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Home > RNJ > 2008 > May/June > Intrathecal Baclofen Therapy in Adults and Guideline for Clinical Nursing Care

Intrathecal Baclofen Therapy in Adults and Guideline for Clinical Nursing Care
Rozina Bhimani, MSN RN FNP

Advancements in healthcare technology for patients with spasticity are promising. Nurses are expected to be well-versed in the use of technology to provide individualized and safe care. The focus of this article is on the current nursing care of patients who use technology such as intrathecal baclofen pumps to manage spasticity. Three phases of intrathecal baclofen therapy and concurrent clinical nursing care are outlined. A fundamental understanding of the intrathecal baclofen pump allows nurses to provide cutting-edge technological and individualized care with compassion.

This article focuses on the nursing care of patients using intrathecal baclofen (ITB) therapy. Technology is an integral part of the U.S. healthcare delivery system, and nurses are major players in the microdelivery of care. They not only are expected to understand the art of nursing but also are required to be well- versed in the science of nursing, including the use of technology in daily practice. One such technology incorporates the use of pumps to deliver medications. Pumps used to deliver ITB to manage spasticity and resulting pain are the focus of this article (Figure 1). The clinical implications of the use of such pumps differ from those of other medications and other kinds of pumps, yet there has been little investigation into possible divergences or consequences of their use. Therefore, this discussion is organized around the phenomenon of spasticity, the method of delivering medication for spasticity with intrathecal pumps, and the three phases of therapy: the screening trial, surgery to implant the device, and maintenance.

Spasticity

Spasticity is a sequela of many neuromuscular disorders, such as spinal cord injuries, multiple sclerosis, stroke, traumatic brain injury, and cerebral palsy. Spasticity is an upper motor neuron dysfunction in the central nervous system that leads to tight and stiff muscles. The exact mechanisms of spasticity are unknown; however, it is thought to be caused by an imbalance of excitatory and inhibitory input in the spinal cord caused by neuromuscular diseases (Cleveland Clinic Health Information Center, 2006). Spasms can be painful. Spasticity can increase caregiver burden by making independent and dependent activities of daily living (ADLs) difficult to perform.

ADLs

Spasticity affects more than half a million people in the United States alone and more than 12 million worldwide (MD Virtual University, 2006). A person with spasticity may have difficulty performing ADLs because of rigidity and stiffness, making daily hygiene difficult.

A retrospective analysis of ADLs and mobility outcome variables in patients receiving ITB therapy was reported by Ochs and Tonn (1996). Mobility was improved: 58% of bedridden patients were able to use wheelchairs, 14% of patients using wheelchairs were able to stand, and 10% of these patients were able to ambulate with crutches. Participants needed 67% less help in dressing themselves. Overall satisfaction with the ITB was reported by physicians to be 86% and by patients to be 91%. Dario, Scamoni, Bono, Ghezzi, and Zaffaroni (2001) also reported a decrease in spasticity, with improved ADLs and mobility (p < .05). They also noted that paraplegics’ arm functions improved because a reduction of spasticity in the lower extremities improved patients’ balance.

Pain

Spasticity causes pain through muscle rigidity and stiffness. Increased flexor and extensor tone interferes with sleep, causing pain and stiffness. Untreated spasticity not only causes pain but also can lead to permanent contractures and limb deformities. Dario et al. (2001) found a statistically significant (p < .05) reduction in pain with the use of ITB therapy. Pain reduction has been reported after use of ITB therapy in all neurological disorders including cerebral palsy (p = .0078) (Schaeybroeck et al., 2000). Parke, Penn, Savoy, and Corcos (1989) also reported a decrease in pain and better sleep in their participants who used the ITB intervention.

Caregiver Burden

Most people experiencing spasticity are partially or fully dependent on other people for their daily functioning. Increased tone and stiffness in extremities lead to difficulty in performing daily hygiene, including perineal care and bathing. Spasticity also translates into difficult transfers because the patient’s limbs and body are rigid, making sitting in a wheelchair and performing pivot transfers unsafe. This can increase the risk of injury to caregivers.

After using ITB therapy, Gwartz (2001) reported improvements in the social life of research participants and decreases in caregiver burden. Azouvi and colleagues (1996) and Boviatsis, Kouyialis, Korfias, and Sakas (2005) also reported a decrease in caregiver burden after ITB therapy was used.

ITB Therapy

ITB is a therapy that delivers medication directly to the intrathecal space in the spinal canal. Baclofen is an oral or intrathecal muscle relaxant medication used to decrease spasticity. Baclofen (a gamma-aminobutyric acid agonist) works by blocking the release of excitatory neurotransmitters in the spinal cord (Penn et al., 1989). The intrathecal space is embedded in the spinal meninges and is also known as the subarachnoid space, where cerebrospinal fluid (CSF) bathes the central nervous system (Figure 2).

ITB delivers baclofen directly to the intrathecal space in the spinal canal. The intrathecal system consists of a very thin catheter connected to the baclofen pump. The pump stores and releases prescribed amounts of medication through the catheter, as instructed by the external programmer (Figure 3).

The initial line of treatment for spasticity is oral antispasmodic medication. Typical oral antispasmodic agents are baclofen, diazepam, tizanidine, and dantrolene sodium. Oral medications’ usefulness may be limited by side effects such as hepatotoxicity, fatigue, drowsiness, weakness, and nausea. Regardless of the dosage, patients may not receive adequate control of spasticity. Use of botulinum toxin, although helpful, may not be enough to control spasticity, and large amounts may cause toxicity. Rhizotomy entails cutting of the nerves, and the effects are permanent, which may not be acceptable to patients and physicians (Sampson, Hayward, Evans, Morton, & Collett, 2002).

The intrathecal pump can continuously deliver baclofen in small dosages directly to the CSF, increasing the therapeutic benefits and causing fewer and less severe side effects than are seen with oral medications. Intrathecal pumps allow adjustment of infusion rates according to the patient’s needs. The ITB pump can be turned off if spasticity reduction has shown no benefit (Cleveland Clinic, 2006).

Symptoms of spasticity can be assessed using the Ashworth scale or modified Ashworth scale (Table 1) or the spasm scale (Table 2). Interpretation of these scales is easy but may vary slightly between interpreters. These scales can be used in both inpatient and outpatient settings. Another scale, Functional Independence Measures, is more extensive and most commonly used by physical and occupational therapists to assess the impact of spasticity. Functional Independence Measures scores are used in the hospital setting to assess the patient’s ability to perform ADLs.

Three Phases of ITB Therapy and Nursing Care

Most patients start with a trial of oral antispasmodic or botulinum toxin therapy. If these therapies provide suboptimal or no relief, the patient and physician may explore the use of an ITB pump. This therapy is subdivided into three phases, each with associated nursing practice.

Phase 1: Screening Trial

In this phase the patients who will benefit most from this therapy with the lowest risks are selected. When a patient meets the criteria (Figure 4), the physician or nurse practitioner explains the risks and benefits of the therapy in detail. Realistic, patient-specific outcomes must be discussed to ensure that the patient, family, and caregivers understand the risks and benefits associated with the therapy. The patient must provide informed consent for the screening trial because it is an invasive procedure. Before the screening trial, the patient is examined by an interdisciplinary team including nurses, physicians, and physical and occupational therapists to evaluate the patient’s condition and health status. If no contraindications are found, the patient is admitted to an outpatient or inpatient medical facility where immediate access to resuscitation equipment is available (Medtronic, 2004).

On the day of the screening trial, the patient is admitted, and any oral antispasmodic medications are withheld. The patient receives an intrathecal bolus injection of baclofen via lower lumbar puncture. After the injection, the nursing staff monitors the patient closely for the effects of the intrathecal injection.

Phase 1 Nursing Care

Nurses are key players in monitoring the patient and providing safe care during the screening trial. Upon patient arrival, the nurse must perform a brief review of the system checklist to ensure that the patient is in appropriate condition to proceed with the trial. Baseline vital signs and oxygen saturation are obtained, and an intravenous saline lock is inserted. After the patient has received the bolus injection, frequent assessment of vital signs, pulse oximetry, and spasticity is essential. The onset of effect occurs within 60 minutes, and the bolus dose peaks at 4 hours (Medtronic, 2004). Most patients start to experience the return of spasticity within 8 hours. The initial recommended dosage for a screening trial is 50 mg; however, this may produce different responses in different patient populations, based on their condition. Serious complications of the trial may include hypotonia and respiratory depression secondary to the antispasmodic effects on the muscles and the diaphragm. Therefore, the nurse must be vigilant and alert the physician immediately if complications arise. Some patients may experience headache after lumbar puncture; the patient must lie flat and resume a sitting position slowly, as tolerated.

During the trial, the patient is evaluated by the interdisciplinary team, including physicians, nurses, nurse practitioners, and physical and occupational therapists. A minimum decrease of 1 point on the Ashworth spasticity scale from the prescreening evaluation score is needed for a successful trial. The patient’s and caregiver’s verbal reports about changes in spasticity add to the overall picture to indicate whether this therapy would be beneficial. If the trial is successful, the patient is referred to a surgeon for implantation of the baclofen pump.

Phase 2: Implantation of the Baclofen Pump

If the screening trial is successful, the patient and caregiver may or may not choose to proceed with the surgery. If the patient and caregiver agree to this therapy, a presurgical consultation is sought with the surgeon to determine whether the patient is a surgical candidate. If no contraindications are noted, informed consent is obtained. The patient must have enough body mass to support the weight of the pump and must undergo a preoperative physical before the surgery.

During the surgery, two incisions are made. The first is made at the abdominal level, where the pump is surgically placed under the skin. Another incision is made for insertion of the catheter. The catheter is commonly inserted via lumbar puncture into the intrathecal space, where medication can be dispensed into the CSF. Once the patient is admitted to the hospital for surgery, nursing care begins.

Phase 2 Nursing Care

Surgical nursing care for implantation of the baclofen pump is similar to that of other surgeries. First, the patient is observed and monitored in the preoperative area until the surgery is performed. After surgery, the patient is monitored in the recovery room. Once the vital signs are stabilized, the patient may return to his or her hospital room. Because the intrathecal device dispenses antispasmodic medication into the CSF, diligent care is needed. Nurses monitor and provide routine postoperative care such as pain management, demonstrate effective breathing techniques, and monitor for signs of infection at the incision site, and they must be alert for ITB withdrawal and overdose symptoms (Medtronic, 2004; [Table 3]). Another common complication after surgery is a CSF leak from the lumbar incision site, causing headache. If a patient experiences this symptom, the nurse should ensure that the patient lies flat and has adequate hydration; use of caffeine may be helpful. If these measures fail, use of a blood patch may be warranted (Medicinenet, 2006).

After the surgery, most patients stay in the hospital for 2–3 days; some may receive inpatient rehabilitation services to optimize ITB therapy while the pump dosage is titrated to the optimal level. At this time oral medications are also tapered to prevent overdose. Once patients are discharged, it is crucial that they follow up for routine management.

Phase 3: Maintenance of the Baclofen Pump

Once the patient is discharged from the hospital, he or she must follow up with a physician or nurse practitioner. The ITB dosage is titrated and oral medications are adjusted to optimize ITB therapy. Outpatient physical, occupational, and sometimes speech therapy are recommended to restore function and improve comfort. The patient must return to the clinic periodically for medication refills. In older versions of the SynchroMed-EL pump, the baclofen supply lasts 90 days, whereas in the newer SynchroMed-11 pump the baclofen supply lasts 180 days. This means patients must have their pumps refilled at least every 3 or 6 months depending on the pump model used.

Phase 3 Nursing Care

During the maintenance phase, pumps are refilled before the alarm date. Intrathecal pumps are equipped with alarms to indicate certain functions. A low reservoir alarm indicates that medication is getting low in the pump, and a low battery alarm indicates that the pump is failing and must be replaced. The SynchroMed-EL alarm has a soft, chirping single beep, and the SynchroMed-11 has a more audible alarm. Whenever an alarm is heard, nurses must ensure that proper medical attention is provided immediately, including notification to the managing physician. If the alarm sounds outside normal business hours, the patient should go to the emergency room for appropriate care. It is also important that nurses be aware of symptoms of overdose and withdrawal.

Patients with ITB pumps can undergo magnetic resonance imaging (MRI) if needed. However, an MRI scanner strength above 2.0 Tesla is not recommended. The pump must be interrogated before and after the MRI scan to ensure proper functioning because an MRI scan may stall the pump. Patients who travel must remember to carry their pump identification card with them because the pump will activate the airport security alarm. Patients also should have a prescription of oral baclofen available to them in case they experience withdrawal symptoms.

The patient and caregiver must understand the importance of refilling the pump to avoid withdrawal symptoms. Refilling of the intrathecal pump is an invasive procedure and is performed under sterile conditions. Once the pump is refilled, the volume is reset using the programmer, and the alarm date is noted to schedule the next refill visit. Patients should carry a printed telemetry strip from their latest pump refill with them in case more information about the pump is needed in an emergency (Figure 5).

Symptoms of Nonoptimal ITB Therapy

Nonoptimal intrathecal therapy can cause several complications. For example, if the pump is refilled with the wrong baclofen concentration, overdose can happen. Catheter disconnection from the pump or a leak or tear in the catheter can produce withdrawal symptoms. It is strongly recommended that both withdrawal and overdose symptoms be evaluated in conjunction with a thorough review of the system. A thorough review of the system allows the physician to pinpoint other causes of withdrawal and overdose symptoms without delaying care.

Withdrawal Symptoms and Management

Withdrawal symptoms may be produced by simple infections such as urinary tract infections and decubitus ulcers. Severe withdrawal symptoms warrant troubleshooting procedures such as a roller and dye study under fluoroscopy to prevent serious sequelae, including death (see Table 3). Nurses must seek immediate attention for the patient experiencing these symptoms. In some cases ITB withdrawal may resemble conditions such as autonomic dysreflexia, sepsis, malignant hyperthermia, neuroleptic malignant syndrome, and hypermetabolic state. Treatment may include oral baclofen supplementation, intravenous benzodiazepine, and supportive care (Medtronic, 2004).

Overdose Symptoms and Management

Like withdrawal symptoms, overdose symptoms are serious (see Table 3). Nurses caring for this population must be able to recognize these symptoms and seek immediate help for their patients. The most common baclofen concentrations used are 500 mg/ml and 2,000 mg/ml. Other concentrations and mixtures may be used for some patients, based on their condition. Use of an excessive concentration of baclofen can cause overdose symptoms. No specific antidote for ITB overdose exists, but anecdotal reports suggest that physostigmine may reverse drowsiness and respiratory depression. The patient will need supportive care, and the intrathecal pump may need to be stopped (Medtronic, 2004).

ITB therapy demands diligent nursing care, which entails understanding the risks and benefits of this therapy.

Potential Risks and Benefits of ITB Therapy

As with any modality or medication, many risks are associated with ITB therapy. It is highly invasive, which puts patients at risks for surgical complications. Malfunction of the pump or catheter necessitates surgery for correction. Pump refill is also invasive: A needle is used to access and refill the pump. Programming error, the wrong medication concentration, and malfunction of the pump or catheter place the patient at risk for overdose and withdrawal symptoms. Also, the side effects of the medication are similar to overdose and withdrawal symptoms.

The risks of ITB therapy can be minimized as follows:

  • Patients and their caregivers must be educated about overdose and withdrawal symptoms and seek immediate help when needed.
  • Two healthcare professionals should verify the medication concentration before the pump is refilled.
  • Withdrawal symptoms can be managed with oral baclofen until the error is corrected. Ensuring that patients have a supply of oral baclofen in case they experience withdrawal is prudent.

Despite these risks, ITB is a great option to improve function and comfort. Baclofen is delivered in much smaller dosages (micrograms rather than milligrams) and therefore has fewer side effects. This therapy allows individualized dosage titration to reduce spasticity and pain and improve ADLs and mobility. Such improvements also decrease caregiver burden.

Future Research

ITB therapy holds promise for patients suffering from spasticity. Taricco, Adone, Pagliacci, and Telaro (2000) noted that both clinical indicators and subjective evaluation of antispasmodic therapy by patients who are using these therapies are needed. Further research is needed to address functional gain, quality of life issues, and appropriate outcome measures to evaluate spasticity in the ITB population and promote evidence-based practice.

Conclusion

ITB therapy uses state-of-the-art technology to deliver medication in a minute amount directly into the CSF. Although this technology is helpful in decreasing spasticity and improving function and comfort, meticulous nursing care is needed to use this therapy safely. Nurses must know how to provide competent clinical care in all phases of this drug delivery system. It is imperative that nurses know what to do if complications arise and provide anticipatory guidance to patients who are using this therapy. The art and science of nursing allow nurses to differentiate ITB therapy from the other drug delivery systems. It is imperative that nurses caring for this population understand ITB therapy.

About the Author

Rozina Bhimani, MSN RN FNP, is a nurse practitioner with Sister Kenny Rehabilitation Associates at Abbott Northwestern Hospital in Minneapolis, MN. Address correspondence to her at rozina.bhimani@allina.com.

References

Azouvi, P., Mane, M., Thiebaut, J. B., Denys, P., Remy-Neris, O., & Bussel, B. (1996). Intrathecal baclofen administration for control of severe spinal spasticity: Functional improvement and long-term follow-up. Archives of Physical Medicine and Rehabilitation, 77(1), 35–39.

Boviatsis, E. J., Kouyialis, A. T., Korfias, S., & Sakas, D. E. (2005). Functional outcome of intrathecal baclofen administration for severe spasticity. Clinical Neurology and Neurosurgery, 107, 289–295.

The Cleveland Clinic Health Information Center. (2006). Overview of intrathecal baclofen. Retrieved September 15, 2006, from www.clevelandclinic.org/health/health-info/docs/0300/0369.asp?index=4590.

Dario, A., Scamoni, C., Bono, G., Ghezzi, A., & Zaffaroni, M. (2001). Functional improvement in patients with severe spinal spasticity treated with chronic intrathecal baclofen infusion. Functional Neurology, 16(4), 311–315.

Gwartz, B. L. (2001). Intrathecal baclofen for spasticity caused by thrombotic stroke. American Journal of Physical Medicine and Rehabilitation, 80(5), 383–387.

MD Virtual University. (2006). Spasticity. Retrieved September 28, 2006, from www.mdvu.org/library/disease/spasticity/.

Medicinenet. (2006). Management of spinal headache. Retrieved October 1, 2006, from www.medicinenet.com/spinal_headaches/article.htm.

Medtronic. (2004). Clinical reference guide: Management of spasticity using intrathecal baclofen pump. Minneapolis: Author.

Ochs, G. A., & Tonn, J. C. (1996). Functional outcome and clinical significance of long-term intrathecal baclofen therapy for severe spasticity. Journal of Neurology and Rehabilitation, 10, 159–166.

Parke, B., Penn, R. D., Savoy, S., & Corcos, D. (1989). Functional outcome after delivery of intrathecal baclofen. Archives of Physical Medicine Rehabilitation, 70, 30–32.

Penn, R. D., Savoy, S. M., Corcos, D., Latish, M., Gottlier, G., Parke, B., et al. (1989). Intrathecal baclofen for severe spinal spasticity. New England Journal of Medicine, 320, 1517–1521.

Sampson, F. C., Hayward, A., Evans, G., Morton, R., & Collett, B. (2002). Functional benefits and cost/benefit analysis of continuous intrathecal baclofen infusion for the management of severe spasticity. Journal of Neurosurgery, 96, 1052–1057.

Schaeybroeck, P. V., Nuttin, B., Lagae, L., Schrijvers, E., Borghgraeef, C., & Feys, P. (2000). Intrathecal baclofen for intractable cerebral spasticity: A prospective placebo-controlled double blind study. Neurosurgery, 46(3), 603–612.

Taricco, M., Adone, R., Pagliacci, C., & Telaro, E. (2000). Pharmacological interventions for spasticity following spinal cord injury. Cochrane Database of Systemic Reviews, 2(CD001131).