Nephrology Practice Questions

Q: Which is the most common symptom of medullary sponge kidney disease?

UTI. ***UTI*** - **Medullary sponge kidney disease** often leads to **urinary stasis** within the dilated collecting ducts, creating a favorable environment for **bacterial growth** and recurrent **urinary tract infections (UTIs)** [1]. - The abnormal kidney structure and presence of stones can also cause **obstruction**, further increasing the risk of UTIs [1], [2]. *Anuria* - **Anuria**, the absence of urine production, is a severe symptom usually indicative of **acute kidney injury** or **bilateral urinary obstruction**. - While medullary sponge kidney can lead to complications, **anuria** is a rare initial or primary presentation. *Anemia* - **Anemia** in kidney disease is typically associated with **chronic kidney disease** stages where there is reduced **erythropoietin production**. - Medullary sponge kidney alone does not commonly cause significant **anemia**, unless it progresses to advanced chronic kidney disease, which is not its most common presentation. *Azotemia* - **Azotemia** refers to elevated levels of **nitrogenous waste products** (like urea and creatinine) in the blood, indicating **impaired kidney function**. - While medullary sponge kidney can sometimes lead to impaired function due to recurrent infections or stones, **azotemia** is not the most common direct symptom; **UTIs** are more frequent [2].

Q: What is the definition of polyuria?

Urine output more than 3 liters per day. ***Urine output more than 3 liters per day*** - **Polyuria** is defined as excessive urination, typically characterized by a daily urine output greater than **3 liters** or **3000 mL** in adults. - This increased volume can be indicative of various underlying medical conditions such as **diabetes mellitus**, **diabetes insipidus**, or excessive fluid intake. *Urine output between 1 to 2 liters per day* - This range usually falls within the **normal daily urine output** for healthy adults, which is typically between **0.8 to 2 liters** (800 to 2000 mL). - It does not represent polyuria, as it is not an abnormally high volume. *Urine output between 2 to 3 liters per day* - While this is on the higher side of normal, it is often referred to as **high-normal** or mild polyuria, but the clinical definition typically sets the threshold at **>3 liters** for polyuria. - It could warrant further investigation but doesn't meet the strict definition of polyuria. *Urine output less than 1 liter per day* - A urine output of less than 1 liter (1000 mL) per day is generally classified as **oliguria**, a condition where urine production is abnormally low [1]. - Oliguria is the opposite of polyuria and can indicate conditions like **dehydration**, **kidney injury**, or **heart failure** [1].

Q: A 25-year-old male patient presents with ingestion of antifreeze solution. His arterial blood gas analysis report is as follows: pH = 7.20 Anion gap = 15 PCO2 = 25 HCO3 = 10 What is the most likely diagnosis?

High anion gap metabolic acidosis. ***High anion gap metabolic acidosis*** - The patient has a **low pH (7.20)**, indicating **acidosis**. The **bicarbonate (HCO3-) is low (10 mEq/L)**, which confirms it is a metabolic acidosis [1]. - The **anion gap is calculated as Na+ - (Cl- + HCO3-)**. With the given anion gap of 15, which is above the normal range (typically 8-12 mEq/L), it indicates a **high anion gap metabolic acidosis** [2]. This is consistent with **antifreeze (ethylene glycol) ingestion**, which produces acidic metabolites [2]. *Normal anion gap metabolic acidosis* - This type of acidosis occurs when the **anion gap remains within the normal range** (8-12 mEq/L), even though blood pH is low. - It usually results from a **loss of bicarbonate**, often through the gastrointestinal tract (e.g., severe diarrhea) or via the kidneys (e.g., renal tubular acidosis) [3], with a compensatory increase in chloride. *None of the options* - This option is incorrect as the presented clinical and lab findings clearly point to a specific type of acid-base disturbance. - The calculated anion gap and the pH/bicarbonate levels provide sufficient information for diagnosis. *Both* - This option is incorrect because the patient's lab values, specifically the **elevated anion gap**, distinctly categorize the condition as a high anion gap metabolic acidosis, ruling out a normal anion gap metabolic acidosis. - An acid-base disorder cannot simultaneously be both high and normal anion gap.

Q: Hyperkalemia and metabolic acidosis are commonly associated with which type of renal tubular acidosis?

Type IV renal tubular acidosis. ***Type IV renal tubular acidosis*** - This type is characterized by **hypoaldosteronism** or **aldosterone resistance**, leading to impaired potassium excretion and bicarbonate reabsorption [2]. - The resulting **hyperkalemia** inhibits ammonium excretion, contributing to a **non-anion gap metabolic acidosis** [1]. *Type I renal tubular acidosis* - This is a **distal RTA** caused by a defect in acid secretion in the collecting duct, leading to an inability to acidify urine [1]. - It typically presents with **hypokalemia**, **nephrolithiasis** (kidney stones), and an alkaline urine pH. *Type II renal tubular acidosis* - This is a **proximal RTA** due to impaired bicarbonate reabsorption in the proximal tubule. - It is typically associated with **hypokalemia**, and the urine can be acidified when systemic acidosis is severe. *Type III renal tubular acidosis* - This is a rare, historically used term, sometimes referring to a combination of features from Type I and Type II RTA. - It is not routinely used in current classification systems and does not specifically or primarily feature hyperkalemia and metabolic acidosis as its defining characteristics.

Q: The following are complications of haemodialysis except

Hypercalcemia. ***Hypercalcemia*** - **Hypercalcemia** is generally *not* a complication of hemodialysis; instead, patients often experience **hypocalcemia** due to chelation of calcium by dialysate or secondary hyperparathyroidism. - While dialysate can be adjusted to increase calcium, persistent hypercalcemia is more indicative of other underlying issues, such as **over-supplementation** or **adynamic bone disease**, rather than a direct complication of the dialysis procedure itself. *Hypotension* - **Hypotension** is a common complication of hemodialysis, often caused by **excessive fluid removal**, rapid solute shifts, or vasodilation [1]. - It can lead to symptoms like dizziness, nausea, and cramping, and in severe cases, may cause organ hypoperfusion. *Chest pain* - **Chest pain** can occur during hemodialysis due to several factors, including **myocardial ischemia** from hypotension or fluid shifts, or musculoskeletal pain [1]. - It may also be related to **pericarditis** or **pleuritis**, which are uremic complications sometimes exacerbated or triggered by dialysis. *Bleeding tendency* - A **bleeding tendency** is a well-known complication of hemodialysis, primarily due to the use of **anticoagulants** like heparin during the procedure to prevent clotting in the dialyzer [1]. - Additionally, chronic **uremia** itself can cause platelet dysfunction, further contributing to an increased risk of bleeding.

Q: Acute onset of anuria in elderly men is typically associated with which of the following conditions?

Obstructive urinary disease. ***Obstructive urinary disease*** - In elderly men, **prostatic enlargement** (benign prostatic hyperplasia or prostate cancer) is a common cause of urinary obstruction, leading to **bilateral hydronephrosis** and anuria [1]. - Anuria in this context is typically acute because the obstruction causes a sudden inability for urine to pass from the kidneys [1]. *Bilateral infarction of kidneys* - This is a rare cause of anuria and usually results from **atheroembolic disease** or other vascular catastrophes. - While it can cause anuria, it is less common than obstructive causes in older men and often presents with more severe **systemic symptoms**. *Acute tubular necrosis* - This typically presents with **oligo-anuria** rather than complete anuria, and often follows an **ischemic or nephrotoxic insult** [2]. - While it can cause significant renal dysfunction, complete anuria for an extended period is less typical compared to obstruction [1]. *Acute cortical necrosis* - This is a rare and severe form of acute kidney injury, often associated with obstetric complications (e.g., **placental abruption**), severe sepsis, or disseminated intravascular coagulation (DIC). - While it causes anuria, it is not typically associated with elderly men as a primary cause compared to obstructive etiologies.

Q: Which of the following is NOT a feature of type 4A renal tubular acidosis?

Hypokalemia. Type 4 renal tubular acidosis (RTA) is characterized by **hyperkalemia**, not hypokalemia, due to impaired aldosterone function or renal tubular insensitivity to aldosterone [1]. The primary defect in Type 4 RTA is a disordered ammonia production and hydrogen ion secretion, aggravated by **hyperkalemia**, all of which impair kaliuresis and acid excretion. Type 4 RTA often occurs in the context of **mild to moderate chronic kidney disease** [3], as impaired GFR can contribute to aldosterone deficiency or resistance. While not the direct cause, renal impairment sets the stage for the specific tubular defects seen in Type 4 RTA [2]. A defining feature of type 4 RTA is **hyperkalemia**, resulting from either inadequate aldosterone production or tubular resistance to aldosterone's effects on potassium excretion. This leads to decreased potassium secretion in the principal cells of the collecting duct [1]. Type 4 RTA is frequently seen in patients with **diabetic nephropathy**, often termed **hyporeninemic hypoaldosteronism**. This condition involves damage to the juxtaglomerular apparatus, leading to reduced renin and subsequently reduced aldosterone levels [1].

Q: A patient in chronic renal failure presents with tall, peaked T waves on ECG. Management includes:

CaCl2. ### CaCl2 - **Calcium chloride** (CaCl2) is indicated to **stabilize the cardiac membrane** in cases of severe hyperkalemia, as evidenced by the **tall, peaked T waves** on ECG in a patient with chronic renal failure [1]. - While it does not lower serum potassium levels, it **antagonizes the cardiac effects of hyperkalemia**, preventing potentially fatal arrhythmias [1]. *IV K-bicarbonate* - **Sodium bicarbonate** can be used in hyperkalemia, especially in the presence of **metabolic acidosis**, to shift potassium into cells. - However, **IV K-bicarbonate** as a term is problematic; administering potassium (K) in addition to bicarbonate would worsen hyperkalemia. *KCl* - Administering **potassium chloride (KCl)** would exacerbate hyperkalemia, which is the underlying cause of the ECG changes [2]. - KCl is used to treat hypokalemia, not hyperkalemia [2]. *None of the options* - This option is incorrect because **CaCl2** is a crucial and appropriate initial intervention for the cardiac manifestations of hyperkalemia. - Delaying treatment for severe hyperkalemia can lead to life-threatening cardiac arrhythmias.

Q: Sine wave pattern in an ECG is seen in which of the following conditions?

Hyperkalemia. ***Hyperkalemia*** - As **hyperkalemia** worsens, the ECG may show a loss of P waves, widening of the QRS complex, and tall, peaked T waves that merge with the QRS complex, creating a **sine wave pattern** [1]. - This pattern indicates severe electrical instability, often progressing to **ventricular fibrillation** [2] or **asystole** if not urgently treated. *Hypokalemia* - **Hypokalemia** typically manifests on ECG with U waves, T wave flattening or inversion, and prolongation of the QT interval [3]. - It does not cause a **sine wave pattern**, which is characteristic of severe hyperkalemia. *Hyponatremia* - While severe **hyponatremia** can affect cardiac function, it does not typically produce a specific **sine wave pattern** on the ECG [1]. - ECG changes in hyponatremia are often non-specific and may include bradycardia or arrhythmias due to altered nerve conduction. *Hypernatremia* - **Hypernatremia** can lead to various cardiac effects, but a **sine wave pattern** is not a characteristic ECG finding of this condition. - ECG changes in hypernatremia are often non-specific and are more related to volume status and associated electrolyte imbalances.

Question 1

A 43-year-old man who had a subarachnoid hemorrhage from an intracranial aneurysm 8 years ago and has also experienced progressive renal impairment associated with hematuria is most likely to have which diagnosis?

Accepted Answer

A genetic disorder causing renal cysts and associated with intracranial aneurysms

Answer

A genetic condition causing hypertension due to sodium retention

Answer

A condition characterized by cystic dilation of renal pyramids

Answer

An autoimmune condition causing glomerulonephritis and pulmonary hemorrhage

Question 2

Which is the most common symptom of medullary sponge kidney disease?

Accepted Answer

UTI

Answer

Anuria

Answer

Anemia

Answer

Azotemia

Question 3

What is the definition of polyuria?

Accepted Answer

Urine output more than 3 liters per day

Answer

Urine output between 1 to 2 liters per day

Answer

Urine output between 2 to 3 liters per day

Answer

Urine output less than 1 liter per day

Question 4

A 25-year-old male patient presents with ingestion of antifreeze solution. His arterial blood gas analysis report is as follows:
pH = 7.20
Anion gap = 15
PCO2 = 25
HCO3 = 10
What is the most likely diagnosis?

Accepted Answer

High anion gap metabolic acidosis

Answer

None of the options

Answer

Normal anion gap metabolic acidosis

Answer

Both

Question 5

Hyperkalemia and metabolic acidosis are commonly associated with which type of renal tubular acidosis?

Accepted Answer

Type IV renal tubular acidosis

Answer

Type II renal tubular acidosis

Answer

Type I renal tubular acidosis

Answer

Type III renal tubular acidosis

Question 6

The following are complications of haemodialysis except

Accepted Answer

Hypercalcemia

Answer

Chest pain

Answer

Bleeding tendency

Answer

Hypotension

Question 7

Acute onset of anuria in elderly men is typically associated with which of the following conditions?

Accepted Answer

Obstructive urinary disease

Answer

Bilateral infarction of kidneys

Answer

Acute tubular necrosis

Answer

Acute cortical necrosis

Question 8

Which of the following is NOT a feature of type 4A renal tubular acidosis?

Accepted Answer

Hypokalemia

Answer

Hyperkalemia

Answer

Occur in diabetic nephropathy

Answer

Mild renal failure

Question 9

A patient in chronic renal failure presents with tall, peaked T waves on ECG. Management includes:

Accepted Answer

CaCl2

Answer

IV K-bicarbonate

Answer

None of the options

Answer

KCl

Question 10

Sine wave pattern in an ECG is seen in which of the following conditions?

Accepted Answer

Hyperkalemia

Answer

Hypokalemia

Answer

Hyponatremia

Answer

Hypernatremia

Nephrology — MCQs

Nephrology — MCQs

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