Central Venous Access Devices (CVAD) are catheters inserted into a vein through the venous system, which are then advanced to the lower third of the superior vena cava, which has a higher blood flow than any other peripheral vein. This allows irritant drugs and fluids to get diluted quickly, thus avoiding damage to the vein.
A Central Venous Access Device is a central venous catheter which is inserted either through a peripheral vein (PICC Line) or through a proximal central vein, usuall through the internal jugular vein, subclavian vein or femoral vein (CVC).
A CVAD is inserted using a sterile technique in a theatre setting.
Indications for Central Venous Access Devices
ACCESS FOR DRUGS:
- irritant drug infusion (eg. Chemotherapy & Total Parenteral Nutrition)
- poor peripheral access (eg. patient is experiencing a hypovolaemic shock)
- long term drug administration (eg. IV antibiotic treatment for weeks)
ACCESS FOR EXTRACORPOREAL BLOOD CIRCUITS:
- renal placement therapy (dialysis)
- plasma exchange
Both of the above are high-flow procedures for which peripheral venous access cannot be chosen.
ACCESS FOR INTERVENTION MONITORING:
- central venous pressure
- central venous O2 saturation
- pulmonary artery pressure
- temporary transvenous pacing
- targeted temperature management
- frequent blood sampling
Central Venous Access Devices Contraindications
- site trauma
- site infection
- vein thrombosis or stenosis (narrowing)
- coagulopathy (impaired ability to clot blood, leading to increased risk of bleeding) and thrombocytopaenia (decreased number of platelets in blood, leading to increased risk of bleeding)
- vessel haemorrhage
- proximal vascular injury eg. blunt or penetrating injury on site
CVAD Classification
- Site (jugular or subclavian or femoral or brachial)
- Lumens (single or double or triple or quad)
- Time (short term or mid term or long term)
- Type (central or peripheral)
- Tunnelling (tunnelled or non-tunnelled <6 weeks or totally implantable port-a-cath for years)
Central Venous Catheter Insertion
- May be inserted under ultrasound directed technique
- Inserted by an anaesthetist in a theatre setting
- Anatomical landmarks can be used in emergency situations
- Trendelburg position (supine with head declined) is used during procedure to avoid air embolus
CVC (central venous catheter) is inserted through the internal jugular vein, subclavian vein or femoral vein.
PICC (peripherally inserted central catheter) is inserted through a peripheral vein eg. basilic vein or cephalic vein.
Protective Measures and Protective Equipment for Insertion
Sterility and an aseptic technique with PPEs including sterile gown, sterile gloves and sterile drape. In case of increased risk of contact with blood or body fluids, eye and/or full protection should be used.
2% Chlorhexidine Gluconate in 70% Isopropyl alcohol should be used and allowed to dry (in case of patient sensitivity use Povidone-Iodine instead).
Dressing used should be sterile, semi-permeable and transparent to allow insertion site observation.
Blood is aspirated from all lumens to confirm lumen patency.
Chest x-ray is to be performed prior to use so as to rule out pneumothorax and confirm correct placement.
Central Venous Access Devices Tip Placement
- CVAD position must be verified through an x-ray prior to use
- CVC distal tip inserted into the upper body must be placed in the cavoatrial junction (the point in which the superior vena cava meets the right atrium)
- CVC distal tip inserted through the femoral vein must be placed in the inferior vena cava right above the diaphragm level
- PICC line distal tip inserted into a peripheral vein must be placed resting in the superior vena cava
Incorrect catheter tip placement increases the risk of mechanical and thrombotic complications. Tip positioning depends on the indications for catheterisation and the chosen site of insertion in the patient.
CVC Care
- Use an aseptic technique for CVC care
- Needleless injection ports must be changed once a week
- Catheter site must be cleaned at least once a week using 2% chlorhexidine in 70% alcohol unless visibly soiled
- Ports should be cleaned with 2% chlorhexidine in 70% alcohol prior to use
- Use a gauze dressing if entry site is bleeding or oozing until resolved; otherwise use a transparent semi-permeable dressing for easy observation of entry site
- Push-pause technique with 0.9% saline in a 10ml syringe is recommended for flushing of lumens, as this technique creates turbulence and allows the flushing of any debris in the lumens
- Apply positive pressure (hold plunger down) when disconnecting syringe to avoid air entering the catheter
- Apply central line dressing using aseptic technique; Use a sterile dressing pack and sterile gloves (since you’re accessing entry site); Disinfect skin with 2% Chlorhexidine in 70% Alcohol foam; Write date of dressing change on dressing
- Replace administration set immediately after blood products administration; after 24 hours after total parenteral nutrition containing lipids; otherwise within 72 hours
- Remove catheter if no longer required
CVC Blood Sampling
CVC blood sampling must be performed using a Vacutainer via a needleless injection cap to maintain a closed system and prevent being contaminated with patient blood. Following blood sampling from a CVC, flush using at least 20ml 0.9% sodium chloride using a 10ml and another 10ml syringe.
CVAD Care in the Community
Patient family members may be required to care for a CVAD within the community setting. Teaching correct procedures is crucial in avoiding unnecessary infections.
- Change dressing weekly unless soiled or not intact, cleaning insertion site with 2% chlorhexidine in 70% alcohol prior to dressing change
- Aspirate and flush lumens weekly if not regularly used
- Take a shower, not a bath, to reduce infection risk
- Swimming (submerging of CVC) is not recommended
- Avoid vigorous physical activity so as not to dislodge CVC
- Implanted ports require no such restrictions
CVC Complications
DELAYED: central line dysfunction and/or infection
IMMEDIATE: vascular, cardiac and/or pulmonary
INFECTIOUS : sepsis (widespread infection) and/or site infection
EMBOLIC: thrombosis (eg. air embolus)
MECHANICAL: dislodgement, incorrect plaement, catheter damage and/or catheter migration
If occlusion within the catheter is noted, ask patient to cough and take deep breaths and raise arm over head, as occlusion can be a positional issue.
Central Venous Catheter Blood Stream Infection (CVCBSI)
A CLABSI (central line associated bloodstream infection) is an infection that develops within 48 hours of a central line insertion, which is unrelated to any other infection site.
EXTRALUMINAL COLONISATION – originating from skin insertion site, commonly occurring in non-tunnelled CVCs
INTRALUMINAL COLONISATION – originating from catheter hub, commonly occurring in long-term lines eg. tunnelled CVCs
HEMATOGENOUSLY COLONISED – originating from a distant infection site
Below you can find a collection of videos that can help provide a more visual approach to Central Venous Access Devices.
Ultrasound Guided Subclavian Central Lines
Applying a Central Line Dressing
Blood Culture from Central Venous Access Devices
Drug Administration via Central Venous Access Devices
Special thanks to the creators of the featured videos on this post, specifically Youtube Channels American Thoracic Society, SmithandNephewUKI and Infection Prevention and Control – Malta.
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