Intrathecal Drug Delivery

Patient Profile

33-year-old female with pain in her peri-umbilical region following a sledding accident that ruptured her spleen. Her pain was constant, severe, and burning and radiated into her pelvis, with areas of intermittent stabbing pain. Allodynia, edema, and color changes were noted.

Intervention Prior to Referral

The patient had a long history of hospitalizations and repeated surgeries following a sledding accident in 1977. At that time she underwent an exploratory laparotomy and splenectomy.

Between 1981 and 1982, the patient was repeatedly hospitalized for abdominal pain, and she underwent repeated exploratory laparotomies for lysis of adhesions. An appendectomy was also performed during one of the procedures. The pain abated for approximately 2 years, when she worked as a hospital nurse.

The patient began experiencing severe abdominal pain, nausea, and vomiting in December 1984. An exploratory laparotomy, lysis of intestinal adhesions, removal of a right corpus luteum ovarian cyst, and repair of an umbilical hernia were performed. The pain resolved.

The abdominal pain returned in January 1987, and the patient underwent repeat exploratory laparotomy for lysis of adhesions, which required 3 weeks of hospitalization. A diagnosis of endometriosis was made, and she received danazol until August 1987. Satisfactory pain relief was achieved.

In December 1987, return of the patient's abdominal pain necessitated an exploratory laparotomy, lysis of adhesions, and removal of a right ovarian cyst. Her pain dissipated following surgery.

In May 1989, the patient delivered a healthy baby via C-section. In December of that year she was admitted to the hospital on an emergency basis because of abdominal pain, spiking temperatures, and high WBC count.

She was diagnosed with intra-ovarian abscesses, a massive pelvic infection, and peritonitis and was treated with IV antibiotics. The pain terminated within a few weeks.

In September 1990, she was admitted to the emergency room for pain from pelvic inflammatory disease and treated with IV antibiotics. The pain resolved.

The patient experienced pain again within 2 months, and underwent an exploratory laparotomy, left salipingio-oophorectomy, presacral neurectomy, and lysis of adhesions.

Post-operative pain required administration of epidural morphine. The patient continued to experience moderate pain after her release from the hospital. She reduced her work schedule because of the pain.

The patient's pain increased and radiated into her lower extremities. In February 1991, 3 lumbosacral epidurals were performed with sciatic nerve blocks. These offered excellent relief of her symptoms, and she was asymptomatic for 2 months. (Pain in her lower extremities did not recur.)

When the pelvic and abdominal pain returned, she received another lumbosacral epidural, but this time it provided no pain relief. In December 1991, severe pain prompted a re-exploration and extensive lysis of abdominal and pelvic adhesions, a cystoscopy, and a partial right salipingio-oophorectomy. Moderate pain relief was attained for approximately 1 year.

Mounting pain in 1993 compelled the patient to undergo evaluation at a pain center in Long Island, N.Y., where she received multiple injections of anti-inflammatories in the peri-umbilical area.

A number of oral pain medications were attempted over the next few years, including: morphine sulfate controlled-release tablets, hydromorphone hydrochloride, diazepam, venlafaxine hydrochloride, tramadol hydrochloride, metaxalone, aspirin, and ibuprofen. These provided moderate pain relief but also caused excessive somnolence. It was very difficult for the patient to cope, and she left her nursing job.

The patient became very dependent on the pain medications. In September 1995, she exhibited nervousness, agitation, and suicidal tendencies and subsequently underwent drug detoxification. Within a few weeks, the patient's pain medication was reduced to only tramadol hydrochloride. This provided very minor relief.

An epidurogram with neurolysis was attempted late in 1995, but did not provide pain relief. Her pain continued to be severe. She rated it as 10 on a 10-point scale. In view of the patient's repeated surgical interventions and the relative failure of pharmacotherapy for pain relief, a screening test for intrathecal drug delivery was chosen.

Physical Examination Prior to SynchroMed^® Implantation

On April 10, 1996, the patient underwent a screening test for intrathecal drug delivery and received an injection of 1 cc of preservative-free morphine sulfate at the L1 vertebral level. She experienced a tremendous reduction of her pain symptoms for 1½ days. During the test period the patient rated her pain at 0/10 to 2/10.

The patient was extremely pleased with the results of the test. She did not experience any side effects from the screening test and was released the next day.

Intrathecal Drug Delivery

On May 3, 1996, the patient underwent implantation of the SynchroMed^® Infusion System while under general anesthesia. A catheter was introduced into the lumbar intrathecal space, and the catheter tip was positioned at L1.

The catheter was then tunneled under the skin and connected to the SynchroMed Pump, which was placed in a subcutaneous pocket in the left upper quadrant of her abdomen. The pump reservoir was filled with preservative-free morphine sulfate, and she was started on a dose of 1 mg/day.

Her pain control was excellent. The patient did not experience any complications from the surgery and was discharged the next day.

Results*

With the exception of an intermittent dull ache, the patient's abdominal and pelvic pain has been reduced. She occasionally uses nonprescription naproxen sodium tablets, but requires no other medications for pain.

The patient's pain has decreased and she is able to perform all activities of daily living comfortably. She walks, bathes, shops, does housework, and participates in social and recreational activities, such as coaching soccer teams. She is starting a support group for other patients with pain and plans to return to work, applying her nursing skills in the pain-management field.

Follow-up

The patient's dosage was increased to 1.5 mg/day in November 1996 and has remained unchanged.

Dr. Adler is the Director of Pain Management at Good Samaritan Medical Center in West Islet, N.Y., and the Director of Comprehensive Pain Care of Long Island in Long Island, N.Y. She has extensive experience with Medtronic intrathecal drug delivery systems.

* Individual results may vary. Not every individual will experience the same benefits. See Indications, Safety & Warnings for information about the risks associated with intrathecal drug delivery.

Patient Profile

The 39-year-old patient injured his back in a lifting/twisting incident while doing his job as a laborer. Secondary to two laminectomies and two fusions, the patient developed epidural fibrosis and significant nociceptive, somatic pain in his back and both legs.

The pain in the left leg was more severe than the pain in his right leg. His back and left leg pain were equally severe.

Intervention Prior to Referral

A neurostimulation system was implanted in the late 1980s, and provided some pain relief for over 1 year. However, the electrode migrated over time and the patient opted to have the system removed. Subsequently, his continuing pain was aggressively treated with oral narcotics.

At the time of his referral for evaluation to receive an intrathecal drug infusion system, the patient had developed medication dependence and tolerance. Blood tests revealed elevated liver enzyme levels. He was severely depressed, obese, and physically deconditioned.

Both physical and psychological assessments revealed this patient to be a poor candidate for intrathecal drug delivery. His drug dependence and tolerance were believed to be iatrogenic in nature. His MMPI testing revealed hypochondriasis, over-reactivity, and mental confusion. He was recommended for detoxification.

Following a 2-week detoxification program, the patient was admitted to a 4-week residential pain and rehabilitation program. He responded extremely well to the physical and behavioral therapy and his level of pain was reduced by 60 to 70 percent. All his psychological test scores improved. He was able to return to work without further intervention.

His pain remained in good control for 1 year, but then he slipped and fell re-injuring his back. The pain returned to its prior intensity, and he was unable to regain control of it through rehabilitation.

Intrathecal Drug Delivery: Evaluation and Results*

Experience with the patient indicated that he was now a physically and psychologically appropriate candidate to evaluate for intrathecal drug delivery. All prior concerns regarding the patient's psychological appropriateness had been addressed during the patient's prior rehabilitation process. The patient was no longer addicted, he had a good understanding of behavioral techniques for controlling pain, and realistic treatment expectations.

As is typical in our practice, in preparation for a two-stage screening test with intraspinal opioids, the patient was hospitalized to withdraw him completely from all opioids. His pain was managed with anti-inflammatory agents, anti-depressants, muscle relaxants, and antihistamines for one week prior to the screening test.

In the first stage of the screening test, the patient received a single intraspinal injection of morphine on an outpatient basis.

His favorable response to the bolus dose allowed him to proceed to the second stage of the screening test. Some days later, the patient was hospitalized on a 23-hour admission basis for the placement of an epidural catheter and an external pump system for a screening test with epidural morphine.

During this time, the patient received 2 to 3 hours of physical conditioning therapy, 5 days per week. The patient responded extremely well. He experienced at least 80 percent relief of pain and was able to increase his activity level. His ability to sleep improved and he was not seeking other medications. His spouse corroborated improvements in all these areas.

He experienced no cognitive or physical side-effects from the morphine. At the end of the successful 2-stage screening test, the patient was implanted with a SynchroMed^® infusion system and experienced excellent pain relief with the initial dose of 1 mg per day of intrathecal morphine. He returned to work and all his usual activities.

Follow-up

At the end of 1 year his dose had increased to 3.5 mg per day to provide pain relief appropriate for his active lifestyle. At 2 years post-implant, the patient was still on the job and coping well.

Discussion

Careful patient selection, thorough assessment, and aggressive rehabilitation are key to achieving a good outcome with intrathecal drug delivery. In this case study, the patient's initial assessment found him to be an unsuitable candidate for intrathecal drug delivery because of his addiction to pain medication.

With detoxification and rehabilitation, this patient's pain was reduced sufficiently to allow him to return to work without further intervention—until he was re-injured.

The barriers to the patient's consideration for intrathecal drug delivery were removed by his previous detoxification and rehabilitation process, and he was deemed a suitable candidate following his second injury.

The screening process at the Pain and Rehabilitation Institute is complex by design. The 2-stage screening process is more expensive than screening with a single bolus dose. However, if it can assure that inappropriate patients are eliminated from consideration early, the expense is well worth it.

Throughout the process the patient's commitment to getting well and willingness to cooperate with the therapy are tested.

The withdrawal of all pain medications for a minimum of 7 to 10 days prior to the first stage of the screening test assures an uncompromised screening test and demonstrates the patient's commitment.

Under these conditions if the bolus injection does not provide the patient reduction in pain greater than 60 to 70 percent, no further screening with this therapy is warranted.

If the patients respond positively to the first stage of the screening test, they progress to the second stage of the screening test.

During this second stage patients participate in rehabilitation and have the opportunity to test their experience of the therapy more fully. Patients are encouraged to plan for their return to work, if appropriate. The multidisciplinary treatment team works with patients to set realistic treatment goals.

During this 2-week period both the patient and the multidisciplinary team have the opportunity to thoroughly assess whether the patient will benefit sufficiently to make implanting a SynchroMed drug infusion system a good investment.

For the patient under discussion, the therapy was indeed cost-effective. It allowed him to return to work. At age 39, the patient has many working years remaining. It is likely that these would otherwise have been unproductive years—paid for by the Workers' Compensation system.

When a patient is implanted, the clinic's commitment to the patient is just beginning. Post-implant rehabilitation is required to assure that therapeutic goals are realized. The patient will also return for dose adjustments and drug refills. Patients are required to sign a contract stipulating that they will not seek pain medications from any other source.

There is a maxim among physicians involved in the therapy: "If you implant the patient, you are married to the patient." An important corollary to this is: "If you are uncomfortable with the patient, don't implant him or her." Keeping these 2 sayings in mind will help physicians make judicious decisions in patient selection and thereby improve patient outcomes.

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* Individual results may vary. Not every individual will experience the same benefits. See Indications, Safety & Warnings for information about the risks associated with intrathecal drug delivery.

Patient Profile

In April 1997, Clyde, a 77-year old male patient, was admitted to the University of Pittsburgh Medical Center-Beaver Valley Hospital with complaints of intractable back pain. The patient had been diagnosed with cancer of the prostate in 1982. As the cancer metastasized to his bones, the patient experienced increasing pain.

As standard pain treatment therapies had not been successful in managing the patient's pain, his primary care physician referred him to Hector C. Pagan, M.D., for further treatment options.

Intervention Prior to Referral

Prior to the pain specialist intervention, his cancer pain radiated to the thoracic spine and was treated with Casodex^® (bicalutamide).

Initially, conservative pain management therapies helped to provide moderate pain relief, but the patient was limited by their side effects and breakthrough pain as his condition worsened. Oral analgesics tried included Darvocet^® (propoxyphene napsylate and acetaminophen), Percocet^® (oxycodone and acetaminophen) and morphine. Opioid skin patches also were used with many side effects, including extreme nausea, vomiting and bowel blockage—resulting in admittance and treatment at the local hospital emergency room in March 1997.

The patient returned home using oral analgesics. His pain increased in intensity and his quality of life diminished. He was unable to care for himself or participate in activities of daily living. His wife had to help him eat, bathe, dress and ambulate. He was bedridden and in constant pain—leading up to his second hospital admittance in April.

Intrathecal Drug Delivery

Upon presenting to the hospital on April 17, 1997, and based on his successful trial treatment with epidural narcotics, it was recommended that Medtronic intrathecal drug delivery be considered for long-term pain therapy.

During the initial hospital screening test with this therapy, the patient did not suffer any side effects and tolerated the treatment fairly well. Surgical implantation of a SynchroMed^® Infusion System was scheduled for May 1997, after insurance approval was obtained.

On May 9, 1997, the patient underwent implantation of the SynchroMed infusion system while under general anesthesia. A catheter was introduced into the upper lumbar intrathecal space and the catheter tip was positioned up 3 vertebrae segments.

The catheter was then tunneled under the skin and connected to the SynchroMed pump, which was placed in a subcutaneous pocket in the left lower quadrant of the abdomen.

The pump reservoir was filled with preservative-free morphine sulfate and the patient was started on a simple continuous infusion of 0.8 mg/day. The patient did not experience any complications from the surgery and was discharged after 1 day. During the initial post-operative period, the patient had some pain—meanwhile his dose was titrated to effect. As his medication dose stabilized, there was marked improvement in his ability to stand and walk until eventually, he obtained approximately 90 percent reduction in his original pain level. The infusion was eventually tailored to a complex continuous infusion.

In this case, the patient experienced most pain during the day, with little pain present at night. The drug delivery system was programmed to address these pain control requirements. Therefore patients do not generally start out on complex continuous infusion therapy. They start on simple continuous, then as they stabilize, the infusion type is advanced/adjusted to complex continuous.

Results*

Since the implantation of the SynchroMed infusion system, the patient has not been re-admitted to the hospital for cancer pain-associated treatment.

An increase in pain in other areas of the body occurred as the metastatic disease process progressed. Strontium treatments were prescribed by his oncologist in conjunction with the morphine infusion with excellent results.

The patient experienced no side effects from the therapy, however complications can occur.

Risks may include:

• Surgical complications, such as infection
• Drug side effects (symptoms of overdose or underdose)
• Blood (hematoma) or fluid (seroma) in the pocket where the pump is implanted
• Spinal fluid leaks resulting in headaches or other problems, and damage to the spinal cord
• A dislodged or blocked catheter
• The pump could stop working
• Inflammatory mass at the tip of the catheter

These complications could cause a reduction in or loss of pain relief and may require surgery to correct. See Indications, Safety & Warnings for more details.

Since the initiation of intrathecal drug delivery, Clyde has had increased ability to participate in activities of daily living and an improved quality of life—with reduced side effects of the high dosages of oral opioids that were required to control his pain.

He walks unassisted, bathes and feeds himself and helps out around the house. He is able to get out more and enjoys spending time with his wife and visiting family.

Follow-up

Clyde is seen on an outpatient basis once every 2 to 3 months for a refill of his pump. His dosage level was gradually increased to 2.25 mg/day, where it has remained relatively stable since that time.

Dr. Pagan is the Director of Pain Management at the Advanced Pain Management Center in Beaver, PA. He has considerable experience in using intrathecal drug delivery to treat intractable pain, such as cancer pain and complex regional pain syndrome.

Dr. Pagan says that he would like to help increase awareness of Medtronic Pain Therapies because of the effective results he has seen in his patients.

* Individual results may vary. Not every individual will experience the same benefits. See Indications, Safety & Warnings for information about the risks associated with intrathecal drug delivery.

Patient Profile

The 40-year-old male patient presented in 1989. His left knee and low back were injured in 1975 in an automobile accident. He underwent a lumbar spinal fusion, but had continuing excruciating pain of the lower back and frontal midsection radiating bilaterally to his feet. He described this pain as burning and throbbing, with diffuse numbness from the knee downward.

In 1986, the patient was assaulted, sustaining significant left facial injuries that resulted in chronic maxillary sinusitis.

He underwent multiple surgeries to address this problem: debridement of the sinus, treatment of facial cellulitis, sinus and jaw reconstruction, and microvascular decompression of the trigeminal nerve. The pain in the lower left quadrant of his face was not improved by the surgeries.

The patient was unable to chew or brush his teeth because of the pain. He was unable to sleep. If he ground his teeth during sleep he would awake with excruciating pain. He described the facial pain in the second and third trigeminal nerve distribution areas as a chronic ache with lancination.

The patient's diagnoses were chronic mechanical and radicular pain secondary to failed back syndrome and chronic unremitting post-traumatic facial pain. His complex mixed pain problems involved both neuropathic and nociceptive pain. He described both areas of pain as equally debilitating. A solution that would address both areas and types of pain was required.

Intervention Prior to Referral

Since the onset of his pain in 1975, the patient had been treated with a wide variety of treatments and therapies, none of which had brought relief. In addition to surgeries, he had undergone multiple rounds of physical therapy, biofeedback therapy, TENS, aqua therapy, oral narcotics, intramuscular injections of opioids, cutaneous opioid patches, and intravenous morphine.

At the time of the patient's first visit with Dr. Khalouf, he was taking oral opioids costing $600 per month and visiting the emergency department twice monthly for intramuscular injections of morphine.

Intrathecal Morphine Infusion Therapy: Evaluation and Results*

Neurostimulation might have been helpful in addressing this patient's back and leg pain. However, a second system would have been required to stimulate the trigeminal nerve for the facial pain.

Implanting 2 systems was not an attractive option. It was felt that intrathecal morphine therapy would be a more direct way of controlling the pain in both areas.

Following appropriate evaluation, the patient underwent a 2-day trial with morphine delivered epidurally by catheter. He responded within the first few hours of the screening test and was pleased to be able to brush his teeth for the first time since his facial injury in 1986.

The patient was subsequently implanted with a SynchroMed^® drug infusion system. The catheter was implanted in the lumbar spine at L3/L4 and directed cephalad. The standard abdominal placement was chosen for pump implant. The patient was discharged from the hospital the day following the procedure.

The patient's initial dose was set at 1/10th the epidural dose that had proven effective during the trial. The patient responded extremely well and was able to engage in many activities that had not been possible for him in many years—including chewing food, brushing his teeth, and sleeping.

He was also able to resume his hobby of restoring vintage automobiles. The improvement in his quality of life was dramatic.

Post-Implant Patient Follow-up

Within the first 6 months of the patient's therapy, he experienced drug tolerance, marked by a rapid escalation of drug requirement and breakthrough pain.

The patient was gradually withdrawn from the intrathecal morphine and a 4-week therapeutic interruption (sometimes referred to as a "drug holiday") was instituted during which the patient's pain was managed with oral agents. The intrathecal drug delivery was then resumed.

The patient at this time was able to achieve pain relief with a somewhat lower dose. Peaks in dosage that followed the therapeutic interruption were associated with a hospitalization for edema of the legs and sinus infections. The patient's dose requirements have actually decreased over time and have remained stable for the past 7 months.

The patient's pain is currently being managed on 1 mg of morphine per hour. He is pain-free in his face, back, and legs, and he is taking no other pain medications.

Patient Profile

This 60-year-old male was electrocuted in 1984 by 18,000 volts of electricity from high tension lines on his job at a chemical plant. He did not suffer cardiac arrest at that time and had only a few minor burns. However, he fell at the time of his electrocution and sustained compression fractures at T4 to T6 that left him with intractable thoracic pain.

In 1985 he had a myocardial infarction and subsequently underwent a coronary artery bypass graft. He has been unable to work since his accident.

Intervention Prior to Referral

Since his injury, he has seen a number of physicians for his thoracic pain, has had multiple courses of physical therapy, and several types of injection therapies including trigger point injections, cervical, and lumbar epidural steroid injections.

The patient's past medications included multiple oral opioids, multiple nonsteroidals, and tricyclic antidepressants. He was previously managed at another pain clinic, but he found that the oral opioids and other treatments did not bring pain relief.

At the time of the patient's presentation for treatment in 1993, he was taking carisoprodol 4 times a day, amlodipine besylate for hypertension, and aspirin once a day for his heart.

The patient went to the urgent care center 1 to 3 times per week to receive intramuscular meperidine hydrochloride. This treatment allowed him to rest for 1 night after the intramuscular injection. He described his pain as a tearing sensation in his back and rated it as an "8" on the 10-point visual analog scale.

Physical Examination Prior to SynchroMed^® Implantation

Upon examination, the patient exhibited hyperesthesia along the thoracic paraspinous area. His pain was located in the mid back just below the scapula, radiating midline 3 to 4 inches on either side of the spine. It did not radiate into the anterior chest, arms, or legs. It was worsened by any activity. Neurological examination showed the upper and lower extremities and the cranial region to be within normal limits. X-rays showed compression fractures at T4 to T6.

Intrathecal Drug Delivery: Evaluation and Results*

The patient was evaluated by the clinic's psychologist who felt that the pain complaint was somewhat exaggerated. The patient's poor coping ability was felt to pre-date his accident. He also suffered significant depression.

The patient's post-evaluation treatment included detoxifying him from carisoprodol, placing him on amitriptyline HCl 25 mg at bedtime, and psychological therapy. The amitriptyline HCl resulted in better sleep and the patient's attitude improved somewhat.

The patient was not a surgical candidate, and neurostimulation was not indicated because of the nature and location of the pain. He had experienced no benefit in the past from oral narcotics, but did experience improved rest for 1 day when meperidine hydrochloride was administered intramuscularly. The possibility of intrathecal drug delivery was discussed with the patient.

Approximately 2 months following his initial evaluation at the clinic, the patient underwent the first of 2 Workers' Compensation-approved intrathecal morphine trials. He was admitted to the hospital for overnight monitoring of the clinical effects of a bolus intrathecal dose of .5 mg preservative-free morphine.

With that screening test, the patient experienced 24 hours of pain relief greater than 90 percent. However, he also experienced some nausea and itching which are common side effects of morphine.

A second screening test was conducted a few weeks later with a bolus intrathecal dose of .35 mg preservative-free morphine. At the point of this trial, the patient was taking 50 mg of amitriptyline HCl at bedtime, seeing the psychologist for therapy on a regular basis, and was no longer taking carisoprodol.

The second screening test also provided 24 hours of pain relief greater than 90 percent, but without the nausea and itching associated with the first trial.

On the basis of his response to the intrathecal drug delivery screening tests, the patient elected to be implanted with a SynchroMed^® drug infusion system. Implantation was uneventful and the patient was discharged within 2 days on an initial morphine dose of .8 mg per day delivered intrathecally. Post-discharge, the patient experienced nausea, vomiting, and itching. He was hospitalized, treated with ondansetron HCl for nausea, and his morphine dose was reduced to .6 mg per day. All side-effects improved.

At the patient's 1 month follow-up, he characterized his pain as "0 to 1" on the 10-point visual analog scale. Within the limitations imposed during the first 6 weeks post-implant, the patient was doing many activities he had not done for the previous 9 years.

Post-Implant Patient Follow-up

At the patient's 1 month follow-up, on a dosage of .6 mg per day the patient described his back as feeling tight at the end of the day, but not actually painful. He continued to see the psychologist and to take amitriptyline HCl at bedtime.

At 2 months post-implant the patient became more active and began to experience increased pain at the end of the day. A .25 mg bolus dose was added at 2:00 p.m. to provide late day pain relief, bringing his daily dose to .85 mg of morphine.

At 3 months post-implant the patient had begun to do woodworking in his garage on a daily basis and noted an increase in pain in the late morning. A second bolus dose of .25 mg was added at 11:00 a.m. to bring his daily dose to 1.1 mg per day.

At eight-months post-implant the patient's base rate of infusion was increased by .25 mg, bringing his daily dose to 1.35.

At 10 months post-implant his activity level warranted further dose increase. Each bolus dose was increased an additional .225 mg to bring his daily dose to 1.8 mg. His dose had remained at that level for the past eight months.

At 18 months post-implant, the patient was still receiving 1.8 mg of morphine daily. He was not taking any other medication with the exception of his antihypertensive medication. He was a different person: he traded gruff and tearful behavior for laughing and joking with the clinic staff.

His activity level was relatively high. He did woodworking in his garage daily and drives a car. He characterized his pain as a "0" on the 10-point visual analog scale. He noted that the therapy had virtually changed his life.

Discussion

This patient previously sought pain relief from an urgent care center 1 to 3 times weekly. While it might appear from this that he had a substance abuse problem, he had complied with all treatment directives given him in the 9 years since his injury, had discontinued ineffective oral narcotics, and did not drink any alcohol.

The meperidine hydrochloride he received intramuscularly provided only 1 night of improved sleep. The psychological evaluation identified concordant physical pain with no pattern of substance abuse. In the months preceding his implant, he cooperated fully with the detoxification process from carisoprodol and attended his counseling sessions faithfully.

At the Northern West Virginia Pain Management Center, all patients who receive an intrathecal drug pump are required to sign a contract with the clinic. The contract specifies that they agree not to seek any other type of opioid pain medication through another source. The contract also specifies that requests for changes in dose levels must be made during regular clinic hours. In return, the clinic agrees to respond to questions and to provide adjunct services that may be needed to address the patient's pain.

This patient required 3 different kinds of changes in his dose: initial dose reduction to minimize side effects, and subsequent moderate dose increase and change in infusion pattern to provide adequate pain relief as the patient became more active. Note that the patient's dose requirement has reached a plateau, having remained at the same level for the past eight months.

Careful attention to the timing of the patient's increased discomfort can guide the manner in which the dose is increased so that dose escalation achieves the desired result with relatively small increments. The SynchroMed system is capable of complex programming to allow drug delivery that is customized to meet the individual's needs.

Another factor that limits dose escalation is the understanding that the therapy is not intended to relieve 100% of patients' pain. Setting realistic goals for the therapy, referring to pre- and post-implant activity assessment sheets, and experience during the trial with intrathecal drug delivery all helps patients understand what they should expect from the therapy.

* Individual results may vary. Not every individual will experience the same benefits. See Indications, Safety & Warnings for information about the risks associated with intrathecal drug delivery.

Patient Profile

This 53-year-old female patient presented in June 1995, with severe pain of her lower back, right buttock, leg, and foot.

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 rated the pain at 8-9 on a 10-point scale and described the pain as a constant intense "aching cramping, burning, radiating, and squeezing." 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.

Intervention Prior to Referral

The patient had 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 2 epidural steroid injections, but no pain relief was achieved. The patient also received 3 series of 3 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 2 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 2 more 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. 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 6 months, but experienced constipation, sweating, confusion, and urinary retention.

She then received 2 more 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 2 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.

Physical Exam Prior to SynchroMed Implantation

Physical examination showed a 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.

Intrathecal Drug Delivery

In late October 1997, the patient underwent placement of a temporary intrathecal catheter for a screening test of 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.

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.

Post-Implant Patient Follow-up

The patient's infusion pump is refilled percutaneously approximately every 3 months, and the nurse has reported no difficulties with this procedure. The current dosage is 6.05 mg/day.

The patient experienced no side effects from the therapy, however complications can occur.

Risks may include:

• Surgical complications, such as infection
• Drug side effects (symptoms of overdose or underdose)
• Blood (hematoma) or fluid (seroma) in the pocket where the pump is implanted
• Spinal fluid leaks resulting in headaches or other problems, and damage to the spinal cord
• A dislodged or blocked catheter
• The pump could stop working
• Inflammatory mass at the tip of the catheter

These complications could cause a reduction in or loss of pain relief and may require surgery to correct. See Indications, Safety & Warnings for more details.

Dr. Krames is the medical director at Pacific Pain Treatment Center in San Francisco.

*Individual results may vary. Not every individual will experience the same benefits. See Indications, Safety & Warnings for information about the risks associated with intrathecal drug delivery.