VABC Vascular Access Devices & Technologies 5 — Questions and Answers
Question 1: A patient with an implanted port reports inability to withdraw blood but medications infuse freely. The FIRST intervention should be:
- Remove and replace the port immediately
- Reposition the patient and attempt aspiration with a 10 mL syringe using gentle pressure (Correct answer)
- Order a CT scan to confirm port position
- Administer alteplase immediately without further assessment
Correct answer: Reposition the patient and attempt aspiration with a 10 mL syringe using gentle pressure
Positional fibrin flap or tip malposition can cause withdrawal occlusion; repositioning (raising arms, Valsalva, changing position) often resolves the issue before pharmacological intervention.
Question 2: Which statement about the basilic vein is TRUE regarding PICC insertion?
- It is smaller and more tortuous than the cephalic vein
- It runs medially in the upper arm and is the preferred vein for PICC insertion due to its larger diameter and more direct path (Correct answer)
- It should never be used for PICC insertion due to proximity to the brachial artery
- It terminates in the subclavian vein, bypassing the axillary vein
Correct answer: It runs medially in the upper arm and is the preferred vein for PICC insertion due to its larger diameter and more direct path
The basilic vein is the largest and most direct upper extremity vein for PICC insertion, with fewer valves and a more favorable anatomy compared to the cephalic vein.
Question 3: The primary reason to avoid placing a PICC in the antecubital fossa (versus the upper arm) is:
- The vein is too small in the antecubital fossa
- Arm flexion at the elbow increases catheter complications including occlusion, phlebitis, and dislodgement (Correct answer)
- Antecubital veins are too superficial for ultrasound guidance
- INS guidelines prohibit antecubital PICC placement in all patients
Correct answer: Arm flexion at the elbow increases catheter complications including occlusion, phlebitis, and dislodgement
Antecubital placement creates a flexion point that increases mechanical stress on the catheter, leading to higher rates of occlusion, phlebitis, and catheter damage.
Question 4: Which catheter-to-vein ratio is recommended to minimize PICC-related thrombosis?
- Catheter occupying no more than 50% of the vein lumen
- Catheter occupying no more than 33-45% of the vein lumen (Correct answer)
- Catheter occupying no more than 25% of the vein lumen
- No ratio standard exists; vessel size is not considered
Correct answer: Catheter occupying no more than 33-45% of the vein lumen
Evidence supports that a catheter-to-vein ratio ≤33-45% reduces turbulent blood flow around the catheter and lowers the risk of deep vein thrombosis.
Question 5: A split-tip (bifurcated tip) CVC design, such as the Ash Split Cath used in dialysis, offers the advantage of:
- Allowing higher flow rates in a smaller outer diameter catheter by separating arterial and venous ports (Correct answer)
- Preventing air embolism without requiring a clamp
- Eliminating the need for heparin locks
- Reducing catheter length for shorter-term use
Correct answer: Allowing higher flow rates in a smaller outer diameter catheter by separating arterial and venous ports
Split-tip designs separate the inflow and outflow lumens at the tip to reduce recirculation and improve flow efficiency, enabling high-flow dialysis through a catheter with smaller outer diameter.
Question 6: When comparing positive-displacement, neutral-displacement, and negative-displacement needleless connectors, which type is associated with LOWEST risk of blood reflux into the catheter on syringe disconnection?
- Negative-displacement connector
- Neutral-displacement connector
- Positive-displacement connector (Correct answer)
- All three types have equivalent reflux risk
Correct answer: Positive-displacement connector
Positive-displacement connectors push a small volume of fluid outward upon syringe disconnection, displacing blood away from the catheter tip and reducing reflux-related thrombosis.
Question 7: Antimicrobial-impregnated CVCs (e.g., chlorhexidine-silver sulfadiazine or minocycline-rifampin) are MOST indicated for patients who:
- Have a known allergy to heparin
- Are expected to require short-term CVC access (1-3 weeks) in high-risk settings with elevated CRBSI rates (Correct answer)
- Need long-term vascular access greater than 3 months
- Are receiving blood products exclusively
Correct answer: Are expected to require short-term CVC access (1-3 weeks) in high-risk settings with elevated CRBSI rates
Antimicrobial CVCs are most cost-effective for short-term catheters (typically <30 days) in ICU settings where CRBSI rates remain elevated despite standard bundle adherence.
VABC Vascular Access Devices & Technologies 5
A patient with an implanted port reports inability to withdraw blood but medications infuse freely.
The FIRST intervention should be: