Several risks are involved with placement of baclofen pumps. Stempien and Tsai[35] published perhaps the single most comprehensive study of ITB complications in a survey of 40 centers with a total experience of 1002 test doses and 936 pump placements. Common test-dose complications were nausea/vomiting (2.6%) and sedation (2.2%). Pump complications included CSF collection (3.3%), constipation (2.9%), and headache (2.4%). Common long-term complications were catheter kink or migration (4%) and in fection (1.2%).
Even with safe surgical techniques, some common com plications of baclofen pump placement still occur. Ex cessive swelling may be a sign of a developing seroma, sometimes requiring percutaneous drainage. A CSF leak may be detected by a spongy swelling around the incision site, sometimes characterized by a ripple effect when tap ped. Standard measures to reduce local CSF pressure at the level of the defect, such as having the patient lie flat without a pillow, are often sufficient. Other measures in clude using a blood patch and/or abdominal binder.
In the product manual, Medtronic warns of specific risks related to the pump itself. For instance, heating of local tissue in circumstances such as short-wave dia thermy within 30 cm of the pump or catheter has been shown to elevate temperatures and cause baclofen overinfusion. Sour ces of electromagnetic interference like magnetic resonance imaging will temporarily stop the pump motor’s ro tor due to the magnetic field of the imager, leading to brief disruption of intrathecal therapy. Furthermore, in creases in environmental pressure have been found to lead to slower infusion rates. Therefore, a patient must be warn ed before participating in activities such as scuba diving. Con versely, lower pressures will lead to higher infusion rates. Patients participating in extended high-altitude ac tiv ities or stays may therefore require readjustment.
A special note should be made about the risks of infection. Normal hallmarks of infection such as warmth or red ness around the incision site should be observed and monitored closely. More ominous signs, such as purulent drainage, should be dealt with on an emergency basis, be cause severe infections may lead to meningitis. Pump removal and intravenously administered antibiotic drugs appropriate for the infecting bacteria are then indicated. In general, infection rates for baclofen pumps implanted to deliver the drug in an effort to treat spasticity appear to range from 0.7 to 1.7%.[30,35] Meningitis in patients with implanted pumps ranges from 0 to 0.7%.[28] Infections of the pump rather than the reservoir or catheter appear to be most prevalent in the literature. Reported infections ap pear to involve the perioperative period after placement of the pump. The most common offending bacteria are Staph y lo coccus aureus or S. epidermidis. Repeated percutaneous refills appear to carry little risk of infection. One theory suggests that the host-derived albumin coating of the pump pocket reduces the risk of colonization.[37] There are also reports of colonization of implanted pump reservoirs by bacteria and fungus without clinical infection.[31]
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Read More: Intrathecal Baclofen In the Treatment of Adult Spasticity: Risks