ASCP Recalls 2026/2027 50 Questions with All Correct Answers
with Detailed Rationales | Complete Exam-Style Questions |
Graded A+ Pass Guaranteed
SECTION I: CLINICAL CHEMISTRY
Question 1
A 24-year-old with type 1 diabetes presents with Kussmaul respirations. Laboratory
results show pH 7.15, glucose 480 mg/dL, and serum ketones weakly positive by
nitroprusside reaction. Which metabolite is the predominant contributor to the
metabolic acidosis?
A. Acetone
B. Acetoacetate
C. Beta-hydroxybutyrate
D. Lactic acid
Correct Answer: C. Beta-hydroxybutyrate
Rationale: In DKA, the redox shift favoring NADH drives ketogenesis toward
beta-hydroxybutyrate, which typically predominates at a 3:1 to 4:1 ratio over
acetoacetate. The standard nitroprusside method detects acetoacetate and acetone but
does not react with beta-hydroxybutyrate, explaining the weakly positive ketone result
despite severe acidosis.
Question 2
A 55-year-old with jaundice has an isolated alkaline phosphatase of 420 U/L (reference
40–120). All other liver enzymes and bilirubin are normal. Which test best confirms the
hepatic origin of this elevated enzyme?
,A. Alanine aminotransferase (ALT)
B. Gamma-glutamyl transferase (GGT)
C. Lactate dehydrogenase (LDH)
D. Aspartate aminotransferase (AST)
Correct Answer: B. Gamma-glutamyl transferase (GGT)
Rationale: GGT is highly specific for hepatobiliary tissue. While ALP is also produced by
bone, intestine, and placenta, an elevated GGT confirms the ALP is of liver origin. ALT,
AST, and LDH are present in multiple tissues and do not specifically distinguish hepatic
from bone-derived ALP.
Question 3
A patient on phenytoin for seizure disorder has a reported trough level of 8.2 mcg/mL
(therapeutic range 10–20 mcg/mL) drawn 4 hours after the morning dose. Which
statement is most accurate?
A. The result is subtherapeutic and the dose should be increased immediately.
B. The timing of the draw is inappropriate for trough interpretation.
C. Phenytoin follows first-order kinetics and the level is accurate.
D. The sample should be redrawn 2 hours after the next dose.
Correct Answer: B. The timing of the draw is inappropriate for trough interpretation.
Rationale: Trough levels for therapeutic drug monitoring must be drawn immediately
before the next scheduled dose. A sample drawn 4 hours after dosing does not
represent the minimum concentration and cannot be reliably interpreted. Phenytoin
exhibits zero-order (saturation) kinetics at therapeutic concentrations, making timing
even more critical.
Question 4
Arterial blood gas results: pH 7.32, pCO2 30 mmHg, HCO3 15 mEq/L. What is the
primary acid-base disturbance?
, A. Metabolic acidosis with appropriate respiratory compensation
B. Respiratory alkalosis with metabolic compensation
C. Mixed metabolic and respiratory acidosis
D. Uncompensated metabolic acidosis
Correct Answer: A. Metabolic acidosis with appropriate respiratory compensation
Rationale: The pH is low (acidemia) and the bicarbonate is reduced, indicating a primary
metabolic acidosis. Using Winter’s formula, the expected compensatory pCO2 = (1.5 ×
15) + 8 = 30.5 ± 2 mmHg. The measured pCO2 of 30 mmHg falls within this expected
range, confirming appropriate respiratory compensation rather than a mixed disorder.
Question 5
A patient presents with fatigue and constipation. Laboratory results show calcium 12.8
mg/dL, phosphorus 2.2 mg/dL, and intact PTH 88 pg/mL (elevated). What is the most
likely diagnosis?
A. Primary hyperparathyroidism
B. Malignancy-associated hypercalcemia
C. Vitamin D intoxication
D. Secondary hyperparathyroidism
Correct Answer: A. Primary hyperparathyroidism
Rationale: Primary hyperparathyroidism is characterized by hypercalcemia with an
inappropriately elevated or normal PTH level, indicating autonomous secretion. In
malignancy and vitamin D intoxication, PTH is typically suppressed by negative
feedback. Secondary hyperparathyroidism presents with elevated PTH but
hypocalcemia.
Question 6
A patient with chest pain has normal CK-MB and total CK at 8 hours post-presentation,
but cardiac troponin-I is markedly elevated. Which statement best explains this pattern?
with Detailed Rationales | Complete Exam-Style Questions |
Graded A+ Pass Guaranteed
SECTION I: CLINICAL CHEMISTRY
Question 1
A 24-year-old with type 1 diabetes presents with Kussmaul respirations. Laboratory
results show pH 7.15, glucose 480 mg/dL, and serum ketones weakly positive by
nitroprusside reaction. Which metabolite is the predominant contributor to the
metabolic acidosis?
A. Acetone
B. Acetoacetate
C. Beta-hydroxybutyrate
D. Lactic acid
Correct Answer: C. Beta-hydroxybutyrate
Rationale: In DKA, the redox shift favoring NADH drives ketogenesis toward
beta-hydroxybutyrate, which typically predominates at a 3:1 to 4:1 ratio over
acetoacetate. The standard nitroprusside method detects acetoacetate and acetone but
does not react with beta-hydroxybutyrate, explaining the weakly positive ketone result
despite severe acidosis.
Question 2
A 55-year-old with jaundice has an isolated alkaline phosphatase of 420 U/L (reference
40–120). All other liver enzymes and bilirubin are normal. Which test best confirms the
hepatic origin of this elevated enzyme?
,A. Alanine aminotransferase (ALT)
B. Gamma-glutamyl transferase (GGT)
C. Lactate dehydrogenase (LDH)
D. Aspartate aminotransferase (AST)
Correct Answer: B. Gamma-glutamyl transferase (GGT)
Rationale: GGT is highly specific for hepatobiliary tissue. While ALP is also produced by
bone, intestine, and placenta, an elevated GGT confirms the ALP is of liver origin. ALT,
AST, and LDH are present in multiple tissues and do not specifically distinguish hepatic
from bone-derived ALP.
Question 3
A patient on phenytoin for seizure disorder has a reported trough level of 8.2 mcg/mL
(therapeutic range 10–20 mcg/mL) drawn 4 hours after the morning dose. Which
statement is most accurate?
A. The result is subtherapeutic and the dose should be increased immediately.
B. The timing of the draw is inappropriate for trough interpretation.
C. Phenytoin follows first-order kinetics and the level is accurate.
D. The sample should be redrawn 2 hours after the next dose.
Correct Answer: B. The timing of the draw is inappropriate for trough interpretation.
Rationale: Trough levels for therapeutic drug monitoring must be drawn immediately
before the next scheduled dose. A sample drawn 4 hours after dosing does not
represent the minimum concentration and cannot be reliably interpreted. Phenytoin
exhibits zero-order (saturation) kinetics at therapeutic concentrations, making timing
even more critical.
Question 4
Arterial blood gas results: pH 7.32, pCO2 30 mmHg, HCO3 15 mEq/L. What is the
primary acid-base disturbance?
, A. Metabolic acidosis with appropriate respiratory compensation
B. Respiratory alkalosis with metabolic compensation
C. Mixed metabolic and respiratory acidosis
D. Uncompensated metabolic acidosis
Correct Answer: A. Metabolic acidosis with appropriate respiratory compensation
Rationale: The pH is low (acidemia) and the bicarbonate is reduced, indicating a primary
metabolic acidosis. Using Winter’s formula, the expected compensatory pCO2 = (1.5 ×
15) + 8 = 30.5 ± 2 mmHg. The measured pCO2 of 30 mmHg falls within this expected
range, confirming appropriate respiratory compensation rather than a mixed disorder.
Question 5
A patient presents with fatigue and constipation. Laboratory results show calcium 12.8
mg/dL, phosphorus 2.2 mg/dL, and intact PTH 88 pg/mL (elevated). What is the most
likely diagnosis?
A. Primary hyperparathyroidism
B. Malignancy-associated hypercalcemia
C. Vitamin D intoxication
D. Secondary hyperparathyroidism
Correct Answer: A. Primary hyperparathyroidism
Rationale: Primary hyperparathyroidism is characterized by hypercalcemia with an
inappropriately elevated or normal PTH level, indicating autonomous secretion. In
malignancy and vitamin D intoxication, PTH is typically suppressed by negative
feedback. Secondary hyperparathyroidism presents with elevated PTH but
hypocalcemia.
Question 6
A patient with chest pain has normal CK-MB and total CK at 8 hours post-presentation,
but cardiac troponin-I is markedly elevated. Which statement best explains this pattern?
