Med-Surg Lab Interpretation Practice Exam
answers and rationales
1. A patient has a sodium level of 128 mEq/L. What is the primary
concern?
Hyponatremia
Hyponatremia is defined as sodium <135 mEq/L and can cause
confusion, seizures, and fluid shifts.
2. A potassium level of 6.2 mEq/L in a patient indicates:
Hyperkalemia
Hyperkalemia can lead to life-threatening cardiac arrhythmias;
normal potassium range is 3.5–5.0 mEq/L.
3. The nurse notes a hemoglobin of 9 g/dL. What condition is most
likely?
Anemia
Normal hemoglobin ranges are 12–16 g/dL for women and 14–
18 g/dL for men; low levels indicate anemia.
4. A WBC count of 2,000/mm³ suggests:
Leukopenia
Leukopenia is a decreased WBC count, which increases infection
risk; normal is 4,500–11,000/mm³.
5. A patient’s platelet count is 45,000/mm³. What is the priority
concern?
Thrombocytopenia
Normal platelets are 150,000–450,000/mm³; low levels increase
bleeding risk.
,6. A blood glucose level of 250 mg/dL indicates:
Hyperglycemia
Normal fasting blood glucose is 70–99 mg/dL; elevated levels
indicate hyperglycemia and potential diabetes complications.
7. A patient has an INR of 5.0 while on warfarin. The nurse should
anticipate:
Risk of bleeding
Normal INR on warfarin is typically 2–3; INR >4 significantly
increases bleeding risk.
8. A patient’s creatinine is 2.0 mg/dL. This suggests:
Impaired kidney function
Normal creatinine is 0.6–1.3 mg/dL; elevated levels indicate
reduced renal clearance.
9. A BUN of 30 mg/dL may indicate:
Dehydration or renal dysfunction
Normal BUN is 7–20 mg/dL; elevated BUN can result from
dehydration, high protein intake, or renal impairment.
10. A patient presents with a calcium level of 7.5 mg/dL. The
nurse anticipates:
Hypocalcemia
Normal calcium is 8.5–10.5 mg/dL; low calcium can cause tetany,
muscle cramps, and cardiac arrhythmias.
11. A magnesium level of 1.2 mEq/L is concerning for:
Hypomagnesemia
Normal magnesium is 1.5–2.5 mEq/L; low magnesium can cause
tremors, seizures, and cardiac dysrhythmias.
12. A patient’s ABG shows pH 7.32, PaCO2 50 mmHg, HCO3 24
mEq/L. The nurse interprets this as:
, Respiratory acidosis
Low pH with elevated CO2 indicates respiratory acidosis, often
from hypoventilation or COPD exacerbation.
13. ABG: pH 7.50, PaCO2 30 mmHg, HCO3 24 mEq/L. Diagnosis:
Respiratory alkalosis
High pH with low CO2 indicates respiratory alkalosis, commonly
due to hyperventilation.
14. ABG: pH 7.28, PaCO2 40 mmHg, HCO3 18 mEq/L. Diagnosis:
Metabolic acidosis
Low pH with low HCO3 indicates metabolic acidosis, seen in
renal failure, DKA, or diarrhea.
15. ABG: pH 7.48, PaCO2 40 mmHg, HCO3 32 mEq/L. Diagnosis:
Metabolic alkalosis
High pH with elevated HCO3 indicates metabolic alkalosis, often
due to vomiting or diuretic use.
16. Hematocrit 30% in an adult female suggests:
Anemia
Normal hematocrit is 36–46%; low hematocrit usually parallels
low hemoglobin.
17. Total cholesterol of 280 mg/dL indicates:
Hypercholesterolemia
Normal total cholesterol is <200 mg/dL; elevated levels increase
cardiovascular risk.
18. A triglyceride level of 250 mg/dL suggests:
Hypertriglyceridemia
Normal triglycerides are <150 mg/dL; high levels increase risk for
pancreatitis and cardiovascular disease.
answers and rationales
1. A patient has a sodium level of 128 mEq/L. What is the primary
concern?
Hyponatremia
Hyponatremia is defined as sodium <135 mEq/L and can cause
confusion, seizures, and fluid shifts.
2. A potassium level of 6.2 mEq/L in a patient indicates:
Hyperkalemia
Hyperkalemia can lead to life-threatening cardiac arrhythmias;
normal potassium range is 3.5–5.0 mEq/L.
3. The nurse notes a hemoglobin of 9 g/dL. What condition is most
likely?
Anemia
Normal hemoglobin ranges are 12–16 g/dL for women and 14–
18 g/dL for men; low levels indicate anemia.
4. A WBC count of 2,000/mm³ suggests:
Leukopenia
Leukopenia is a decreased WBC count, which increases infection
risk; normal is 4,500–11,000/mm³.
5. A patient’s platelet count is 45,000/mm³. What is the priority
concern?
Thrombocytopenia
Normal platelets are 150,000–450,000/mm³; low levels increase
bleeding risk.
,6. A blood glucose level of 250 mg/dL indicates:
Hyperglycemia
Normal fasting blood glucose is 70–99 mg/dL; elevated levels
indicate hyperglycemia and potential diabetes complications.
7. A patient has an INR of 5.0 while on warfarin. The nurse should
anticipate:
Risk of bleeding
Normal INR on warfarin is typically 2–3; INR >4 significantly
increases bleeding risk.
8. A patient’s creatinine is 2.0 mg/dL. This suggests:
Impaired kidney function
Normal creatinine is 0.6–1.3 mg/dL; elevated levels indicate
reduced renal clearance.
9. A BUN of 30 mg/dL may indicate:
Dehydration or renal dysfunction
Normal BUN is 7–20 mg/dL; elevated BUN can result from
dehydration, high protein intake, or renal impairment.
10. A patient presents with a calcium level of 7.5 mg/dL. The
nurse anticipates:
Hypocalcemia
Normal calcium is 8.5–10.5 mg/dL; low calcium can cause tetany,
muscle cramps, and cardiac arrhythmias.
11. A magnesium level of 1.2 mEq/L is concerning for:
Hypomagnesemia
Normal magnesium is 1.5–2.5 mEq/L; low magnesium can cause
tremors, seizures, and cardiac dysrhythmias.
12. A patient’s ABG shows pH 7.32, PaCO2 50 mmHg, HCO3 24
mEq/L. The nurse interprets this as:
, Respiratory acidosis
Low pH with elevated CO2 indicates respiratory acidosis, often
from hypoventilation or COPD exacerbation.
13. ABG: pH 7.50, PaCO2 30 mmHg, HCO3 24 mEq/L. Diagnosis:
Respiratory alkalosis
High pH with low CO2 indicates respiratory alkalosis, commonly
due to hyperventilation.
14. ABG: pH 7.28, PaCO2 40 mmHg, HCO3 18 mEq/L. Diagnosis:
Metabolic acidosis
Low pH with low HCO3 indicates metabolic acidosis, seen in
renal failure, DKA, or diarrhea.
15. ABG: pH 7.48, PaCO2 40 mmHg, HCO3 32 mEq/L. Diagnosis:
Metabolic alkalosis
High pH with elevated HCO3 indicates metabolic alkalosis, often
due to vomiting or diuretic use.
16. Hematocrit 30% in an adult female suggests:
Anemia
Normal hematocrit is 36–46%; low hematocrit usually parallels
low hemoglobin.
17. Total cholesterol of 280 mg/dL indicates:
Hypercholesterolemia
Normal total cholesterol is <200 mg/dL; elevated levels increase
cardiovascular risk.
18. A triglyceride level of 250 mg/dL suggests:
Hypertriglyceridemia
Normal triglycerides are <150 mg/dL; high levels increase risk for
pancreatitis and cardiovascular disease.
