The placement of intrathecal medication for pain consists of administering medication into the spinal fluid which surrounds the spinal cord. The intrathecal administration of opioids is used quite often for postoperative pain. The use of the intrathecal space is also sometimes used for the treatment of chronic pain.
There are several advantages to the use of the intrathecal space. In particular, doses of medications are a small fraction of those used for the oral, intravenous, or epidural route. The resultant serum levels therefore are barely detectable, thus limiting the systemic effects while maximizing the analgesic properties. Several, different medications may be used for the treatment of pain via the intrathecal route. Opioids are most commonly used. Other medications that can be used intraspinally (intrathecally) include ketamine and ziconotide. Local anesthetics and clonidine also may be applied to help with pain control.
The indications for chronic intraspinal analgesia include treatment of cancer pain and treatment of chronic pain with known pathophysiology.
Procedure
The placement of an intrathecal catheter is achieved with the use of fluoroscopy to identify the exact location of the catheter. A trial is usually performed for 24 hours which does require an overnight stay in a hospital. The role of the trial is to identify proper dosing of medication and also to see if the patient is going to respond in a favorable way. After the trial, the catheter is removed. Discussion is then undertaken at which point the decision is made either to proceed to implantation or not.
The implantation is an approximately one to two hour procedure which is performed in a local hospital or surgical center. Due to what is commonly the administration of opioids (morphine for example), an overnight stay is usually required for patient safety.
As with any procedure, there are potential complications, including infection, failure of the system, headache, and bleeding. Not all patients are candidates for the implantation of a drug-delivery device, and your physician at Pain Management Associates can discuss this with you in greater detail.
References:
Benzon, H. T. et al. (2005) Essentials of Pain Medicine and Regional Anesthesia(2nd ed.). Amsterdam. Elsevier.
Pain Management Secrets, by Charles E. Argoff MD, Gary McCleane MD. Mosby; (July 27, 2009)