Arterial Blood Gas Collection Flashcards
8 cards from real Phlebotomy Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 8 Arterial Blood Gas Collection flashcards as text
Which of the following is a contraindication to using the brachial artery for ABG collection?
Answer: There is no collateral circulation to the forearm if the brachial artery is damaged
The brachial artery is the sole blood supply to the forearm; there is no collateral circulation, so damage can cause forearm and hand ischemia—a significant risk consideration.
A patient has a PaO2 of 58 mmHg while breathing room air. This finding indicates:
Answer: Hypoxemia requiring clinical intervention
PaO2 of 58 mmHg is below the normal range (80–100 mmHg on room air) and represents clinically significant hypoxemia requiring assessment and potential supplemental oxygen.
An ABG shows: pH 7.30, PCO2 55 mmHg, HCO3 26 mEq/L. The phlebotomist correctly identifies this as:
Answer: Respiratory acidosis (uncompensated)
pH 7.30 (acidotic), PCO2 55 (elevated—respiratory parameter), HCO3 26 (normal—no metabolic compensation yet) indicates uncompensated respiratory acidosis.
The femoral artery is used as an alternative ABG site primarily in which clinical scenario?
Answer: When radial and brachial sites are inaccessible (e.g., severe peripheral vascular disease, cardiac arrest)
The femoral artery is reserved for situations where upper extremity access is impossible, such as in severe peripheral vascular disease, bilateral AV fistulas, or cardiac arrest resuscitation.
How much pressure must be applied to a radial artery puncture site to achieve hemostasis in a patient with normal coagulation?
Answer: At least 3–5 minutes of continuous firm pressure
A minimum of 3–5 minutes of continuous, firm pressure is required at an arterial puncture site in a normally coagulating patient; less time risks hematoma formation.
A patient's ABG specimen was left at room temperature for 2 hours before analysis. Which result is MOST likely to be falsely altered?
Answer: pH falsely decreased, PO2 falsely decreased, PCO2 falsely increased
Cellular metabolism continues after collection: WBCs and platelets consume O2 (↓PO2), produce CO2 (↑PCO2), and generate acidic byproducts (↓pH)—all in the same direction over time.
What does the term 'base excess' (BE) represent in an ABG report?
Answer: The amount of strong acid or base required to return blood pH to normal at standard conditions
Base excess represents the metabolic component of acid-base balance—the amount of acid or base needed to correct blood pH to 7.40 at standard conditions, isolating the metabolic from respiratory contribution.
After ABG collection, the phlebotomist must label the syringe with which of the following patient information immediately at the bedside?
Answer: Patient name, date of birth (or ID number), date and time of collection, and FiO2 or oxygen delivery information
ABG labels require full patient ID plus FiO2/oxygen status because gas values are meaningless without knowing what oxygen concentration the patient was breathing at collection.