Indwelling venous catheters

Synonyms: skin-tunnelled central venous catheter

What are indwelling venous catheters?

These devices allow venous access for a period of months or even years, allowing infusions and withdrawal of venous samples.¹

They are usually inserted into major veins with a section tunnelled under the skin. Such devices are often inserted with the aid of radiological guidance.

Peripheral devices are also used which gain access to the major veins from a distal insertion point, usually in the antecubital fossa. Catheters may be made of polyurethane or silicone and can have 1, 2 or 3 lumens.

Central venous catheters (CVCs) are often used in critically ill patients and offer several advantages to peripheral intravenous access. However, indwelling CVCs have the potential to lead to bloodstream infections.²

Types of long-term venous access devices

Hickman® catheter

• The catheter is placed such that its tip lies within the right atrium, the superior vena cava (SVC) or at the junction between them.

• It is most often placed via the subclavian vein, as it is nearest to the SVC; however, the right internal jugular vein is a straighter route with less risk of damage to the carotid artery and vagus nerve.

• The cephalic or external jugular veins may also be used.

• The line has a section tunnelled subcutaneously to separate the venous entry site from the external environment and potential infecting micro-organisms.

• A cuff helps to anchor the line in situ and subcutaneous tissue grows around it to help make the line less prone to displacement.

• A Hickman® catheter cuff should be placed not less than 5 cm from the point of entry on the skin but other types of catheter are widely used, some with cuffs much further from the exit.

• Such lines usually need a cut-down procedure to remove them, usually under general anaesthesia, because of the need to use traction/surgical techniques to dissect out the embedded cuff.³

Groshong® catheter

• These lines may be used centrally as for a Hickman® catheter but can be inserted peripherally.

• They have a valve which closes off the lumen of the line from the blood.

• Infusion or aspiration of the line will open the pressure-sensitive valve.

Implantable venous access port (Portacath®, totally implantable venous access system (TIVAS) - subcutaneous port)

• This device is usually attached to a tunnelled central line and completely hidden under the skin.

• A thin rubber self-sealing disc with an underlying cavity allows a needle to be inserted through the skin and infusions to be given/blood samples to be withdrawn.

• Infection may occur, necessitating Portacath® removal.⁴

Peripherally inserted central catheter (PICC)

• These lines are inserted into a peripheral vein, usually the cephalic vein in the antecubital fossa and 'unwound' upwards into the subclavian vein/SVC.

• They are firmly secured with tape or sutures.

• They tend to be used for relatively short-term venous access (eg, a prolonged course of antibiotics) but can be used for periods of up to several months.

• Use of the Sherlock 3CG® tip confirmation system avoids the need for CXR to view placement and has been recommended as an option by the National Institute for Health and Care Excellence (NICE).⁵

• Peripherally inserted central catheters are associated with upper extremity deep vein thrombosis.⁶

• One study found that PICCs are associated with higher risk for catheter-related deep venous thrombosis and other adverse events when compared with PORTs.⁷

Common indications for insertion

• Adminstration of a course of chemotherapy.

• Administration of long-term intravenous medications - eg, antibiotics.

• Administration of parenteral nutrition.

• Recurrent transfusion of blood products.

• Temporary venous access for haemodialysis before construction of surgical anatomical access.

• Drawing of multiple blood samples for disease/treatment monitoring.

Care of long-term indwelling venous catheters

• Patients may manage their lines themselves or with the help of carers/nursing staff.

• Patients with lines in situ should receive instructions on how to care for their lines and advice on complications and what to do if they experience problems.

• When assessing a patient with a line in situ, it's a good idea to ask to see any literature they have regarding it, to confirm initial indication and see if any support is available to manage complications, or appropriate place of referral to deal with problems.

Flushing

• To prevent occlusion and thrombosis, such devices require regular flushing, usually with a heparinised saline solution.

• This is usually done on a daily- to alternate-day/twice-weekly basis.

• Patients (and healthcare professionals) should be aware that they shouldn't use force to flush an occluded catheter.

• Groshong® catheters require less frequent flushing (approximately weekly) and are purported to be cheaper to maintain and to occlude less frequently.

Hygiene

• The venous access port and entry site should be kept scrupulously clean and the latter regularly checked for any signs of infection.

• Alcohol-impregnated wipes may be used to clean the exterior surfaces of the devices.

• When bathing and showering, the access ports are usually kept dry in plastic coverings.

Prevention of air entry into line

Non-valved lines must be kept clamped closed when not in use and care should be taken not to unclamp them until the port entry is sealed.

Avoidance of damage

Care must be taken not to cut lines with scissors, etc, whilst adjusting dressings, or to allow chemicals that may damage the line to come into contact with it.

Complications of indwelling venous catheters

Early complications (associated with insertion or immediate aftermath)

• There is a complication rate of around 4% of all procedures, with bruising and pain affecting about 8%.⁸

• The rate of complications of insertion is significantly decreased by the use of radiological guidance.⁸

• Potential early complications include:
  

  • Haemorrhage.

  • Arterial puncture.

  • Pneumothorax.

  • Venous thrombosis.

  • Air embolism.

  • Malpositioning.

  • Catheter transection.

  • Catheter migration.

  • Guidewire entrapment.

Late complications

• Catheter occlusion may occur due to:
  

  • Intraluminal thrombus.

  • Fibrin sheath formation at the catheter tip.

  • Malpositioning of the tip against a vessel wall.

  • 'Pinch-off' of catheter between clavicle and first rib.

  • Thrombosis within the vessel in which the line is located.

• Thrombosis rate is approximately 3%.⁸ However, asymptomatic thrombosis rate is probably significantly higher. Thrombolytic agents may be used to remove clots.

• Infection occurs in about 4 %.⁸ This should be treated with systemic antibiotics and/or removal of the device, according to clinical condition and local procedures/guidelines. Efforts have been made to try to distinguish the risk of infection with the various different types of catheters.^{9 10} Having dedicated line management teams for inpatients may be helpful.¹¹

• The following may be used to treat colonisation/infection of long-term indwelling central venous catheters:

  • Intraluminal antibiotic solutions.¹²

  • Antifungal agents.¹³

  • Ethanol/water mixtures (currently an experimental treatment).¹⁴

• Chemotherapy patients are obviously at increased risk of infection and any suspicion of sepsis should prompt referral to secondary care for assessment.

• The device may fail in about 1% of cases.⁸

• Air embolus appears to be rare if lines are correctly cared for.

• Catheters may break and be dislodged, especially if 'pinch-off' occurs repeatedly.

Legal notice

• Hickman® is a registered trademark of CR Bard Inc, as applied to a central venous catheter.

• Groshong® is a registered trademark of CR Bard Inc, as applied to a central venous catheter.