Phlebotomy Test Arterial Blood Gas Collection

Question 1

The Allen test is performed before radial artery puncture to assess:

Accepted Answer

Adequacy of collateral circulation from the ulnar artery

Answer

The depth of the radial artery

Answer

The patient's pain threshold before arterial puncture

Answer

Patency of the brachial artery

Question 2

What angle of needle insertion is recommended for radial artery puncture for ABG collection?

Accepted Answer

45–60 degrees

Answer

15–30 degrees

Answer

90 degrees

Answer

10–15 degrees

Question 3

After collecting an ABG sample, the syringe should be gently rotated/rolled for at least 5 seconds before capping. This step ensures:

Accepted Answer

The heparin anticoagulant is thoroughly mixed with the blood

Answer

The sample cools to room temperature before analysis

Answer

Air bubbles rise to the top for easier removal

Answer

The sample clots before being placed on ice

Question 4

A patient presents with uncontrolled hypertension and is on anticoagulation therapy. When preparing to collect an ABG, the phlebotomist should recognize that anticoagulation therapy requires:

Accepted Answer

Applying pressure for an extended period (5–10 minutes or more) after collection

Answer

Using a larger bore needle to ensure adequate sample

Answer

Avoiding the radial artery and using femoral access only

Answer

No special precautions—the procedure is unchanged

Question 5

If an air bubble enters the ABG syringe during collection, the IMMEDIATE action should be to:

Accepted Answer

Expel the air bubble immediately before capping the syringe

Answer

Place the syringe on ice to prevent gas exchange

Answer

Mix the syringe contents to incorporate the air bubble

Answer

Discard the entire sample and recollect

Question 6

The preferred site for ABG collection in most adult patients is the:

Accepted Answer

Radial artery

Answer

Femoral artery

Answer

Brachial artery

Answer

Dorsalis pedis artery

Question 7

An ABG result shows pH 7.52, PCO2 28 mmHg, HCO3 22 mEq/L. This pattern is consistent with:

Accepted Answer

Respiratory alkalosis

Answer

Respiratory acidosis

Answer

Metabolic alkalosis

Answer

Metabolic acidosis

Question 8

After an ABG collection, which of the following complications should the phlebotomist monitor for BEFORE leaving the patient?

Accepted Answer

Hematoma formation, continued bleeding, and adequacy of distal pulse

Answer

Needle phobia and vasovagal response only

Answer

Changes in the patient's blood pressure only

Answer

Allergic reaction to the heparin in the syringe