NURS 231/NURS231 Module 7 V3 |
Pathophysiology Q&A with Rationale | Portage
Learning
1. A patient presents with a sudden decrease in urine output following significant blood loss
from a motor vehicle accident. Which category of acute kidney injury (AKI) is this patient
most likely experiencing?
A. Intrarenal AKI
B. Chronic Kidney Disease
C. Postrenal AKI
D. Prerenal AKI
Correct Answer: D
Explanation: Prerenal AKI is characterized by a reduction in renal blood flow that leads to
a decrease in the glomerular filtration rate. In this scenario, significant blood loss results in
hypovolemia and hypotension, which are classic triggers for prerenal failure. If the
underlying cause is not corrected quickly, the prolonged ischemia can lead to intrarenal
damage such as acute tubular necrosis.
2. Which of the following is considered the gold standard for assessing the overall functional
capacity of the kidneys?
A. Serum Creatinine
B. Blood Urea Nitrogen (BUN)
,C. Urine Specific Gravity
D. Glomerular Filtration Rate (GFR)
Correct Answer: D
Explanation: The Glomerular Filtration Rate (GFR) measures the volume of plasma filtered
through the glomerular capillaries into Bowman’s capsule per unit of time. It is widely
considered the best overall indicator of renal function because it reflects the sum of all
functioning nephrons. While serum creatinine is often used to estimate GFR, the GFR itself
provides a more direct assessment of kidney health and disease staging.
3. A patient with chronic kidney disease (CKD) presents with a hemoglobin level of 8.2 g/dL.
What is the primary pathophysiological mechanism for this finding?
A. Iron deficiency due to poor diet
B. Increased destruction of red blood cells by toxins
C. Deficiency of erythropoietin production
D. Chronic blood loss during hemodialysis
Correct Answer: C
Explanation: Erythropoietin is a hormone produced by the interstitial fibroblasts in the
kidney that stimulates the bone marrow to produce red blood cells. As renal function
declines in CKD, the kidneys are unable to produce sufficient amounts of this hormone,
leading to normochromic normocytic anemia. This condition typically becomes significant
,when the GFR falls below 60 mL/min/1.73m² and often requires synthetic erythropoietin
replacement therapy.
4. Which clinical finding is specifically characteristic of nephrotic syndrome rather than
nephritic syndrome?
A. Gross hematuria
B. Hypertension
C. Heavy proteinuria (>3.5 g/day)
D. Oliguria
Correct Answer: C
Explanation: Nephrotic syndrome is defined by massive proteinuria exceeding 3.5 grams
per day due to increased glomerular permeability. This loss of albumin leads to
hypoalbuminemia and subsequent generalized edema (anasarca) through decreased
oncotic pressure. In contrast, nephritic syndrome is primarily characterized by
inflammation, resulting in hematuria, hypertension, and mild to moderate proteinuria.
5. What is the most common cause of intrarenal acute kidney injury (AKI) in the clinical
setting?
A. Benign Prostatic Hyperplasia (BPH)
B. Acute Tubular Necrosis (ATN)
C. Renal artery stenosis
, D. Nephrolithiasis
Correct Answer: B
Explanation: Acute Tubular Necrosis (ATN) is the most frequent cause of intrarenal AKI,
often resulting from prolonged ischemia or exposure to nephrotoxic agents. Ischemic ATN
occurs when prerenal conditions are severe enough to cause cellular death in the renal
tubules. Toxic ATN can be caused by medications like aminoglycosides, radiocontrast dyes,
or endogenous substances like myoglobin from rhabdomyolysis.
6. A patient’s arterial blood gas (ABG) shows a pH of 7.30, PaCO2 of 35 mmHg, and HCO3- of
18 mEq/L. Which acid-base imbalance is present?
A. Respiratory Acidosis
B. Metabolic Acidosis
C. Respiratory Alkalosis
D. Metabolic Alkalosis
Correct Answer: B
Explanation: The low pH (less than 7.35) indicates acidosis, and the low bicarbonate level
(less than 22 mEq/L) identifies the cause as metabolic. The PaCO2 is within the normal
range (35-45 mmHg), suggesting that respiratory compensation has not yet significantly
altered the carbon dioxide levels. This pattern is commonly seen in conditions such as
diabetic ketoacidosis, lactic acidosis, or renal failure where the body cannot excrete fixed
acids.
Pathophysiology Q&A with Rationale | Portage
Learning
1. A patient presents with a sudden decrease in urine output following significant blood loss
from a motor vehicle accident. Which category of acute kidney injury (AKI) is this patient
most likely experiencing?
A. Intrarenal AKI
B. Chronic Kidney Disease
C. Postrenal AKI
D. Prerenal AKI
Correct Answer: D
Explanation: Prerenal AKI is characterized by a reduction in renal blood flow that leads to
a decrease in the glomerular filtration rate. In this scenario, significant blood loss results in
hypovolemia and hypotension, which are classic triggers for prerenal failure. If the
underlying cause is not corrected quickly, the prolonged ischemia can lead to intrarenal
damage such as acute tubular necrosis.
2. Which of the following is considered the gold standard for assessing the overall functional
capacity of the kidneys?
A. Serum Creatinine
B. Blood Urea Nitrogen (BUN)
,C. Urine Specific Gravity
D. Glomerular Filtration Rate (GFR)
Correct Answer: D
Explanation: The Glomerular Filtration Rate (GFR) measures the volume of plasma filtered
through the glomerular capillaries into Bowman’s capsule per unit of time. It is widely
considered the best overall indicator of renal function because it reflects the sum of all
functioning nephrons. While serum creatinine is often used to estimate GFR, the GFR itself
provides a more direct assessment of kidney health and disease staging.
3. A patient with chronic kidney disease (CKD) presents with a hemoglobin level of 8.2 g/dL.
What is the primary pathophysiological mechanism for this finding?
A. Iron deficiency due to poor diet
B. Increased destruction of red blood cells by toxins
C. Deficiency of erythropoietin production
D. Chronic blood loss during hemodialysis
Correct Answer: C
Explanation: Erythropoietin is a hormone produced by the interstitial fibroblasts in the
kidney that stimulates the bone marrow to produce red blood cells. As renal function
declines in CKD, the kidneys are unable to produce sufficient amounts of this hormone,
leading to normochromic normocytic anemia. This condition typically becomes significant
,when the GFR falls below 60 mL/min/1.73m² and often requires synthetic erythropoietin
replacement therapy.
4. Which clinical finding is specifically characteristic of nephrotic syndrome rather than
nephritic syndrome?
A. Gross hematuria
B. Hypertension
C. Heavy proteinuria (>3.5 g/day)
D. Oliguria
Correct Answer: C
Explanation: Nephrotic syndrome is defined by massive proteinuria exceeding 3.5 grams
per day due to increased glomerular permeability. This loss of albumin leads to
hypoalbuminemia and subsequent generalized edema (anasarca) through decreased
oncotic pressure. In contrast, nephritic syndrome is primarily characterized by
inflammation, resulting in hematuria, hypertension, and mild to moderate proteinuria.
5. What is the most common cause of intrarenal acute kidney injury (AKI) in the clinical
setting?
A. Benign Prostatic Hyperplasia (BPH)
B. Acute Tubular Necrosis (ATN)
C. Renal artery stenosis
, D. Nephrolithiasis
Correct Answer: B
Explanation: Acute Tubular Necrosis (ATN) is the most frequent cause of intrarenal AKI,
often resulting from prolonged ischemia or exposure to nephrotoxic agents. Ischemic ATN
occurs when prerenal conditions are severe enough to cause cellular death in the renal
tubules. Toxic ATN can be caused by medications like aminoglycosides, radiocontrast dyes,
or endogenous substances like myoglobin from rhabdomyolysis.
6. A patient’s arterial blood gas (ABG) shows a pH of 7.30, PaCO2 of 35 mmHg, and HCO3- of
18 mEq/L. Which acid-base imbalance is present?
A. Respiratory Acidosis
B. Metabolic Acidosis
C. Respiratory Alkalosis
D. Metabolic Alkalosis
Correct Answer: B
Explanation: The low pH (less than 7.35) indicates acidosis, and the low bicarbonate level
(less than 22 mEq/L) identifies the cause as metabolic. The PaCO2 is within the normal
range (35-45 mmHg), suggesting that respiratory compensation has not yet significantly
altered the carbon dioxide levels. This pattern is commonly seen in conditions such as
diabetic ketoacidosis, lactic acidosis, or renal failure where the body cannot excrete fixed
acids.
