Nephrology Practice Questions

Q: Dialysis is not indicated in which of the following conditions?

Digitalis toxicity. The decision to initiate urgent dialysis is often guided by the mnemonic **AEIOU** (Acidosis, Electrolytes, Ingestion, Overload, Uremia). **Why Digitalis Toxicity is the Correct Answer:** Dialysis is ineffective for **Digitalis (Digoxin) toxicity** because the drug has an exceptionally **large volume of distribution (Vd)** and is highly tissue-bound (primarily to skeletal muscle). For a toxin to be removed via hemodialysis, it must be present in high concentrations within the intravascular compartment. Since Digoxin resides mostly in the tissues rather than the blood, dialysis cannot clear it from the body. The definitive treatment for severe toxicity is **Digoxin-specific antibody fragments (DigiFab).** **Analysis of Incorrect Options:** * **Hyperkalemia (Option A):** This is a classic "E" (Electrolyte) indication. Life-threatening hyperkalemia (K+ >6.5 mEq/L) refractory to medical management is a primary indication for emergent dialysis. * **Hypercalcemia (Option B):** While not as common as hyperkalemia, severe, symptomatic hypercalcemia (Calcium >18 mg/dL) or hypercalcemic crisis that does not respond to hydration and bisphosphonates is an indication for dialysis. * **Aspirin Intoxication (Option C):** This falls under "I" (Ingestion). Salicylates are small, water-soluble molecules with low Vd, making them highly dialyzable [2]. Dialysis is indicated if levels exceed 100 mg/dL or in the presence of severe metabolic acidosis/altered mental status [2]. **NEET-PG High-Yield Pearls:** * **Drugs NOT dialyzable (Large Vd):** Digoxin, Tricyclic Antidepressants (TCAs), Benzodiazepines, Calcium Channel Blockers, and Beta-blockers [1]. * **Drugs that ARE dialyzable (Small Vd):** **M**ethanol, **E**thylene glycol, **L**ithium, **S**alicylates (Mnemonic: **MELS**). * **Note:** While dialysis doesn't remove Digoxin, it may be used to treat the life-threatening **hyperkalemia** that often accompanies acute Digoxin poisoning.

Q: What is the initial treatment of choice for a patient with chronic kidney disease and hypertension?

ACE inhibitors. The primary goal in managing hypertension in Chronic Kidney Disease (CKD) is not just blood pressure control, but also **renoprotection**. **Why ACE Inhibitors are the Correct Choice:** ACE inhibitors (or ARBs) are the initial treatment of choice because they specifically dilate the **efferent arteriole** of the glomerulus [1]. This reduces intraglomerular capillary pressure, which directly decreases proteinuria—the single most important predictor of CKD progression [1]. By slowing the rate of decline in the Glomerular Filtration Rate (GFR), they provide a survival benefit beyond their antihypertensive effect [1]. **Analysis of Incorrect Options:** * **B. Calcium Channel Blockers (CCBs):** While Dihydropyridine CCBs (like Amlodipine) are potent antihypertensives, they primarily dilate the *afferent* arteriole, which can sometimes increase intraglomerular pressure if used as monotherapy [2]. * **C. Diuretics:** These are essential adjuncts (especially Loop diuretics when GFR <30 ml/min) to manage fluid overload, but they do not possess the same intrinsic renoprotective properties as ACE inhibitors [3]. * **D. Beta-blockers:** These are generally considered third or fourth-line agents in CKD unless there is a specific cardiac indication like heart failure or post-MI status. **High-Yield Clinical Pearls for NEET-PG:** 1. **The "30% Rule":** A rise in serum creatinine up to 30% after starting an ACE inhibitor is acceptable and not an indication to stop the drug [1]. 2. **Hyperkalemia:** This is the most common limiting side effect; monitor potassium levels closely [2]. 3. **Contraindication:** ACE inhibitors/ARBs are strictly contraindicated in **Bilateral Renal Artery Stenosis** and **Pregnancy** [2]. 4. **Choice by GFR:** Use Thiazides if GFR >30; switch to Loop diuretics (Furosemide) if GFR <30 [3].

Q: A patient presents to the emergency department in an unconscious state after a 15-minute delay following a call. The patient has a barely palpable radial pulse and no signs of trauma. The systolic blood pressure is 58 mm Hg. An ECG and ultrasound film are shown. Which electrolyte abnormality is most likely to cause this clinical scenario?

Hyperkalemia. ***Hyperkalemia*** - **Severe hyperkalemia** (>6.5 mEq/L) causes **cardiac conduction abnormalities** leading to **bradycardia**, **hypotension**, and potential **cardiac arrest**, explaining the unconscious state and barely palpable pulse. - ECG findings progress from **peaked T waves** to **wide QRS complexes** to **sine wave pattern** and ultimately **asystole**; ultrasound may show **hypokinetic** or **dilated heart** with poor contractility. *Hypokalemia* - Typically causes **muscle weakness** and **paralysis** but rarely leads to such severe **hemodynamic collapse** with unconsciousness. - ECG shows **flattened T waves**, **U waves**, and **prolonged QT interval**, not the pattern typically associated with cardiac arrest. *Hypocalcemia* - Primarily causes **neuromuscular irritability** with **tetany**, **seizures**, and **laryngospasm** rather than severe cardiovascular collapse. - ECG findings include **prolonged QT interval** and **T wave inversions**, but rarely cause hemodynamic instability severe enough for unconsciousness. *Hypercalcemia* - Usually presents with **"stones, bones, groans, and psychiatric overtones"** including **kidney stones**, **bone pain**, and **confusion**. - ECG shows **shortened QT interval** and rarely causes acute cardiovascular collapse leading to unconsciousness and severe hypotension.

Q: Renal artery stenosis is associated with which of the following?

High renin hypertension. **Explanation:** **Renal Artery Stenosis (RAS)** is the most common cause of secondary hypertension [1]. The pathophysiology is rooted in the **Goldblatt phenomenon**. 1. **Why Option A is correct:** Stenosis of the renal artery leads to decreased renal perfusion pressure (ischemia) at the level of the **Juxtaglomerular (JG) apparatus** [2]. This triggers the JG cells to secrete excessive **Renin** [3]. Renin converts Angiotensinogen to Angiotensin I, which is then converted to Angiotensin II by ACE. Angiotensin II causes potent vasoconstriction and stimulates Aldosterone secretion (leading to sodium and water retention) [2]. This sequence results in **High Renin Hypertension** [1]. 2. **Why other options are incorrect:** * **Options B & C:** RAS is the classic prototype of high-renin states [1]. Low-renin hypertension is typically seen in conditions of primary mineralocorticoid excess, such as **Conn’s Syndrome** (Primary Hyperaldosteronism), where high aldosterone levels feedback to suppress renin. * **Option D:** Fibrinoid necrosis is a histological hallmark of **Malignant Hypertension** or certain vasculitides (like Polyarteritis Nodosa), rather than a specific association of the underlying stenosis itself. **High-Yield Clinical Pearls for NEET-PG:** * **Etiology:** Atherosclerosis (older males, involves the ostium) vs. Fibromuscular Dysplasia (younger females, "string of beads" appearance on angiography). * **Clinical Clue:** Presence of an abdominal bruit or unexplained worsening of renal function after starting an **ACE inhibitor** (due to loss of efferent arteriolar vasoconstriction). * **Diagnosis:** Renal Doppler is the initial screening test; **Digital Subtraction Angiography (DSA)** remains the gold standard [1]. * **Treatment:** Medical management is preferred for atherosclerotic RAS; angioplasty is highly effective for Fibromuscular Dysplasia.

Q: All of the following are indicated in the management of acute hyperkalemia except?

Sodium polystyrene sulfonate. **Explanation:** The management of **acute hyperkalemia** (typically defined as $K^+ > 6.5$ mEq/L or presence of ECG changes) focuses on three immediate goals: stabilizing the cardiac membrane, shifting potassium into cells, and removing potassium from the body [1]. **Why Option D is the correct answer:** **Sodium polystyrene sulfonate (Kayexalate)** is a cation-exchange resin. While it does remove potassium from the body via the GI tract, its onset of action is very slow (several hours to days). Therefore, it has **no role in the emergency/acute management** of life-threatening hyperkalemia. Furthermore, recent guidelines discourage its use due to the risk of intestinal necrosis. **Analysis of Incorrect Options (Indicated Treatments):** * **A. IV Calcium Gluconate:** This is the first-line treatment if ECG changes are present [1]. It **stabilizes the cardiac myocyte membrane** (antagonizes the membrane effect of hyperkalemia) without lowering serum potassium levels [1]. * **B. IV Glucose and Insulin:** This is the most reliable method to **shift potassium intracellularly**. Insulin stimulates the Na-K ATPase pump; glucose is co-administered to prevent hypoglycemia [2]. * **C. Beta-2 Agonist Inhalation:** Salbutamol (Albuterol) nebulization also promotes the **intracellular shift** of potassium [2]. It acts synergistically with insulin. **NEET-PG High-Yield Pearls:** 1. **Fastest acting:** IV Calcium Gluconate (onset 1-3 mins) – but it does *not* lower $K^+$. 2. **Most effective for shifting $K^+$:** Insulin + Glucose. 3. **Definitive management:** Hemodialysis is the fastest way to *remove* potassium in patients with renal failure. 4. **ECG Sequence:** Tall peaked T-waves $→$ PR prolongation $→$ Loss of P-wave $→$ Widening of QRS $→$ Sine wave pattern $→$ Asystole.

Question 1

A 40-year-old diabetic woman complains of flank pain and fever. Her temperature is 38.7°C, respirations are 25 per minute, and blood pressure is 150/90 mm Hg. Urinalysis reveals pyuria with WBC casts. Which of the following features of diabetes is the most important contributing factor in the development of flank pain and fever in this patient?

Accepted Answer

Hyperglycemia

Answer

Anti-insulin antibodies

Answer

Glycosylation of hemoglobin

Answer

Peripheral insulin resistance

Question 2

A 56-year-old man presents with hypertension and peripheral edema. He is otherwise healthy and takes no medications. Family history reveals that his father and a brother have kidney disease. His father was on hemodialysis before his death at age 68 of a stroke. Physical examination reveals BP 174/96 and AV nicking on funduscopic examination. He has a soft S4 gallop. Bilateral flank masses measuring 16 cm in length are palpable. Urinalysis shows 15 to 20 RBC/hpf and trace protein but is otherwise normal; his serum creatinine is 2.4 mg/dL. Which is the most likely long-term complication of his condition?

Accepted Answer

End-stage renal disease (ESRD) requiring dialysis or transplantation

Answer

Malignancy

Answer

Ruptured cerebral aneurysm

Answer

Biliary obstruction owing to cystic disease of the pancreas

Question 3

Dialysis is not indicated in which of the following conditions?

Accepted Answer

Digitalis toxicity

Answer

Hyperkalemia

Answer

Hypercalcemia

Answer

Aspirin intoxication

Question 4

What is the initial treatment of choice for a patient with chronic kidney disease and hypertension?

Accepted Answer

ACE inhibitors

Answer

CCB (Calcium Channel Blockers)

Answer

Diuretics

Answer

Beta-blockers

Question 5

A patient presents to the emergency department in an unconscious state after a 15-minute delay following a call. The patient has a barely palpable radial pulse and no signs of trauma. The systolic blood pressure is 58 mm Hg. An ECG and ultrasound film are shown. Which electrolyte abnormality is most likely to cause this clinical scenario?

Accepted Answer

Hyperkalemia

Answer

Hypokalemia

Answer

Hypocalcemia

Answer

Hypercalcemia

Question 6

Renal artery stenosis is associated with which of the following?

Accepted Answer

High renin hypertension

Answer

Normal renin hypertension

Answer

Low renin hypertension

Answer

Fibrinoid necrosis of vessels

Question 7

Metabolic complications in chronic renal failure (CRF) include all of the following EXCEPT?

Accepted Answer

Hypophosphatemia

Answer

Hyperkalemia

Answer

Hypocalcemia

Answer

Hypokalemia

Question 8

All of the following are indicated in the management of acute hyperkalemia except?

Accepted Answer

Sodium polystyrene sulfonate

Answer

Intravenous Calcium gluconate

Answer

Intravenous Glucose and Insulin

Answer

Beta2 agonist inhalation

Question 9

Which of the following conditions causes euvolemic hyponatremia?

Accepted Answer

Syndrome of Inappropriate Antidiuretic Hormone secretion (SIADH)

Answer

Nephrotic syndrome

Answer

Diarrhea

Answer

Vomiting

Question 10

A diabetic male presents with hypertension and 24-hour urine showing 200 mg of albumin. In a diabetic patient with microalbuminuria, what is the appropriate drug for the treatment of hypertension to prevent the progression of renal failure?

Accepted Answer

Angiotensin converting enzyme inhibitor

Answer

Beta blocker

Answer

Thiazide diuretic

Answer

Short-acting dihydropyridine calcium channel blocker for precise control (nifedipine)

Nephrology — MCQs

Nephrology — MCQs

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