Nephrology Practice Questions

Q: In a patient with chronic kidney disease, what is the primary reason for choosing an ARB over an ACE inhibitor for managing proteinuria?

ARB; better tolerated in patients with renal impairment. ARB; better tolerated in patients with renal impairment - Angiotensin receptor blockers (ARBs) are often preferred in patients with chronic kidney disease (CKD) due to a lower incidence of side effects, particularly chronic cough, compared to ACE inhibitors [1]. - This improved tolerability often leads to better patient adherence and sustained treatment for proteinuria management, which is crucial in CKD. ARB; lower risk of adverse effects in renal impairment - While ARBs have a lower incidence of certain side effects like cough compared to ACE inhibitors, both drug classes carry similar risks for other adverse effects in renal impairment, such as hyperkalemia and acute kidney injury [2]. - The primary differentiator is often the prevention of cough and angioedema, leading to better overall tolerability rather than a universally lower risk of *all* adverse effects. ACE inhibitor; more effective at reducing proteinuria in all patients - ACE inhibitors and ARBs are considered equally effective at reducing proteinuria in most patients with CKD by blocking the renin-angiotensin-aldosterone system (RAAS) [2]. - The choice between them in CKD is often driven by tolerability issues rather than superior antiproteinuric efficacy of one over the other [1]. ACE inhibitor; reduces blood pressure more effectively in chronic kidney disease - Both ACE inhibitors and ARBs are highly effective at reducing blood pressure in patients with CKD, which is a critical aspect of kidney protection [2]. - There is no substantial evidence to suggest that ACE inhibitors are inherently more effective than ARBs at lowering blood pressure in this patient population.

Q: A 65-year-old male with chronic kidney disease presents with persistent fatigue and a hemoglobin level of 9 g/dL. Despite optimal dialysis and iron supplementation, his hemoglobin remains low. What is the most appropriate next step in managing his anemia?

Start erythropoiesis-stimulating agents (ESAs). ***Start erythropoiesis-stimulating agents (ESAs)*** - **Anemia of chronic kidney disease (CKD)** is primarily due to insufficient erythropoietin production by the kidneys [1]. - Since iron stores are replete and other causes of anemia have been ruled out, ESAs are indicated to **stimulate red blood cell production** [2]. *Administer blood transfusion* - Blood transfusions provide temporary relief for severe anemia but come with risks like **transfusion reactions**, **iron overload**, and **alloimmunization**, which can complicate future transplantation. - They are generally reserved for cases of **symptomatic anemia** or **acute blood loss**, where immediate hemoglobin elevation is necessary, not for chronic management of CKD-related anemia first-line. *Prescribe oral folic acid* - Folic acid supplementation is crucial for **DNA synthesis** and red blood cell maturation, but there is no indication of **folate deficiency** in this patient. - While important for patients on dialysis due to increased losses, it will not address the primary issue of **erythropoietin deficiency**. *Administer intravenous vitamin B12* - Vitamin B12 is essential for red blood cell production, and a deficiency can lead to **macrocytic anemia**. - However, there is no evidence presented to suggest **vitamin B12 deficiency**, and supplementation would not correct the underlying problem of **insufficient erythropoietin** in CKD.

Q: A patient presents with hyperkalemia. Which of the following ECG changes is most likely to be observed?

Peaked T waves. ***Peaked T waves*** - **Peaked T waves** are an early and characteristic sign of hyperkalemia, due to altered **myocardial repolarization** [1]. - This ECG change becomes apparent even with moderately elevated potassium levels, often preceding other more severe manifestations [1]. *Prolonged QT interval* - A **prolonged QT interval** is associated with conditions like **hypocalcemia** and certain antiarrhythmic medications, not hyperkalemia. - Hyperkalemia tends to shorten the QT interval indirectly due to the effect on repolarization and QRS widening. *Flattened P waves* - **Flattened P waves** can occur in hyperkalemia, but they typically manifest at higher potassium levels (severe hyperkalemia) and are not the *most likely* initial or sole ECG change [1], [2]. - Other conditions like **hypokalemia** can also cause flattened or inverted T waves. *ST depression* - **ST depression** often indicates **myocardial ischemia** or certain drug toxicities (e.g., digoxin). - It is not a typical or primary ECG finding associated with hyperkalemia.

Q: In assessing a patient with suspected metabolic acidosis, which blood gas parameter is most critical for confirming the diagnosis?

Blood pH. ***Blood pH*** - A **low blood pH** (below 7.35) is the defining characteristic of **acidemia**, which is central to the diagnosis of any acidosis, including metabolic acidosis [1], [2]. - While other parameters help classify the type of acidosis, the pH directly reflects the overall acid-base balance and confirms the presence of an acidic state [2]. *Oxygen saturation* - **Oxygen saturation** indicates the percentage of hemoglobin binding sites occupied by oxygen and is crucial for assessing **oxygenation status**. - It does not directly provide information about the **acid-base balance** of the blood. *Carbon dioxide partial pressure* - **Carbon dioxide partial pressure (PaCO2)** is a primary indicator of the **respiratory component** of acid-base balance [1]. - While important for differentiating respiratory from metabolic acidosis (e.g., in compensatory mechanisms), it does not directly confirm an acidic state in the same way pH does [2]. *Blood urea nitrogen* - **Blood urea nitrogen (BUN)** is a marker of **kidney function** and can be elevated in various conditions, including dehydration or kidney disease. - It is not a direct measure of **acid-base status** but may be indirectly related if kidney dysfunction is causing metabolic acidosis.

Q: A 60-year-old woman with a history of smoking presents with hematuria. What is the most appropriate initial investigation?

Urinalysis. ***Urinalysis*** - A **urinalysis** is the most appropriate initial investigation for hematuria [1] to confirm the presence of red blood cells, rule out pseudobloody urine, and identify potential causes like infection or proteinuria [1]. - It helps differentiate between glomerular and non-glomerular hematuria and can guide further imaging or invasive procedures [1]. *Cystoscopy* - While cystoscopy is crucial for directly visualizing the bladder and prostatic urethra in cases of confirmed hematuria, it is an **invasive procedure** and not typically the first step. - It is often performed after initial urinalysis and imaging have been completed and a source of bleeding is still unclear or to confirm a bladder lesion. *CT urogram* - A **CT urogram** is an excellent imaging modality for evaluating the entire urinary tract (kidneys, ureters, bladder) in cases of confirmed hematuria, especially when malignancy is suspected [1]. - However, it should be performed after urinalysis confirms true hematuria and provides context for the imaging findings. *Ultrasound* - **Ultrasound** is a non-invasive imaging technique that can assess the kidneys and bladder for structural abnormalities, stones, or masses [2]. - It is a good initial imaging study but follows urinalysis and may not fully evaluate the *entire* urinary tract or subtle lesions as effectively as a CT urogram.

Q: A 35-year-old woman with systemic lupus erythematosus (SLE) presents with worsening proteinuria and edema. A kidney biopsy reveals diffuse proliferative glomerulonephritis. Which combination of therapies would be the most effective?

Corticosteroids and mycophenolate mofetil. Corticosteroids and mycophenolate mofetil - This combination is often used for treating **diffuse proliferative glomerulonephritis** in SLE, targeting the **immune-mediated inflammation** effectively. - **Corticosteroids** reduce inflammation quickly, while **mycophenolate mofetil** helps in long-term disease management by inhibiting lymphocyte proliferation. [1] *NSAIDs and angiotensin receptor blockers* - NSAIDs can be used for pain in SLE but are **not effective** for addressing significant glomerulonephritis or proteinuria. [1] - Angiotensin receptor blockers help with hypertension and may reduce proteinuria, but do not modify the underlying immune pathogenesis. [1] *Plasmapheresis and intravenous immunoglobulin* - Plasmapheresis is utilized in severe cases but is not the first-line therapy for **routine diffuse glomerulonephritis** in SLE. - Intravenous immunoglobulin is supportive but does not specifically target the underlying disease process as effectively as corticosteroids and mycophenolate mofetil. *Cyclophosphamide and methotrexate* - Cyclophosphamide is a strong immunosuppressant but has significant **toxicity** and is usually reserved for severe cases or those not responsive to other therapies. - Methotrexate is less effective for **severe renal manifestations** compared to corticosteroids and mycophenolate mofetil. [1]

Q: Evaluating a patient with metabolic acidosis, which test would best determine the anion gap?

Serum electrolyte panel. ***Serum electrolyte panel*** - The **anion gap** is calculated using concentrations of measured cations (primarily **sodium**) and anions (primarily **chloride** and **bicarbonate**), all of which are included in a standard serum electrolyte panel [1]. - The formula for anion gap is: **Na+ - (Cl- + HCO3-)**. *Arterial blood gas (ABG)* - An ABG measures **pH**, **PCO2**, and **bicarbonate** (HCO3-), which are crucial for diagnosing acid-base disorders but do not provide the full electrolyte profile needed to calculate the anion gap directly [1]. - While bicarbonate from an ABG can be used in the anion gap formula, an ABG alone does not provide the **sodium** and **chloride** values necessary for its calculation. *Urine ketone test* - This test detects the presence of **ketone bodies** in the urine, which are indicative of ketoacidosis (a type of high anion gap metabolic acidosis). - However, it does not directly provide the electrolyte concentrations needed to calculate the **anion gap**. *Serum osmolality* - Serum osmolality measures the concentration of chemical particles in the blood and is used to calculate the **osmolal gap**, which can indicate the presence of unmeasured osmoles like alcohols. - It does not provide the specific electrolyte values required for the **anion gap** calculation.

Q: A 70-year-old male with chronic kidney disease stage 4 presents with uremic pericarditis. What is the next best step in management?

Immediate hemodialysis without heparin. **Immediate hemodialysis without heparin** - **Hemodialysis** is the definitive treatment for **uremic pericarditis** as it removes metabolic toxins and creatinine that accumulate in end-stage renal disease (ESRD) [1]. - **Heparin** should be avoided during dialysis in this setting to prevent the worsening of pericardial bleeding, which can lead to **cardiac tamponade**. *Start high-dose corticosteroids* - **Corticosteroids** are generally not indicated as the primary treatment for uremic pericarditis and may carry risks, especially in patients with chronic kidney disease. - The underlying cause, **uremia**, requires removal of toxins, which corticosteroids cannot achieve. *Administer intravenous antibiotics* - **Antibiotics** target bacterial infections, but **uremic pericarditis** is an inflammatory condition resulting from metabolic waste accumulation, not an infection. - Giving antibiotics would not address the root cause and is thus ineffective. *Perform pericardiocentesis* - **Pericardiocentesis** is reserved for cases where there is evidence of **cardiac tamponade** or a large, symptomatic **pericardial effusion** not responsive to dialysis. - Since the question does not mention signs of tamponade, it is not the initial best step, as addressing the uremia is paramount.

Q: A 45-year-old man presents with hematuria, hypertension, and pedal edema. Laboratory results show proteinuria and hypoalbuminemia. What is the most likely diagnosis?

Nephrotic syndrome. ***Nephrotic syndrome*** - The combination of **hematuria, hypertension, pedal edema, proteinuria**, and **hypoalbuminemia** is classic for **nephrotic syndrome** [3]. - **Proteinuria** (>3.5 g/24h in adults), associated with **hypoalbuminemia**, causes reduced oncotic pressure, leading to **edema** [2]. *Acute kidney injury* - Characterized by a **sudden decline in kidney function**, leading to retention of waste products. - While it can cause fluid retention and potentially hypertension, **significant proteinuria and hypoalbuminemia** are not primary features. *Chronic kidney disease* - Involves **progressive, irreversible loss of kidney function** over months or years. - While it may involve proteinuria and edema in later stages, the sudden onset implied by the presentation and the classic nephrotic features point away from this. *Urinary tract infection* - Primarily presents with **dysuria, frequency, urgency**, and sometimes hematuria [1]. - It does not typically cause **hypertension, pedal edema**, or significant **proteinuria and hypoalbuminemia**.

Question 1

In a patient with chronic kidney disease, what is the primary reason for choosing an ARB over an ACE inhibitor for managing proteinuria?

Accepted Answer

ARB; better tolerated in patients with renal impairment

Answer

ARB; lower risk of adverse effects in renal impairment

Answer

ACE inhibitor; more effective at reducing proteinuria in all patients

Answer

ACE inhibitor; reduces blood pressure more effectively in chronic kidney disease

Question 2

A 65-year-old male with chronic kidney disease presents with persistent fatigue and a hemoglobin level of 9 g/dL. Despite optimal dialysis and iron supplementation, his hemoglobin remains low. What is the most appropriate next step in managing his anemia?

Accepted Answer

Start erythropoiesis-stimulating agents (ESAs)

Answer

Administer blood transfusion

Answer

Prescribe oral folic acid

Answer

Administer intravenous vitamin B12

Question 3

A patient presents with hyperkalemia. Which of the following ECG changes is most likely to be observed?

Accepted Answer

Peaked T waves

Answer

Prolonged QT interval

Answer

Flattened P waves

Answer

ST depression

Question 4

In assessing a patient with suspected metabolic acidosis, which blood gas parameter is most critical for confirming the diagnosis?

Accepted Answer

Blood pH

Answer

Oxygen saturation

Answer

Carbon dioxide partial pressure

Answer

Blood urea nitrogen

Question 5

A 60-year-old woman with a history of smoking presents with hematuria. What is the most appropriate initial investigation?

Accepted Answer

Urinalysis

Answer

CT urogram

Answer

Ultrasound

Answer

Cystoscopy

Question 6

A 35-year-old woman with systemic lupus erythematosus (SLE) presents with worsening proteinuria and edema. A kidney biopsy reveals diffuse proliferative glomerulonephritis. Which combination of therapies would be the most effective?

Accepted Answer

Corticosteroids and mycophenolate mofetil

Answer

NSAIDs and angiotensin receptor blockers

Answer

Cyclophosphamide and methotrexate

Answer

Plasmapheresis and intravenous immunoglobulin

Question 7

Evaluating a patient with metabolic acidosis, which test would best determine the anion gap?

Accepted Answer

Serum electrolyte panel

Answer

Arterial blood gas (ABG)

Answer

Urine ketone test

Answer

Serum osmolality

Question 8

A 70-year-old male with chronic kidney disease stage 4 presents with uremic pericarditis. What is the next best step in management?

Accepted Answer

Immediate hemodialysis without heparin

Answer

Start high-dose corticosteroids

Answer

Administer intravenous antibiotics

Answer

Perform pericardiocentesis

Question 9

A 45-year-old man presents with hematuria, hypertension, and pedal edema. Laboratory results show proteinuria and hypoalbuminemia. What is the most likely diagnosis?

Accepted Answer

Nephrotic syndrome

Answer

Acute kidney injury

Answer

Chronic kidney disease

Answer

Urinary tract infection

Question 10

A 60-year-old male with chronic kidney disease has metabolic acidosis, hyperkalemia, high creatinine, and low bicarbonate. What is the most likely explanation?

Accepted Answer

Decreased renal ammonium excretion and reduced renal bicarbonate reabsorption

Answer

Increased renal potassium reabsorption and enhanced acid production

Answer

Decreased renal sodium reabsorption and reduced gluconeogenesis

Answer

Increased gastrointestinal potassium absorption and decreased renal perfusion

Nephrology — MCQs

Nephrology — MCQs

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