Nephrology Practice Questions

Q: Renal tubular acidosis with ABG value pH = 7.24 PO2=80; PaCO2= 36 Na = 131; HCO3 = 14 Cl= 90; BE = -13 Glucose = 135 the above ABG picture suggests –

Metabolic acidosis. The ABG shows a pH of 7.24, indicating **acidemia** [1]. The HCO3 is 14 mEq/L, which is significantly **low**, and the base excess (BE) is -13 [1]. The PaCO2 of 36 mmHg is within the normal range, indicating no significant primary respiratory derangement [2]. The overall picture is consistent with an uncompensated or partially compensated **metabolic acidosis** [1][2]. ***Metabolic acidosis*** - The **low pH (acidemia)**, **low bicarbonate (HCO3)**, and **negative base excess (BE)** are direct indicators of metabolic acidosis [1]. - The **PaCO2 within normal limits** or slightly decreased suggests either no respiratory compensation or insufficient compensation for the metabolic derangement [1][2]. *Respiratory acidosis* - This would present with a **low pH** and an **elevated PaCO2** as the primary defect, which is not seen here (PaCO2 is normal) [1]. - Bicarbonate would typically be normal or elevated if compensated, not significantly decreased. *Respiratory alkalosis* - This would be characterized by an **elevated pH** and a **low PaCO2**, which is the opposite of the findings in this ABG [1]. - HCO3 would be normal or low if compensated. *Metabolic alkalosis* - This would present with an **elevated pH** and an **elevated HCO3**, which contradicts the given ABG values (low pH and low HCO3) [2].

Q: RIFLE criteria is used for diagnosis of

Acute kidney injury. ***Acute kidney injury*** - The **RIFLE criteria** (Risk, Injury, Failure, Loss, End-stage kidney disease) is a classification system specifically developed to define and stage **acute kidney injury (AKI)** based on changes in serum creatinine and/or urine output [1]. - It provides a standardized method for diagnosing AKI, allowing for consistent communication and research in nephrology. *Acute splenic injury* - **Splenic injury** is typically diagnosed based on **trauma history, imaging studies** (e.g., CT scan), and clinical signs like left upper quadrant pain and hypovolemia [2]. - There are no specific criteria like RIFLE for grading splenic injury, which is usually categorized by severity of laceration or hematoma [2]. *Acute liver injury* - **Acute liver injury** is diagnosed using criteria such as a rapid increase in **liver enzymes** (AST, ALT), **bilirubin**, and often signs of hepatic encephalopathy. - Classification systems for liver injury exist (e.g., King's College Criteria for acute liver failure), but RIFLE specifically pertains to kidney function. *Acute bowel injury* - **Acute bowel injury** (e.g., ischemic bowel, perforation) is diagnosed by **clinical presentation** (abdominal pain, signs of peritonitis), **imaging** (X-ray, CT scan), and sometimes **endoscopy**. - There are no standardized staging criteria like RIFLE for acute bowel injury.

Q: Which of the following is a clinical abnormality of uremia?

All of the options. ***All of the options*** - **Uremia** is a syndrome caused by the accumulation of **nitrogenous waste products** and other toxins in the blood due to failing kidneys. All listed options are recognized clinical abnormalities that can manifest in patients with uremia. [1] - This option correctly identifies that uremia can lead to a broad spectrum of clinical manifestations, including metabolic derangements like **hyperphosphatemia**, dermatological signs like **uremic frost**, and gastrointestinal issues like **peptic ulcers**. *Hyperphosphatemia* - **Hyperphosphatemia** is a common electrolyte imbalance in uremia because the kidneys are unable to adequately excrete phosphate. - Elevated phosphate levels contribute to **renal osteodystrophy** and metabolic bone disease in patients with chronic kidney disease. *Uremic frost* - **Uremic frost** is a dermatological manifestation of severe uremia, characterized by the deposition of **urea crystals** on the skin, particularly on the face and neck. - It occurs when urea concentrations in sweat exceed its solubility, leading to crystallization as sweat evaporates. *Peptic ulcer* - **Peptic ulcers** are more common in patients with uremia due to a combination of factors, including increased gastrin levels from impaired renal clearance, impaired mucosal defense, and increased acid secretion. [1] - The gastrointestinal system is significantly affected by uremia, leading to a variety of symptoms such as nausea, vomiting, and gastrointestinal bleeding. [1]

Q: What is oliguria?

Excretion of less than 500 ml in 24 hrs. ***Excretion of less than 500 ml in 24 hrs*** - **Oliguria** is clinically defined as a urine output of less than **500 ml over a 24-hour period** in adults. [1] - This threshold is significant because it is generally considered the minimum urine volume required to excrete the daily obligatory solute load, preventing **azotemia**. *Excretion of less than 300 ml in 24 hrs* - While a very low urine output, this volume typically falls under the definition of **anuria** or severe oliguria, which is less than 100 ml/24 hours, or very close to it. [1] - It indicates a more profound impairment of kidney function than the standard definition of oliguria. *Excretion of less than 300 ml in 12 hrs* - This statement refers to a shorter time frame (12 hours) and does not align with the standard 24-hour definition used for **oliguria**. - A proportional output over 24 hours would be 600 ml, which is above the threshold for oliguria. *Excretion of less than 100 ml in 24 hrs* - This urine output level is specifically defined as **anuria**, indicating almost complete cessation of urine production. [1] - Anuria represents a more severe state of renal dysfunction compared to oliguria.

Q: Decrease in plasma osmotic pressure is cause of edema in?

Nephrotic syndrome. ***Nephrotic syndrome*** [2] - Characterized by **massive proteinuria**, leading to a significant decrease in plasma albumin levels which reduces plasma osmotic pressure [2]. - The resultant decrease in oncotic pressure causes **edema**, particularly in the periorbital and lower extremity regions [1][2]. *CHF* - Congestive heart failure (CHF) typically leads to **increased hydrostatic pressure** due to impaired cardiac output, not decreased plasma osmotic pressure. - Edema in CHF is more related to **fluid overload** rather than a decrease in protein levels. *DVT* - Deep vein thrombosis (DVT) causes localized edema due to **venous obstruction**, leading to increased hydrostatic pressure in the affected limb. - It does not primarily affect plasma osmotic pressure, instead causing **unilateral edema**. *None* - This does not provide a pathological condition associated with decreased plasma osmotic pressure causing edema. - There are known conditions, like **nephrotic syndrome**, that directly link decreased osmotic pressure to edema formation [1][2].

Q: Most common cause of hypernatremia.

Renal losses. ***Renal losses*** - **Renal losses** are a very common cause of hypernatremia, particularly when the kidneys cannot adequately reabsorb water, leading to increased free water excretion. [1] - This can be seen in conditions like **diabetes insipidus (central or nephrogenic)**, where there is either a deficiency of ADH or renal unresponsiveness to ADH, resulting in dilute urine and high serum sodium. [1] *Adipsic diabetes insipidus* - **Adipsic diabetes insipidus** is a rare form of central diabetes insipidus characterized by impaired thirst sensation. [2] - While it directly leads to profound hypernatremia, its **rarity** makes it an uncommon overall cause compared to other etiologies. *Carcinoid syndrome* - **Carcinoid syndrome** is caused by tumors that release excessive amounts of vasoactive substances, like serotonin. - It is primarily associated with symptoms like flushing, diarrhea, and bronchospasm, and **does not directly cause hypernatremia**. *Sweating* - **Sweating** causes loss of hypotonic fluid (more water than electrolytes), which can lead to hypernatremia if not adequately replaced. - While a contributing factor, severe hypernatremia specifically due to sweating alone is **less common** than that caused by renal free water losses, especially in the context of impaired thirst or access to water.

Q: Among the following, which is the most characteristic urinary finding in chronic renal failure (CRF)?

Broad casts in urine. ***Broad casts in urine*** [3] - **Broad casts** are pathognomonic for **chronic renal failure (CRF)** and signify irreversible nephron loss because they are formed in dilated tubules that have undergone compensatory hypertrophy. - They are composed of cellular debris and Tamm-Horsfall protein and indicate severe and long-standing renal parenchymal damage. *Elevated blood urea* - While elevated blood urea, or **azotemia**, is characteristic of CRF, it is a blood chemistry finding, not a urinary finding [3], [4]. - It reflects impaired glomerular filtration and accumulation of nitrogenous waste products. *Bleeding diathesis* - **Bleeding diathesis** is a common complication of CRF due to uremia-induced platelet dysfunction, but it is a systemic clinical manifestation, not a urinary finding [1]. - It manifests as easy bruising, epistaxis, or prolonged bleeding. *Proteinuria* - **Proteinuria** is a common finding in many forms of kidney disease, including CRF, but it is not the most *characteristic* finding specifically for the **chronicity** and severity of CRF [2]. - Its presence indicates glomerular or tubular injury, but broad casts offer more specific evidence of advanced, irreversible damage.

Q: Which of the following biomarkers is not typically involved in the diagnosis of acute kidney injury?

Micro RNA 122. Micro RNA 122 - **MicroRNA-122** is primarily a biomarker for **liver injury** [1] and not typically used in the diagnosis of **acute kidney injury (AKI)**. - Its expression is highly enriched in the liver and is released into circulation upon **hepatocyte damage**. *NGAL* - **Neutrophil gelatinase-associated lipocalin (NGAL)** is an early biomarker for **AKI**, found in both urine and plasma. - It rapidly increases in response to **renal tubular damage**, making it useful for early detection. *KIM 1* - **Kidney injury molecule-1 (KIM-1)** is a transmembrane protein expressed at very low levels in healthy kidneys but significantly upregulated in the **proximal tubular epithelial cells** during **AKI** [2]. - Its presence in urine is a strong indicator of **renal tubular injury**. *Cystatin C* - **Cystatin C** is a **glomerular filtration rate (GFR)** marker that increases in the blood earlier than creatinine in cases of **AKI**. - It is unaffected by muscle mass, age, or sex, making it a more reliable indicator of **renal function decline** in certain populations.

Q: Which of the following is a feature of cerebral salt wasting syndrome?

Normal aldosterone levels. Detailed examination of sodium balance disorders highlights that in cerebral salt wasting (CSW), the primary defect is renal sodium loss due to a central nervous system disorder. Unlike other sodium-regulating disorders, in CSW aldosterone levels are typically normal or may even be slightly elevated paradoxically due to volume depletion. *Urine sodium 20 mEq/L, and often > 40 mEq/L) due to renal sodium loss [1]. - A urine sodium level less than 20 mEq/L would suggest **extrarenal causes of sodium loss** or a compensatory renal response to hypovolemia [1]. *Hypervolemia* - **Cerebral salt wasting** leads to significant **volume depletion (hypovolemia)** due to excessive renal sodium and water loss [1], [2]. - **Hypervolemia** is characteristic of conditions like **syndrome of inappropriate antidiuretic hormone secretion (SIADH)**, which can present with similar hyponatremia but with euvolemia or mild hypervolemia [1]. *Hyponatremia* - While **hyponatremia** is a common feature of **cerebral salt wasting (CSW)**, it is also a feature of many other conditions such as **SIADH**, adrenal insufficiency, and severe heart failure [1]. - Therefore, hyponatremia alone is not a *distinguishing* feature but rather a *result* of the sodium and water imbalance in CSW.

Q: True about Bartter's syndrome are all except?

Hyperkalemic alkalosis. Hypokalemic alkalosis - Bartter's syndrome is characterized by **hypokalemia**, not hyperkalemia, due to impaired reabsorption of electrolytes in the loop of Henle. - The disorder typically leads to a **metabolic alkalosis**, but the key electrolyte disturbance is low potassium. *Autosomal recessive inheritance* - This statement is **true**; Bartter's syndrome is inherited in an autosomal recessive pattern. - It results from mutations in genes encoding transporters in the thick ascending limb of the loop of Henle. *Decreased K+ absorption from thick ascending loop of Henle* - This statement is **true**; Bartter's syndrome primarily involves a defect in the **Na+-K+-2Cl- cotransporter (NKCC2)** in the thick ascending limb. [1] - This leads to impaired reabsorption of sodium, potassium, and chloride, causing increased delivery of these ions to the distal nephron and subsequent potassium wasting. *Presents in neonate with ototoxicity have bartin gene mutation* - This statement is **true**; some forms of Bartter's syndrome, particularly type IV, are associated with mutations in the **BSND (barttin) gene**. - This mutation can lead to sensorineural **deafness (ototoxicity)** in addition to the renal manifestations, and often presents in the neonatal period.

Question 1

Renal tubular acidosis with ABG value pH = 7.24 PO2=80; PaCO2= 36 Na = 131; HCO3 = 14 Cl= 90; BE = -13 Glucose = 135 the above ABG picture suggests –

Accepted Answer

Metabolic acidosis

Answer

Respiratory alkalosis

Answer

Metabolic alkalosis

Answer

Respiratory acidosis

Question 2

RIFLE criteria is used for diagnosis of

Accepted Answer

Acute kidney injury

Answer

Acute splenic injury

Answer

Acute liver injury

Answer

Acute bowel injury

Question 3

Which of the following is a clinical abnormality of uremia?

Accepted Answer

All of the options

Answer

Hyperphosphatemia

Answer

Uremic frost

Answer

Peptic ulcer

Question 4

What is oliguria?

Accepted Answer

Excretion of less than 500 ml in 24 hrs

Answer

Excretion of less than 300 ml in 24 hrs

Answer

Excretion of less than 300 ml in 12 hrs

Answer

Excretion of less than 100 ml in 24 hrs

Question 5

Decrease in plasma osmotic pressure is cause of edema in?

Accepted Answer

Nephrotic syndrome

Answer

CHF

Answer

DVT

Answer

None of the options

Question 6

Most common cause of hypernatremia.

Accepted Answer

Renal losses

Answer

Carcinoid syndrome

Answer

Adipsic diabetes insipidus

Answer

Sweating

Question 7

Among the following, which is the most characteristic urinary finding in chronic renal failure (CRF)?

Accepted Answer

Broad casts in urine

Answer

Elevated blood urea

Answer

Bleeding diathesis

Answer

Proteinuria

Question 8

Which of the following biomarkers is not typically involved in the diagnosis of acute kidney injury?

Accepted Answer

Micro RNA 122

Answer

Cystatin C

Answer

NGAL

Answer

KIM 1

Question 9

Which of the following is a feature of cerebral salt wasting syndrome?

Accepted Answer

Normal aldosterone levels

Answer

Urine sodium < 20mEq/L

Answer

Hypervolemia

Answer

Hyponatremia

Question 10

True about Bartter's syndrome are all except?

Accepted Answer

Hyperkalemic alkalosis

Answer

Decreased K+ absorption from thick ascending loop of Henle

Answer

Autosomal recessive inheritance

Answer

Presents in neonate with ototoxicity have bartin gene mutation

Nephrology — MCQs

Nephrology — MCQs

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