Guidelines for Patient Care of Epidural and Intrathecal Analgesia.
Westmead Hospital Cancer Pain Service

 

 

Introduction

Epidural and intrathecal analgesia are used for pain relief when other methods are either insufficient, or produce excessive adverse effects. The technique involves the insertion of a catheter that is used to give pain-relieving drugs into the intrathecal/epidural space. The epidural space is a narrow sleeve like area that surrounds the spinal cord. The intrathecal space contains the cerebro-spinal fluid and the spinal cord. When pain relieving drugs are given in this way they produce pain relief by spreading into the spinal cord or to nearby nerves to block the transmission of pain impulses. Several different drugs can be used either alone or in a combination.

 

Benefits

Epidural or intrathecal analgesia is usually much more effective for relief of severe pain than other types of pain relief. The dose of drugs is much smaller than if given as a normal injection or swallowed as a tablet. Epidural or intrathecal analgesia usually produces fewer unwanted effects such as drowsiness.

 

Possible Problems

Because epidural or intrathecal analgesia requires the insertion of a small plastic tube (or catheter) it can be associated with particular problems. These could be the catheter becoming dislodged or kinking causing failure of the pain relief. The catheter may also become infected which may require the catheter to be removed and antibiotics to be given. A new catheter would then need to be inserted afterwards. It is very important to check for onset of new back pain especially with swelling, tenderness or a discharge near the epidural. With intrathecal catheters there is the significant but rare problem of development of meningitis with fever, neck stiffness and altered level of consciousness There are also some extremely rare complications (about 1 in 100,000) such as irreversible nerve injury.

 

Care of a patient with epidural or intrathecal analgesia

  • Routine Checks

    1. Check for dislodgment of the catheter or the dressing.

    2. Check for signs of infection:
    This may be either near the catheter and where it runs under the skin or at the back. Note it is not a problem if some small degree or redness appears around the catheter entry point through the skin. If a patient develops elsewhere any bacterial infection this could lead to bacteraemia and spread of infection to the catheter. If a patient develops sudden onset of back pain, signs of epidural infection, fever, with altered level of consciousness or leg weakness this needs immediate consultation with a member of the Cancer Pain Service.

    3. Check connections for leaks
    a) Loose connections.
    This can be fixed by carefully re-tightening of the screw connections around the filter.
    b) Disconnection
    If this has been only very brief and uncontaminated, then it can be fixed by decontaminating the catheter end (with alcohol free antiseptic) and reconnecting using a new filter. If the disconnection has been prolonged or contamination has occurred then the catheter will need to be removed and another form of pain relief will need to be used. Call the Cancer Pain Service for advice.
    c) Damaged or cracked filter
    The filter may be replaced with a new one using a sterile technique.

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    Weekly maintenance

    Change the filter in a sterile manner (ie gloves and aqueous chlorhexidine). When unscrewing the filter be careful not to remove the catheter adaptor as well. The dressing (Opsite and Fixomul) must be removed carefully to avoid accidental dislodging the epidural catheter. Replace with new dressings.

     

    Epidural or intrathecal drug dosing

    This may be done by intermittent injections either from a syringe or by continuous infusion from a pump.

     

    Infusion pump

    This method uses the Baxter LV infusor mechanical pump. This works by 275ml latex balloon that provides a pumping force e. The drug mixture is given a slow rate through a tube connected to the epidural filter. A flow regulator inside the Luer lock connector controls the flow rate. It is important that the pump and regulator valve are kept at body temperature to ensure correct flow rate.

     

    Change of new drug infusion bag:

    The 275ml pump will last 7 days at 1.5ml/hr. It should be changed weekly before the bag has emptied. New pumps are collected from the Westmead Outpatients Pharmacy (or Inpatient Pharmacy on public holidays). The contact person in the Pharmacy is Peter Barclay, if necessary.

    Specific points to ensure:

    • Check bag label

  • • Use sterile technique

    Use aqueous chlorhexidine, gloves, swab all connections and nearby tubing.
    The flow regulator in the Luer lock connector of the giving set must be in skin contact to keep it at body temperature to ensure flow accuracy

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    Breakthrough Pain

    This can be managed as usual with oral morphine PRN. Note that the usual rules for the size of the breakthrough dose do not apply as intrathecal/epidural morphine dose is much smaller than an equivalent oral dose. If breakthrough doses are needed frequently then the patient will need to be reviewed and the intrathecal/epidural drug dose adjusted.

     

    Contact People

    1. Community Nurse (Palliative care or General)

     

    2. Patient’s Local Doctor

     

    3. Westmead Acute Pain Registrar (24hrs page via switch number 08596)
    Westmead Acute Pain Nurse (7 days, page via switch number 01555)

     

    4. B5c ward staff phone 9485 6854