An intrathecal pump is a medical device used to deliver medication via an intrathecal catheter (tube), directly into the space between the spinal cord and the protective sheath (dura mater) surrounding the spinal cord. This is the CSF (cerebrospinal fluid).
Medications such a baclofen, morphine, and ziconotide are approved for administration by the FDA. Other medications that may also be administered include hydromorphone, fentanyl, bupivacaine, clonidine. The dose of medications required for similar or better results when delivered intrathecally, are substantially less than oral or intravenous route. This helps to reduce side effects of medications with improved pain control and functionality, the primary goal of implanting an intrathecal pump. In most cases patients can stop oral medications.
Used in patients with spasticity due to multiple sclerosis, cerebral palsy.
In chronic pain conditions like post laminectomy pain syndrome, chronic pancreatitis. In addition, cancer patients with uncontrolled pain, chronic cancer pain may also benefit from this therapy.
Cancer patients with severe, difficult to control pain, and with significant side effects due to opioids may also benefit. Good pain control at the end of life is very important.
The implantable intrathecal pump is constructed from non-allergic metal. It has a few sections, including a battery, computer, a motor and reservoir which stores and delivers the medication. This pump is attached to a catheter via a nipple. An intrathecal catheter delivers the medication from the pump to the intrathecal space in the spine where the medication takes effect. Two types of pumps are available: a constant rate pump delivers the medication at a constant rate, and a programmable pump delivers the medication according to a rate determined by the physician using a computer program. In addition, patients can also use a personal therapy manager. This device allows patients to deliver extra medications if needed. It reduces the need for oral breakthrough pain medication.
Also, external pumps, with or without a subcutaneous port are used for intrathecal delivery.
Before a pump is placed, a trail is conducted. Trial may be a single shot of baclofen, or placement of a temporary epidural catheter. Medications are infused. These trials may continue for a few days to 10 days depending on the circumstances. A permanent intrathecal pump is then implanted if the patient derives at least 50% improvement in his or her symptoms.
Intrathecal pumps require maintenance. Individuals who use these pumps will need to come into their physician's office to have the pump refilled. How frequently this occurs is dependent on several factors, including drug concentration and dosage, and pump size. The refill frequency can range between one and six months for baclofen pumps.
Intrathecal pumps periodically need to be replaced once every 6–7 years. Usually, only the pump needs to be replaced and not the catheter.