When accessing a central venous access device, what should practitioners do?: A guide to best practices

Healthcare-associated bloodstream infections, many related to central venous catheters, are a significant risk. When accessing a central venous access device, what should practitioners do? Strict adherence to aseptic technique is paramount to ensure patient safety and prevent these critical infections.

Quick Summary

Properly accessing a central venous access device requires strict aseptic technique, including meticulous hand hygiene, scrubbing the hub with antiseptic, and using sterile supplies to prevent infection. Catheter patency is maintained with appropriate flushing, and troubleshooting occurs when resistance is met.

Key Points

• Hand Hygiene: Always perform hand hygiene before and after interacting with any part of the CVAD to prevent infection.

• Scrub the Hub: Vigorously scrub the needleless connector with an approved antiseptic for 15 seconds and let it air dry before each access.

• Use Aseptic Non-Touch Technique (ANTT): Adhere strictly to ANTT, protecting all key sites and parts from potential contamination.

• Utilize 10 mL or Larger Syringes: Employ only 10 mL or larger syringes for flushing to prevent high-pressure damage to the catheter.

• Assess for Occlusion: If resistance is met while flushing, stop immediately, check for kinks, reposition the patient, and never force the flush.

• Maintain Patency: Flush all CVAD lumens with an appropriate solution (saline or heparin) before and after each use to maintain patency.

• Check Dressings Regularly: Assess dressings daily and change any that are wet, soiled, or loose, using sterile technique.

A central venous access device (CVAD) provides a direct and reliable route into the central venous circulation for administering fluids, medications, and drawing blood samples. Given this direct access, strict adherence to protocols is non-negotiable for preventing severe complications, most notably central line-associated bloodstream infections (CLABSIs). The following guidelines outline the critical steps practitioners must take to ensure patient safety and device integrity during every access.

Preparation for Access

Proper preparation is the first line of defense against contamination. Rushing through these initial steps can lead to serious errors.

• Patient and Practitioner Preparation:
  • Identify the patient using two unique identifiers to confirm you are accessing the correct device on the correct patient.
  • Explain the procedure to the patient, ensuring they understand and providing a mask for the patient to wear during the procedure.
  • Perform meticulous hand hygiene using soap and water or an alcohol-based hand sanitizer.
  • Wear a mask to protect the access site from respiratory flora.
  • Don clean gloves for dressing removal and sterile gloves for accessing the hub.
• Gather and Prepare Supplies:
  • Assemble all necessary sterile supplies on a clean work surface before beginning the procedure.
  • Check all supply expiration dates and package integrity.
  • Prime all new tubing, injection caps, and syringes with saline, ensuring no air bubbles are present.
  • Use only 10 mL or larger syringes for flushing to prevent excessive pressure on the catheter, which could cause a rupture.
• Inspect the Site and Device:
  • Carefully assess the insertion site for any signs of infection, such as redness, swelling, drainage, or tenderness.
  • Ensure the CVAD dressing is clean, dry, and intact.
  • Verify the integrity of the catheter tubing for any visible cracks or leaks.

The Aseptic Non-Touch Technique (ANTT)

ANTT is the cornerstone of safe CVAD care. It is a systematic approach to protecting key parts and key sites from contamination.

Accessing the Needleless Connector

• Before each and every access, vigorously scrub the hub of the needleless connector with an antiseptic wipe (such as 70% alcohol or alcoholic chlorhexidine) for at least 15 seconds.
• Allow the hub to air dry completely for at least 15 seconds. Do not wave or fan the hub to speed up drying, as this can introduce airborne contaminants.
• Access the hub with the sterile syringe or tubing connector. The sterile tip of the syringe must not touch anything non-sterile before connecting.
• If the hub or syringe tip is accidentally touched, repeat the entire scrubbing and drying process.

Flushing the CVAD

• Unclamp the catheter lumen before flushing.
• Attach the pre-primed syringe containing saline or heparin (as per facility policy).
• Use a push-pause or turbulent flushing method to create turbulence within the lumen, which helps dislodge any debris or clots from the catheter wall.
• Observe for blood return and check for any resistance during flushing.
• Do not force the flush if resistance is met.
• After flushing, clamp the catheter, and then disconnect the syringe.

Drawing Blood from a CVAD

Drawing blood from a central line is a common procedure that requires specific steps to ensure an accurate sample and prevent complications.

1. Stop infusions: Pause any ongoing infusions for at least one minute before drawing blood to prevent diluting the sample.
2. Scrub the hub: Disinfect the needleless connector with an antiseptic scrub for 15 seconds and allow to dry.
3. Draw waste blood: Attach a 10 mL syringe and withdraw a waste sample of blood (typically 5–10 mL) to clear the line of any residual infusate. Discard this syringe appropriately.
4. Collect sample: Attach a new 10 mL syringe or a Vacutainer holder to collect the required blood samples for laboratory analysis.
5. Flush the line: After collection, flush the line thoroughly with 10–20 mL of sterile saline using the push-pause technique.
6. Reconnect infusions or lock the line: Reconnect the appropriate infusions or, if accessing is complete, instill the prescribed lock solution (heparin or citrate).

Comparison of CVAD Access Hub Types

Feature	Luer-Lock Cap (Standard)	Disinfecting Cap (e.g., Curos)	Implanted Port Septum (e.g., Port-a-Cath)
Scrub Technique	Vigorously scrub for 15 seconds and allow to dry for 15 seconds.	Cap is left on the hub when not in use; it self-disinfects.	Palpate and stabilize the port, then access with a non-coring needle. Scrub skin over septum for 30 seconds with chlorhexidine/alcohol and allow to dry.
Aseptic Protection	Relies entirely on the practitioner's meticulous scrubbing and non-touch technique.	Active disinfection technology reduces reliance on manual scrubbing consistency.	Skin disinfection is key; non-coring needle maintains sterility.
Risk of Contamination	Highest risk if scrubbing technique is inadequate or hub is touched post-scrub.	Lower risk due to continuous disinfection, but still requires hub access protocols.	Risk of skin flora introduction during needle insertion.
Best Practices	Double-check scrubbing duration, use a new wipe for each access.	Use according to manufacturer's instructions; ensure proper fit and application.	Wear sterile gloves during access, use a non-coring needle, ensure needle is fully seated.

Troubleshooting an Occluded Central Line

If resistance is met while flushing or blood cannot be aspirated, an occlusion may have occurred. Never force a flush, as this could rupture the catheter or cause an embolism.

1. Assess the Line: Check for any kinks in the external catheter tubing or clamps that may be closed.
2. Patient Repositioning: Ask the patient to change position by raising their arms, lying down, or coughing. This can sometimes dislodge a temporary occlusion.
3. Consult with a Specialist: If the problem persists, notify the appropriate specialist or physician. They may order a fluoroscopy to visualize the catheter tip or approve a declotting procedure using a thrombolytic agent.
4. Confirm Patency: After any troubleshooting, reconfirm catheter patency by gently aspirating for blood return and flushing.

Conclusion

Safe central venous access is a critical skill for any healthcare practitioner. The core principles of meticulous hand hygiene, strict adherence to aseptic technique (ANTT), and consistent disinfection of access ports are the most important steps in preventing serious infections. Proper CVAD care, from initial preparation to troubleshooting, directly impacts patient safety and well-being. By following these evidence-based best practices, practitioners can significantly reduce the risk of complications and ensure the therapeutic effectiveness of the device.

For additional resources, the Agency for Healthcare Research and Quality (AHRQ) offers a comprehensive checklist for preventing central line-associated bloodstream infections.

Frequently Asked Questions

How long should a practitioner scrub the needleless connector before accessing a central line?

A practitioner should vigorously scrub the needleless connector with an antiseptic for a minimum of 15 seconds, allowing it to air dry completely afterward.

What is the correct way to flush a central venous access device?

After cleaning and drying the hub, attach a pre-primed syringe and use a push-pause or turbulent flushing motion to create turbulence within the catheter lumen, which helps clear it of debris.

What should be done if resistance is felt when flushing a central line?

Stop immediately and do not force the flush. Check for external kinks or clamps, and try repositioning the patient. If resistance persists, notify a physician, as the line may be occluded.

When should the dressing on a central line be changed?

Transparent dressings should be changed at least every seven days, or sooner if they become damp, soiled, or loose. Gauze dressings should be changed every two days or as needed.

Are there specific syringe sizes to use when accessing a CVAD?

Yes, always use a 10 mL or larger syringe when accessing a CVAD. Smaller syringes can create excessive pressure that may cause catheter damage or rupture.

How should a central line be handled if it is accidentally touched after being disinfected?

If the needleless connector is accidentally touched after being scrubbed, it must be re-scrubbed with a new antiseptic wipe for the full 15 seconds and allowed to air dry again.

What is the proper technique for removing an old central line dressing?

To remove an old dressing, peel it slowly toward the insertion site while stabilizing the catheter to prevent accidental dislodgement. Perform hand hygiene and put on sterile gloves before applying the new dressing.