Lithium heparin in a green-top tube keeps blood from clotting by:

Boosting antithrombin's inhibition of thrombin

Binding calcium ions in the sample

Precipitating calcium as an insoluble salt

Blocking glycolysis in the red cells

A patient's name and medical record number match the request, but the request gives the date of birth as 12 March 1980 and the wristband 21 March 1980. The patient states 21 March. What should the phlebotomist do?

Hold the draw until the records match

Draw, and correct the date on the tube labels

Draw, as the name and record number match

Draw, and write a note on the request form

In the CLSI order of draw, which tube follows the light-blue sodium citrate tube?

EDTA tube (lavender or pink top)

When should tubes from a venipuncture be labeled?

At the bedside, right after filling, in the patient's presence

Before the draw, so the tubes are ready

In the laboratory, from the request form on receipt

At the ward desk once all patients are drawn

An unconscious man with no identification arrives in the emergency department and needs urgent blood tests and a crossmatch. How should his samples be identified?

With a temporary unique number on a wristband and on every tube

With the name given by the ambulance crew, to be checked later

With 'Unknown male' and the bed number on each tube

Draw now, and label the tubes once relatives confirm his name

Phlebotomy: patient identification and order of draw

9 DOH Abu Dhabi (HAAD) lab licensing practice questions on Phlebotomy: patient identification and order of draw, part of General Laboratory, Quality and Safety. The first 9 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Easy
Lithium heparin in a green-top tube keeps blood from clotting by:
1. ABinding calcium ions in the sample
2. BBoosting antithrombin's inhibition of thrombin
3. CPrecipitating calcium as an insoluble salt
4. DBlocking glycolysis in the red cells
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Answer: B · Boosting antithrombin's inhibition of thrombin
Heparin binds antithrombin and greatly speeds its inactivation of thrombin and factor Xa, so fibrin cannot form. Calcium stays free in the sample, which is why heparin plasma suits ionized calcium and most chemistry tests. EDTA and citrate work the other way, by binding calcium, and oxalate removes calcium as an insoluble salt. A lithium heparin tube must never be used for a lithium level.
- A: Binding calcium is how EDTA and citrate work.
- C: Precipitating calcium as an insoluble salt is how oxalate works.
- D: Blocking glycolysis is the job of fluoride, not heparin.
Question 2 · Medium
A patient's name and medical record number match the request, but the request gives the date of birth as 12 March 1980 and the wristband 21 March 1980. The patient states 21 March. What should the phlebotomist do?
1. ADraw, and correct the date on the tube labels
2. BHold the draw until the records match
3. CDraw, as the name and record number match
4. DDraw, and write a note on the request form
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Answer: B · Hold the draw until the records match
Any difference between the wristband, the request and what the patient says must be resolved before collection, not after. Ward staff correct the record or the request so that all three agree, and only then is the blood drawn. Transposed digits may be a typing error, but they may also mean the request belongs to another patient with a similar name. Hand-corrected labels or notes leave a sample whose identity the laboratory cannot trust.
- A: Hand-correcting labels hides the mismatch and is not allowed.
- C: All identifiers must agree; two matches do not cancel a mismatch.
- D: A note does not settle which patient the request belongs to.
Question 3 · Easy
In the CLSI order of draw, which tube follows the light-blue sodium citrate tube?
1. ASerum tube (red or gold top)
2. BEDTA tube (lavender or pink top)
3. CHeparin tube (green top)
4. DFluoride tube (gray top)
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Answer: A · Serum tube (red or gold top)
CLSI GP41 orders tubes as blood culture bottles, sodium citrate, serum tubes with or without clot activator or gel, heparin, EDTA, then fluoride/oxalate. Serum tubes come after citrate so that clot activator cannot carry over into the coagulation sample and alter clotting times. Heparin, EDTA and fluoride tubes come later because their additives would affect serum chemistry and coagulation results. The same order applies when tubes are filled from a syringe with a transfer device.
- B: EDTA comes after the serum and heparin tubes, to keep EDTA out of them.
- C: Heparin follows the serum tubes, not the citrate tube directly.
- D: Fluoride/oxalate tubes are drawn last.
Question 4 · Easy
When should tubes from a venipuncture be labeled?
1. ABefore the draw, so the tubes are ready
2. BIn the laboratory, from the request form on receipt
3. CAt the bedside, right after filling, in the patient's presence
4. DAt the ward desk once all patients are drawn
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Answer: C · At the bedside, right after filling, in the patient's presence
Tubes are labeled at the bedside immediately after filling, while the patient is still present, so each label can be checked against the wristband. Labeling tubes before the draw risks a spare labeled tube being filled with another patient's blood. Carrying unlabeled tubes away from the patient, even briefly, is a leading cause of wrong-blood-in-tube errors. The label carries at least two identifiers, the date and time of collection and the collector's identity.
- A: Pre-labeled tubes can end up holding another patient's blood.
- B: The laboratory cannot confirm whose blood is in an unlabeled tube.
- D: Unlabeled tubes from several patients are easily mixed up.
Question 5 · Hard
An unconscious man with no identification arrives in the emergency department and needs urgent blood tests and a crossmatch. How should his samples be identified?
1. AWith a temporary unique number on a wristband and on every tube
2. BWith the name given by the ambulance crew, to be checked later
3. CWith 'Unknown male' and the bed number on each tube
4. DDraw now, and label the tubes once relatives confirm his name
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Answer: A · With a temporary unique number on a wristband and on every tube
An unidentified patient is given a temporary unique identifier, such as an emergency or trauma number, on a wristband that stays on him. Every tube and request carries this number, and the blood bank links it to his name once he is identified. A generic name with a bed number is not unique, because two unidentified patients may arrive together and beds change. Unlabeled tubes and unconfirmed names lead directly to wrong-blood-in-tube errors and ABO-incompatible transfusions.
- B: An unconfirmed name may belong to someone else.
- C: A generic name and bed number are not unique and change when he moves.
- D: Unlabeled tubes must never leave the bedside.
Question 6 · Medium
If an EDTA tube is filled before a serum chemistry tube and additive carries over, which pattern is expected?
1. AGlucose falsely low, phosphate falsely high
2. BPotassium falsely high, calcium falsely low
3. CSodium falsely high, chloride falsely low
4. DPotassium falsely low, calcium falsely high
Answer and explanation in LearnFree account
Question 7 · Easy
Before drawing blood from an alert adult inpatient, the phlebotomist should confirm identity by:
1. AAsking the ward nurse to point out the patient
2. BAsking the patient to state full name and date of birth
3. CReading the name on the bed card or door
4. DAsking 'Are you Mr. ...?' and waiting for a yes
Answer and explanation in LearnFree account
Question 8 · Easy
What is the minimum identification needed on a patient sample label?
1. AThe room and ward number only
2. BThe bed number and the name of the ward doctor
3. CThe patient's full name only
4. DTwo identifiers, such as name and birth date
Answer and explanation in LearnFree account
Question 9 · Medium
What is the recommended order of draw for evacuated blood collection tubes?
1. AFluoride, EDTA, heparin, serum, citrate, blood culture
2. BSerum, blood culture, EDTA, citrate, fluoride, heparin
3. CEDTA, citrate, serum, heparin, blood culture, fluoride
4. DBlood culture, citrate, serum, heparin, EDTA, fluoride
Answer and explanation in LearnFree account

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Phlebotomy: patient identification and order of draw

Lithium heparin in a green-top tube keeps blood from clotting by:

A patient's name and medical record number match the request, but the request gives the date of birth as 12 March 1980 and the wristband 21 March 1980. The patient states 21 March. What should the phlebotomist do?

In the CLSI order of draw, which tube follows the light-blue sodium citrate tube?

When should tubes from a venipuncture be labeled?

An unconscious man with no identification arrives in the emergency department and needs urgent blood tests and a crossmatch. How should his samples be identified?

If an EDTA tube is filled before a serum chemistry tube and additive carries over, which pattern is expected?

Before drawing blood from an alert adult inpatient, the phlebotomist should confirm identity by:

What is the minimum identification needed on a patient sample label?

What is the recommended order of draw for evacuated blood collection tubes?