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PATH 370 – QUIZ 8 PRACTICE QUESTIONS Cumulative Review & Advanced Topics
– Comprehensive Pathophysiology
SECTION 1: ACID-BASE BALANCE AND ELECTROLYTE
DISORDERS
1. A patient presents with the following arterial blood gas: pH
7.28, PaCO₂ 52 mm Hg, HCO₃⁻ 24 mEq/L. What is the acid-base
disturbance?
A) Metabolic acidosis
B) Respiratory acidosis
C) Metabolic alkalosis
D) Respiratory alkalosis
Answer: B
Rationale: Low pH (acidosis) with elevated PaCO₂ (> 45 mm Hg)
and normal HCO₃⁻ indicates respiratory acidosis from CO₂
retention.
2. A patient presents with: pH 7.48, PaCO₂ 30 mm Hg, HCO₃⁻ 22
mEq/L. What is the acid-base disturbance?
A) Metabolic acidosis
B) Respiratory acidosis
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C) Metabolic alkalosis
D) Respiratory alkalosis
Answer: D
Rationale: High pH (alkalosis) with low PaCO₂ (< 35 mm Hg)
indicates respiratory alkalosis from hyperventilation.
3. A patient presents with: pH 7.30, PaCO₂ 35 mm Hg, HCO₃⁻ 16
mEq/L. What is the acid-base disturbance?
A) Metabolic acidosis
B) Respiratory acidosis
C) Metabolic alkalosis
D) Respiratory alkalosis
Answer: A
Rationale: Low pH with normal PaCO₂ and low HCO₃⁻ (< 22
mEq/L) indicates metabolic acidosis.
4. A patient presents with: pH 7.50, PaCO₂ 42 mm Hg, HCO₃⁻ 32
mEq/L. What is the acid-base disturbance?
A) Metabolic acidosis
B) Respiratory acidosis
C) Metabolic alkalosis
D) Respiratory alkalosis
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Answer: C
Rationale: High pH with normal PaCO₂ and high HCO₃⁻ (> 26
mEq/L) indicates metabolic alkalosis.
5. Which of the following is a cause of high anion gap metabolic
acidosis?
A) Diarrhea
B) Renal tubular acidosis
C) Diabetic ketoacidosis
D) Acetazolamide use
Answer: C
Rationale: DKA causes high anion gap acidosis due to ketoacid
accumulation. Diarrhea and RTA cause normal anion gap
acidosis.
6. Which of the following is a cause of normal anion gap
(hyperchloremic) metabolic acidosis?
A) Diabetic ketoacidosis
B) Severe diarrhea (bicarbonate loss)
C) Lactic acidosis
D) Salicylate poisoning
Answer: B
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Rationale: Diarrhea causes bicarbonate loss with compensatory
chloride retention, resulting in normal anion gap acidosis.
7. The anion gap is calculated as:
A) Na⁺ − (Cl⁻ + HCO₃⁻)
B) Na⁺ + Cl⁻ + HCO₃⁻
C) K⁺ − (Cl⁻ + HCO₃⁻)
D) Na⁺ − K⁺ − Cl⁻
Answer: A
Rationale: Anion gap = Na⁺ − (Cl⁻ + HCO₃⁻). Normal is
approximately 8–12 mEq/L.
8. Lactic acidosis is a common cause of metabolic acidosis in
which condition?
A) Vomiting
B) Shock or severe hypoxia
C) Diuretic use
D) Nasogastric suctioning
Answer: B
Rationale: Tissue hypoperfusion and hypoxia cause anaerobic
metabolism with lactic acid production.
PATH 370 – QUIZ 8 PRACTICE QUESTIONS Cumulative Review & Advanced Topics
– Comprehensive Pathophysiology
SECTION 1: ACID-BASE BALANCE AND ELECTROLYTE
DISORDERS
1. A patient presents with the following arterial blood gas: pH
7.28, PaCO₂ 52 mm Hg, HCO₃⁻ 24 mEq/L. What is the acid-base
disturbance?
A) Metabolic acidosis
B) Respiratory acidosis
C) Metabolic alkalosis
D) Respiratory alkalosis
Answer: B
Rationale: Low pH (acidosis) with elevated PaCO₂ (> 45 mm Hg)
and normal HCO₃⁻ indicates respiratory acidosis from CO₂
retention.
2. A patient presents with: pH 7.48, PaCO₂ 30 mm Hg, HCO₃⁻ 22
mEq/L. What is the acid-base disturbance?
A) Metabolic acidosis
B) Respiratory acidosis
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C) Metabolic alkalosis
D) Respiratory alkalosis
Answer: D
Rationale: High pH (alkalosis) with low PaCO₂ (< 35 mm Hg)
indicates respiratory alkalosis from hyperventilation.
3. A patient presents with: pH 7.30, PaCO₂ 35 mm Hg, HCO₃⁻ 16
mEq/L. What is the acid-base disturbance?
A) Metabolic acidosis
B) Respiratory acidosis
C) Metabolic alkalosis
D) Respiratory alkalosis
Answer: A
Rationale: Low pH with normal PaCO₂ and low HCO₃⁻ (< 22
mEq/L) indicates metabolic acidosis.
4. A patient presents with: pH 7.50, PaCO₂ 42 mm Hg, HCO₃⁻ 32
mEq/L. What is the acid-base disturbance?
A) Metabolic acidosis
B) Respiratory acidosis
C) Metabolic alkalosis
D) Respiratory alkalosis
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Answer: C
Rationale: High pH with normal PaCO₂ and high HCO₃⁻ (> 26
mEq/L) indicates metabolic alkalosis.
5. Which of the following is a cause of high anion gap metabolic
acidosis?
A) Diarrhea
B) Renal tubular acidosis
C) Diabetic ketoacidosis
D) Acetazolamide use
Answer: C
Rationale: DKA causes high anion gap acidosis due to ketoacid
accumulation. Diarrhea and RTA cause normal anion gap
acidosis.
6. Which of the following is a cause of normal anion gap
(hyperchloremic) metabolic acidosis?
A) Diabetic ketoacidosis
B) Severe diarrhea (bicarbonate loss)
C) Lactic acidosis
D) Salicylate poisoning
Answer: B
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Rationale: Diarrhea causes bicarbonate loss with compensatory
chloride retention, resulting in normal anion gap acidosis.
7. The anion gap is calculated as:
A) Na⁺ − (Cl⁻ + HCO₃⁻)
B) Na⁺ + Cl⁻ + HCO₃⁻
C) K⁺ − (Cl⁻ + HCO₃⁻)
D) Na⁺ − K⁺ − Cl⁻
Answer: A
Rationale: Anion gap = Na⁺ − (Cl⁻ + HCO₃⁻). Normal is
approximately 8–12 mEq/L.
8. Lactic acidosis is a common cause of metabolic acidosis in
which condition?
A) Vomiting
B) Shock or severe hypoxia
C) Diuretic use
D) Nasogastric suctioning
Answer: B
Rationale: Tissue hypoperfusion and hypoxia cause anaerobic
metabolism with lactic acid production.
