Laboratory & Diagnostic Tests 11th Edition Study Guide
&Test Bank | Exam Questions with Rationale |A+
1. Which laboratory test is most commonly used to evaluate long-term glucose
control?
A. Random blood glucose
B. Fasting blood glucose
C. HbA1c
D. Urine glucose
Answer: C. HbA1c
Rationale: HbA1c reflects average blood glucose levels over the past 2–3 months.
2. A patient must fast before which test?
A. Serum sodium
B. Fasting blood glucose
C. CBC
D. Urinalysis
Answer: B. Fasting blood glucose
Rationale: Food intake affects glucose levels, so fasting ensures accurate baseline measurement.
3. Which lab value indicates anemia?
A. Elevated hemoglobin
B. Low hemoglobin
C. Elevated platelets
D. High WBC count
Answer: B. Low hemoglobin
Rationale: Hemoglobin measures oxygen-carrying capacity; low levels indicate anemia.
,4. Which electrolyte imbalance is most dangerous due to risk of cardiac
arrhythmias?
A. Sodium imbalance
B. Potassium imbalance
C. Chloride imbalance
D. Magnesium only
Answer: B. Potassium imbalance
Rationale: Potassium directly affects cardiac electrical activity.
5. What is the normal adult white blood cell (WBC) range?
A. 1,000–3,000/mm³
B. 4,500–11,000/mm³
C. 12,000–20,000/mm³
D. 20,000–30,000/mm³
Answer: B. 4,500–11,000/mm³
Rationale: This is the standard reference range for WBC count.
6. Elevated troponin levels indicate:
A. Liver disease
B. Kidney failure
C. Myocardial injury
D. Lung infection
Answer: C. Myocardial injury
Rationale: Troponin is a highly specific marker for cardiac muscle damage.
7. Which specimen is required for a culture and sensitivity test?
A. Blood or body fluid
B. Stool only
,C. Saliva only
D. Urine dipstick only
Answer: A. Blood or body fluid
Rationale: Cultures identify infectious organisms in sterile body fluids.
8. A patient with elevated creatinine most likely has:
A. Liver disease
B. Kidney dysfunction
C. Lung infection
D. Thyroid disorder
Answer: B. Kidney dysfunction
Rationale: Creatinine is a marker of renal filtration function.
9. Which test evaluates liver function?
A. ALT and AST
B. Troponin
C. Amylase only
D. Hemoglobin
Answer: A. ALT and AST
Rationale: These enzymes increase with liver cell damage.
10. A high D-dimer level suggests:
A. Liver failure
B. Blood clot formation
C. Diabetes
D. Infection only
Answer: B. Blood clot formation
Rationale: D-dimer is a breakdown product of fibrin, elevated in clotting disorders.
, 11. Which condition increases serum bilirubin?
A. Anemia
B. Liver disease
C. Hypertension
D. Asthma
Answer: B. Liver disease
Rationale: Impaired liver function reduces bilirubin processing.
12. Before a lumbar puncture, the nurse should ensure:
A. Patient has eaten
B. No anticoagulant use
C. Increased fluid intake only
D. Exercise performed
Answer: B. No anticoagulant use
Rationale: Anticoagulants increase risk of spinal bleeding.
13. Which lab value indicates infection?
A. Low WBC count
B. Elevated WBC count
C. Low platelets
D. Low sodium
Answer: B. Elevated WBC count
Rationale: WBC increases as part of immune response to infection.
14. What does a low hematocrit indicate?
A. Dehydration
B. Anemia
&Test Bank | Exam Questions with Rationale |A+
1. Which laboratory test is most commonly used to evaluate long-term glucose
control?
A. Random blood glucose
B. Fasting blood glucose
C. HbA1c
D. Urine glucose
Answer: C. HbA1c
Rationale: HbA1c reflects average blood glucose levels over the past 2–3 months.
2. A patient must fast before which test?
A. Serum sodium
B. Fasting blood glucose
C. CBC
D. Urinalysis
Answer: B. Fasting blood glucose
Rationale: Food intake affects glucose levels, so fasting ensures accurate baseline measurement.
3. Which lab value indicates anemia?
A. Elevated hemoglobin
B. Low hemoglobin
C. Elevated platelets
D. High WBC count
Answer: B. Low hemoglobin
Rationale: Hemoglobin measures oxygen-carrying capacity; low levels indicate anemia.
,4. Which electrolyte imbalance is most dangerous due to risk of cardiac
arrhythmias?
A. Sodium imbalance
B. Potassium imbalance
C. Chloride imbalance
D. Magnesium only
Answer: B. Potassium imbalance
Rationale: Potassium directly affects cardiac electrical activity.
5. What is the normal adult white blood cell (WBC) range?
A. 1,000–3,000/mm³
B. 4,500–11,000/mm³
C. 12,000–20,000/mm³
D. 20,000–30,000/mm³
Answer: B. 4,500–11,000/mm³
Rationale: This is the standard reference range for WBC count.
6. Elevated troponin levels indicate:
A. Liver disease
B. Kidney failure
C. Myocardial injury
D. Lung infection
Answer: C. Myocardial injury
Rationale: Troponin is a highly specific marker for cardiac muscle damage.
7. Which specimen is required for a culture and sensitivity test?
A. Blood or body fluid
B. Stool only
,C. Saliva only
D. Urine dipstick only
Answer: A. Blood or body fluid
Rationale: Cultures identify infectious organisms in sterile body fluids.
8. A patient with elevated creatinine most likely has:
A. Liver disease
B. Kidney dysfunction
C. Lung infection
D. Thyroid disorder
Answer: B. Kidney dysfunction
Rationale: Creatinine is a marker of renal filtration function.
9. Which test evaluates liver function?
A. ALT and AST
B. Troponin
C. Amylase only
D. Hemoglobin
Answer: A. ALT and AST
Rationale: These enzymes increase with liver cell damage.
10. A high D-dimer level suggests:
A. Liver failure
B. Blood clot formation
C. Diabetes
D. Infection only
Answer: B. Blood clot formation
Rationale: D-dimer is a breakdown product of fibrin, elevated in clotting disorders.
, 11. Which condition increases serum bilirubin?
A. Anemia
B. Liver disease
C. Hypertension
D. Asthma
Answer: B. Liver disease
Rationale: Impaired liver function reduces bilirubin processing.
12. Before a lumbar puncture, the nurse should ensure:
A. Patient has eaten
B. No anticoagulant use
C. Increased fluid intake only
D. Exercise performed
Answer: B. No anticoagulant use
Rationale: Anticoagulants increase risk of spinal bleeding.
13. Which lab value indicates infection?
A. Low WBC count
B. Elevated WBC count
C. Low platelets
D. Low sodium
Answer: B. Elevated WBC count
Rationale: WBC increases as part of immune response to infection.
14. What does a low hematocrit indicate?
A. Dehydration
B. Anemia
