title: Magnetic fields and intrathecal pump malfunction.
abstract: Medical technology has impacted the overall life expectancy. Many conditions traditionally considered fatal are now curable. Surviving chronic diseases and aging of the population have increased the number of people with chronic pain. Many devices are also available to manage severe refractory pain. As such, implantable drug-delivery system (IDDS) is a small battery-powered, programmable pump implanted under the subcutaneous tissue of the abdomen and connected to a small catheter tunneled into the spine. Implantable drug-delivery system is used for the administration of morphine, ziconotide, baclofen, or their mixtures into the cerebrospinal fluid. Like many medical devices, IDDS has technical glitch which limits its performance under certain conditions. Implantable drug-delivery system is susceptible to magnetic field such as a magnetic resonance imaging (MRI) which can temporarily stall the rotor of the pump motor and suspend drug delivery. We encountered a patient from out of town seen at emergency department with increased pain and symptoms of opiates withdrawal after intermittent IDDS malfunction. He denied any exposure to magnetic fields or MRI. However, the pump interrogation showed multiple motor stall events in the event log. After a detailed inquiry, the most likely cause of pump malfunction appears to be frequent placement of a laptop computer on his abdomen close to the pump. The magnets in the laptop speakers may have caused the rotor of the pump motor to stall during the computer use, and frequent stall has caused symptoms of withdrawal. No other mechanical failures were found. The patient was discharged home after the symptoms resolved, and the pump was reprogrammed.
authors.affiliation: Department of Pain Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: Billy
authors.initials: B
authors.lastname: Huh
authors.affiliation: Department of Pain Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX; Department of Emergency Medicine, The University of Texas Health Science Center at Houston, Houston, TX; Memorial Hermann-Texas Medical Center, Houston, TX; Lyndon B. Johnson General Hospital, Houston, TX; The University of Texas MD Anderson Cancer Center, Houston, TX. Electronic address: croldan@mdanderson.org.
authors.forename: Carlos J
authors.initials: CJ
authors.lastname: Roldan
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage*; D001416:Back Pain / Q000188:drug therapy* / Q000209:etiology; D019544:Equipment Failure Analysis; D006801:Humans; D007260:Infusion Pumps / Q000009:adverse effects*; D060526:Magnetic Fields / Q000009:adverse effects*; D008297:Male; D008838:Microcomputers; D008875:Middle Aged; D009101:Multiple Myeloma / Q000150:complications
chemical_list: D000701:Analgesics, Opioid