Nephrology Practice Questions

Q: Polyuria with low fixed specific gravity urine is seen in ?

Chronic glomerulonephritis. ***Chronic glomerulonephritis*** - Damage to the **renal tubules** in chronic glomerulonephritis impairs their ability to concentrate urine, leading to polyuria with a **low, fixed specific gravity**. [1] - This fixed specific gravity reflects the kidneys' inability to adjust urine concentration in response to hydration status, a hallmark of **chronic kidney disease**. [2] *Diabetes mellitus* - Polyuria in diabetes mellitus is caused by **osmotic diuresis** due to high glucose levels in the urine, leading to increased urinary volume. [2] - While there is polyuria, the specific gravity is not necessarily fixed and can vary, often being high due to the presence of glucose. *Diabetes insipidus* - Diabetes insipidus causes polyuria and dilute urine due to either a deficiency of **ADH (central DI)** or renal unresponsiveness to ADH **(nephrogenic DI)**. - While it causes polyuria with low specific gravity, it's typically *not* fixed; the urine specific gravity can still fluctuate to some extent depending on the patient's hydration, or in response to ADH if it's central DI. *Potomania* - Potomania, or **primary polydipsia**, is excessive water intake that leads to dilutional hyponatremia and polyuria. - The kidneys are otherwise healthy and can still concentrate urine to some extent if water intake is restricted, preventing a truly fixed low specific gravity.

Q: What condition is characterized by hypertension and hypokalemia?

Liddle's Syndrome. ***Liddle's Syndrome*** - This syndrome is characterized by **overactivity of the epithelial sodium channel (ENaC)** in the collecting ducts, leading to increased sodium reabsorption and potassium excretion. [1] - The resulting **sodium retention causes hypertension**, while the **potassium excretion leads to hypokalemia**. *Gitelman's Syndrome* - This is an **autosomal recessive kidney disorder** causing a defect in the **thiazide-sensitive NaCl cotransporter** in the distal convoluted tubule. - It presents with **hypokalemia and hypomagnesemia**, but typically with **normal or low blood pressure**, not hypertension. *Bartter Syndrome* - This is a group of **autosomal recessive salt-wasting tubulopathies** affecting the **Na-K-2Cl cotransporter** in the thick ascending limb of the loop of Henle. - It leads to **hypokalemia, metabolic alkalosis, and normal or low blood pressure**, similar to chronic loop diuretic use. *All of the options* - While all mentioned conditions involve **hypokalemia**, only **Liddle's Syndrome** is consistently associated with **hypertension**. - **Gitelman's and Bartter syndromes** typically present with **normal or low blood pressure**.

Q: Which of the following symptoms is least likely to be associated with hyponatremia?

Myalgia. Myalgia - While muscle cramps can occur with electrolyte imbalances, generalized myalgia (muscle pain) is not a typical or primary symptom of hyponatremia. - Hyponatremia primarily affects neurological function due to osmotic shifts in the brain. anorexia - Anorexia (loss of appetite) is a common, non-specific symptom of many metabolic disturbances, including hyponatremia, and often accompanies nausea and vomiting. - It arises from the general malaise and gastrointestinal upset associated with the condition. Convulsions - Convulsions are a severe neurological symptom of acute and profound hyponatremia, resulting from cerebral edema and increased intracranial pressure [1]. - This occurs when the brain swells due to the osmotic shift of water into brain cells. Drowsiness - Drowsiness is a frequent neurological manifestation of hyponatremia, indicative of altered mental status [1]. - It reflects impaired brain function due to the osmotic disturbances and potential cerebral edema [1].

Q: Which of the following conditions is a direct indication for initiating dialysis?

Severe hyperkalemia. ### Severe hyperkalemia - **Severe hyperkalemia** (potassium levels typically >6.5 mEq/L or rapidly rising, especially with ECG changes) is an immediate life-threatening indication for dialysis when conservative measures fail or are insufficient [1]. - Dialysis effectively removes **excess potassium** from the blood, preventing fatal cardiac arrhythmias. *Severe metabolic acidosis* - While **severe metabolic acidosis** (pH <7.1-7.2) can be an indication, it is often managed first with bicarbonate administration and is typically not a stand-alone **direct** *emergency* indication for dialysis unless accompanied by other severe features or resistance to medical therapy. - The decision to dialyze for acidosis often depends on the underlying cause, degree of renal failure, and response to initial management [2]. *Fluid overload* - **Fluid overload** is a common complication of kidney failure, but it becomes a *direct* indication for dialysis when it is **refractory to diuretic therapy** and causes life-threatening symptoms such as **pulmonary edema** [2]. - Without such refractory state and immediate danger, fluid overload itself is not always an *immediate* trigger for dialysis compared to severe hyperkalemia. *Acute kidney injury* - **Acute kidney injury** (AKI) is the underlying *condition* that can lead to indications for dialysis, but AKI itself is not a *direct indication* for dialysis. - Dialysis is initiated for the *complications* of AKI, such as refractory hyperkalemia, severe metabolic acidosis, or fluid overload, rather than the diagnosis of AKI alone [2].

Q: Which of the following is not a feature of Poststreptococcal Glomerulonephritis (PSGN)?

Normal C3 level. ***Normal C3 level*** - In Post-streptococcal glomerulonephritis (PSGN), **C3 levels are typically decreased** due to complement consumption during the inflammatory process. [1] - A **normal C3 level** would not be consistent with PSGN, as it suggests no significant complement activation. *Increased urea* - Increased urea can occur due to **impaired renal function**, which is common in PSGN due to glomerular inflammation. [1] - It's a typical finding reflecting the kidneys' inability to excrete waste products properly. *HTN* - Hypertension is frequently associated with PSGN due to **volume overload** and activation of the renin-angiotensin system. [1] [2] - It is a common clinical feature that results from increased fluid retention. *Increased creatinine* - Increased creatinine levels indicate **renal impairment**, which is characteristic of PSGN as kidney function is affected during this condition. [1] - This finding highlights the reduction in glomerular filtration rate (GFR), typical in glomerulonephritis. [2]

Q: What does the measurement of Glomerular Filtration Rate (GFR) help determine in kidney function?

Stage of kidney disease. Stage of kidney disease - A low GFR indicates impaired kidney function, helping to classify the severity and stage of chronic kidney disease (CKD) [1]. - Monitoring GFR over time is crucial for assessing disease progression and guiding treatment strategies [1]. *Heart rate* - Heart rate is a measure of cardiac function and is not directly assessed by GFR. - Kidney function can indirectly affect heart rate over time (e.g., in advanced kidney disease with fluid overload), but GFR itself doesn't measure it. *Recovery from shock* - While kidney function is important during shock, GFR primarily measures the kidney's filtration capacity at a given moment. - Recovery from shock involves many physiological parameters beyond just kidney filtration, such as blood pressure and organ perfusion. *Blood volume* - Blood volume is regulated by many mechanisms, including hormonal systems (e.g., renin-angiotensin-aldosterone system) and fluid intake/excretion. - Although kidneys play a role in fluid balance, GFR specifically measures the rate of filtration of blood plasma, not the overall blood volume [1].

Q: Calciphylaxis is a severe life-threatening condition. Which of the following is most commonly associated with it?

End stage Renal disease. ***End stage Renal disease*** - Calciphylaxis frequently occurs in patients with **end-stage renal disease**, primarily associated with **secondary hyperparathyroidism** [1] and **calcium-phosphate imbalance**. - It leads to **cutaneous ischemia** and necrosis, often requiring aggressive management due to its high **mortality rate**. *Parathyroidectomy* - While parathyroidectomy may affect calcium levels, it is not directly linked to calciphylaxis. - Calciphylaxis more commonly develops due to underlying **chronic renal failure** [1] rather than surgical interventions. *Hyperthyroidism* - Hyperthyroidism primarily causes symptoms related to metabolism, **thyroid hormone excess**, and does not lead to calciphylaxis. - There is no direct correlation between hyperthyroid states and the pathophysiology of calciphylaxis. *Medullary carcinoma thyroid* - This condition involves **medullary thyroid carcinoma**, associated with calcitonin production and does not cause calciphylaxis. - Patients typically experience **thyroid-related symptoms** rather than the vascular complications seen in calciphylaxis.

Q: Which of the following is not a feature of distal renal tubular acidosis

Hyperkalemia. ***Hyperkalemia*** - **Distal renal tubular acidosis (dRTA)** is characterized by impaired acid excretion, leading to metabolic acidosis. The impaired excretion of acid is often accompanied by impaired potassium secretion, resulting in **hypokalemia**, not hyperkalemia. - While hyperkalemia is a feature of **type 4 RTA**, which is characterized by hypoaldosteronism or renal tubular unresponsiveness to aldosterone, it is not a feature of **distal RTA (type 1)**. [1] *Normal anion gap* - **Distal RTA** is a form of **normal anion gap metabolic acidosis**, also known as **hyperchloremic metabolic acidosis**. [1] - The anion gap is calculated as [Na+] - ([Cl-] + [HCO3-]), and in dRTA, the bicarbonate loss is compensated by an increase in chloride, maintaining a normal anion gap. *Renal hypercalciuria* - **Distal RTA** is associated with **impaired acid excretion**, which leads to chronic metabolic acidosis. - This **acidosis** promotes the dissolution of bone, releasing calcium, and decreases tubular reabsorption of calcium, resulting in **hypercalciuria**. *Alkaline urine* - In **distal RTA**, the distal tubule is unable to acidify the urine due to a defect in hydrogen ion secretion. - This leads to a persistent **urine pH > 5.5** (typically alkaline or inappropriately normal) despite systemic acidosis, making it a key diagnostic feature. [1]

Q: Hyperkalemia aciduria is seen in

Type IV Renal Tubular Acidosis. Type IV Renal Tubular Acidosis - This condition is characterized by **hyperkalemia** and **aciduria**, often due to a deficiency in aldosterone or a renal tubular insensitivity to aldosterone [1]. - The impaired aldosterone action leads to reduced potassium excretion and decreased ammonium production, both contributing to **hyperkalemia** and metabolic acidosis [1]. *Type I Renal Tubular Acidosis* - Type I RTA (distal RTA) is characterized by a defect in acid secretion in the distal tubule, leading to **hypokalemia** and metabolic acidosis with persistently high urine pH [2]. - Patients typically excrete an alkaline urine despite systemic acidosis, contrasting with the aciduria seen with hyperkalemia [2]. *Sigmoidocolostomy procedure* - A sigmoidocolostomy can lead to **hyperchloremic metabolic acidosis** due to the reabsorption of chloride and excretion of bicarbonate by the colonic mucosa. - However, it typically causes **hypokalemia** as potassium is secreted into the colonic lumen from the blood. *Type II Renal Tubular Acidosis* - Type II RTA (proximal RTA) involves a defect in bicarbonate reabsorption in the proximal tubule, resulting in **hypokalemia** and metabolic acidosis. - The kidney's ability to acidify urine is still largely intact in the distal nephron once the bicarbonate buffer system is overwhelmed.

Question 1

Polyuria with low fixed specific gravity urine is seen in ?

Accepted Answer

Chronic glomerulonephritis

Answer

Diabetes mellitus

Answer

Diabetes insipidus

Answer

Potomania

Question 2

What condition is characterized by hypertension and hypokalemia?

Accepted Answer

Liddle's Syndrome

Answer

Gitelman's Syndrome

Answer

Bartter Syndrome

Answer

All of the options

Question 3

Which of the following symptoms is least likely to be associated with hyponatremia?

Accepted Answer

Myalgia

Answer

anorexia

Answer

Drowsiness

Answer

Convulsions

Question 4

Which of the following conditions is a direct indication for initiating dialysis?

Accepted Answer

Severe hyperkalemia

Answer

Severe metabolic acidosis

Answer

Fluid overload

Answer

Acute kidney injury

Question 5

Which of the following is a cause of post-transplantation hypertension? I. Rejection II. Cyclosporine nephrotoxicity III. Renal transplant artery stenosis (RTAS) IV. Recurrent disease in the allograft. Select the correct option.

Accepted Answer

All of the options are correct causes of post-transplantation hypertension.

Answer

None of the above are correct causes.

Answer

I, II, and IV are correct causes.

Answer

I and III are correct causes.

Question 6

Which of the following is not a feature of Poststreptococcal Glomerulonephritis (PSGN)?

Accepted Answer

Normal C3 level

Answer

HTN

Answer

Increased urea

Answer

Increased creatinine

Question 7

What does the measurement of Glomerular Filtration Rate (GFR) help determine in kidney function?

Accepted Answer

Stage of kidney disease

Answer

Heart rate

Answer

Recovery from shock

Answer

Blood volume

Question 8

Calciphylaxis is a severe life-threatening condition. Which of the following is most commonly associated with it?

Accepted Answer

End stage Renal disease

Answer

Parathyroidectomy

Answer

Medullary carcinoma thyroid

Answer

Hyperthyroidism

Question 9

Which of the following is not a feature of distal renal tubular acidosis

Accepted Answer

Hyperkalemia

Answer

Renal hypercalciuria

Answer

Normal anion gap

Answer

Alkaline urine

Question 10

Hyperkalemia aciduria is seen in

Accepted Answer

Type IV Renal Tubular Acidosis

Answer

Type I Renal Tubular Acidosis

Answer

Sigmoidocolostomy procedure

Answer

Type II Renal Tubular Acidosis

Nephrology — MCQs

Nephrology — MCQs

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