Nephrology Practice Questions

Q: Hypokalemia is a feature of all the following conditions except?

Gordon syndrome. The correct answer is **Gordon syndrome** because it is characterized by **hyperkalemia**, not hypokalemia. [1] **1. Why Gordon Syndrome is the correct answer:** Gordon syndrome (also known as Pseudohypoaldosteronism Type II) is a rare genetic disorder caused by mutations in WNK kinases (WNK1 or WNK4). This leads to increased activity of the Na-Cl cotransporter (NCC) in the distal convoluted tubule. The resulting volume expansion suppresses aldosterone, but the primary defect causes decreased potassium secretion, leading to the triad of **Hypertension, Hyperkalemia, and Metabolic Acidosis**. It is essentially the "mirror image" of Gitelman syndrome. **2. Why the other options are incorrect:** * **Bartter syndrome:** A defect in the thick ascending limb of the Loop of Henle (mimicking loop diuretics). It presents with metabolic alkalosis and significant **hypokalemia**. * **Gitelman syndrome:** A defect in the Na-Cl cotransporter in the distal tubule (mimicking thiazide diuretics). It presents with metabolic alkalosis, **hypokalemia**, and hypomagnesemia. * **Renal Tubular Acidosis (RTA) Type 1:** A distal tubule defect in H+ secretion. To maintain electrical neutrality, the kidney excretes potassium instead of hydrogen, leading to severe **hypokalemia**. **High-Yield Clinical Pearls for NEET-PG:** * **The "Rule of Hyperkalemia":** Most RTAs cause hypokalemia, **except Type 4 RTA** (Hyporeninemic hypoaldosteronism). * **Gordon vs. Liddle:** Both have hypertension. However, **Liddle syndrome** has hypokalemia (ENaC overactivity), while **Gordon syndrome** has hyperkalemia. * **Treatment of Gordon Syndrome:** Low-dose **Thiazide diuretics** are highly effective as they directly block the overactive NCC transporter.

Q: Which of the following drugs is NOT useful in the management of hepatorenal syndrome?

Alpha blockers. **Explanation:** **Hepatorenal Syndrome (HRS)** is characterized by intense renal vasoconstriction occurring in the setting of advanced cirrhosis and portal hypertension. [1] The pathophysiology involves splanchnic vasodilation (mediated by nitric oxide), which leads to a decrease in effective arterial blood volume. This triggers a compensatory activation of the renin-angiotensin-aldosterone system (RAAS) and the sympathetic nervous system, causing profound renal artery constriction. [1] **Why Alpha Blockers are NOT useful:** Alpha blockers (like Prazosin or Tamsulosin) cause systemic vasodilation. In HRS, the patient is already in a state of systemic hypotension and splanchnic vasodilation. Administering alpha blockers would further decrease the effective arterial blood volume and worsen renal perfusion, potentially exacerbating the syndrome. **Why the other options are used (The Standard Medical Management):** The goal of treatment is to reverse splanchnic vasodilation and increase renal perfusion: * **Octreotide (A):** A somatostatin analogue that causes splanchnic vasoconstriction. * **Midodrine (B):** An alpha-1 agonist that increases systemic vascular resistance and blood pressure. * **Intravenous Albumin (C):** Acts as a plasma expander to increase effective circulatory volume and improve the efficacy of vasoconstrictors. [1] **Clinical Pearls for NEET-PG:** * **Gold Standard Treatment:** The combination of **Terlipressin** (a vasopressin analogue) and **Albumin** is considered the most effective medical therapy for HRS. [1] * **Definitive Treatment:** Liver transplantation is the only curative treatment. [1] * **TIPS:** Transjugular Intrahepatic Portosystemic Shunt can be used in selected patients as a bridge to transplant. * **Diagnostic Criteria:** HRS is a diagnosis of exclusion; one must first rule out shock, nephrotoxic drugs, and organic kidney disease (proteinuria <500mg/day). [1]

Q: Clinical features of uremia will appear when the Glomerular Filtration Rate (GFR) is less than what value (ml/min/1.73 m2)?

15. **Explanation:** The correct answer is **A (15 ml/min/1.73 m²)**. **Medical Concept:** Uremia is a clinical syndrome characterized by the accumulation of nitrogenous waste products (urea, creatinine) and toxins that are normally excreted by the kidneys [1]. According to the KDIGO classification of Chronic Kidney Disease (CKD), Stage 5 is defined by a **GFR <15 ml/min/1.73 m²**, also known as **End-Stage Renal Disease (ESRD)** [1]. While mild symptoms like nocturia or hypertension may appear earlier, the full constellation of uremic symptoms—including uremic encephalopathy, pericarditis, asterixis, symptoms such as nausea and vomiting, and respiratory depth changes—typically manifests only when the GFR falls below this critical threshold [1]. **Analysis of Incorrect Options:** * **B (30 ml/min/1.73 m²):** This marks the transition from Stage 3b to Stage 4 CKD. While patients may show anemia and secondary hyperparathyroidism, they are usually asymptomatic regarding uremic toxins. * **C (45 ml/min/1.73 m²):** This is the threshold for Stage 3b. Complications like bone mineral disorders begin here, but uremia does not occur. * **D (60 ml/min/1.73 m²):** This is the cutoff for diagnosing CKD (Stage 3a). At this level, kidney function is reduced, but the remaining nephrons compensate sufficiently to prevent toxin buildup [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Indications for Urgent Dialysis (AEIOU):** **A**cidosis (refractory), **E**lectrolytes (Hyperkalemia), **I**ngestion (Toxins), **O**verload (Fluid), **U**remia (Pericarditis/Encephalopathy). * **Earliest sign of CKD:** Often hypertension or albuminuria. * **Most common cause of death in CKD:** Cardiovascular disease (not uremia itself). * **Uremic Bleeding:** Due to platelet dysfunction (defective adhesion/aggregation); treated with Desmopressin (DDAVP).

Q: What is the first line of management for hyperkalemia presenting with ECG changes?

Calcium gluconate. **Explanation:** The management of hyperkalemia is a high-yield topic for NEET-PG, prioritized based on the urgency of the patient's condition. When **ECG changes** (such as peaked T-waves, PR prolongation, or QRS widening) are present, the immediate priority is to prevent life-threatening arrhythmias [1], [2]. **1. Why Calcium Gluconate is Correct:** Calcium gluconate is the **first-line treatment** because it acts as a **membrane stabilizer** [1]. It antagonizes the effect of potassium on the cardiac cell membrane by shifting the threshold potential, thereby reducing myocardial excitability and preventing cardiac arrest. It does *not* lower serum potassium levels; its role is purely cardioprotective. **2. Why Other Options are Incorrect:** * **Glucose-Insulin Drip:** This is the next step after membrane stabilization. It works by shifting potassium from the extracellular space into the intracellular space. It is effective for lowering serum levels but does not provide immediate cardiac protection. * **Hemodialysis:** This is the most definitive method for removing potassium from the body, but it is time-consuming to initiate and is reserved for refractory cases or patients with renal failure. * **Potassium Chelating Resins:** These (e.g., Kayexalate) remove potassium via the GI tract. They have a slow onset of action (hours to days) and are never used for acute management with ECG changes. **Clinical Pearls for NEET-PG:** * **The "C-Big-K" Mnemonic for Order of Treatment:** **C**alcium (Stabilize) → **B**eta-agonists/Bicarbonate/Insulin-**G**lucose (Shift) → **K**ayexalate/Diuretics/Kidney dialysis (Remove). * **Dose:** Usually 10 ml of 10% Calcium Gluconate IV over 2–5 minutes [1]. * **Caution:** Use with extreme care in patients taking **Digoxin**, as hypercalcemia can precipitate digoxin toxicity ("stone heart").

Q: Which of the following is NOT an absolute indication for dialysis?

Hyperphosphatemia. ### Explanation In nephrology, the decision to initiate urgent dialysis is based on life-threatening complications of renal failure that cannot be managed with conservative medical therapy. These are often remembered by the mnemonic **AEIOU**. **Why Hyperphosphatemia is the Correct Answer:** Hyperphosphatemia (Option C) is a common feature of both acute and chronic kidney disease, but it is **not** an absolute indication for dialysis [1]. It is typically managed through dietary restriction and oral phosphate binders (e.g., calcium acetate, sevelamer) [1]. While severe, prolonged hyperphosphatemia contributes to secondary hyperparathyroidism and vascular calcification, it does not pose an immediate, acute threat to life compared to the other options. **Analysis of Incorrect Options (Absolute Indications):** * **A. Persistent/Severe Hyperkalemia:** Potassium levels >6.5 mEq/L or ECG changes refractory to medical therapy (insulin/glucose, calcium gluconate) are absolute indications due to the risk of fatal arrhythmias. * **B. Congestive Cardiac Failure (Fluid Overload):** Diuretic-resistant pulmonary edema or fluid overload causing respiratory distress is a critical indication for emergent ultrafiltration/dialysis. * **D. Severe Acidosis:** Metabolic acidosis with a pH 6.5 mEq/L). 3. **I**ngestion: Toxic alcohols (methanol, ethylene glycol), Salicylates, Lithium, Theophylline. 4. **O**verload: Refractory pulmonary edema. 5. **U**remia: Symptomatic uremia (Uremic pericarditis, encephalopathy, or neuropathy). *Note: A high BUN/Creatinine level alone, without symptoms, is generally considered a relative rather than an absolute indication.*

Q: An adolescent male presents with hypokalemia, metabolic alkalosis, hypercalciuria, and nephrocalcinosis. His blood pressure is normal. What is the likely diagnosis?

Bartter syndrome. **Explanation:** The clinical presentation of **hypokalemia**, **metabolic alkalosis**, and **normal blood pressure** narrows the differential diagnosis to salt-wasting tubulopathies. The presence of **hypercalciuria** and **nephrocalcinosis** is the pathognomonic feature that confirms **Bartter syndrome**. 1. **Bartter Syndrome (Correct):** This condition results from a defect in the thick ascending limb of the Loop of Henle (mimicking chronic loop diuretic use). The failure of the Na-K-2Cl cotransporter leads to salt wasting, secondary hyperaldosteronism (causing hypokalemia and alkalosis), and a failure to reabsorb calcium. This excess urinary calcium (hypercalciuria) leads to nephrocalcinosis. 2. **Gitelman Syndrome:** Often confused with Bartter, it mimics thiazide diuretic use (defect in the distal convoluted tubule). Crucially, Gitelman presents with **hypocalciuria** (low urine calcium) and hypomagnesemia. It typically presents later in childhood and does not cause nephrocalcinosis. 3. **Liddle Syndrome:** While it causes hypokalemia and alkalosis, it presents with **hypertension** (due to ENaC overactivity) and low renin/aldosterone levels. 4. **Renal Tubular Acidosis (RTA):** Distal RTA (Type 1) can cause hypokalemia and nephrocalcinosis, but it results in **metabolic acidosis**, not alkalosis. **High-Yield Clinical Pearls for NEET-PG:** * **Bartter vs. Gitelman:** Look at urine calcium. Bartter = High Calcium (Loop diuretic-like); Gitelman = Low Calcium (Thiazide-like). * **Bartter Syndrome:** Often associated with polyhydramnios in utero and failure to thrive in infancy. * **Liddle Syndrome:** "Pseudo-hyperaldosteronism"—presents like Conn’s syndrome but with low aldosterone. Treatment is Amiloride, not Spironolactone.

Question 1

Hypokalemia is a feature of all the following conditions except?

Accepted Answer

Gordon syndrome

Answer

Baer syndrome

Answer

Gitelman syndrome

Answer

Renal tubular acidosis Type 1

Question 2

Which of the following drugs is NOT useful in the management of hepatorenal syndrome?

Accepted Answer

Alpha blockers

Answer

Octreotide

Answer

Midodrine

Answer

Intravenous albumin

Question 3

Clinical features of uremia will appear when the Glomerular Filtration Rate (GFR) is less than what value (ml/min/1.73 m2)?

Accepted Answer

15

Answer

30

Answer

45

Answer

60

Question 4

What is the first line of management for hyperkalemia presenting with ECG changes?

Accepted Answer

Calcium gluconate

Answer

Glucose insulin drip

Answer

Hemodialysis

Answer

Potassium chelating resins

Question 5

Which of the following statements is false regarding renal artery stenosis?

Accepted Answer

Renal function improves with angiotensin II receptor blockers.

Answer

Hypertension is a common presentation.

Answer

Renin levels are typically elevated.

Answer

Kidneys may show asymmetrical sizes.

Question 6

Which of the following is NOT an absolute indication for dialysis?

Accepted Answer

Hyperphosphatemia

Answer

Persistent or severe hyperkalemia

Answer

Congestive cardiac failure

Answer

Severe acidosis

Question 7

A 42-year-old man presents with sudden onset, severe left-sided flank pain radiating into the groin. He experienced a similar episode years ago that resolved spontaneously. He denies fever, chills, nausea, vomiting, diarrhea, or dysuria. Physical examination reveals left flank and groin tenderness. Urinalysis shows microscopic hematuria without casts. Serum chemistry reveals: Sodium: 143 mEq/L, Potassium: 2.4 mEq/L, Bicarbonate: 17 mEq/L, Chloride: 115 mEq/L, Blood urea nitrogen: 12 mg/dL, Creatinine: 1.0 mg/dL, Glucose: 85 mg/dL. Which of the following acid-base disturbances is MOST likely present in this patient?

Accepted Answer

Metabolic acidosis

Answer

Normal acid-base status

Answer

Metabolic alkalosis

Answer

Respiratory acidosis

Question 8

Which of the following is NOT a feature of hepatorenal syndrome?

Accepted Answer

Plasma osmolality > Urine osmolality

Answer

Low GFR with serum creatinine level >1.5 mg/dL

Answer

Urine sodium level <10 mEq/L

Answer

Urine red blood cell count <50/HPF

Question 9

An adolescent male presents with hypokalemia, metabolic alkalosis, hypercalciuria, and nephrocalcinosis. His blood pressure is normal. What is the likely diagnosis?

Accepted Answer

Bartter syndrome

Answer

Gitelman syndrome

Answer

Liddle syndrome

Answer

Renal tubular acidosis

Question 10

Bence Jones proteinuria is not seen in which of the following conditions?

Accepted Answer

Chronic interstitial nephritis

Answer

Multiple myeloma

Answer

Macroglobulinemia

Answer

Non-Hodgkins lymphoma

Nephrology — MCQs

Nephrology — MCQs

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