Nephrology Practice Questions

Q: A patient presents with pain in the metatarsophalangeal joints and is a known case of chronic renal failure. This is due to the accumulation of:

Uric acid. Uric acid - **Chronic renal failure** impairs the kidney's ability to excrete **uric acid**, leading to its accumulation in the body [1], [2]. - High levels of uric acid can crystalize in joints, particularly the **metatarsophalangeal joints**, causing painful inflammation known as **gout** [2], [3]. *Rheumatoid factor* - **Rheumatoid factor** is an autoantibody primarily associated with **rheumatoid arthritis**, an autoimmune disease. - While it can be present in other conditions, it is not directly responsible for joint pain in the context of renal failure [3]. *Blood urea nitrogen* - **Blood urea nitrogen (BUN)** is a marker of kidney function and accumulates in renal failure. - However, BUN itself does not directly cause joint pain in the metalsophalangeal joints, unlike uric acid. *HLA B27 typing* - **HLA-B27** is a human leukocyte antigen strongly associated with seronegative spondyloarthropathies like **ankylosing spondylitis** and **reactive arthritis**. - It does not accumulate in chronic renal failure and is not directly related to joint pain caused by renal dysfunction.

Q: Mainstay of treatment of nephrogenic diabetes insipidus is:

Thiazide / Amiloride diuretics and salt restriction. ***Thiazide / Amiloride diuretics and salt restriction*** - **Thiazide diuretics** (e.g., hydrochlorothiazide) are the mainstay in nephrogenic diabetes insipidus by causing mild **volume depletion**, which enhances proximal tubular reabsorption of water and solutes, reducing urine volume. [1] - **Salt restriction** further supports this mechanism by helping to decrease filtered sodium load and consequently reducing water excretion. [1] *Desmopressin* - **Desmopressin** is a synthetic analog of **vasopressin** and is the primary treatment for **central diabetes insipidus**, where there is insufficient ADH production. [2] - In **nephrogenic diabetes insipidus**, the kidneys are resistant to ADH, so desmopressin would be ineffective. [2] *Vasopressin and salt restriction* - **Vasopressin** (arginine vasopressin, AVP) is the natural antidiuretic hormone whose action is impaired in nephrogenic diabetes insipidus due to **renal resistance**, making its administration ineffective. [2] - While salt restriction is beneficial, combining it with ineffective vasopressin would not be the mainstay of treatment. *Desmopressin with salt restriction* - As mentioned, **desmopressin** is ineffective in **nephrogenic diabetes insipidus** because the renal tubules are unresponsive to its action. [2] - Although **salt restriction** is a useful adjunct, its combination with an ineffective drug does not make it the mainstay of treatment for this specific condition.

Q: Polycystic disease of the kidney may have cysts in all of the following organs except?

Lung. ***Lung*** - While Polycystic Kidney Disease (PKD) is a **systemic disorder**, cysts are exceptionally rare or not typically found in the **lungs**. - PKD primarily affects organs that develop from common embryonic pathways, such as the kidney, liver, pancreas, and spleen. *Liver* - **Hepatic cysts** are the most common extrarenal manifestation of **autosomal dominant polycystic kidney disease (ADPKD)**, occurring in a majority of patients [1]. - These cysts can range from asymptomatic to causing significant hepatomegaly, pain, and liver dysfunction. *Pancreas* - **Pancreatic cysts** are another common finding in ADPKD, though generally **smaller and less clinically significant** than hepatic cysts. - They are usually asymptomatic but can sometimes lead to pancreatitis or pain. *Spleen* - **Splenic cysts** are a recognised but **less common** extrarenal manifestation in patients with ADPKD. - Like other extrarenal cysts, they are often asymptomatic and discovered incidentally.

Q: A boy is suffering from acute pyelonephritis. The most specific urinary finding will be:

W.B.C. casts. ***W.B.C. casts*** - **WBC casts** are pathognomonic for **pyelonephritis** as they indicate inflammation and infection within the **renal tubules**. - They form when white blood cells aggregate in the **tubular lumen** and are encased in **Tamm-Horsfall protein**, reflecting their renal origin. *Leucocyte esterase test* - The **leukocyte esterase test** detects the presence of enzymes released by **neutrophils**, indicating pyuria (white blood cells in urine). - While positive in pyelonephritis, it is not specific to the kidney and can be positive in **lower urinary tract infections** as well. *Nitrite test* - A **nitrite test** detects the presence of **nitrites**, which are formed by gram-negative bacteria that convert urinary nitrates. - This test is indicative of a bacterial infection but is not specific to the **upper urinary tract** (pyelonephritis) versus a **lower urinary tract infection** (cystitis). *Bacteria in gram stain* - The presence of **bacteria** on a Gram stain of unspun urine indicates a significant bacterial presence, often associated with a urinary tract infection. - However, it does not differentiate between **upper** (pyelonephritis) and **lower** (cystitis) urinary tract infections and is therefore not specific for pyelonephritis.

Q: A patient presents with acute renal failure (ARF) and complete anuria, with a normal ultrasound of the kidneys. Which investigation will provide the best initial information regarding renal function?

DTPA Scan (Radiorenogram). DTPA Scan (Radiorenogram) - A DTPA scan can assess renal perfusion and glomerular filtration rate (GFR), providing crucial information about the functional status of the kidneys, particularly in cases of anuria [1]. - In the context of anuria with a normal ultrasound, it helps differentiate between pre-renal (poor perfusion), post-renal (if obstruction was missed), or intrinsic renal failure by evaluating blood flow and tracer uptake [1]. Serum Creatinine - While serum creatinine is a marker of renal function, it reflects the current state and doesn't provide real-time or dynamic information about renal blood flow or GFR at the onset of anuria [2]. - In acute renal failure, particularly with anuria, creatinine levels can rise rapidly, but assessing the cause and degree of functional impairment beyond simple filtration requires more advanced imaging. Urine Output Assessment - The patient is already presenting with complete anuria, meaning there is no urine output, rendering this assessment uninformative for further diagnostic steps. - While typically a crucial initial indicator, in this specific scenario, it only confirms the clinical presentation and does not provide insight into the underlying etiology of the anuria. Renal Biopsy - A renal biopsy is an invasive procedure primarily used for definitive diagnosis of intrinsic renal diseases and is not a first-line investigation for immediate assessment of renal function in acute anuria [2]. - It would typically be considered after non-invasive tests have failed to provide a diagnosis or if a specific intrinsic renal disease is strongly suspected and requires histological confirmation [2].

Q: Hyperkalemia without ECG changes may be treated with all except one of the following medications:

Atenolol. ***Atenolol*** - **Atenolol** is a beta-blocker that does not play a direct role in the acute management of hyperkalemia. In fact, beta-blockers can sometimes **worsen hyperkalemia** by impairing cellular potassium uptake [3]. - Its primary use is for conditions like hypertension or angina, and it has no mechanism to significantly lower serum potassium levels or stabilize cardiac membranes in hyperkalemia. *Calcium gluconate* - **Calcium gluconate** is used to stabilize the cardiac membrane and prevent arrhythmias in hyperkalemia, particularly when ECG changes are present [1]. - While it doesn't lower serum potassium levels directly, it is crucial for **cardioprotection**, and its absence here implies the question is about potassium-lowering agents. *Na bicarbonate* - **Sodium bicarbonate** can be used to shift potassium intracellularly, particularly in patients with **metabolic acidosis**. - It increases intracellular pH, which promotes the movement of potassium into cells, thus lowering extracellular potassium. *Insulin with dextrose* - **Insulin with dextrose** is a common and effective treatment for hyperkalemia, as insulin promotes the uptake of potassium into cells. - Dextrose is administered concurrently to prevent **hypoglycemia**, which would otherwise occur due to the insulin [2].

Q: What is a common electrolyte disturbance seen in chronic renal failure?

Hyperkalemia. **Hyperkalemia** - As **glomerular filtration rate (GFR)** decreases in chronic renal failure, the kidneys' ability to excrete potassium is significantly impaired, leading to its accumulation [1]. - This is a common and potentially life-threatening complication due to its effects on **cardiac rhythm** [1]. *Hypercalcemia* - While possible in some renal conditions, **hypercalcemia** is not a typical electrolyte disturbance seen primarily due to the loss of kidney function; instead, **hypocalcemia** is more characteristic [2]. - Renal failure often leads to impaired vitamin D activation and phosphate retention, which tend to lower, not raise, serum calcium [2]. *Hypocalcemia* - Although **hypocalcemia** is also a common feature of chronic renal failure, the question asks for "a common electrolyte disturbance" and **hyperkalemia** is often considered more immediately life-threatening and directly linked to impaired excretion. - It results from decreased production of **1,25-dihydroxyvitamin D** by the kidneys and phosphate retention, which binds to calcium [2]. *Hyperphosphatemia* - **Hyperphosphatemia** is indeed a very common electrolyte disturbance in chronic renal failure, resulting from the kidney's inability to excrete phosphate [2]. - However, the options present multiple common disturbances, and **hyperkalemia** is often highlighted due to its acute danger.

Question 1

Which of the following statements about autosomal dominant polycystic kidney disease (ADPKD) is incorrect?

Accepted Answer

Low Renin due to pressure atrophy of JG apparatus is a common finding in ADPKD.

Answer

Spider leg deformity

Answer

Anemia

Answer

Cysts increase in size with age

Question 2

A patient presents with pain in the metatarsophalangeal joints and is a known case of chronic renal failure. This is due to the accumulation of:

Accepted Answer

Uric acid

Answer

HLA B27 typing

Answer

Rheumatoid factor

Answer

Blood urea nitrogen

Question 3

Mainstay of treatment of nephrogenic diabetes insipidus is:

Accepted Answer

Thiazide / Amiloride diuretics and salt restriction

Answer

Vasopressin and salt restriction

Answer

Desmopressin

Answer

Desmopressin with salt restriction

Question 4

Polycystic disease of the kidney may have cysts in all of the following organs except?

Accepted Answer

Lung

Answer

Liver

Answer

Pancreas

Answer

Spleen

Question 5

A boy is suffering from acute pyelonephritis. The most specific urinary finding will be:

Accepted Answer

W.B.C. casts

Answer

Bacteria in gram stain

Answer

Leucocyte esterase test

Answer

Nitrite test

Question 6

A patient presents with acute renal failure (ARF) and complete anuria, with a normal ultrasound of the kidneys. Which investigation will provide the best initial information regarding renal function?

Accepted Answer

DTPA Scan (Radiorenogram)

Answer

Serum Creatinine

Answer

Urine Output Assessment

Answer

Renal Biopsy

Question 7

Hyperkalemia without ECG changes may be treated with all except one of the following medications:

Accepted Answer

Atenolol

Answer

Na bicarbonate

Answer

Insulin with dextrose

Answer

Calcium gluconate

Question 8

What is a common electrolyte disturbance seen in chronic renal failure?

Accepted Answer

Hyperkalemia

Answer

Hypocalcemia

Answer

Hypercalcemia

Answer

Hyperphosphatemia

Nephrology — MCQs

Nephrology — MCQs

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