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The following case study was
written for Medtronic with consultation from: Elliot Krames, M.D. The experiences presented here are specific to this particular patient. Results may vary; not every response is the same. Clinical History and Presentation This 53-year-old female patient presented in June 1995, with severe pain of her lower back, right buttock, leg, and foot. She rated the pain at 8-9 on a 10-point scale and described the pain as "cramping, burning, radiating, and squeezing." She said the pain was constant, with an intense ache in her lower back. Pain radiated hot across her hip and buttock, down the posterolateral aspect of her leg to the sole and top of her foot. The pain also affected her anterior thigh and tibia. Walking, sitting, squatting, or standing for long periods of time increased her pain. The patient's sleep was frequently interrupted by pain. She complained of a decreased libido and social life, and said she felt edgy and distracted by her pain. Physical examination showed decreased ankle reflex on the right side. Hyposthesia was noted in the distribution of L5 and S1 on the right side. Motor examination was within normal limits. She was receiving hydrocodone bitartrate/acetaminophen (6-8/day), which provided inadequate pain relief and caused nausea. She also received cyclobenzaprine hydrochloride, which provided occasional minor relief; and fluoxetine, which alleviated some depression. The patient's pain began in February 1987, when she slipped on a cleaning solvent in her home and experienced low-back, right buttock, and leg pain, which subsided with rest. She again experienced back, buttock, and leg pain while transferring a patient as an O.R. nurse in January 1989. The pain pattern was identical, and the severity did not abate during the ensuing months. She received hydrocodone bitartrate/acetaminophen, which provided minor relief but caused nausea. In May 1989, she was again at work in the O.R. when extreme pain erupted in her back, buttock, leg, and foot. She received a trigger-point injection, which did not provide relief. She was unable to work because of intolerable pain. In June 1989, an MRI revealed an L4/5 disk herniation, and the patient entered a physical therapy program, which afforded minor pain relief. She received two epidural steroid injections, but no pain relief was achieved. The patient also received three series of three colchicine injections in her arm. They did not provide pain relief. In October 1989, the patient underwent a posterior lumbar interbody fusion procedure (PLIF), and her pain was reduced considerably. However, the pain returned within four months. Her physical therapy regimen provided inadequate pain relief. She received two epidural steroid injections, which failed to provide relief. A CAT scan in October 1990, revealed a non-union of the PLIF. Her pain continued to increase and the procedure was repeated in May 1991. The patient’s pain remained severe. Fluoxetine was moderately effective for depression. In October 1991, she tried a TENS unit, which was ineffective for pain relief. She received oxycodone and acetaminophen, but no pain relief was achieved. She also received two epidural steroid injections, but these were ineffective. Cyclobenzaprine hydrochloride was prescribed and occasionally provided minor relief. A screening test for neurostimulation was performed in August 1993, but provided no significant pain relief. Her severe pain remained. Bilateral sympathetic nerve blocks were negative in April 1995. After presentation at the Pacific Pain Treatment Center in San Francisco, the patient enrolled in a pain rehabilitation program with little result. She received methadone for approximately six months, but experienced constipation, sweating, confusion, and urinary retention. She also received two epidural steroid injections and bilateral sympathetic nerve blocks, all of which were ineffective. Oxycodone controlled-release tablets were added to the pain-control regimen, but discontinued after two weeks because of nausea. The patient received 90 mg/day of morphine sulfate controlled-release tablets in November 1996, which produced fair pain control. As her pain increased, the dosage was increased to 180 mg/day, which improved pain control, but produced cognitive impairment. A trial with gabapentin and fentanyl transdermal patches extended pain control, but also caused cognitive impairment. The patient returned to a regimen of only morphine sulfate controlled-release tablets, but her memory was poor, and her pain was severe (8-9+/10). The patient was very depressed as she was unable to work, cook, socialize, take care of her home, or tend to her grandchildren. [Top]Intrathecal Drug Delivery In late October 1997, the patient underwent placement of a temporary intrathecal catheter for a screening test for intrathecal drug delivery. A 24-gauge pediatric spinal catheter was placed at the T10 level using fluoroscopic guidance, and connected to an external pump. An infusion of preservative-free morphine sulfate was started at 100 mcg/hr. The patient experienced excellent pain control of all painful areas and was discharged the same day. During the four-day test period, the patient reported 100 percent pain relief and slept comfortably. On Nov. 3, 1997, the catheter was removed and she experienced a spinal headache, which resolved with a blood patch. On Nov. 13, 1997, while under general anesthesia, the patient underwent implantation of the SynchroMed® Infusion System. A catheter was introduced into the intrathecal space and the catheter tip was positioned at T10. The catheter was then tunneled beneath the skin and connected to the SynchroMed pump, which was placed in a subcutaneous pocket in the right lower quadrant of her abdomen. The pump reservoir was filled with preservative-free morphine sulfate, and the patient was started on a continuous infusion rate of 2 mg/day. [Top] Results The patient initially experienced a sharp pain in her right leg, which was attributed to catheter irritation of a nerve root. This pain resolved without treatment over the following week. Three weeks after implantation, the patient rated her pain at 6/10 and reported that she was sleeping more comfortably. Her intrathecal morphine was increased to 4 mg/day, and the oral morphine dosage was reduced from 180 mg/day to 60 mg/day. The oral medication was completely eliminated four weeks after the implant surgery, and the patient was gratified to reclaim her cognitive abilities. Two months after implant, the patient reported 95 percent pain relief. She occasionally experiences urinary hesitation. The patient is able to garden, cook, travel, socialize, and sleep comfortably with intrathecal drug delivery. Nine months after the implant surgery, she and her husband took a 15,000-mile road trip around the United States. The patient’s infusion pump is refilled percutaneously approximately every three months, and the nurse has reported no difficulties with this procedure. The current dosage is 6.05 mg/day. Because the pump and catheter are implanted, surgical complications, such as infections, are possible. The catheter could become dislodged or blocked, or in rare cases, the pump could stop working. This could cause a reduction in or loss of pain relief that would require surgical revision to correct. The most common drug side effects reported are pruritus, urinary retention, and constipation. See the SynchroMed infusion system technical manual and prescribed drug labeling for complete information regarding indications, contraindications, warnings, precautions, and adverse events. Dr. Krames is the medical director at Pacific Pain Treatment Center in San Francisco. [Top]
Individual results may vary. Not every individual will experience the same benefits. See Important Safety Information and Risks for information about the risks associated with intrathecal drug delivery. [Top] To
see Patient Selection for Intrathecal Drug Delivery. . . |
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Chronic
Back and Leg Pain