Central Vascular Access Devices and Power PICC Lines
A central vascular access device (CVAD) is a catheter whose tip is positioned in the central venous circulation (at the cavo-atrial junction or right atrium), while a power PICC line is a specialized peripherally inserted central catheter designed to withstand high-pressure contrast injection for CT imaging in addition to standard infusion therapies. 1
Central Vascular Access Devices: Core Definition
Central venous access refers to catheters placed in veins that lead directly to the heart, with the catheter tip positioned at the cavo-atrial junction or in the right atrium 1. These devices are distinct from peripheral IV access because they terminate in the central circulation rather than peripheral veins 1.
Four main classifications of CVADs exist: 2
Non-tunneled (temporary) catheters: Short-term devices (1-3 weeks) inserted directly into central veins (subclavian, internal jugular, innominate, axillary, or femoral), ranging from 5F to 14F with single or multiple lumens 1
Peripherally Inserted Central Catheters (PICCs): Non-tunneled catheters inserted through peripheral arm veins (basilica, brachial, or cephalic) that extend to the superior vena cava, ranging from 2F to 7F, designed for intermediate use (<3 months) 1, 2
Tunneled central catheters: Long-term devices (>30 days to >3 months) that travel through a subcutaneous tunnel before entering the vein, with a cuff that induces fibrosis for fixation and infection prevention (e.g., Hickman, Broviac, Groshong) 1, 2, 3
Totally implantable ports (port-a-caths): Long-term devices consisting of a subcutaneous reservoir connected to a catheter, accessed via special needle through intact skin, associated with the lowest infection rates among all CVADs 1, 2
Clinical Indications for CVADs
Diagnostic indications include: 1
- Establishing/confirming diagnosis
- Monitoring treatment response
- Repeated blood sampling
Therapeutic indications include: 1
- Chemotherapy administration
- Parenteral nutrition
- Blood product transfusion
- Intravenous medications/fluids
- Plasmapheresis or hemodialysis
Power PICC Lines: Specialized Features
Power PICC lines are a specific type of PICC catheter engineered to withstand high-pressure injection rates required for contrast-enhanced CT imaging 4. Standard PICCs cannot tolerate the injection pressures used in power injectors for radiological studies, but power-injectable PICCs are constructed with reinforced materials that allow safe contrast administration at higher flow rates 4.
Key performance characteristics of power PICCs include: 4
- High success rates for completing therapy (81.8%)
- Excellent catheter patency (93.9%)
- Successful placement in single attempt (90.4%)
- Low complication rates: symptomatic venous thrombosis (1.6%), catheter-related bloodstream infection (1.6%)
- Ease of use with guidewire and stylet (>93% clinician satisfaction)
Optimal Catheter Tip Positioning
Upper body CVADs should be positioned with the tip in the lower third of the superior vena cava, at the cavo-atrial junction, or in the high right atrium 2, 5. The tip should sit parallel to the vessel wall and below the azygous vein for maximum blood flow 5.
Approximate insertion distances to cavo-atrial junction: 5
- Right internal jugular: 13-15 cm
- Left internal jugular: 17-20 cm
- Right axillary vein: 17-20 cm
- Left axillary vein: 20-24 cm
Radiographic landmarks for tip verification: 2, 5
- Immediately lateral to right trachea-bronchial junction
- Two vertebral bodies or 4 cm below the carina
- Between lower border of right main bronchus and high right atrium
Device Selection Based on Duration
Short-term (1-3 weeks): Non-tunneled CVCs for continuous infusions, drug delivery, hemodialysis, or CV pressure monitoring 1
Intermediate (<3 months): PICCs or Hohn catheters for prolonged continuous or intermittent therapies in hospitalized or outpatient settings 1, 3
Long-term (>3 months): Tunneled CVCs for patients requiring continuous access; totally implantable ports for patients requiring intermittent access 1, 3
Comparative Safety: PICCs vs. Traditional CVCs
PICCs demonstrate superior safety profiles for longer-term use compared to traditional CVCs: 6
- Lower overall colonization rate: 5.67 per 1,000 catheter-days for PICCs vs. 14.73 for CVCs
- Significantly fewer multidrug-resistant organism colonizations: 19% for PICCs vs. 59.7% for CVCs
- High colonization rates by MDROs arise later during catheterization in PICCs compared to CVCs
Primary limitation of PICCs: Higher risk of thrombosis compared to other long-term devices, which may limit longevity 2
Critical Insertion Considerations
Insertion should occur under strict sterile conditions using: 2
- Chlorhexidine solutions with alcohol for skin preparation
- Local anesthesia with or without sedation
- Ultrasound guidance for venous access (higher first-attempt success rates)
- Radiological confirmation of tip position via fluoroscopy or chest X-ray
Antimicrobial prophylaxis before insertion or during maintenance is NOT recommended 2
The femoral vein should be avoided unless contraindications exist to other sites due to increased infection risk and thrombosis concerns 2
Catheter Design Principles
Use the smallest diameter catheter with minimum number of lumens necessary to minimize complications 1, 7. Multi-lumen catheters increase infection risk due to more frequent manipulations 7.
When multi-lumen catheters are required, dedicate one lumen exclusively to parenteral nutrition or chemotherapy; avoid using for blood sampling, transfusions, or pressure monitoring 7