What type of sheath is recommended for a patient undergoing hemodialysis?

Hemodialysis Catheter Selection

For hemodialysis access, use tunneled cuffed catheters made of silicone or polyurethane, with the right internal jugular vein as the preferred insertion site, and ensure catheter tips are positioned in the right atrium for long-term use or superior vena cava for short-term use. 1

Catheter Type Selection

Short-Term vs Long-Term Access

• Uncuffed (non-tunneled) catheters should only be used in hospitalized patients for less than 1 week 1
• Tunneled cuffed catheters (TCCs) are recommended for access lasting more than 3 weeks 1
• Femoral uncuffed catheters must be limited to bed-bound patients and removed within 5 days 1
• Always establish a plan to discontinue or convert short-term catheters to long-term catheters within 1 week 1

Catheter Material

Silicone and polyurethane are the two preferred materials for dialysis catheters 1:

• Silicone offers better compatibility with infusates but is more prone to compression and "pinch-off" syndrome 1
• Polyurethane provides greater durability and stiffness but degrades more easily with certain drug solvents 1
• Antimicrobial-coated catheters (minocycline and rifampin) reduce catheter-related bloodstream infection risk 1

Insertion Site Selection

Site Hierarchy for Acute Kidney Injury

The American Journal of Kidney Diseases establishes this specific order 1:

1. Right internal jugular vein (first choice)
2. Femoral vein (second choice)
3. Left internal jugular vein (third choice)
4. Subclavian vein (last resort only)

Critical Site Considerations

• Avoid subclavian vein access whenever possible due to high risk of central venous stenosis, which permanently compromises future access options 1
• Never place long-term catheters on the same side as a maturing arteriovenous fistula 1
• Femoral catheters must be at least 19 cm long to reach the inferior vena cava and minimize recirculation 2
• Longer femoral catheters (24-27 cm) provide better flow rates and reduce thrombosis risk 2

Catheter Tip Positioning

Anatomic Targets

• Short-term catheter tips: position in the superior vena cava, confirmed by chest radiograph or fluoroscopy 1
• Long-term catheter tips: position within the right atrium for optimal flow, confirmed by fluoroscopy 1
• Position catheter tips parallel to the vessel wall to reduce thrombosis risk 2

Technical Requirements

Insertion Technique

• Ultrasound guidance must be used for all dialysis catheter insertions 1, 3
• Obtain chest radiograph promptly after placement and before first use of internal jugular or subclavian catheters 1
• Use real-time 2-D ultrasound to substantially reduce mechanical complications and failed cannulation attempts 3

Flow Rate Specifications

• Catheters must achieve blood flow rates of 350 mL/min at prepump pressures not more negative than 250 mm Hg 1
• Monitor for adequate blood flow rates (≥300 mL/min) to detect catheter dysfunction 2

Common Pitfalls to Avoid

• Never perform routine scheduled catheter replacement—this does not reduce infection rates 1
• Prolonged catheter use increases mortality by 51% and severe infection by 130% compared to arteriovenous fistulas 1
• Catheter complications from insertion range from 5% to 19% 4
• Infection accounts for removal of 30-60% of hemodialysis catheters 4

Infection Prevention Measures

• Use strict aseptic technique with alcohol-based chlorhexidine (>0.5% solution) at the exit site for at least 60 seconds 3
• Scrub the catheter hub with chlorhexidine or 70% alcohol for at least 15 seconds before connection and disconnection 3
• Apply chlorhexidine disk with Tegaderm dressing, changed weekly 3
• Healthcare staff must wear gloves and surgical masks for all bloodstream access procedures 5