Section 5, Chapter 22: The Role of Ultrasound in Central Vascular Access Device Placement

Introduction

• Discussion on options for vascular access devices.
• Veins accessed for central line placement.
• Techniques to obtain venous access.
• Potential complications of central venous access.

Background

• Central Venous Access: Vital for critically ill patients.
  • IV antibiotic therapy.
  • Venous pressure monitoring.
  • Dialysis, chemotherapy, or total parenteral nutrition (TPN).
  • TPN bypasses the GI tract, providing nutrition through a vein.
• Catheter Placement: Tip of the catheter is typically in the superior vena cava.
  • Type of device depends on therapy, patient characteristics, and infusion number.

Veins Used for Central Access

• Common veins: Basilic, Brachial, Cephalic, Subclavian, and Internal Jugular Veins.
• Procedure: Initial puncture, catheter insertion towards the superior vena cava.
• Imaging: Chest X-ray to confirm placement.

Types of Central Vascular Access Devices

• Non-Tunneled Devices: For short-term use (days to weeks).
  • Used in critical care, temporary dialysis, apheresis.
  • Secured with sutures or tape.
• Tunneled Devices: Long-term use (more stable and comfortable).
  • Reduces infection risk as the exit site is away from the neck.
• Implanted Ports: Under skin, used for intermittent therapy (weekly/monthly).
  • No dressings needed.
  • High flow contrast injection compatible.

Vein Selection for Catheterization

• Upper extremity veins preferred:
  • Basilic vein preferred for larger diameter and higher flow rate.
  • Cephalic vein smaller, lower flow rate.
  • Brachial vein near artery, risk of puncturing artery.
• Lower extremity veins (saphenous or foot veins) used if upper extremities are inaccessible.

Role of Ultrasound in Placement

• Used to guide catheter placement, increasing success and reducing complications.
• Common Sites: Internal Jugular Vein (IJV) and Subclavian Veins.
  • Right IJV preferable due to a straight course to the heart.
• Documentation: Depth, patency, diameter, and proximity to arteries.
  • Avoid puncturing arteries to prevent pseudo-aneurysm.

Ultrasound Guidance

• Helps in distinguishing veins from arteries.
• Ensures veins are not thrombosed and are patent.
• Real-time visualization of needle entry.
• Sterile procedure using ultrasound sheath covers.
• Confirmation of catheter placement with chest X-ray.

Complications and Risk Management

• Possible complications: Thrombus formation, fistulas, non-target punctures.
• Minimized by identifying all vessels in the area and using ultrasound guidance.
• Immediate removal and pressure application if artery is punctured.
• Risk of pneumothorax if lungs are punctured.

Conclusion

• Ultrasound guidance is crucial for reducing complications and ensuring successful catheter placement in central vascular access.