How do you check access to a central venous access port (CVAP) in a patient?

How to Check Port Access

To check access to a central venous access port (CVAP), you must first palpate the port reservoir through the skin, then access it with a non-coring needle using strict aseptic technique, followed by aspiration to confirm blood return and flushing to verify patency. 1

Pre-Access Preparation

Hand Hygiene and Sterile Technique

• Perform hand hygiene using either alcohol-based waterless product or soap and water before accessing the port 2
• Use maximum sterile barrier precautions including mask, cap, sterile gloves, and sterile drapes 2, 3
• Apply alcoholic chlorhexidine solution (minimum 2% CHG) to the skin over the port and allow it to dry completely before needle insertion 2, 3

Equipment Assembly

• Gather all necessary supplies before beginning: non-coring (Huber) needle, 10 mL syringes with normal saline, antiseptic solution, sterile gloves, and transparent dressing 1
• Prepare equipment in advance to minimize the time the system is open 2

Accessing the Port

Locating and Stabilizing the Port

• Palpate the port reservoir through intact skin to identify its location and orientation 1, 4
• Stabilize the port between your non-dominant thumb and index finger to prevent it from moving during needle insertion 4

Needle Insertion

• Insert the non-coring needle perpendicular to the port septum through the skin until you feel it contact the back of the port reservoir 4
• A common pitfall is using a regular needle instead of a non-coring (Huber) needle, which will damage the port septum and cause leakage 4

Confirming Patency

Blood Return Assessment

• Attach a 10 mL syringe and aspirate to confirm blood return 1
• Aspirate 2-5 mL of blood to clear the catheter of any locking solution 1
• If no blood return is obtained, do NOT assume the port is non-functional—this may indicate fibrin sheath formation rather than complete occlusion 5, 6

Flushing Technique

• After confirming blood return, flush the port with 10 mL of normal saline using a turbulent (push-pause) flushing technique 1
• Observe for resistance during flushing—mild resistance that resolves with slow, gentle flushing may indicate temporary obstruction that can be cleared 6
• Check for signs of extravasation: swelling, pain, or resistance to injection suggests the catheter is not properly positioned in the vein 6

Troubleshooting Non-Patent Ports

When Blood Return is Absent

• Ensure the patient is in different positions (sitting, lying, arms raised) as catheter tip position may affect blood return 6
• If resistance is high and flushing is impossible, suspect fibrin sheath formation or catheter fracture 5, 6
• Consider contrast examination under fluoroscopy to evaluate for complications such as fibrin sheath or catheter fracture 6

Management of Suspected Occlusion

• If fibrin sheath is suspected, thrombolytic therapy may restore patency 6
• Do not force flush against high resistance, as this may cause catheter rupture or embolization of clot material 5
• Ports that cannot be flushed despite troubleshooting require imaging evaluation before continued use 6

Post-Access Care

Securing and Dressing

• Apply a sterile, transparent dressing over the insertion site to secure the needle and allow visualization 1, 2
• Replace dressings no more than once weekly unless soiled or loose 2

Maintenance Flushing

• Flush with saline after completion of any infusion or blood sampling 1
• For ports not in active use, perform a four-weekly flush with saline to maintain patency 1
• Inadequate flushing is a major cause of port occlusion—ensure the full 10 mL flush volume is used 1

Monitoring for Complications

Immediate Post-Access Observation

• Monitor vital signs (temperature, pulse, blood pressure, respiratory rate) every 4 hours after accessing the port 1, 2
• Inspect the site daily for signs of infection: redness, warmth, swelling, or purulent drainage 3

Long-Term Surveillance

• Assess for catheter-related bloodstream infection if fever or systemic signs develop—collect paired blood cultures from the port and a peripheral vein before starting antibiotics 1, 3
• Implantable ports have the lowest incidence of catheter-related bloodstream infection compared to other central venous access devices 1