Intrathecal
Pumps
Intrathecal
pumps are mechanical devices used to deliver medications directly into the
area of the spinal cord. These devices consist of a computerized pump, a resevoir
and a catheter. The resevoir can be filled with various medications including
opioids, Clonidine, Baclofen, Bupivocaine and Ziconatide. The medications
are used at much lower concentrations than necessary for systemic absorption
and side effects are generally lower.
Studies
have been done with intrathecal opioids that show less side effects than oral
medication. Drowsiness is improved, as is nausea and constipation. Improvement
in pain control is particularly effective with multiple medications aimed
at different parts of the pain control system. Another advantage of the intrathecal
pump is that Medicare will pay for parenteral medications, while they will
not pay for oral medications. Additionally these pumps can improve compliance
with patients who have trouble regulating their oral medications due to addiction
or pseudoaddiction.
Intrathecal
medication delivery also has its drawbacks. Implanting a pump is not an inocuous
procedure. It causes significant cosmetic alteration at the implant site,
that is unacceptable to many patients. The pump is a mechanical device that
is prone to problems ranging from glitches and mechanical compromise, to total
mechanical failure. Rare instances of catheter tip granulomas can cause significant
neurological symptoms. The patient is dependent on refills of medications
and adjustment of the pump to the few professionals and delivery organizations
available to do this and expertise is still still developing. If a patient
with a pump is in an accident, the pump can stop working and the catheter
can be displaced. Emergency room physicians and personnel are usually not
well versed in how to deal with pump patients.
There
is still considerable question about whether intrathecal delivery of opioids
shows any statistical advantage from a pain standpoint over oral medication
delivery. While statistically it appears that oral delivery is just as effective
as intrathecal delivery, it appears that for patients who have failed oral
opioid treatment or received only limited benefit, a trial with indwelling
epidural catheter may prove more effective. If so, than the use of intrathecal
opioids may prove to be more effective for the individual patient.
There
are patient oriented groups on the internet that can give perspectives, advice
and experiential information. For many people who have tried less invasive
alternatives the pump can make a huge difference in improved pain control
and quality of life.