ABPath Chemical Pathology 2

Question 1

Which analyte is most affected by prolonged tourniquet application during venipuncture?

Accepted Answer

Potassium

Answer

Venous stasis and hemoconcentration falsely elevate potassium due to leakage from cells and muscle activity.

Question 2

An elevated anion gap metabolic acidosis with high osmolar gap suggests ingestion of which substance?

Accepted Answer

Ethylene glycol

Answer

Ethylene glycol raises both the anion gap (from metabolic acids) and the osmolar gap (from the parent alcohol).

Question 3

Which is the most sensitive and specific biomarker for acute myocardial infarction?

Accepted Answer

Cardiac troponin I/T

Answer

Cardiac troponin has near-absolute myocardial tissue specificity and remains the gold-standard marker.

Question 4

A low TSH with elevated free T4 is most consistent with which condition?

Accepted Answer

Primary hyperthyroidism

Answer

Excess thyroid hormone from the gland suppresses pituitary TSH via negative feedback.

Question 5

Which finding best confirms a diagnosis of diabetes mellitus in an asymptomatic patient?

Accepted Answer

HbA1c of 6.8% confirmed on repeat testing

Answer

An HbA1c ≥6.5% confirmed on a separate occasion meets diagnostic criteria for diabetes.

American Board of Pathology (ABPath) Practice Test