Lab values & electrolytes worksheet with answers

Why is serum creatinine a better marker of kidney function than BUN?

1. AIt is made by the liver, so it rises in every kind of illness
2. BIt is less affected by diet, hydration and bleeding in the gut
3. CIt is not filtered by the kidneys, so its level stays very stable
4. DIt is affected mainly by protein intake, which is easy to control

What does the specificity of a diagnostic test describe?

1. AThe cost of the test compared with other tests
2. BThe total number of people who take the test each year
3. CThe proportion of people with the disease who test positive
4. DThe proportion of people without the disease who test negative

A laboratory flags a result as high using its own reference range, but the value is inside the range in your textbook. Which range should you use for this patient?

1. AThe widest range that you can find in any source
2. BThe reference range of the laboratory that ran the test
3. CThe textbook range, because textbooks are the national standard
4. DThe range used at the hospital where you trained

A patient had a right mastectomy with removal of axillary lymph nodes. Where is the best place to draw blood?

1. AThe right arm
2. BEither arm equally
3. CThe left arm
4. DThe right hand

Why is a baseline platelet count taken before starting heparin therapy?

1. ABecause heparin increases the platelet count to dangerous levels
2. BSo that the INR can be calculated from the platelet count later
3. CBecause heparin is given at a dose based on the platelet count
4. DSo a later fall from heparin-induced thrombocytopenia is detected

A patient takes valproate (valproic acid) for epilepsy. Which tests are monitored regularly?

1. AThyroid function and serum calcium
2. BTroponin and B-type natriuretic peptide
3. CSerum lithium and urine specific gravity
4. DLiver function tests and platelet count

A patient's creatinine was 0.9 mg/dL (80 µmol/L) on admission and is 1.3 mg/dL (115 µmol/L) 36 hours later. Using the common KDIGO criteria, what does this show?

1. ANo kidney injury, because the creatinine is still within the normal range
2. BChronic kidney disease, because creatinine has risen above baseline
3. CA laboratory error, because creatinine cannot change within 2 days
4. DAcute kidney injury, because it rose by at least 0.3 mg/dL within 48 hours

A young man has a swollen knee after minor trauma. His aPTT is prolonged, but his PT/INR and platelet count are normal. Which condition fits best?

1. AImmune thrombocytopenia (ITP)
2. BHemophilia A (factor VIII deficiency)
3. CVitamin K deficiency from poor diet
4. DDisseminated intravascular coagulation