A central line is a catheter placed into a major central vein, typically the internal jugular, subclavian, or femoral vein, with the tip positioned in the superior or inferior vena cava. Types include central venous catheters, dialysis catheters, tunnelled lines (e.g., Hickman), and ports. 

Indications

• Challenging vascular access
• Prolonged courses of IV medications
• Administration of medications that cannot be given peripherally 
• Haemodialysis
• Parenteral nutrition
• Transvenous pacing
• Central venous pressure monitoring

Contraindications

Absolute contraindications include:

• Vein thrombosis, cutaneous infection over insertion site, and patient refusal

Relative contraindications include:

• Coagulopathy, patient inability to lie flat for 20 minutes, subclavian access in those with severe lung disease or likely to need formation of an AV fistula for dialysis. 

Complications

Early complications:

• Arrhythmia (guidewire/catheter irritation)
• Bleeding or haemorrhage
• Accidental arterial puncture
• Pneumothorax
• Air embolism
• Failed insertion (attempts should be limited to one side of the neck)
• Respiratory compromise (from positioning in critically ill patients)
• Cardiac arrest

Late complications:

• Infection (catheter-related bloodstream infection – CRBSI)
• Venous thrombosis
• Vascular stenosis

CRBSI

Can be life-threatening but is largely preventable. Strict asepsis at insertion and meticulous aftercare are essential. Trusts use central line care bundles to standardise best practice. Key measures to reduce infection risk include:

• Use of transparent, semi-permeable dressings to allow site inspection
• Change IV administration sets every 24 hours
• Access the line only when necessary and always with aseptic non-touch technique
• Restrict handling to trained staff
• Review the ongoing need for the line daily; remove promptly if no longer required
• For long-term therapy, consider a tunnelled catheter.

Vein Selection

Ultrasound

NICE advise the use of ultrasound guidance for all internal jugular central venous catheter insertions to minimise procedural complications. Ultrasound enables assessment for anatomical abnormalities or venous thrombosis, whilst directly visualising the needle entering the vessel. 

Sonographic features to distinguish between artery and vein include:

• Relative position – confirm the orientation of the probe and identify the vein in relation to the artery (can be challenging to delineate in morbid obesity).
• Pulsation – veins lack visible pulsation (tricuspid regurgitation may cause a pulsatile venous signal). 
• Doppler – Veins do not demonstrate pulsatile flow on colour doppler
• Compressibility – veins, unlike arteries, are readily compressible (in severely hypotensive or hypovolaemic patients, arterial compressibility may be misleading). 

Equipment

• ECG monitoring
• Pulse oximeter
• Non-invasive BP (+/- arterial line if indicated)
• Capnography if sedated/ventilated
• Resus trolley and oxygen available
• Surgical scrub
• Sterile gown, gloves, mask, hat
• Large sterile drape and sterile ultrasound probe cover
• 2% chlorhexidine in alcohol
• Gauze/swabs
• 1% lidocaine and syringe and fine needle
• Ultrasound with linear probe
• Sterile ultrasound gel
• 0.9% saline
• Central line kit:
  • Introducer needle and syringe
  • J-tipped guide wire (with markings)
  • Scalpel (No. 11/15)
  • Dilator (short, catheter sized)
  • Central venous catheter
  • Suture and needle holder
  • Transparent sterile dressing

Procedure (Internal Jugular CVC)

1. Wash hands, introduce yourself to the patient and gain consent
2. Ensure the patient has ECG and oxygenation monitoring throughout the procedure. When sedation is administered or in critically ill patients, blood pressure and capnography should also be monitored. 
3. Ensure a clean, bright, spacious environment is being used to perform insertion.
4. Scrub and gown up, donning sterile gloves, surgical mask, and hat. 
5. Check the CVC insertion pack to ensure the presence of all required functioning equipment. Prime all lumens of the CVC with 0.9% saline to minimise air embolus risk. 
6. Position the patient supine with a 10-15° head-down tilt to distend the vein and reduce air embolism risk; ask them to turn their head away from the insertion site. 
7. Clean the skin at the identified insertion site using 2% alcoholic chlorhexidine. Using sterile drapes and maintaining asepsis, cover the ultrasound probe and the insertion site identified on the patient.  
8. Ultrasound the neck to accurately identify the vein. Following vein identification, inject 1% Lidocaine into the skin and subcutaneous tissue at the planned needle insertion site. 
9. Insert the cannula into the vein at the level of the thyroid cartilage (C4) under ultrasound guidance. Aspirate blood to confirm venous entry. Use real-time ultrasound to continuously track the needle tip and minimise risk of arterial puncture. 
10. To maintain patient safety, confirm venous placement before proceeding further by one of the following:
    • Absence of pulsatile flow
    • Attachment to transducer
    • Ultrasound confirmation of guidewire within vein.
11. Advance the guidewire through the cannula into the Internal Jugular Vein and towards the superior vena cava. Use guidewire marking to prevent over-insertion. Monitor ECG for arrythmias indicating myocardial irritation. If arrhythmia occurs, withdraw the guidewire 2-4cm to resolve it. Remove the cannula, leaving the guidewire in place. 
12. Make a small incision at the guidewire entry site. Pass the dilator over the guidewire to create a tract through skin and subcutaneous tissue. Avoid advancing the dilator into the vessel, as this may cause vascular injury and bleeding. Remove the dilator, keeping the wire in place. Ensure the guidewire moves freely within the introducer to prevent kinking or damage. 
13. Advance the catheter over the stationary guidewire into the vessel. Do not release the guidewire at any stage. Observe the ECG during catheter advancement. Select catheter length before insertion (see below). Remove the guidewire once the catheter is in place and cap the distal port. Confirm patency by aspirating from all ports, then flush with saline. 
    • Right internal jugular: approx. 12-14cm
    • Left internal jugular: short (12-14cm, brachiocephalic vein) or log (17-19cm, into SVC).
14.  Suture the line to the skin. Always place a stitch through the true hub, not just the securement device, to prevent accidental dislodgement. Apply a sterile dressing over the insertion site. 
15. Document the procedure using trust-approved documentation. Connect the catheter to a pressure-transducing fluid system:
    • Ensure the fluid does not contain glucose
    • Deliver at 3mL/hour to maintain line patency
    • Prescribe the fluid like any IV therapy
    • Avoid glucose-containing fluid to prevent erroneous blood glucose readings and inappropriate insulin administration. 
16. Always transduce the line immediately before use to verify position. Perform a chest x-ray at the earliest opportunity to confirm correct placement:
    • Tip should be above the carina
    • Film rotation can make the line appear mispositioned
    • Left internal jugular lines should not abut the lateral wall of the SVC

Written by Dr Amina Aslam (CTF)