Baclofen pump catheter leakage after migration of the abdominal catheter in a pediatric patient with spasticity

Baclofen Stability up to One Year in In Vivo Intrathecal Infusion Pumps

OBJECTIVES

Commercial intrathecal baclofen treatment (ITBT) infusion pumps are recommended to be refilled within a maximum of 180 days, thus necessitating at least twice-yearly outpatient visits and refill injections. In particular, pumps with 40-mL reservoir volumes would allow much longer refill intervals. We investigated baclofen stability in active implanted ITBT infusion pumps in vivo with refill intervals up to 367 days to study the feasibility of lengthening refill intervals beyond six months.

MATERIALS AND METHODS

We obtained 25 baclofen samples from 19 patients receiving ITBT with varying pump refill intervals. All patients had a baclofen infusion system delivering undiluted 2 mg/mL baclofen at continuous rates of 96.1 to 673.7 μg/d with a concentration of 2.002 mg/mL. Baclofen concentrations of the infusate samples acquired during the refill procedures were analyzed using a validated high-performance liquid chromatography with diode-array detection (HPLC-DAD) assay, later complemented with repeat assay with pH and physical measurements. We also present the validation data of the HPLC-DAD assay.

RESULTS

During the mean refill interval of 247 days (SD 90, range 54-367 days), the mean change in baclofen concentration was -0.0156 mg/mL (-0.8%, SD 0.14, range -0.30 to 0.32 mg/mL, paired t-test p = 0.57, t24 = 0.57). Only a low negative correlation was found between the baclofen concentration and the refill interval (Pearson's r = -0.32, p = 0.12).

CONCLUSIONS

We could not show a significant change in baclofen concentration over the time studied; 2 mg/mL baclofen ITBT refill intervals could be lengthened to up to one year-the theoretical maximum refill interval in our cohort would have been 489 days. Further studies with larger sample sizes and other baclofen brands are warranted.

Characterizing Baclofen Withdrawal: A National Survey of Physician Experience

OBJECTIVE

We studied physicians' opinions and experiences concerning clinical concerns, perceived severity, occurrence, and management of baclofen withdrawal due to abrupt discontinuation.

METHODS

A nationwide 26-question electronic survey was distributed via e-mail to physicians (N = 952) representing varying specialties who manage spasticity with baclofen. A total of 110 physicians provided responses to the survey (response rate = 11.6%). Results were evaluated using descriptive statistics.

RESULTS

Withdrawal from both oral and intrathecal (IT) baclofen was recognized as a significant concern and was observed by most respondents. However, approximately 75% and 35% of respondents or their clinic sites lack established management protocols for managing anticipated interruption of oral or IT baclofen, respectively.

CONCLUSIONS

These findings highlight the need for further research on and the development of guidelines for the prevention and treatment of baclofen withdrawal. The results of this survey, along with a systematic literature review and multidisciplinary stakeholder input, may be helpful in establishing guidelines for the treatment and prevention of baclofen withdrawal.

Adverse events associated with paediatric intrathecal baclofen in Australia: 5 years of data collection

AIM

This study aims to examine the adverse event (AE) rate for intrathecal baclofen (ITB) therapy in an Australian paediatric population and to clarify type and frequency of AEs.

METHODS

AE data were extracted from the Australian Paediatric ITB Research Group national database, to include the first 5 years of data collection. Raw data were collated and analysed descriptively.

RESULTS

Data were collected for 40 patients. Forty-seven AEs in 23 patients were reported. Ten (25%) patients required surgical intervention related to their AE. Five patients (12.5%) required pump removal. The most frequent ITB-related AEs were catheter dysfunction (24%), drug overdose, withdrawal or sensitivity (19%), seromas and haematomas (15%) and infections (13%).

CONCLUSIONS

The AE rate for ITB therapy is high and needs to be considered when counselling patients regarding ITB as a therapeutic option.

The use ultrasound guided for refilling intrathecal baclofene pump in complicated clinical cases: A practical approach

Muscular spasticity due to neurological disorders is a heavy cause of severe pain and disability for many patients, compromising the independence and quality life. Baclofene is a good tool to guarantee patients independence and pain control. Anyway in chronic therapy oral treatment become unsatisfactory. In all these cases, intrathecal baclofen therapy (ITB), after sub fascial implantation of intrathecal pumps is used as an important long term treatment to reduce spasticity. After pump implantation the drug reservoir must be refilled periodically in order to maintain the reduction of spasticity and avoid the symptoms and signs of withdrawal. ITB refilling, which involves the insertion of a needle through the skin until the access port of the pump, is often hard, mainly due to the layer of abdominal fat, spasticity, suboptimal pump positioning, pump rotation or inversion, and scar formation over the implantation site. To avoid the difficulties of ITB refilling radiography or other invasive supportive examinations are sometimes needed. We reported here our experience and we suggest a simple method to use the ultrasound in refilling with particular attention to some cases with complications after implantation with a difficult approach in refilling. We used the ultrasound examination to identify the access port of her pump so as to avoid multiple needle punctures and infections and radiation exposition. Ultrasound-guided technique may facilitate ITB refill in technically challenging cases. With ultrasound ITB was easily detectable and was quite simple to identify the exact point of needle injection. In the last years different new applications for ultrasounds are emerging. In our opinion the use of Doppler ultrasounds in the study of muscles and nerves represent an emerging tool for the physician's neurological rehabilitation.

Plain radiography in patients treated with intrathecal drug delivery using an implantable pump device

OBJECTIVES

Intrathecal drug administration using an implanted pump system is well established in intractable spasticity and pain. However, despite continuous advancements in manufacturing technology, adverse events related to the pump and catheter still occur. Most of them, such as migration, damage, disconnection and occlusion, are related to the spinal catheter. The aim of this overview is to update radiologists on how plain radiography of the implanted delivery system for intrathecal drug administration should be interpreted and to increase awareness for the need of urgent and timely multidisciplinary troubleshooting.

METHODS

Plain radiographic images of patients treated with intrathecal drug administration using an implantable drug delivery system were analysed in a multidisciplinary setting at our (university) referral centre for complications in intrathecal drug administration.

RESULTS

Examples of catheter-related adverse events are described and a proposal is made for stepwise interpretation of standard plain radiographic images.

CONCLUSIONS

Plain radiological images are the mainstay for the diagnosis of catheter-related adverse events in intrathecal drug delivery. Radiologists play an important role in an early diagnosis. An awareness of abnormal radiological findings seems important to avoid a life-threatening withdrawal syndrome.

TEACHING POINTS

• Untimely cessation of intrathecal drug delivery can lead to a life-threatening withdrawal syndrome. • Initially mild symptoms can lead to an exacerbation of a withdrawal syndrome. • Most intrathecal catheter-related problems are visible on plain radiography. • Common causes of catheter problems are migration, lacerations, occlusion and disconnection. • Knowledge on implanted intrathecal catheters is crucial for interpretation of plain radiography.