Intraspinal narcotics have dramatically influenced the way chronic pain is managed. If patient fails oral opioids, he may be a candidate for implanted pump device. Failure of oral opioids means that pain is sensitive to opioids and patient cannot tolerate side effects like nausea, vomiting, constipation, and sedation.
Intraspinal pump is a completely implanted device under the skin with a small incision in the stomach or hips of the patient.
The dose of the pump can be adjusted by placing an outside programmer on the pump reservoir that communicates with the pump through the skin. The new generation pumps have the capacity to be programmed where patient can bolus himself with a personal therapy manager.
If the patient failed oral opioids due to intolerable side effects, he or she may be a candidate for intraspinal morphine pump.
Patient may be a candidate for intraspinal baclofen pump due to intractable spasticity from the following conditions
Patient usually needs a smaller dose of opioids in the spine compared to the oral medications. In some studies, it indicates one milligram of morphine in the spine is equivalent to 100 milligrams of oral morphine.
Pump infused continuously small dose of morphine via catheter in the spine
It is a two-phased procedure.
Patient is usually hospitalized to inject morphine into the spine in a series of two or three days. Medicine can be injected in the spine once daily or by placement of the catheter in the spine that is connected to an outside infusion pump.
T qualify for permanent pump placement, patient must experience at least 50% improvement in pain relief that should last at least 8-12 hours after the intraspinal injection.
Patient is hospitalized because the narcotics can travel from the spine to the brain that can result in suppression of respiratory center, so patient is closely watched in the hospital for any sedation after the intraspinal injection.
I usually discharge my patients to their homes after the trial period without the implantation of a permanent morphine pump. It gives them time to think through it and plan before their morphine pump implantation.
The permanent pump implantation is done usually under general anesthesia. A catheter is placed in the spine through a needle. The catheter is then tunneled under the skin and connected to a programmable pump. Pump is usually placed in the stomach with a small incision in the skin.
The pump battery life is usually five-seven years, and after that the pump needs to be replaced with a new pump by connecting it to the existing catheter.
Patient is observed in the hospital for 23 hours or can be released home on the same day of the surgery and an abdominal binder is used to prevent a fluid collection around the pump. Patient will continue some of their oral pain medications during the recovery period.
I tell my patients, don�t expect significant pain improvement for about 2-3 weeks following pump implantation because post-operative pain and time needed to adjust the dose of the morphine pump. Patient returns to my office once or twice a week and on each visit, the pump dose is increased 10-20%, until patient reports significant improvement in their pain levels.
The pump needs to be refilled usually every 1-6 months depending upon the dosage of the pain medication. The refill is done in the physician�s office by placing a needle through the skin into the pump reservoir.
Patient may experience spinal headaches due to fluid leakage around the spine. The spinal headaches usually subside in a few days without any treatment . If headaches do not improve, some patients may require an epidural blood patch. Other complications include spinal damage during the catheter placement, catheter dislodgement, and infection.