Clinical Guidelines (Nursing)

Intrathecal Baclofen Therapy

  • Introduction

    Aim

    Definition of terms

    Important points

    Complications

    Special considerations

    Assessment-pre pump implantation

    Documentation

    Companion Documents

    References

    Evidence Table


    Introduction

    Baclofen is a GABA ß-agonist and is thought to diminish spasticity primarily by acting at a spinal cord level. It has muscle relaxing properties and is administered to reduce spasticity or dystonia.  Patient groups receiving Intrathecal Baclofen (ITB) may include:

    • patients with cerebral palsy and allied conditions
    • patients with acquired brain injury
    • patients with severe metabolic or neurodegenerative conditions associated with spasticity and/or dystonia

    Baclofen can be administered orally or intrathecally.  Intrathecal baclofen (ITB) has a much greater effect with significantly reduced doses as opposed to oral baclofen that crosses the blood brain barrier poorly. 

    Long term intrathecal baclofen therapy is administered via a surgically implanted programmable pump that continuously infuses baclofen into the intrathecal space. Patients on ITB have reported reduced pain associated with spasticity, improved positioning, speech, quality of sleep and quality of life.   


    Aim

    The aim of the guideline is to outline the management of the implantation of an ITB pump, and ongoing care for patients requiring ITB therapy for all clinicians at RCH.


    Definition of terms

    • Intrathecal space: space surrounding spinal cord enclosed by the dura and containing Cerebrospinal fluid (CSF).
    • Spasticity: Involuntary muscle tightness and stiffness.  
    • Athetosis: repetitive involuntary, slow, sinuous writhing movements.
    • Dystonia:  sustained muscle contractions, frequently causing twisting and repetitive movements or abnormal postures.
    • Autonomic dysreflexia: an uninhibited and exaggerated reflex of the autonomic nervous system to stimulation.(1)
    • Malignant hyperthermia:  Malignant hyperthermia is an inherited disease that causes a rapid rise in body temperature and severe muscle contractions when the affected person undergoes general anaesthetic.(2)
    • Neuroleptic-malignant syndrome: condition that occurs in patients being treated with high-potency neuroleptics.  Symptoms include, diaphoresis, muscle rigidity, hyperpyexia.(1)
    • Somnolence: sleepiness, unnatural drowsiness.(1)
    • Pruritus: itching.(1)
    • Rhabdomyolysis: disintegration of striated muscle fibres with excretion of myoglobulin in the urine.(1)
    • Monopolar cautery: Cauterization using high frequency electrical current passed from a single electrode where cauterization occurs; the patient's body serves as a ground.(3)

     

    Important points 

    • ITB therapy is managed by three primary teams:
      • Surgical and hardware complications are managed by the Neurosurgical team 
      • The administration of ITB and management of refills, dosing and complications are managed by either a) A Consultant Developmental Medicine paediatrician or B) A Consultant Rehabilitation Paediatrician. You will need to consult the patient's history to determine if your patient is an ITB patient of Developmental Medicine or Rehabilitation. 
    • ITB therapy on-call arrangements:
      • In business hours call the on-call consultant for the patient’s usual ITB team (Rehabilitation or Developmental Medicine) via switch.  If the Developmental Medicine Consultant requires assistance in regards to ITB programming or trouble shooting and that assistance cannot be sourced from within Developmental Medicine, the Rehabilitation Consultant on-call will provide support as required. 
      • After hours call Developmental Medicine Consultant on-call. If the Developmental consultant requires support in regards to ITB troubleshooting after hours the on-call Rehabilitation Consultants is to be contacted
      • If a hardware issue is suspected the Neurosurgical Team will be contacted after a review by ITB Paediatrician.
      • The ITB pump is programmed by the Developmental Medicine Consultant or Rehabilitation Consultant (depending on patient's primary managing team)using an external device that communicates with the pump via telemetry. 
      • The action of baclofen peaks four hours post administration, therefore overdose symptoms often appear long after boluses or a dose increase.
      • The device is designed to 'beep' when the reservoir is almost empty or the battery of the pump is becoming flat.  If 'beeping' from a patient can be heard page the Developmental Medicine Consultant or Rehabilitation Consultant (depending on patient's primary managing team) urgently, to avoid the patient withdrawing from Baclofen.
      • The pump has a battery life of 5-7 years depending on pump model and dose given. The pump, but not the catheter, must then be replaced surgically. The Developmental Medicine Consultant or Rehabilitation Consultant (depending on patient's primary managing team) is responsible for ensuring the pump is replaced in a timely manner before battery becomes low.
      • An empty pump will malfunction after 48 hours, it will then need to be surgically removed and replaced.
      • After a pump has been insitu for three months (approximate only) the patient becomes dependent on the baclofen. Regardless of how long a pump has been insitu there is a very low threshold for suspicion if the patient displays any symptoms of withdrawal.
      • Notify the Developmental Medicine Consultant or Rehabilitation Consultant (depending on patient's primary managing team)- Developmental Medicine or Rehabilitation Consultant (depending on patient's primary consultant) when a patient presents to Emergency Department with ITB therap

        ITB pumps should only be accessed or programmed by a clinician familiar with the ITB programmer

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      Complications

       

       

      Complication

      Signs and Symptoms

      Management

      Overdose

      Overdose may occur when:

      • A pump or catheter malfunctions.
      • Human error during programming the pump.
      • Patient sensitivity to the dose of intrathecal baclofen.

      Overdose may appear insidiously or suddenly.

      • light headedness
      • respiratory depression
      • hypotonia
      • somnolence/dizziness/drowsiness
      • seizures
      • loss of consciousness
      • If overdose is suspected and the patient is not clinically compromised and observations are within acceptable limits contact the patient’s ITB team immediately: Developmental Medicine or Rehabilitation consultant (depending on patient's primary managing team) on call, via switch.
      • If overdose is suspected and patient is clinically compromised and/or meets MET criteria e.g.decreased consciousness, respiratory depression:
        • Initiate MET call 777
        • Contact Developmental Medicine Consultant or Rehabilitation  Consultant (depending on patient's primary  managing team) on call, via switch immediately 

      Withdrawal

       

       

       

       

       

       

       

       

       

       

       

       

      Withdrawal symptoms may be experienced when:

      • A patient's dose of baclofen is suddenly decreased or stopped.
      • Pump malfunction.
      • A break or leak in the catheter.
      • Disconnection of the catheter from the pump.
      • Movement of the catheter at a spinal level.
      • Human error during programming the pump.
      • Pruritus
      • Altered mental state, irritability
      • Exaggerated spasticity & muscle rigidity
      • Temperature > 38 °C
      • flushed' appearance to face
      • Hypertension
      • Tachycardia
      • May resemble autonomic dysreflexia, sepsis, malignant hyperthermia & neuroleptic-malignant syndrome
      • Multiple organ system failure
      • Rhabdomyolsis
      • If withdrawal is suspected but observations are within acceptable limits and the patient is not clinically compromised Contact Developmental Medicine Consultant or Rehabilitation Consultant (depending on patient's primary team) on call, via switch.


      • If withdrawal is suspected and patient is clinically compromised:
        • Initiate MET call 777
        • Page ITB Team immediately Developmental Medicine Consultant or Rehabilitation Consultant (depending on patient's primary managing team) on call, via switch'.
        • Consider stat dose of oral Baclofen 10mg - -- 20mg and oral diazepam (5-10mg) and cyproheptidine (4-8mg) depending on severity of symptoms.  These medications should be given sequentially. If not effective consider Intravenous diazepam.
      Pump/Catheter Malfunction

      May occur due to:

      • Catheter disconnection.
      • A crack or break in catheter.
      • Malfunction of the pump motor.
      • End of battery life.

       

      • Patient may exhibit withdrawal symptoms (see above).
      • Swelling may appear around pump. 
      • Lack of efficacy of baclofen despite dose increases.
      • Notify Neurosurgical team and Developmental Medicine Consultant or Rehabilitation Consultant (depending on the patients primary managing team) on call, via switch immediately
      • Investigations might include: 
        • Imaging of the pump and catheter.
        • Nuclear medicine/Dye flow study under video fluoroscopy- should be performed by a Neurosurgeon. If the catheter access port needs to be used for any procedure the needling of the port must be done by the neurosurgical team.
        • Surgical exploration of pump and catheter.

      Infection

      Infection may occur due to:

      • The risks of the procedure itself
      • Implantation of external hardware to a normally sterile environment.
      • Colonisation of bacteria in hardware of pump/catheter.
      • Temperature > 38 °C
      • Redness or inflammation of wound
      • Swelling around pump
      • Page neurosurgical team for review
      • Inform Developmental Medicine Consultant or Rehabilitation Consultant (depending on patient's primary managing team) on call, via switch'.
      • Commence septic work up to determine source of infection including:
        • Temperature
        • Urinalysis
        • MC&S
        • FBE
        • Blood cultures
        • Respiratory assessment and chest X-ray if indicate
      • Do not consider Lumbar Puncture until first consulting neurosurgery AND team managing ITB.

      CSF Leak

      may occur due to:

      • Catheter crack/break
      • Catheter disconnection.
      • Leak around insertion site of  catheter into the intrathecal space.

       

      • Postural headaches.
      • Swelling around pump and abdomen.
      • Clear fluid discharge around surgical wound.
      • Notify Neurosurgical team and team managing IBT: Developmental Medicine Consultant or Rehabilitation Consultant (depending on patient's primary team) on call, via switch immediately. 
      • Investigations may include:
        • Imaging of the pump and catheter
        • Nuclear medicine/Dye flow study under video fluoroscopy- should be performed by a neurosurgeon.
        • Surgical exploration of pump and catheter


      Special Considerations

      • MRI can alter or stop the ITB pump program.  The Developmental Medicine Consultant or Rehabilitation Consultant (depending on patient's primary managing team)ITB team must be notified prior to the MRI and be available immediately following the MRI.  Following MRI the ITB pump must be re-programmed as soon as possible.
      • If the patient requires an epidural insertion contact the Developmental Medicine Consultant or Rehabilitation Consultant (depending on patient's primary managing team).
      • Monopolar cautery can interfere with the pump program and must only be used in small bursts infrequently with careful placement of the grounding plate in patients with ITB pumps.  The ITB pump should be re-programmed post operatively to ensure pump is functioning correctly.
      • Lumbar puncture may be performed if the proceduralist is confident that the catheter can be avoided.  Micro holes in the catheter from inadvertent injury can lead to Baclofen withdrawal.  Prior to performing a lumbar puncture check x-ray as catheter loops subcutaneously beyond incision site. If a patient with an ITB pump requires a lumbar puncture the Neurosurgical and Developmental Medicine Consultant or Rehabilitation Consultant (depending on patient's primary managing team) should be contacted.
      • Patients receiving ITB therapy may have an increased sensitivity to opiates. Opiates should be given with caution, and in smaller doses in children with ITB pumps as respiratory depression may be more than anticipated.
      • Oral baclofen and oral diazepam and oral cyproheptidine are likely to be required in the management of acute baclofen withdrawal.  They should be readily available in the ward area when a patient with ITB pump is admitted.

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      Assessment- pre pump implantation

      Obtain and document a thorough patient history and baseline observations including:

      • Temperature
      • Heart rate
      • Respiratory rate 
      • Blood Pressure
      • Neurological observations
      • Baseline urinalysis
      • Full Blood Examination 
      • Assess PEG site (if applicable).
      • Determine continence status
      • Assess patient for any signs of infection that may contraindicate surgery, e.g. temperature, upper or lower respiratory tract infection.

        Refer to nursing assessment nursing guideline 

      Ensure:

      • A referral to the Children's Pain Management Service (CPMS) has been made.  
      • Regular medications, including aperients are prescribed. 
      • Appropriate multidisciplinary health care team involvement by contacting all relevant departments. 


      Management

      Elective Replacement of ITB pump:

      Elective Replacement Procedure:


      The "Elective Replacement Interval" (ERI) on every pump program report indicates the length, in months, of life left in the ITB pump. This ERI indicates how long is left until the ERI alarm occurs. Once the ERI alarm has occurred there is no guarantee of remaining battery life in the pump; although it may be up to 3 months before the pump expires.

      Paediatric Assessment:


      Elective pump replacement is the time to consider continuation of Baclofen therapy. In many instances this is apparent, however in some clinical situations the paediatrician may elect to try withdrawal of Baclofen to help with this decision.

      Trial of Weaning:

      In some centres, it is common practice to trial weaning of ITB therapy (slow decrease in dose) prior to pump replacement due to ERI. Trial of weaning is done to assess the ongoing need for ITB therapy. All children who require an elective pump replacement due to ERI should be considered for weaning of ITB therapy. Trial of weaning is to be done at the discretion of the ITB paediatrician managing the child’s care, taking into consideration the opinion of the family and the child. 


      Neurosurgical referral:

      When the ERI has 3-6 months remaining (approximately) the consultant paediatrician who manages the child’s ITB therapy makes a written referral to the child’s Neurosurgeon indicating the ERI alarm date. The neurosurgeon will arrange to review the patient, as an outpatient, in a timely manner. If there are any concerns regarding the hardware integrity or the effectiveness of delivery then a discussion between the paediatrician and the surgeon is recommended

      Surgical assessment:

      Elective pump replacement is also an opportunity to change the intrathecal catheter if this is indicated and or revise pump positioning and or scars. Surgical assessment therefore includes assessment of the catheter position, the pump position and the scars. A pump series of X-rays is recommended as it allows assessment of the implanted hardware and reduces the incidence of surprise findings at replacement. The catheter height may be a point of discussion with the treating paediatrician if there has been significant growth of the child. In patients with the older catheters (radio opaque catheters) an X-ray may show disruptions in the system, however these are frequently occult.

      It is recommended that at the time of the pump replacement the existing catheter be tested for patency if it is not going to be replaced. As catheter failure and Baclofen withdrawal can be occult, the treating surgeon should discuss with the family and paediatrician how a surprise finding of a non-functioning system would be managed (e.g. explant of system or revision of system and reprogramming to a starting dose). It is the surgeon’s responsibility to organise the X-rays, surgical booking and consent when the child is seen in clinic, and to assess the X-rays pre-operatively. When the patient is booked for theatre the hardware needs to be ordered from Medtronic and the booking discussed with the paediatric team who will need to be available for the re-programming at implantation.

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      Initial post operative management (days 1- 2)

      • ½ hourly Heart Rate, Blood Pressure, Respiratory Rate and neurological observations for first 4 hours then hourly for the first 24 hours. Unless otherwise indicated cease neurological observations after 24 hours.   NB: any change in the patient's neurological status should be documented and the appropriate medical staff notified immediately.
      • Continuous oxygen saturation monitoring for the first 24 hours.
      • Observe for any signs of complications
      • Check the operative note for any patient specific orders e.g. modifications of usual medication regime.
      • Check the operative note for orders in regard to patient mobilization.  If a new catheter has been replaced the patient should remain flat for the initial 48 hours of the post-operative period, (flat is defined as the patient is able to move side to side and back to front but not sit up). This is to reduce the risk of CSF leak. 
      • The patient is to remain Nil by Mouth/PEG until bowel sounds are audible, as there is a risk of paralytic ileus from abdominal surgery.
      • Ensure patient is comfortable and has adequate analgesia in collaboration with the Children's Pain Management Service.
      • Observe dressing of abdominal and lumbar wounds hourly for first 24 hours then observe with 4 hourly observations.  Document description of wound site and dressing in the medical record. If dressings are replaced they should be replaced with the same type of dressing as applied in the operating theatre.  Silicon dressings applied in theatre allow observation of the wound.  Consider the re-application of the original dressing if it is not contaminated.
      • Report any discharge or CSF leakage to neurosurgeon immediately. 
      • For patients who have incontinence problems prior to admission an Indwelling Catheter may be inserted in theatre to reduce the risk of contaminating the wound.  The IDC should remain in situ until the patient is mobilising as usual. 
      • It is recommended that IV antibiotics be prescribed for at least the first 48 hours post-operative as per neurosurgical team. 

      Post-operative investigations

      • AP and lateral x-ray to check catheter position and height postoperatively, once the patient is mobilising.
      • Full Blood Examination (FBE), Urea, Electroytes and Creatinine (UEC) C Reactive Protein (CRP) day 1 and day 3 postoperatively to assess for infection and obtain baseline for comparison.

      Ongoing inpatient management (day 2 to discharge):

      • The ITB pump will be reviewed and re-programmed daily (as required) by the  Developmental Medicine Consultant or Rehabilitation Consultant (depending on patient's primary managing team) until the optimum dose for the patient is reached.
      • Continue routine observations including the patient's wound site and dressing until patient is discharged.
      • Baclofen is known to decrease gastric motility and cause constipation.  Therefore it is important to monitor the patient's bowel actions to ensure regularity.
      • The dose and concentration of baclofen the patient is receiving will determine when the patient is due for their first pump refill.  The Developmental Medicine Consultant or Rehabilitation Consultant (depending on patient's primary managing team) will book an appointment before the patient is discharged.  ITB can cause changes in oral motor tone.  A referral to Speech Pathology should be considered.
      • A referral should be made to Speech Pathology to assess any changes to oral motor function that may occur due to ITB.
      • A referral should be made to Physiotherapy and Occupational Therapy because:
        • Changes in muscle tone can affect the patients positioning in their wheel chair (if applicable) and/or car seat.
        • If The profile of the pump creates a protrusion in the patient's abdomen which, in turn can cause pressure areas. 

      Ongoing outpatient management

      • The ITB pump is refilled every 1-6 months depending on pump capacity and dose. 
      • Pump refills are undertaken in Developmental Medicine or the Victorian Paediatric Rehabilitation Service at RCH and various refill sites throughout Victoria and Tasmania. 
      • Patients will be assessed 3, 6 and 12 months post pump insertion to determine the affect of ITB therapy and if the patients goals have been achieved. 
      • If a pump or catheter malfunction is suspected the patient will be readmitted for investigation.

      Initial Assessment of child with an ITB pump who presents to Emergency

      A child with an ITB pump insitu may present to the Emergency department for a number of reasons, many of those reasons will not be related to ITB therapy. The following steps are recommended in the initial assessment of the child who is clinically stable but showing signs of lack of efficacy of intrathecal baclofen:

      • Physical Exam and comprehensive history- as per any child with Cerebral Palsy or Movement Disorder. Particular to children with ITB pumps insitu it is important to ask the parents/primary care givers when the next pump refill is due. They should also be asked if they have heard the pump alarming.  Pump alarms can be quiet and as infrequent as every hour, parents have mistaken the pump alarm for the sounds of an electronic device or toy.
      • If the family are unaware of the refill date, it can be found on the ITB program report in the child’s medical record. 
      • If you are concerned about baclofen withdrawal consider taking:
        • A blood sample - consider taking a Creatinine Kinase (CK) level. CK is an indicator of muscle injury and may become elevated if a child experiences an acute escalation in tone. CK can be an indicator of ITB withdrawal, when assessed within the context of other symptoms. 
        • A plain x-ray; anterior, posterior, lateral and oblique views– specifically state on the image request that images of the pump and catheter are required. It is important to note that not all hardware issues will be found on a plain x-ray.
      • If you are concerned about baclofen overdose or withdrawal contact the attending Developmental Medicine or Rehabilitation Physician who will consider:
        • Interrogation the ITB pump, with a programmer. This will provide the most up-to-date information on the status of the pump. Pump interrogation will provide: low reservoir alarm date, volume of expected baclofen left in pump, dose and concentration of ITB and it will also show any alarms or events that have occurred with the pump programming; battery life, low volume warning, malfunctions. It is important to note the program report is not inclusive of all possible ITB complications.
        • Contacting Medtronic for technical support. In the event that technical support is required for the management of ITB therapy. Medtronic, the manufacturers of the ITB pump hardware provide technical support.


      Contacting Medtronic:

      When support for Medtronic Neuromodulation products is required, please follow the instructions below:

      1. During working hours, attempt to contact your Neuromodulation representative directly. 
        Please note: they may be supporting theatre cases or patient follow up.
      2. Working hours are defined as 7am to 7pm, Monday to Friday
      3. Outside of working hours or if you have no response, call the Medtronic Neuromodulation helpline on 1800 652 972. The call service will contact other local Medtronic staff to help you with your questions. 
      4. If your call is an emergency and between the hours of 10pm and 6am, you will be transferred directly to the US Technical services team who will assist you with your questions

      Please note: Medtronic Neuromodulation does not provide a 24 hour support service in Australia


      Documentation

      • Document All ITB prescriptions on the Intrathecal Baclofen Therapy Treatment Order.
      • Document cardio/respiratory observations on clinical observations chart.
      • Document neurological observations on the Neurological observation chart.
      • Document description of wound site and dressing on observation chart.
      • Document patient's pain score on the observation chart. 

      Companion Documents


      References

      1. Albright AL, (1996) Intrathecal Baclofen in Cerebral Palsy Movement Disorders. Journal of Child Neurology, 11 (1) p29-35
      2. O'toole, M., (ed), (1997) Miller-Keane Encyclopaedia & Dictionary of Medicine, Nursing & Allied Health (6th Ed), W.B. Saunders Company, Pennsylvania, USA
      3. Stedman (2002) Medical Dictionary. Houghton Mifflin Company USA.

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      Evidence Table

      Intrathecal Baclofen Evidence Table


      Please remember to read the disclaimer.


      The development of this nursing guideline was coordinated by Sacha Petersen, Clinical Nurse Consultant, Developmental Medicine, and approved by the Nursing Clinical Effectiveness Committee. Updated November 2015.