PCT Lab Procedures 3 — Questions and Answers
Question 1: What is the primary purpose of inverting blood collection tubes after drawing?
- To separate serum from cells
- To mix the blood with the tube additive (Correct answer)
- To prevent the tube from breaking
- To cool the specimen rapidly
Correct answer: To mix the blood with the tube additive
Gentle inversion mixes the blood with anticoagulants or other additives to prevent clotting or ensure proper preservation.
Question 2: A urinalysis report shows 3+ protein. Which condition should the PCT alert the nurse about?
- Urinary tract infection
- Possible kidney disease or nephrotic syndrome (Correct answer)
- Dehydration
- Normal post-exercise finding
Correct answer: Possible kidney disease or nephrotic syndrome
Significant proteinuria (3+) is a hallmark of nephrotic syndrome and other serious kidney disorders requiring medical evaluation.
Question 3: Which of the following is the correct order of draw when using a multi-tube system?
- Blood culture, light blue, red/gold, green, lavender, gray (Correct answer)
- Lavender, red, light blue, green, gray
- Gray, green, lavender, red, light blue
- Red, lavender, light blue, gray, green
Correct answer: Blood culture, light blue, red/gold, green, lavender, gray
The standard order of draw minimizes cross-contamination of additives between tubes and ensures accurate results.
Question 4: A 24-hour urine collection is ordered. What instruction should the PCT give the patient?
- Discard the first void, then collect all urine for 24 hours (Correct answer)
- Collect only the first morning void
- Collect a random sample at any point in the day
- Refrigerate the container before starting collection
Correct answer: Discard the first void, then collect all urine for 24 hours
The first void is discarded to establish a clean start time, then all subsequent urine is collected for exactly 24 hours.
Question 5: When performing a blood glucose test using a glucometer, the PCT should calibrate the device using:
- Distilled water
- The patient's urine
- A control solution provided by the manufacturer (Correct answer)
- Normal saline
Correct answer: A control solution provided by the manufacturer
Manufacturer-provided control solutions verify that the glucometer is reading accurately within acceptable ranges.
Question 6: What does a specific gravity of 1.030 in a urinalysis indicate?
- Dilute urine, possible overhydration
- Normal hydration
- Concentrated urine, possible dehydration (Correct answer)
- Presence of glucose in the urine
Correct answer: Concentrated urine, possible dehydration
A specific gravity of 1.030 is at the high end of normal, indicating highly concentrated urine often caused by dehydration.
Question 7: Which laboratory value is MOST directly used to monitor warfarin (Coumadin) therapy?
- Complete blood count (CBC)
- Prothrombin time/INR (PT/INR) (Correct answer)
- Basic metabolic panel (BMP)
- Activated partial thromboplastin time (aPTT)
Correct answer: Prothrombin time/INR (PT/INR)
PT/INR measures the extrinsic coagulation pathway, which warfarin directly affects, making it the standard monitoring tool.
PCT Lab Procedures 3
What is the primary purpose of inverting blood collection tubes after drawing?