VABC Vascular Access Devices & Technologies 2 — Questions and Answers
Question 1: Which catheter feature is most important when selecting a PICC for frequent blood sampling in an adult patient?
- Smallest available French size
- Largest lumen diameter compatible with vessel size (Correct answer)
- Single-lumen design to reduce infection risk
- Shortest possible catheter length
Correct answer: Largest lumen diameter compatible with vessel size
Larger lumen diameters allow adequate blood draw flow rates without collapsing the catheter during aspiration.
Question 2: A valved PICC differs from a non-valved PICC primarily in that it:
- Requires heparin flushing after each use
- Eliminates the need for a clamp to prevent air embolism (Correct answer)
- Cannot be used for blood sampling
- Has a lower infection rate due to antimicrobial coating
Correct answer: Eliminates the need for a clamp to prevent air embolism
Valved PICCs (e.g., Groshong or PASV valve) open only under pressure differentials, eliminating the need for external clamping to prevent air entry or blood reflux.
Question 3: Which gauge peripheral IV catheter provides the fastest flow rate for emergency fluid resuscitation?
- 24 gauge
- 22 gauge
- 20 gauge
- 14 gauge (Correct answer)
Correct answer: 14 gauge
Flow rate increases dramatically with larger bore catheters; a 14-gauge catheter provides the highest flow rate among standard peripheral IVs per Poiseuille's Law.
Question 4: What is the primary advantage of a power-injectable PICC over a standard PICC?
- Longer dwell time
- Ability to withstand high-pressure contrast injection for CT imaging (Correct answer)
- Reduced risk of catheter-related bloodstream infection
- Smaller outer diameter for easier insertion
Correct answer: Ability to withstand high-pressure contrast injection for CT imaging
Power-injectable PICCs are rated to withstand the high pressures (typically 300 psi) generated by power injectors used for CT contrast studies.
Question 5: An anti-reflux valve integrated into a needleless connector functions by:
- Heparinizing the catheter lumen automatically
- Preventing blood backflow into the catheter upon disconnection (Correct answer)
- Eliminating the need for flushing
- Reducing the dead space volume in the connector
Correct answer: Preventing blood backflow into the catheter upon disconnection
Anti-reflux valves close upon syringe removal to prevent blood from entering the catheter lumen, which can reduce thrombus formation.
Question 6: Which vascular access device is BEST suited for a patient requiring long-term ambulatory antibiotic therapy who will self-administer medications at home?
- Non-tunneled central venous catheter
- Peripheral IV catheter
- PICC line (Correct answer)
- Arterial line
Correct answer: PICC line
PICCs are ideal for outpatient/home infusion therapy due to their safety profile, moderate dwell time, and ease of maintenance by patients or home health nurses.
Question 7: The dead space volume of a needleless connector is clinically significant because it:
- Determines the maximum infusion rate
- Affects the amount of fluid needed to adequately flush the catheter lumen (Correct answer)
- Indicates the risk of air embolism
- Determines compatibility with power injectors
Correct answer: Affects the amount of fluid needed to adequately flush the catheter lumen
Dead space volume represents the fluid volume within the connector that must be displaced during flushing to ensure medication reaches the bloodstream and the catheter is adequately cleared.
VABC Vascular Access Devices & Technologies 2
Which catheter feature is most important when selecting a PICC for frequent blood sampling in an adult patient?