Central line management, Maternity (1163)

Objectives

This guideline and policy aims to provide support to midwifery staff on the management of central venous catheters (referred to subsequently as a “central line” for simplicity) inserted in patients located in maternity areas of the hospital. This guideline provides some background information, guidance on management of central lines, a policy on the circumstances when a central line should be removed, and guidance around how to involve the obstetric anaesthetic team. It references existing health board and national policies on Vascular Access Devices (VAD’s) and Infection control guidelines.

Scope

This guideline and policy is designed for midwifery staff members working in the relevant clinical areas (antenatal ward, labour ward, theatre, theatre recovery, obstetric HDU, postnatal ward) who may be required to care for a patient with a central line in place. During the course of the patient’s clinical journey it is likely there will come a point when the central line can be removed due to an improvement in their clinical condition.

Reasons why a patient in a maternity clinical area may have a central line in place

You may encounter patients with a central line inserted for one of the following reasons:

when a patient is known to have difficult intravenous access
to administer medication that can only be given via a central vein
to provide parenteral nutrition
for monitoring of central venous pressure
where multiple intravenous medications may need to be given simultaneously
where a longer term course of intravenous medication is anticipated
for specialised treatments such as Haemodialysis

For many of these reasons it is likely the patient would require to be outside of the obstetric clinical area in ICU, where the line care will be provided by the ICU nurses. Or they may be in Obstetric HDU with midwifery care, with input from the obstetric anaesthetic team. However a patient may be on a standard antenatal, labour, or postnatal ward with a central line. This is usually because the patient’s condition has improved, and some of the HDU or ICU treatments are no longer needed, or because the line was placed specifically for difficult venous access.

A central line is usually inserted by one of the anaesthetic doctors, but may be done by some other specialists if they have the appropriate training. This may be during the patient’s obstetric care journey, or the patient may present in need of obstetric care with a line already in place. It is the responsibility of whoever inserts the line to confirm it is suitable for use. The central line will have a number of ports that should be covered with a Needle Free Access Device (NFAD), that allows medications to be administered, samples to be taken, and keeps the line ports covered when they are not in use.

Common sites where a central line may be visible

Neck (for a line placed in an internal jugular vein)
Top of Chest (for a line placed in a subclavian vein)
Groin (for a line placed in a femoral vein)
Arm (usually for tunnelled central lines)

Tunnelled Central Lines and PICC’s

Tunnelled central lines have an insertion site some way away from the vein, and the line is then “tunnelled” underneath the skin towards the vein. A PICC is inserted into a peripheral vein, and is a long line with an end point nearer the central veins. These types of lines are usually inserted when a central line is required for an extended period of time (over 4 weeks), and they are inserted in this way to significantly reduce the risk of a line infection. These lines are outside the scope of this guidance, but it is important to be aware they may be there.

Roles / responsibilities

Midwifery Staff Responsibilities

To be able to recognise when a patient has a central line inserted
To provide ongoing line maintenance and safe management of the central line
To be able to administer intravenous medications via a central line
To consult the obstetric anaesthetic team if any advice or support is required
To consult the obstetric anaesthetic team prior to removal of a central venous catheter

Obstetric Anaesthetic Responsibilities

To document appropriately that a central line is suitable and safe for administering IV medications or blood samples once the necessary checks are completed post insertion
To provide advice on line maintenance and usage to the midwifery team
To advise the midwifery team when a central line can be safely removed
To advise the midwifery team if any additional support is required with central line management

POLICY on Removal of Central Lines

When removing a central line there is a balance to be struck between the need for ongoing IV access and blood sampling in a situation of difficult access against the increased risk of infection the longer a line is in place. Removal too early may necessitate a new central line which carries a repeat set of risks to the patient from reinsertion. Therefore removal of a patient central line by a midwife must be discussed with a Consultant Obstetric Anaesthetist before it happens.

GUIDELINE on Central Line Management

Central Line Maintenance and Care

Inadequate central line care can result in an increased infection risk, increased risk of the line becoming dislodged (which can lead to major haemorrhage or air embolism), and blockage of the lumens (rendering the line non-functional). Line care follows a standard Aseptic Non Touch Technique ®. Early troubleshooting can help to minimise problems. Key points of line maintenance are as follows:

Patients should be made aware that they have a central line inserted, to minimise the risk of accidental dislodgement or removal of dressings.
The central line site should be inspected at a minimum of once per day, to ensure the line remains in place, the sutures are intact, the dressing remains intact, and there are no signs of infection or bleeding at the insertion site. The dressing is typically a clear tegaderm dressing which does not need to be removed (unless it is damaged or soiled) to inspect the site.
If the sutures are no longer in place, this should be highlighted to the obstetric anaesthetic team for review and re-suturing. The sutures should be under sufficient tension to hold the line securely.
A clear tegaderm dressing should be placed over the central line. This should be changed at least once per week, or sooner if the dressing has become loose or soiled.
All ports should be covered by a Needle Free Access Device (NFAD).
Lumens usually have a clamp which should be in a closed position when it is not in use.

Obtaining Blood Samples from a Central Line

In a patient with difficult venous access, it is likely to be much easier to obtain blood from a central line that is in place, as opposed to trying in a peripheral vein. Key points are as follows:

A standard ANTT® approach with appropriate PPE must be considered
The Needle Free Access Device (NFAD) covering the lumen should be cleaned with a 2% Chlorhexidine / 70% Alcohol wipe (“Scrub the Hub”) and allowed to dry for at least 30 seconds
The clamp over the line should be released and a 10ml syringe inserted into the end
Using this syringe approximately 3-5ml of blood should be aspirated and discarded
- If a small amount of blood is not discarded this can result in inaccurate results. The volume of blood discarded should be at least 2x the volume contained within the line deadspace, so approximately 3-5ml will be sufficient.
A Vacuette tube is then placed on the NFAD using a “push and twist” technique
Blood bottles can then be filled as required by inserting them into the Vacuette tube, which can then be released and disposed of in the sharps bin when complete.
A fresh 10ml syringe filled with 0.9% saline should be used to flush the lumen through the NFAD using a “push/pause” technique and positive pressure, with the plunger being pushed as the clamp is reapplied.
Once this is complete, the NFAD covering the lumen should be cleaned with a 2% Chlorhexidine / 70% Alcohol wipe (“Scrub the Hub”) and allowed to dry for at least 30 seconds.

There are a few additional points to consider regarding taking blood samples from a central line:

Taking blood cultures from a central line should ideally be avoided if possible due to the risk of bacterial colonisation resulting in a false positive blood culture result. However if there is a suspicion the line is infected, this may be specifically asked for.
It may be difficult or impossible to aspirate blood if the lumen is blocked. Another lumen may be used if this is the case, but if it is not possible to aspirate blood then this should be escalated to the medical team for troubleshooting.
If one of the central line ports is being used for TPN, this port should not be used for blood sampling or medication administration due to an increased infection risk.

Safe Removal of a Central Line

It is important to remove a central line in a safe manner due to the risk of air embolism or haemorrhage if done improperly. As with blood sampling or IV medicines administration, this should be done with a standard ANTT® approach with appropriate PPE. The following should be considered:

An explanation should be given to the patient of what is about to happen.
The patient must be lying flat with a head down tilt (Trendenburg position)
The dressing should be carefully removed and discarded
The area should be cleaned using a 2% chlorhexidine / 70% isopropyl alcohol wand and be allowed to dry for at least 30 seconds
The sutures should be released using a stitch cutter and removed
The patient should then be asked to hold their breath and perform a Valsalva manoeuvre, as this happens the central line should be withdrawn whilst gentle pressure is immediately applied over the insertion site with a sterile swab
The pressure should be maintained until the bleeding has stopped. This may take approximately 5-10 minutes, and should be at least 15 minutes for a femoral line, but could take longer.
The site should then be covered with a hydrocolloid dressing. This should stay in place for at least 2 hours.
Before discarding the central line it should be inspected for any signs of damage
Patients should be advised to minimise any physical exertion for at least 1 hour after removal. If they have had a femoral line in, they should be nursed lying flat for at least 2 hours.
The patients observations should be recorded after line removal, and the limb closest to the insertion site should be observed for any changes in skin colour or signs of swelling.