women and presenting with hypertension. The characteristic ‘string of beads’ appearance on CT imaging helps in diagnosis. While atherosclerotic disease is the most common cause of renal artery stenosis, a combination of antihypertensive therapy and renal artery balloon angioplasty is curative for fibromuscular dysplasia. Kidney transplantation is not usually required, but it is important to recognize the condition in donors to prevent complications in recipients. Nephrectomy is not typically necessary, and surgical reconstruction is rarely recommended. Statins are not used in the management of fibromuscular dysplasia, but may be used in atherosclerotic renal artery stenosis.
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This question is part of the following fields:
- Renal
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Question 10
Correct
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A 62-year-old woman with a history of type II diabetes comes in for her yearly check-up. Her most recent early morning urinary albumin : creatinine ratio (ACR) is 4 mg/mmol (normal for women: < 3.5 mg/mmol). What should be the target blood pressure for managing her diabetic nephropathy?
Your Answer: 130/80 mmHg
Explanation:Blood Pressure Targets for Patients with Diabetes
Blood pressure targets vary depending on the type of diabetes and the presence of co-morbidities. For patients with type II diabetes and signs of end-organ damage, the target is 130/80 mmHg. Ideal blood pressure for most people is between 90/60 mmHg and 120/80 mmHg. Patients with type I diabetes without albuminuria or > 2 features of metabolic syndrome have a target of 135/85 mmHg. Type II diabetics without signs of end-organ damage have a target of 140/80 mmHg. For patients over 80 years old, the target is 150/90 mmHg. It is important for patients with diabetes to work with their healthcare provider to determine their individual blood pressure target.
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This question is part of the following fields:
- Renal
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Question 11
Correct
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A 76-year-old woman is admitted to the hospital feeling generally unwell. She has also developed a fever and diffuse erythematous rash over the last few days. Urinalysis is positive for blood and protein, and blood tests show raised eosinophils and creatinine. Her General Practitioner started her on a new medication two weeks ago, but she cannot remember the name or what it was for.
Which of the following drugs would be safe to continue at present, given the suspected diagnosis?Your Answer: Prednisolone
Explanation:Drug-Induced Acute Tubulointerstitial Nephritis: Common Culprits and Management Options
Acute tubulointerstitial nephritis is a condition characterized by fever, rash, and abnormalities on urinalysis. It can be caused by various drugs, including non-steroidal anti-inflammatory drugs (NSAIDs), beta-lactam antibiotics, allopurinol, and proton pump inhibitors (PPIs). In this case, the patient’s raised eosinophil count suggests drug-induced acute tubulointerstitial nephritis.
Prednisolone, a steroid commonly used to manage this condition, is safe to continue. However, NSAIDs like diclofenac should be stopped as they can inhibit prostaglandins that maintain the glomerular filtration rate. Allopurinol may also need to be withdrawn to determine if it is contributing to the symptoms. Beta-lactam antibiotics like amoxicillin are another common cause and may need to be stopped. PPIs like omeprazole are a relatively rare but known trigger and should be withdrawn promptly. It is important to remember that steroids should not be suddenly stopped in most patients.
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This question is part of the following fields:
- Renal
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Question 12
Correct
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A 30-year-old man presents to the general practitioner (GP) with hypertension which fails to fall into the normal range after three successive measurements at the practice nurse. These were 155/92 mmHg, 158/96 mmHg and 154/94 mmHg. He has a past history of some urinary tract infections as a child. The GP arranges some routine blood tests.
Investigations:
Investigation Result Normal value
Haemoglobin 139 g/l 135–175 g/l
White cell count (WCC) 5.4 × 109/l 4–11 × 109/l
Platelets 201 × 109/l 150–400 × 109/l
Sodium (Na+) 139 mmol/l 135–145 mmol/l
Potassium (K+) 4.9 mmol/l 3.5–5.0 mmol/l
Creatinine 187 μmol/l 50–120 μmol/l
USS Left kidney 8.4 cm and appears scarred.
Right kidney 10.3 cm
Which of the following is the most likely diagnosis?Your Answer: Chronic reflux nephropathy
Explanation:Differential Diagnosis for a 25-Year-Old Man with Renal Issues
Upon reviewing the history and test results of a 25-year-old man with renal issues, several potential diagnoses can be considered. Chronic reflux nephropathy appears to be the most likely diagnosis, given the patient’s history of urinary tract infections as a child, ultrasound scan results, and elevated creatinine levels. Further testing, such as renal tract computed tomography and a voiding cystourethrogram, can confirm this diagnosis.
Essential hypertension, while a risk factor for reno-vascular disease, would not explain the patient’s creatinine rise or asymmetrical kidneys. Renal artery stenosis, while potentially causing a unilaterally reduced kidney size, is rare in young patients and does not fit with the patient’s history of urinary tract infections. White coat hypertension, which is a transient rise in blood pressure in a medical setting, would not explain the patient’s creatinine rise or reduced kidney size and scarring.
IgA nephropathy, which typically presents with haematuria following an upper respiratory or other infection, does not fit with the patient’s history of urinary tract infections or lack of haematuria. Therefore, chronic reflux nephropathy remains the most likely diagnosis for this patient.
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This question is part of the following fields:
- Renal
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Question 13
Correct
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A 12-year-old male patient is referred to the renal physicians after several episodes of frank haematuria. He does not recall any abdominal or loin pain. He had an upper respiratory tract infection a few days ago. Urine dipstick shows blood, and blood tests are normal.
What is the most likely diagnosis?Your Answer: IgA nephropathy
Explanation:Differentiating Glomerulonephritis and Other Possible Causes of Haematuria in a Young Patient
Haematuria in a young patient can be caused by various conditions, including glomerulonephritis, post-streptococcal glomerulonephritis, minimal change disease, sexually transmitted infections, and bladder cancer. IgA nephropathy, also known as Berger’s Disease, is the most common glomerulonephritis in the developed world and commonly affects young men. It presents with macroscopic haematuria a few days after a viral upper respiratory tract infection. A renal biopsy will show IgA deposits in the mesangium, and treatment is with steroids or cyclophosphamide if renal function is deteriorating.
Post-streptococcal glomerulonephritis, on the other hand, presents in young children usually one to two weeks post-streptococcal infection with smoky urine and general malaise. Proteinuria is also expected in a glomerulonephritis. Minimal change disease is the most common cause of nephrotic syndrome in children and is associated with an upper respiratory tract infection. However, nephrotic syndrome involves proteinuria, which this patient does not have.
It is also important to exclude sexually transmitted infections, as many are asymptomatic, but signs of infection and inflammation would likely show up on urine dipstick. Bladder cancer is unlikely in such a young patient devoid of other symptoms. Therefore, a thorough evaluation and proper diagnosis are necessary to determine the underlying cause of haematuria in a young patient.
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This question is part of the following fields:
- Renal
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Question 14
Correct
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A 7-year-old girl presents with haematuria, hearing loss, and poor eyesight caused by lens dislocation. After conducting additional tests, the diagnosis of Alport syndrome is made. What type of collagen is typically affected by a molecular defect in this disease?
Your Answer: Type IV
Explanation:Types and Effects of Collagen Defects on Human Health
Collagen is an essential protein that provides structural support to various tissues in the human body. Defects in different types of collagen can lead to various health conditions. Type IV collagen is crucial for the integrity of the basement membrane, and mutations in its genes can cause Alport syndrome, resulting in haematuria, hearing loss, and visual disturbances. Type III collagen defects cause Ehlers–Danlos syndrome, characterized by joint hypermobility, severe bruising, and blood vessel defects. Type I collagen defects lead to osteogenesis imperfecta, characterized by brittle bones, abnormal teeth, and weak tendons. Kniest dysplasia is caused by defects in type II collagen, leading to short stature, poor joint mobility, and eventual blindness. Kindler syndrome is characterized by the absence of epidermal anchoring fibrils due to defects in type VII collagen, resulting in skin fragility. Understanding the effects of collagen defects on human health is crucial for diagnosis and treatment of these conditions.
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This question is part of the following fields:
- Renal
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Question 15
Correct
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A 49-year-old man presents to the doctor with a week history of frank haematuria. He has no other symptoms to note and is otherwise well although he has been a little tired. He has a history of hypertension which is well controlled on with perindopril. He smokes 10 cigarettes a day and has done so since his teens.
Examination of the abdomen reveals no abnormalities. A dipstick test of the urine reveals blood +++.
The patient is especially concerned that he may have a kidney tumour, as his father died from the condition over 20 years ago.
Which of the following malignancies of the kidney the most common in the adult population ?Your Answer: Renal cell carcinoma
Explanation:Types of Kidney Tumors: An Overview
Kidney tumors are abnormal growths that can develop in different parts of the kidney. The most common type of kidney cancer in adults is renal cell carcinoma, which accounts for about 80% of all renal malignancies. Risk factors for this condition include obesity, hypertension, smoking, and certain genetic conditions. Family history of renal cell carcinoma also increases the risk of developing the disease. Symptoms may include blood in the urine, flank pain, abdominal mass, fatigue, and weight loss. Treatment options depend on the stage of the tumor and may include surgery, immunotherapy, chemotherapy, and radiotherapy.
Other types of kidney tumors are much rarer. Primary renal lymphoma, for instance, is a very uncommon cancer that affects less than 1% of patients. Transitional cell carcinoma, also known as urothelial carcinoma, accounts for about 15% of all adult renal tumors and often starts in the renal pelvis. Renal sarcoma is a rare tumor that makes up less than 2% of all renal tumors in adults. Finally, nephroblastoma, or Wilms tumor, is the most common type of kidney cancer in children but is very rare in adults.
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This question is part of the following fields:
- Renal
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Question 16
Correct
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A 54-year-old woman with a long-standing history of poorly controlled type 2 diabetes mellitus presents to clinic complaining of swelling in her ankles, face and fingers. She states she can no longer wear her wedding ring because her fingers are too swollen. On examination, her blood pressure is 150/90 mmHg; she has pitting oedema in her ankles and notably swollen fingers and face. Her blood results show:
Investigation Results Normal value
Creatinine 353.6 μmol/l 50–120 μmol/l
Potassium (K+) 4.1 mmol/l 3.5–5.0 mmol/l
Phosphate 1.9 mmol/l 0.70–1.40 mmol/l
Parathyroid hormone (PTH) Elevated
Urinalysis 3+ glucose, 3+ protein
Which of the following is the most likely mechanism of this woman's increased PTH?Your Answer: Decreased glomerular filtration rate (GFR)
Explanation:Understanding the Causes of Secondary Hyperparathyroidism
Secondary hyperparathyroidism is a condition that occurs when the parathyroid glands produce too much parathyroid hormone (PTH) in response to low calcium levels in the blood. This can be caused by a variety of factors, including chronic renal failure, vitamin D excess, and the use of certain medications like diuretics.
In cases of chronic renal failure, decreased glomerular filtration rate (GFR) can lead to raised creatinine levels and proteinuria. This can cause diabetic nephropathy, which can result in hyperphosphataemia and secondary hyperparathyroidism. Over time, this can also lead to osteoporosis as a long-term complication of hyperparathyroidism.
Vitamin D excess is another cause of secondary hyperparathyroidism, but it is associated with low phosphate levels rather than hyperphosphataemia. In cases of parathyroid adenoma, a less likely cause in this patient, there is an overproduction of PTH by a benign tumor in the parathyroid gland.
Finally, the use of diuretics can increase phosphate excretion, leading to hypophosphataemia. This can also contribute to the development of secondary hyperparathyroidism.
Understanding the various causes of secondary hyperparathyroidism is important for proper diagnosis and treatment. By addressing the underlying condition, it may be possible to reduce the production of PTH and prevent further complications.
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This question is part of the following fields:
- Renal
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Question 17
Incorrect
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A 20-year-old African-Caribbean woman with sickle-cell anaemia presents with acute kidney injury. Her only medication is hydroxycarbamide (hydroxyurea).
What is the most probable reason for her condition?Your Answer: Drug-induced interstitial nephritis
Correct Answer: Renal papillary necrosis
Explanation:Causes of Acute Kidney Injury
Acute kidney injury (AKI) can be caused by various factors. One of the causes is renal papillary necrosis, which is commonly associated with sickle-cell anaemia. This occurs when sickled red blood cells cause infarction and necrosis of renal papillae. Other causes of renal papillary necrosis include diabetes mellitus, acute pyelonephritis, and chronic paracetamol use.
Another cause of AKI is hypoperfusion of renal tubules from hypotension. This happens when there is a decrease in blood pressure due to shock or dehydration, leading to the hypoperfusion of renal tubules and acute tubular necrosis.
Drug-induced interstitial nephritis is also a cause of AKI. This occurs when there is an allergic reaction to certain drugs such as non-steroidal anti-inflammatory drugs, antibiotics, and loop diuretics. Eosinophils in the urine are associated with this type of AKI.
Pyelonephritis from Salmonella species is not a cause of AKI in patients with sickle-cell disease. However, diffuse cortical necrosis is a rare cause of AKI associated with disseminated intravascular coagulation, especially in obstetric emergencies such as abruptio placentae.
In conclusion, AKI can be caused by various factors, and it is important to identify the underlying cause to provide appropriate treatment.
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This question is part of the following fields:
- Renal
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Question 18
Correct
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A 32-year-old computer programmer presented with blood in the urine. It was painless and not associated with any obstructive feature. On examination, his blood pressure was found to be 166/90 mmHg, although his earlier medical check-up 1 year ago was normal. His only past history was nephrotic syndrome 6 years ago, which was diagnosed histologically as minimal change disease and treated successfully. Urine examination revealed blood only with a trace of protein. He is not currently taking any drugs.
What is the probable diagnosis?Your Answer: Renal arteriovenous (AV) fistula
Explanation:Possible Causes of Hypertension and Haematuria in a Patient with a History of Nephrotic Syndrome
Renal arteriovenous (AV) fistula is a possible cause of hypertension and haematuria in a patient with a history of nephrotic syndrome. This condition may develop after renal biopsy or trauma, which are risk factors for the formation of renal AVMs. Acquired causes account for 70-80% of renal AVMs, and up to 15% of patients who undergo renal biopsy may develop renal fistulae. However, most patients remain asymptomatic. Hypertension in renal AVM is caused by relative renal hypoperfusion distal to the malformation, which activates the renin-angiotensin system. Pre-existing kidney disease is a risk factor for the development of AVM after biopsy. Renal AVMs may produce bruits in the flanks and vermiform blood clots in the urine. Sudden pain in a patient with renal AVM may be due to intrarenal haemorrhage or blood clot obstruction of the ureters. Renal vein thrombosis is unlikely in a patient in remission from nephrotic syndrome. Renal stones are not a likely cause of painless haematuria in this patient. Bladder carcinoma is not a likely cause of hypertension in a young patient without relevant environmental risk factors. Therefore, an AV fistula formation after biopsy is the most likely diagnosis.
Possible Causes of Hypertension and Haematuria in a Patient with a History of Nephrotic Syndrome
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This question is part of the following fields:
- Renal
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Question 19
Correct
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A 54-year-old woman presents with back and flank pain affecting both sides. She has been diagnosed some years ago with antiphospholipid antibody syndrome and has suffered from a previous deep vein thrombosis. On assessment, temperature is 36.7oC, heart rate is 76 bpm, blood pressure 128/80 mmHg and she is still passing urine.
Investigations:
Investigation Result Normal value
Sodium (Na+) 141 mmol/l 135–145 mmol/l
Potassium (K+) 6.3 mmol/l 3.5–5.0 mmol/l
Urea 17.3 mmol/l 2.5–6.5 mmol/l
Creatinine 325 μmol/l 50–120 µmol/l
Urine proteinuria +++
Which of the following diagnoses fits best with this clinical scenario?Your Answer: Bilateral renal vein thrombosis
Explanation:Possible Causes of Bilateral Flank Pain, Renal Failure, and Proteinuria
Bilateral flank pain, renal failure, and marked proteinuria can be caused by various conditions. One possible diagnosis is bilateral renal vein thrombosis, especially if the patient has a history of antiphospholipid antibody syndrome and previous deep vein thrombosis. Other causes of renal vein thrombosis include extrinsic compression of the renal vein by a tumour or a retroperitoneal mass, invasion of the renal vein or inferior vena cava by a tumour, or nephrotic syndrome that increases coagulability. Abdominal ultrasound and angiography can help diagnose renal vein thrombosis, and anticoagulation is the main treatment.
Bilateral ureteric obstruction can cause anuria, while bilateral pyelonephritis can cause sepsis and leukocytes and nitrites in the urine. Medullary sponge kidney, a congenital disorder that causes cystic dilation of the collecting ducts in one or both kidneys, may present with haematuria or nephrocalcinosis but does not affect renal function. Bilateral renal artery stenosis can cause uncontrollable hypertension and reduced renal function but not pain. Therefore, a thorough evaluation is necessary to determine the underlying cause of the patient’s symptoms.
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This question is part of the following fields:
- Renal
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Question 20
Correct
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A 67-year-old retired bus driver presents to the Emergency Department with end-stage renal disease due to diabetic nephropathy. What is the most probable histological finding on kidney biopsy for this patient?
Your Answer: Kimmelstiel–Wilson nodules
Explanation:Renal Biopsy Findings in Diabetic Nephropathy and Other Renal Diseases
Diabetic nephropathy is a progressive kidney disease that damages the glomerular filtration barrier, leading to proteinuria. Renal biopsy is a diagnostic test that can reveal various findings associated with different renal diseases.
Kimmelstiel–Wilson nodules are a hallmark of diabetic nephropathy, which are nodules of hyaline material that accumulate in the glomerulus. In contrast, immune complex deposition is commonly found in crescentic glomerulonephritis, anti-GBM disease, lupus, and IgA/post-infectious GN.
Rouleaux formation, the abnormal stacking of red blood cells, is not associated with diabetic nephropathy but can cause diabetic retinopathy. Clear cells, a classification of renal cell carcinoma, are not a finding associated with diabetic nephropathy either.
Finally, mesangial amyloid deposits are not associated with diabetic nephropathy but may be found in the mesangium, glomerular capillary walls, interstitium, or renal vessels in amyloidosis. Renal biopsy is a valuable tool in diagnosing and managing various renal diseases, including diabetic nephropathy.
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This question is part of the following fields:
- Renal
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