A central venous catheter (CVC) provides reliable access to a patient's central circulatory system for administering medication, fluids, blood products, and for hemodynamic monitoring. Proper securement of the CVC is paramount to prevent accidental dislodgement, minimize catheter movement, and significantly reduce the risk of infection, especially life-threatening catheter-related bloodstream infections (CRBSIs). The choice of suture material for this purpose has evolved, with modern practice favoring options that prioritize infection control and secure fixation.
Key Factors in Suture Selection
Choosing the appropriate suture for a central line involves weighing several factors, including the intended duration of the catheter, the patient's condition, and the potential for infection. The primary considerations are the suture's absorbability, material type, and the presence of any antimicrobial coatings.
Absorbability
- Non-Absorbable Sutures: These are the standard for securing central lines to the skin. They remain intact until manually removed and offer durability for long-term placement.
- Absorbable Sutures: These sutures dissolve over time and are not typically used for external central line fixation.
Material Type
- Monofilament: Composed of a single strand, monofilament sutures have a smooth surface that reduces bacterial adherence, making them preferable for central lines. Examples include nylon and polypropylene. They require more throws for a secure knot.
- Braided: Made of multiple strands, braided sutures are easier to handle and offer higher knot security. However, their structure can harbor bacteria, increasing infection risk. While historically used, braided sutures like silk are less favored now.
Antimicrobial Coating
Since 2021, guidance from NICE recommends using antimicrobial-coated sutures for wound closures, including vascular access devices, due to evidence of reduced infection rates. These are particularly beneficial for central lines in place for over 48 hours.
Suture Size
Suture size is indicated by a numbering system where larger numbers represent finer sutures (e.g., 4-0 is finer than 3-0). For central line fixation, a size between 3-0 and 4-0 is typically used. Using the smallest size with adequate strength minimizes tissue trauma.
Comparison of Central Line Suture Materials
| Feature | Non-Absorbable Monofilament (Nylon/Polypropylene) | Non-Absorbable Braided (Silk) | Absorbable (Vicryl) |
|---|---|---|---|
| Material | Nylon, Polypropylene | Silk | Polyglycolic acid (PGA) |
| Infection Risk | Low | High | Varies; not used for external fixation |
| Knot Security | Lower; requires more throws | High; easy to handle and secure | Good; used for deep closures |
| Handling | Slightly more difficult | Excellent handling | Good |
| Tissue Reactivity | Low | High | Mid-range |
| Use for CVC Fixation | Standard practice for external fixation | Less common | Not used for external fixation |
Alternative Securement Methods
Alternatives to suturing exist and are sometimes chosen to reduce needlestick risks or provide additional benefits.
- Sutureless Securement Devices: These adhesive devices are needle-free and can potentially reduce infection risk by avoiding suture-related trauma. Their use depends on skin condition and protocols.
- Topical Tissue Adhesives: Products like Dermabond can supplement or replace sutures. They form a microbial barrier and seal the insertion site, but may not provide sufficient mechanical security alone.
Professional Judgment and Best Practices
The choice of what kind of suture for central line fixation requires clinical judgment based on the patient's needs and risks. For long-term CVCs, best practice favors an antimicrobial-coated, non-absorbable monofilament suture to maximize security and minimize infection risk. Proper knot-tying is essential, especially for monofilament sutures.
For additional resources on suture selection in emergency medicine, refer to the guide on the CanadiEM website [https://canadiem.org/nice-threads-guide-suture-choice-ed/].
Conclusion
Selecting the appropriate suture for central line fixation balances securement with infection control. The preferred standard is an antimicrobial-coated, non-absorbable monofilament suture like nylon or polypropylene. These offer the lowest infection risk and long-term security, making them optimal for critical care and prolonged access. Alternatives like sutureless devices are considered for specific situations.
