Nephrology Practice Questions

Q: Sine wave pattern in an ECG is seen in which of the following conditions?

Hyperkalemia. ***Hyperkalemia*** - As **hyperkalemia** worsens, the ECG may show a loss of P waves, widening of the QRS complex, and tall, peaked T waves that merge with the QRS complex, creating a **sine wave pattern** [1]. - This pattern indicates severe electrical instability, often progressing to **ventricular fibrillation** [2] or **asystole** if not urgently treated. *Hypokalemia* - **Hypokalemia** typically manifests on ECG with U waves, T wave flattening or inversion, and prolongation of the QT interval [3]. - It does not cause a **sine wave pattern**, which is characteristic of severe hyperkalemia. *Hyponatremia* - While severe **hyponatremia** can affect cardiac function, it does not typically produce a specific **sine wave pattern** on the ECG [1]. - ECG changes in hyponatremia are often non-specific and may include bradycardia or arrhythmias due to altered nerve conduction. *Hypernatremia* - **Hypernatremia** can lead to various cardiac effects, but a **sine wave pattern** is not a characteristic ECG finding of this condition. - ECG changes in hypernatremia are often non-specific and are more related to volume status and associated electrolyte imbalances.

Q: Metabolic complications in chronic renal failure include all of the following except:

Hypokalemia. ***Hypokalemia*** - Chronic renal failure primarily leads to an inability to excrete **potassium**, resulting in **hyperkalemia**, not hypokalemia. - While very specific conditions or medications in ESRD could rarely cause hypokalemia, it is not a typical metabolic complication of chronic kidney disease itself. *Hyperkalemia* - **Renal excretion** is the primary mechanism for potassium balance, and with kidney failure, this process is impaired. - This impaired excretion leads to an accumulation of **potassium** in the blood, causing hyperkalemia. *Hypocalcemia* - The failing kidneys are unable to convert **25-hydroxyvitamin D** to its active form, **1,25-dihydroxyvitamin D**, leading to reduced calcium absorption [1]. - Additionally, hyperphosphatemia (due to impaired phosphate excretion) can bind with calcium and also stimulates parathyroid hormone release, contributing to **hypocalcemia** [1]. *Hypophosphataemia* - Chronic renal failure typically causes **hyperphosphatemia** due to the kidneys' inability to adequately excrete phosphate [1]. - Only in specific and rare instances or aggressive phosphate binding therapy might hypophosphatemia occur, but it is not a characteristic metabolic complication of CKD [2].

Q: In glomerular disease, which substance is primarily excreted in urine?

Albumin. ***Albumin*** [1][2] - Commonly found in the urine during glomerular disease due to increased permeability of the **glomerular barrier** [1][2]. - Its presence is indicative of **nephrotic syndrome** [1][2], characterized by significant proteinuria [1]. *Heavy chain* - Not typically excreted in the urine; heavy chains are part of **Immunoglobulin molecules** and predominantly associated with **antibody responses**. - Their presence in urine can be a sign of specific disorders but is not a primary feature of glomerular disease. *Globulin* - While globulins can be present in urine, they do not represent the specific **proteinuria** typically seen in nephrotic syndrome like albumin does. - They encompass a broad category of proteins, often increased during inflammatory states rather than direct glomerular damage. *Light chain* - Light chains can be excreted in certain conditions, such as **multiple myeloma** [1][2], but are not the primary markers in general glomerular disease. - Their presence in urine is more specific to **Bence Jones proteinuria** [1][2] associated with malignancies rather than the typical scenarios in glomerular diseases.

Q: Pyuria is found in all except

Appendicular abscess. ***Appendicular abscess*** - An appendicular abscess is an **extraluminal collection of pus** originating from a ruptured appendix, usually contained within the peritoneum. - While it causes significant inflammation, it does not typically lead to **pyuria** because it is not directly associated with the urinary tract. *CA bladder* - **Carcinoma of the bladder** can lead to irritation and inflammation of the bladder lining. - This irritation can cause **hematuria** and, in some cases, an influx of white blood cells into the urine, resulting in **pyuria**. *Renal tuberculosis* - This is a form of **extrapulmonary tuberculosis** that affects the kidneys. - The infection directly within the renal parenchyma and urinary collecting system leads to significant **inflammation and pus formation**, causing **pyuria** [1]. *Vaginosis* - **Bacterial vaginosis** is an infection of the vagina [1]. - Due to the close anatomical proximity of the vagina and urethra, vaginal inflammation and discharge can result in **contamination of a urine sample** with white blood cells from the vagina, misinterpreted as pyuria [1].

Q: In a case of autosomal dominant polycystic kidney disease, cysts are present in all of the following organs, except:

Lung. Cysts are generally not found in the lungs of patients with autosomal dominant polycystic kidney disease (ADPKD). - ADPKD primarily affects organs with epithelial linings derived from the mesonephric duct or related embryonic structures. ADPKD is a common autosomal dominant condition characterized by multiple renal cysts that enlarge over time, with mutations in PKD1 and PKD2 genes accounting for the majority of cases [1]. *Liver* - **Hepatic cysts** are the most common extrarenal manifestation of ADPKD, occurring in approximately 50-70% of patients. - Their prevalence and size tend to increase with age and female sex. *Pancreas* - **Pancreatic cysts** are also a recognized extrarenal manifestation of ADPKD, though less common than hepatic cysts. - They are typically asymptomatic but can occasionally cause symptoms. *Seminal vesicles* - **Seminal vesicle cysts** can occur in men with ADPKD, contributing to an increased risk of infertility or other reproductive issues. - They are often asymptomatic and found incidentally.

Q: All of the following are decreased in nephrotic syndrome, except for:

Serum fibrinogen. ***Serum fibrinogen*** - **Fibrinogen** levels are generally **increased** in nephrotic syndrome due to compensatory hepatic synthesis triggered by the loss of other proteins and lipids, contributing to the hypercoagulable state. - The liver increases the production of various proteins, including clotting factors, in an attempt to maintain oncotic pressure, leading to elevated fibrinogen. *Serum transferrin* - **Transferrin** is a plasma protein responsible for iron transport and is significantly **decreased** in nephrotic syndrome due to its loss in the urine. - The urinary loss of transferrin can contribute to **iron-refractory microcytic anemia** seen in some nephrotic patients. *Serum albumin* - **Albumin** is the most abundant plasma protein and its severe **decrease** in nephrotic syndrome (hypoalbuminemia) is a hallmark of the condition due to massive urinary excretion [1]. - The low serum albumin is a primary cause of the characteristic **edema** in nephrotic syndrome due to reduced plasma oncotic pressure [2]. *Serum complement (C3)* - **Complement C3** levels are often **decreased** in nephrotic syndrome, particularly in glomerulonephritic causes like **post-streptococcal glomerulonephritis** or **membranoproliferative glomerulonephritis type 2**, where C3 is consumed [3]. - While not universally decreased in all nephrotic syndromes, significant urinary loss of C3 can occur, leading to reduced serum levels.

Q: What is the most likely diagnosis in a patient presenting with hypertension, proteinuria, and renal failure?

Wegener's granulomatosis. ***Wegener's granulomatosis*** - This condition, now known as **Granulomatosis with Polyangiitis (GPA)**, classically presents as a triad of **upper respiratory tract disease**, **lower respiratory tract disease**, and **renal disease** [1]. - The renal involvement often manifests as **glomerulonephritis**, leading to **hypertension**, **proteinuria**, and potentially rapid progression to **renal failure** [2]. *Mycosis fungoides* - This is a **cutaneous T-cell lymphoma** primarily affecting the skin, presenting with patches, plaques, and tumors. - It typically does not involve the kidneys in a manner that would cause **hypertension**, **proteinuria**, and **renal failure**. *Invasive aspergillosis* - This is a serious **fungal infection** most commonly seen in **immunocompromised individuals**, affecting the lungs and other organs. - While it can cause systemic illness, it does not typically present with the classic triad of **hypertension**, **proteinuria**, and **renal failure** as a primary finding. *Sarcoidosis* - This is a **multisystem inflammatory disease** characterized by the formation of **non-caseating granulomas** in various organs, most commonly the lungs and lymph nodes. - While renal involvement can occur, it's less common and doesn't typically present with the acute, severe combination of **hypertension**, **proteinuria**, and **renal failure** seen in GPA.

Q: Renal biopsy is indicated in which of the following conditions?

Nephrotic syndrome in adults. ***Nephrotic syndrome in adults*** - A **renal biopsy** is indicated in adults with **nephrotic syndrome** to identify the underlying glomerular pathology and guide treatment decisions, as different causes (e.g., focal segmental glomerulosclerosis, membranous nephropathy) require specific therapies [1]. - While other imaging or blood tests may suggest a diagnosis, a biopsy provides a **definitive histological diagnosis** of the specific kidney disease [2]. *Uncontrolled hypertension* - **Uncontrolled hypertension** is usually managed medically, and a renal biopsy is typically not indicated unless there is suspicion of a **secondary cause of hypertension** directly affecting the kidneys (e.g., renovascular disease) that cannot be diagnosed by less invasive means. - Imaging studies like **renal artery Doppler** or CT angiography are usually the first line to investigate renal causes of hypertension, not biopsy [3]. *Solitary kidney* - A **solitary kidney** itself does not typically warrant a renal biopsy unless there is evidence of **acute renal injury**, **proteinuria**, or **hematuria** with no clear cause, and thus a need to investigate the underlying pathology. - The presence of a solitary kidney is a **contraindication to biopsy** if the other kidney is healthy, due to the increased risk of complications (e.g., bleeding, infection) in the only functioning kidney. *Kidneys <60% predicted size* - **Small kidney size** (less than 60% predicted) often indicates **chronic kidney disease** with established scarring or atrophy, where a biopsy may not provide actionable information beyond what is already known. - In such cases, if a biopsy is performed, it is usually to assess for specific, treatable causes of rapid progression in a small, atrophic kidney, but is not a routine indication for small kidneys alone due to difficulty obtaining adequate tissue and increased risk.

Q: Immediate treatment for hyperkalemia with significant ECG changes is?

Calcium chloride. ***Calcium chloride*** - **Calcium** rapidly stabilizes the **cardiac membrane**, reducing the risk of arrhythmias from hyperkalemia [1]. - This is a critical **immediate intervention** for hyperkalemia with **ECG changes**, as it does not lower potassium levels but prevents their cardiotoxic effects [1]. *Calcium hydroxide* - This compound is primarily used as an **antacid** or in industrial applications, not for the treatment of **hyperkalemia** or for stabilizing cardiac membranes. - It does not possess the rapid **cardioprotective effects** necessary to counteract the immediate dangers of severe hyperkalemia. *K+ Binding Resin Enema* - **Potassium-binding resins** work by exchanging potassium for other ions in the gut, thereby **removing potassium** from the body. - While effective for lowering potassium, their **onset of action is slow** (hours), making them inappropriate for emergent treatment of hyperkalemia with significant ECG changes. *Calcium carbonate* - **Calcium carbonate** is mainly used as a **calcium supplement** or an **antacid**, and while it contains calcium, its parenteral administration is not standard for emergent hyperkalemia treatment. - **Calcium chloride** or **calcium gluconate** are the preferred forms for IV administration in hyperkalemia due to their rapid bioavailability and immediate membrane-stabilizing effects [1].

Q: A 63-year-old man is in stable condition after an acute myocardial infarction when he becomes hypotensive for 3 hours before paramedical personnel arrive. Over the next week, the serum urea nitrogen level increases to 48 mg/dL, the serum creatinine level increases to 5 mg/dL, and the urine output decreases. He undergoes hemodialysis for the next 2 weeks and then develops marked polyuria, with a urine output of 2 to 3 L/day. His renal function gradually returns to normal. Which of the following substances is most likely released and participated in the elevation of BUN, creatinine, and reduced urinary output?

Endothelin (vasoconstrictor released in response to ischemia). ***Endothelin (vasoconstrictor released in response to ischemia)*** - **Endothelin** is a potent **vasoconstrictor** released by endothelial cells in response to ischemia and injury, such as that caused by prolonged hypotension in the context of an acute myocardial infarction. Its effects lead to reduced renal blood flow. - Reduced renal blood flow causes **glomerular filtration rate (GFR) to decrease**, leading to the observed increase in **BUN** and **creatinine**, and reduced urine output (oliguria) due to acute kidney injury [2]. *Aldosterone (involved in fluid retention)* - **Aldosterone** is primarily involved in **sodium and water reabsorption** and potassium excretion, primarily by the distal tubules and collecting ducts. - While it contributes to fluid retention, it is not the primary mediator of the initial acute renal vasoconstriction and drop in GFR seen in ischemic acute kidney injury. *Natriuretic peptide (responds to heart failure)* - **Natriuretic peptides** (e.g., ANP, BNP) are released in response to **cardiac stretch** (e.g., in heart failure) and promote vasodilation and natriuresis (sodium excretion) [3]. - These effects would typically **increase GFR** and urine output, which is contrary to the reduced urine output and elevated BUN/creatinine observed in this case [3]. *Erythropoietin (stimulates red blood cell production)* - **Erythropoietin** is a hormone produced by the kidneys in response to **hypoxia**, stimulating red blood cell production in the bone marrow [1]. - It does not directly cause renal vasoconstriction or contribute to the acute rise in BUN and creatinine due to ischemia [1].

Question 1

Sine wave pattern in an ECG is seen in which of the following conditions?

Accepted Answer

Hyperkalemia

Answer

Hypokalemia

Answer

Hyponatremia

Answer

Hypernatremia

Question 2

Metabolic complications in chronic renal failure include all of the following except:

Accepted Answer

Hypokalemia

Answer

Hyperkalemia

Answer

Hypocalcemia

Answer

Hypophosphataemia

Question 3

In glomerular disease, which substance is primarily excreted in urine?

Accepted Answer

Albumin

Answer

Light chain

Answer

Heavy chain

Answer

Globulin

Question 4

Pyuria is found in all except

Accepted Answer

Appendicular abscess

Answer

Renal tuberculosis

Answer

Vaginosis

Answer

CA bladder

Question 5

In a case of autosomal dominant polycystic kidney disease, cysts are present in all of the following organs, except:

Accepted Answer

Lung

Answer

Pancreas

Answer

Seminal vesicles

Answer

Liver

Question 6

All of the following are decreased in nephrotic syndrome, except for:

Accepted Answer

Serum fibrinogen

Answer

Serum complement (C3)

Answer

Serum albumin

Answer

Serum transferrin

Question 7

What is the most likely diagnosis in a patient presenting with hypertension, proteinuria, and renal failure?

Accepted Answer

Wegener's granulomatosis

Answer

Mycosis fungoides

Answer

Invasive aspergillosis

Answer

Sarcoidosis

Question 8

Renal biopsy is indicated in which of the following conditions?

Accepted Answer

Nephrotic syndrome in adults

Answer

Uncontrolled hypertension

Answer

Solitary kidney

Answer

Kidneys <60% predicted size

Question 9

Immediate treatment for hyperkalemia with significant ECG changes is?

Accepted Answer

Calcium chloride

Answer

K+ Binding Resin Enema

Answer

Calcium carbonate

Answer

Calcium hydroxide

Question 10

A 63-year-old man is in stable condition after an acute myocardial infarction when he becomes hypotensive for 3 hours before paramedical personnel arrive. Over the next week, the serum urea nitrogen level increases to 48 mg/dL, the serum creatinine level increases to 5 mg/dL, and the urine output decreases. He undergoes hemodialysis for the next 2 weeks and then develops marked polyuria, with a urine output of 2 to 3 L/day. His renal function gradually returns to normal. Which of the following substances is most likely released and participated in the elevation of BUN, creatinine, and reduced urinary output?

Accepted Answer

Endothelin (vasoconstrictor released in response to ischemia)

Answer

Aldosterone (involved in fluid retention)

Answer

Natriuretic peptide (responds to heart failure)

Answer

Erythropoietin (stimulates red blood cell production)

Nephrology — MCQs

Nephrology — MCQs

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