Nephrology Practice Questions

Q: What is the major cause of death in patients with end-stage renal disease?

Cardiovascular disease. **Explanation:** **Cardiovascular disease (CVD)** is the leading cause of mortality in patients with End-Stage Renal Disease (ESRD), accounting for approximately **40–50% of all deaths**. The risk of cardiovascular death in dialysis patients is 10 to 20 times higher than in the general population. This is due to a combination of "traditional" risk factors (hypertension, diabetes, dyslipidemia) [1] and "non-traditional" uremia-related factors, such as chronic inflammation, oxidative stress, hyperphosphatemia, and secondary hyperparathyroidism leading to extensive **vascular and valvular calcification** [1]. **Analysis of Incorrect Options:** * **Infection:** This is the **second most common** cause of death in ESRD [1]. Patients are immunocompromised due to uremia and have frequent breaches in skin barriers (hemodialysis catheters/fistulas), making them prone to sepsis and pneumonia. * **Uremia:** While uremia [1] is the hallmark of untreated renal failure, it is rarely the direct cause of death in the modern era due to the availability of Renal Replacement Therapy (RRT). * **Respiratory failure:** While pulmonary edema (due to fluid overload) is a common complication, it is usually managed with dialysis and is not the primary statistical cause of mortality compared to CVD. **Clinical Pearls for NEET-PG:** * The most common specific cardiovascular cause of death in ESRD is **Sudden Cardiac Death (SCD)**, often due to arrhythmias secondary to electrolyte shifts and left ventricular hypertrophy (LVH). * **Target Blood Pressure** in ESRD: Generally <140/90 mmHg (pre-dialysis) or <130/80 mmHg (post-dialysis). * **Hyperphosphatemia** is a major driver of vascular calcification; maintaining phosphate balance is crucial for reducing CV risk [1].

Q: A 60-year-old diabetic male developed renal failure and was initiated on Chronic Ambulatory Peritoneal Dialysis (CAPD). After 4 months of CAPD, the patient developed peritonitis. What is the most common organism responsible?

Staphylococcus epidermidis. **Explanation:** Peritonitis is the most common complication of Chronic Ambulatory Peritoneal Dialysis (CAPD). The primary route of infection is **intraluminal or periluminal**, occurring during the manipulation of the catheter or through the exit site. **1. Why Staphylococcus epidermidis is correct:** Coagulase-negative Staphylococci (CoNS), specifically **Staphylococcus epidermidis**, is the most common cause of CAPD-associated peritonitis [1]. These organisms are normal skin commensals [1]. They gain entry into the peritoneal cavity during bag changes or through the catheter tunnel [1]. Their ability to form **biofilms** on the prosthetic material of the catheter makes them particularly persistent [1]. **2. Analysis of Incorrect Options:** * **Staphylococcus aureus:** While it is the second most common cause and often leads to more severe clinical symptoms (including catheter-site infections), it is less frequent than *S. epidermidis* [1]. * **Escherichia coli:** Gram-negative organisms like *E. coli* account for about 15-25% of cases. They usually suggest a bowel-related source (transmigration) or poor hygiene. * **Bacteroides:** Anaerobic peritonitis is rare in CAPD. If present, it strongly suggests a surgical cause, such as bowel perforation or intra-abdominal pathology. **High-Yield Clinical Pearls for NEET-PG:** * **Diagnosis:** Cloudy effluent with a WBC count **>100/μL** (with >50% neutrophils). * **Most common route:** Touch contamination during exchange. * **Empiric Treatment:** A combination of a first-generation cephalosporin (or Vancomycin) and an aminoglycoside (or third-generation cephalosporin) to cover both Gram-positive and Gram-negative organisms. * **Fungal Peritonitis:** Usually caused by *Candida* species; it requires immediate catheter removal.

Q: What is the metabolic defect in accelerated hypertension?

Metabolic alkalosis. In accelerated or malignant hypertension, the pathophysiology is driven by the **activation of the Renin-Angiotensin-Aldosterone System (RAAS)**. ### Why Metabolic Alkalosis is Correct Severe hypertension causes pressure natriuresis and renal ischemia, which triggers the release of Renin. This leads to high levels of Angiotensin II and **Aldosterone**. Aldosterone acts on the cortical collecting ducts of the kidney to [2]: 1. Increase sodium reabsorption. 2. Increase the secretion of **Potassium (K+)** and **Hydrogen ions (H+)** into the urine. The excessive loss of H+ ions leads to **metabolic alkalosis**, typically accompanied by **hypokalemia** [1]. This is often referred to as "secondary hyperaldosteronism." ### Why Other Options are Incorrect * **A & B (Metabolic Acidosis):** Metabolic acidosis is generally seen in chronic kidney disease (CKD) or acute kidney injury (AKI) due to the failure of the kidneys to excrete fixed acids. While accelerated hypertension can cause renal failure, the primary metabolic defect driven by the hormonal response (RAAS) is alkalosis. * **C (Hypomagnesemia):** While electrolyte imbalances occur, hypomagnesemia is not a hallmark or specific metabolic defect of accelerated hypertension; it is more commonly associated with diuretic use or chronic alcoholism. ### NEET-PG High-Yield Pearls * **Definition:** Accelerated hypertension is characterized by a sudden increase in BP (usually >180/120 mmHg) with Grade III hypertensive retinopathy (flame-shaped hemorrhages, cotton wool spots). * **Malignant Hypertension:** Includes the above plus **Papilledema** (Grade IV retinopathy). * **The "Aldosterone Paradox":** Even though the body is hypertensive, the kidneys perceive "low volume" due to ischemia, leading to paradoxically high renin and aldosterone levels [3]. * **Treatment Goal:** Reduce Mean Arterial Pressure (MAP) by no more than 25% within the first hour to prevent cerebral hypoperfusion.

Q: Which of the following is NOT an indication for dialysis in a case of acute renal failure?

Hyponatremia. In management of Acute Kidney Injury (AKI), the decision to initiate Renal Replacement Therapy (RRT) is based on life-threatening metabolic derangements that cannot be managed medically [1]. ### **Why Hyponatremia is the Correct Answer** **Hyponatremia (Option B)** is generally **not** a primary indication for dialysis. While fluid overload (which can cause dilutional hyponatremia) is an indication, mild to moderate low sodium is typically managed through fluid restriction [1]. Dialysis is reserved for severe, symptomatic electrolyte imbalances, primarily **Hyperkalemia**, because it poses an immediate risk of cardiac arrest. ### **Analysis of Other Options (Indications for Dialysis)** * **Uremia (Option A):** Specifically symptomatic uremia. This includes uremic encephalopathy (confusion/seizures), uremic pericarditis (friction rub), or uremic coagulopathy (bleeding). * **Hyperkalemia (Option C):** Refractory hyperkalemia (typically K+ >6.5 mEq/L) or hyperkalemia with associated ECG changes that does not respond to medical "shifting" therapy (Insulin/Glucose, Calcium gluconate). * **Metabolic Acidosis (Option D):** Severe metabolic acidosis (typically pH 6.5 mEq/L). * **I – Intoxications:** Poisoning with SLIME (Salicylates, Lithium, Isopropanol, Methanol, Ethylene glycol). * **O – Overload:** Refractory pulmonary edema/volume overload. * **U – Uremia:** Symptomatic (Pericarditis, Encephalopathy, Neuropathy).

Q: Which of the following is not a feature of Chronic Renal Failure?

Hyperthyroidism. ### Explanation In Chronic Kidney Disease (CKD) or Chronic Renal Failure, the primary metabolic derangement involves the **Calcium-Phosphate-Vitamin D axis**. **Why Hyperthyroidism is the Correct Answer:** Hyperthyroidism is not a feature of Chronic Renal Failure. In fact, CKD is more commonly associated with **"Euthyroid Sick Syndrome"** or occasionally hypothyroidism. While the parathyroid glands are hyperactive, the thyroid gland's function is generally suppressed or altered due to chronic systemic illness, but it does not typically manifest as hyperthyroidism. **Analysis of Incorrect Options:** * **Decreased 1,25(OH)2 Vitamin D3 (Calcitriol):** The kidneys contain the enzyme **1-alpha-hydroxylase**, which converts 25-hydroxyvitamin D into its active form, 1,25-dihydroxyvitamin D3. In CRF, the loss of renal parenchyma leads to a deficiency of this enzyme, resulting in low calcitriol levels [1], [3]. * **Hyperparathyroidism:** Low calcitriol levels and phosphate retention (hyperphosphatemia) lead to hypocalcemia [1]. This triggers the parathyroid glands to secrete excess Parathyroid Hormone (PTH) to maintain calcium levels, a condition known as **Secondary Hyperparathyroidism** [2], [3]. * **Osteomalacia:** This is a component of **Renal Osteodystrophy** [2]. It occurs due to the failure of bone mineralization caused by vitamin D deficiency and chronic metabolic acidosis. **NEET-PG High-Yield Pearls:** 1. **Renal Osteodystrophy Spectrum:** Includes Osteitis fibrosa cystica (high turnover due to PTH), Osteomalacia (low turnover), and Adynamic bone disease [2]. 2. **Phosphate Management:** Hyperphosphatemia is a major driver of mortality in CKD; phosphate binders (like Sevelamer) are mainstay treatments. 3. **FGF-23:** This is the earliest marker of disordered phosphorus metabolism in CKD, rising even before phosphate levels increase [2].

Q: Fluid containing which of the following substances is used in peritoneal dialysis?

Dextrose. **Explanation:** The primary goal of peritoneal dialysis (PD) is to remove excess water and metabolic waste products from the blood. This is achieved through the processes of **osmosis** and **diffusion** across the peritoneal membrane [1]. **Why Dextrose is the Correct Answer:** Dextrose (glucose) serves as the **osmotic agent** in the PD fluid [1]. By creating a high osmotic pressure in the peritoneal cavity relative to the blood, it draws excess water out of the intravascular space and into the dialysate (ultrafiltration) [2]. Standard PD fluids contain dextrose in varying concentrations (e.g., 1.5%, 2.5%, or 4.25%) to tailor the amount of fluid removal required. **Analysis of Incorrect Options:** * **A. NaCl:** While PD fluid contains sodium chloride to maintain electrolyte balance and isotonicity, it is not the active substance used to drive the dialysis process or fluid removal. * **B. Urea:** Urea is a metabolic waste product that PD aims to *remove* from the body. Including it in the dialysate would prevent the concentration gradient necessary for its diffusion out of the blood. * **C. Heparin:** Heparin is sometimes added to PD bags to prevent fibrin clots from plugging the catheter (especially during peritonitis), but it is a pharmacological additive, not a constituent of the standard dialysis process itself. **Clinical Pearls for NEET-PG:** * **Icodextrin:** A glucose polymer used as an alternative osmotic agent for long dwells (e.g., overnight) in patients with high transport characteristics or diabetes. * **Peritonitis:** The most common complication of PD; the most frequent causative organism is *Staphylococcus epidermidis*. * **Contraindication:** PD is generally avoided in patients with recent abdominal surgery or extensive intra-abdominal adhesions.

Q: Which of the following improves after dialysis?

Peripheral neuropathy. ### Explanation In the management of End-Stage Renal Disease (ESRD), it is crucial to distinguish between uremic symptoms that are reversible with dialysis and those that are not. **Why Peripheral Neuropathy is the Correct Answer:** Uremic peripheral neuropathy (typically a distal, symmetric sensory-motor polyneuropathy) is a classic indication for initiating dialysis. While the recovery is often slow and may require months of adequate dialysis or a renal transplant for full resolution, the **progression of the neuropathy is halted**, and sensory symptoms generally show significant improvement following the stabilization of uremic toxins. [1] **Analysis of Other Options:** * **Pericarditis (Option A):** While uremic pericarditis is an absolute indication for urgent dialysis, it is considered a **complication** of uremia rather than a symptom that simply "improves" like a metabolic derangement. * **Metabolic Acidosis (Option C):** While dialysis corrects the pH acutely [1], metabolic acidosis is a **biochemical abnormality**, not a clinical symptom or a chronic pathological state like neuropathy. In many exam patterns, "improvement" refers to the resolution of a pathological clinical condition. **Clinical Pearls for NEET-PG:** * **Indications for Dialysis (AEIOU):** **A**cidosis (refractory), **E**lectrolytes (refractory hyperkalemia), **I**ngestion (toxins), **O**verload (volume), **U**remia (pericarditis, encephalopathy, neuropathy). [1] * **What Dialysis DOES NOT Improve:** Renal osteodystrophy (bone disease), anemia (requires EPO), and hypertension (often requires multi-drug therapy). * **Most common cause of death in ESRD:** Cardiovascular disease (not uremia itself). * **First sign of uremic neuropathy:** Loss of Vibration sense or "Restless Leg Syndrome."

Question 1

What is the major cause of death in patients with end-stage renal disease?

Accepted Answer

Cardiovascular disease

Answer

Infection

Answer

Uremia

Answer

Respiratory failure

Question 2

A 60-year-old diabetic male developed renal failure and was initiated on Chronic Ambulatory Peritoneal Dialysis (CAPD). After 4 months of CAPD, the patient developed peritonitis. What is the most common organism responsible?

Accepted Answer

Staphylococcus epidermidis

Answer

Staphylococcus aureus

Answer

Escherichia coli

Answer

Bacteroides

Question 3

What is the metabolic defect in accelerated hypertension?

Accepted Answer

Metabolic alkalosis

Answer

Normal non-ionic metabolic acidosis

Answer

Ionic gap metabolic acidosis

Answer

Hypomagnesemia

Question 4

What type of renal stone is typically formed in a patient with regional enteritis?

Accepted Answer

Calcium oxalate

Answer

Cysteine

Answer

Struvite

Answer

Urate

Question 5

Which of the following is NOT an indication for dialysis in a case of acute renal failure?

Accepted Answer

Hyponatremia

Answer

Uremia

Answer

Hyperkalemia

Answer

Metabolic acidosis

Question 6

Which of the following is not a feature of Chronic Renal Failure?

Accepted Answer

Hyperthyroidism

Answer

Hyperparathyroidism

Answer

Osteomalacia

Answer

Decreased 1,25(OH)2 vitamin D3 level

Question 7

Fluid containing which of the following substances is used in peritoneal dialysis?

Accepted Answer

Dextrose

Answer

NaCl

Answer

Urea

Answer

Heparin

Question 8

A 71-year-old man presents with blurry vision and blood-tinged urine. He has a history of hypertension treated with a beta-blocker, an ACE inhibitor, and a calcium channel blocker. His symptoms began 3 days ago when he stopped his medications. His blood pressure is 200/110 mmHg, funduscopic examination reveals flame hemorrhages and papilledema, and urinalysis shows red blood cells with dysmorphic red blood cell casts. He has an abdominal bruit. What is the most appropriate next step in management?

Accepted Answer

Administer intravenous medication to reduce his blood pressure.

Answer

Order an ECG and observe the patient.

Answer

Order an abdominal CT scan to rule out aortic aneurysm.

Answer

Administer the patient's usual daily doses of blood pressure medications and observe him.

Question 9

Which of the following is NOT an indication for dialysis?

Accepted Answer

Anemia

Answer

Pericarditis

Answer

Persistent hyperkalemia

Answer

Uremic encephalopathy

Question 10

Which of the following improves after dialysis?

Accepted Answer

Peripheral neuropathy

Answer

Pericarditis

Answer

Metabolic acidosis

Answer

All of the above

Nephrology — MCQs

Nephrology — MCQs

On this page

Practice by Chapter

Want unlimited practice?