实验室检查值与电解质练习卷（附答案）

Why is AST less specific for liver damage than ALT?

1. AAST is made by the bone marrow, not the liver
2. BAST is also found in heart and skeletal muscle
3. CAST is found only in the kidney tubules
4. DAST is not measured in the blood at all

What is a main role of albumin in the blood?

1. AIt fights bacteria by engulfing them in the blood
2. BIt carries oxygen from the lungs to the tissues
3. CIt forms the mesh that holds a blood clot together
4. DIt holds fluid in the vessels by oncotic pressure

A low mean corpuscular hemoglobin concentration (MCHC) means that the red cells are:

1. AMore numerous than normal
2. BShaped like a sickle
3. CPaler than normal (hypochromic)
4. DLarger than normal (macrocytic)

Why must a blue-top (citrate) coagulation tube be filled to the correct level?

1. AThe blood-to-anticoagulant ratio must be right for accurate clotting times
2. BUnderfilled tubes always give a falsely low hemoglobin and hematocrit
3. CAn overfull tube is needed to measure the potassium level
4. DThe laboratory charges extra when a tube is not filled correctly

A patient's potassium is unexpectedly 5.8 mEq/L. The sample was taken after the tourniquet was on for several minutes while the patient pumped their fist. What is the best interpretation?

1. AFist pumping lowers potassium, so the true level is even higher
2. BThe result confirms true hyperkalemia and needs no further checking
3. CThe result may be falsely high and should be repeated with better technique
4. DTourniquet time affects only the glucose result, not the potassium

A patient with a potassium of 2.8 mEq/L has potassium chloride prescribed IV. Which statement about giving it is correct?

1. AIt is added to the IV bag without mixing, so it stays at the bottom
2. BIt is given as an undiluted bolus into a large vein to avoid irritation
3. CIt is always diluted and given by infusion pump, never as an IV push
4. DIt may be given as a slow IV push over one minute if the level is very low

A patient's total calcium is 7.6 mg/dL and the albumin is 2.0 g/dL. Using the common correction (add 0.8 mg/dL for each 1 g/dL that albumin is below 4.0), what is the corrected calcium?

1. A9.2 mg/dL, within the normal range
2. B6.0 mg/dL, well below the normal range
3. C11.6 mg/dL, above the normal range
4. D7.6 mg/dL, below the normal range

A patient on warfarin with an INR of 3.6 fell and hit their head an hour ago. They now report a worsening headache and drowsiness. What is the priority?

1. AEncourage rest in a dark room to settle the pain
2. BReport urgently for imaging and possible reversal
3. CGive acetaminophen (paracetamol) and recheck the INR tomorrow
4. DHold warfarin for one dose and observe at home