Discussion
The objective of this retrospective chart review and database development was to identify trends in ITB management to better choose, educate, and treat patient swith severe spasticity. Findings reflect practices, complications, and effects of ITB described in previously published summaries (Albright, 2003; Albright etal., 2003; Emery, 2003; Stempien & Tsai, 2000; Gilmartin et al., 2000;Ivanhoe et al., 2000). Catheter tip location, infusion mode, and complication rates were three changing trends identified.
Placement of the intrathecal catheter tip at a higher vertebral level was one course in this evolving therapy. In the early 1990s the standard catheter tip placement was the lower thoracic region of the spinal canal. The frequently cited research of Kroin,Amjad, York, and Penn (1993) reported that after intrathecal infusion in 5 patients, there was gradual decline in hydrophilic radionuclide in cerebrospinal fluid between T2 and T12 levels. It was concluded that placing the catheter tipat more rostral levels may not provide any advantage. However, Grabb, Meythaler,and Guin-Renfroe (1999) reported midthoracic (T6-T7) placement of the catheter tip provided greater reduction in upper extremity spasticity without loss of effect on lower extremities despite lower baclofen dosages. In addition, no complications were related to higher positioning of the catheter tip in the spinal canal. Ivanhoe et al. (2001) reported the practice of placing the catheter tip at T6-7 was gaining favor to increase upper extremity benefit without losing lower extremity effectiveness. Experienced ITB therapy providers at high-volume centers reported placing the catheter tip at C7 to T2 region for treatment of spastic quadri-paresis and T10-12 for treatment of spastic-paraparesis as standard practice (L. Albright, M. Turner, G. Bilsky, and L.Krach, personal communication, March 6,2004).
The second change that evolved was dosingpatterns and use of various infusion modes. Although doses vary among allpatients receiving ITB, these findings reflect programming differences fordiagnostic groups as described by others. Simple infusion mode was commonly usedlong term for all patients 10 years ago. Simple infusion continues to be usedfor the titration phase and ongoing dosing for patients with stable andconsistent tone like those with spinal cord injury. However, maximizing therapyby individualizing infusion and dosing has become routine. As stated earlier,two-step complex infusion with higher night dosing aides patients with MS.Multiple dose change throughout the day using complex or periodic bolusaccommodates patients with CP. Periodic bolus provides advantages whilemaintaining total daily dose without increased side effects. In addition, atherapeutic effect was maintained in children with CP with incremental dosetitration over the first 2-3 years, at which time the dose tends to leveloff (Albright et al., 2003; Awaad et al., 2003; Gilmartin et al., 2000). Also, ahigher dose was commonly required for patients with spinal cord injury comparedto patients with multiple sclerosis (Penn et al., 1989). Overall, dosing changeshave become more conservative for patients with cerebral palsy and MS comparedwith dose changes for bed-bound patients with spinal injury or traumatic braininjury.
Safety of ITB therapy varies over timeand mechanism of reporting. However, this report of 44% of more recentlyimplanted patients experiencing adverse events is similar to other reports(Albright et al., 2003; Follett & Naumann, 2000; Gianino, York, Paice, &Shott, 1998; Stempien & Tsai, 2000) and demonstrates the thirdtrenddecreased problems over time. Stempien and Tsai found thatimprovements in equipment such as catheter durability and maneuverabilityprevent system failure. Experienced implanting neurosurgeons state that changesin technique and equipment, particularly catheters, have decreased theircomplication rates (L. Albright & M. Turner, personal communication, March6, 2004).
The improved safety of ITB therapy atthis center can be related to revised equipment, as well as techniques forsystem management. Equipment changes that influenced the decrease incomplications included use of the pump with a catheter access port. This modelwas routinely implanted after the first year, which allowed safe and easyaspiration of the complete catheter volume and infusion of contrast to assesscatheter patency. Therefore, decreased accidental overdosing was prevented. Inaddition, remodeled catheters, connectors, fasteners, and software enhanced thesafety profile.
Changes over time in technique and clinician experience in each phase of the therapy that could explain decreased complications and drug adverse event include the following:
refined patient selection with consideration ofcomorbidities and required treatments
patient education for early identification ofpotential pump/catheter system or drug problems
revised technique for securing catheter at spineentry site
pump replacement at anticipated end-of-batteryservice to avoid withdrawal
rapid and safe evaluation to identify systemfailure
anticipated catheter malfunction if dose increasedwith little or no effect.
Development of realistic goals and measuring change from ITB therapy deserves further discussion. Many report outcomes of chronic ITB therapy. Some quantify functional changes (Awaad et al., 2003) and others use patient and care giver subjective perception of ease of care, improved comfort, and satisfaction with results. This report, like that of Krach, Nettleton, and Klempka (2003),demonstrates that despite complications associated with the developing technology, few patients regret their choice of having the system implanted.However, because the therapy benefits a wide range of disabilities, developing specific team generated goals and quantifying change has been challenging. As therapy evolves, gold standard clinical evaluation of technical, functional,patient satisfaction, care and comfort, and cost-effective outcomes as described by Pierson (1997), as well as multiple levels of evidence, should be applied to further enhance ITB therapy.
J Neurosci Nurs. 2004;36(6):322-327. © 2004 American Association of Neuroscience Nurses
Cite this: Intrathecal Baclofen Therapy Over 10 Years - Medscape - Dec 01, 2004.
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