Continuous Catheter Nerve Block
Performed by Top Pain Management Doctors in San Antonio, Texas
A Continuous Catheter Nerve Block (CCNB)describes the percutaneous (‘through the skin’) installation of a catheter to a site adjacent to targeted peripheral nerves, designed to block pain transmission continuously via a steady infusion of anesthetic medications (Jeng & Rosenblatt, 2011). Primarily used for inpatient procedures, such as post-operative pain management following a surgical procedure, CCNB’s are increasingly being used in an outpatient setting for the treatment of chronic pain.
Post-surgically, CCNB’s are indicated for any procedure with significant expected post-operative pain; this is especially true for surgeries that require mobilization following the procedure which is generally only possible in conjunction with adequate pain control. CCNB’s provide pain relief adequate enough to allow speedy mobilization following surgery, which has become very beneficial for orthopedic surgical cases, such as total knee joint replacements and ACL reconstructions (Fowler, et al., 2008). CCNB’s may be superior to more conventional pain management with sedating intravenous (IV) opioid use, such as morphine, which can cause a variety of systemic side effects such as nausea, constipation and sleep disturbances which can interfere with recovery (Jeng & Rosenblatt, 2011).
The outpatient use of CCNB catheters is significantly more limited, primarily due to novelty. CCNB’s can be used for the continuous treatment of chronic cancer-associated pain affecting large areas innervated by a single peripheral or autonomic nerve group (Kaplan & Portenoy, 2011). There are also reports of CCNB use for persistent shoulder pain (targeting the brachial plexus) and pelvic and lower extremity pain (via continuous epidural infusion). Some studies have shown CCNB’s to be particularly effective for treating a chronic pain from Complex Regional Pain Syndrome (CRPS), also known as reflex sympathetic dystrophy. CRPS is a disorder of the extremities in which afflicted patients experience pain, inflammation, and changes in the temperature, texture and other characteristics of the skin (Sheon & Abdi, 2011). CRPS has been associated with injury, surgery, or vascular injury (such as a heart attack or stroke), but often has no causative agent. CRPS can be a debilitating and difficult disease to treat. CCNB of the stellate ganglion has been shown to be effective for the treatment of CRPS.
The spine consists of a column of bones, known as vertebrae, which are stacked atop one another from the pelvis to the base of the skull, forming a channel to protect the spinal cord (Hansen, 2010). There are 33 of these vertebrae divided into five regions: (1) cervical, which are found in the neck closest to the skull (identified as C1-C7), (2) thoracic, found along the upper back (identified as T1-T12), (3) lumbar, found along the lower back (identified as L1-L5), (4) sacral, which are contiguous with the pelvis or hip (identified as S1-S5), and (5) coccygeal, which are fused as the tailbone. Each of these regions of the spinal cord elicits nerve roots that project out toward the body to comprise the entire peripheral and autonomic nervous system.
Given that CCNB catheters can be placed throughout the body targeted to nearly any major peripheral or autonomic nerve suspected of causing pain, the anatomical aspects of the each CCNB are situationally-dependent. For example, in CRPS, a sympathetic ganglion (cluster of nerve cell bodies) known as the stellate ganglion near the neck is targeted to treat the condition. This ganglion is located near the C7 vertebrae, where the first rib attaches to the spine and just under the subclavian artery traveling out the upper extremities.
Before any CCNB catheters are placed, the pain specialist will take care to rule out or treat any existing infections, blood coagulation problems or abnormal blood cell and plasma counts so as not to pre-dispose a patient to unnecessary risk and complications following the procedure (Kaplan & Portenoy, 2011).
The skin under which the small catheter is to be placed is sterilized, and the treating physician may elect to provide intravascular (IV) sedation or a local anesthetic (numbing agent) into the placement site to prevent discomfort during the procedure. The pain specialist can then insert a needle through the skin and guide it to the nerve targeted for blockade. The catheter is then guided through the needle into the target nervous tissue and the needle withdrawn- leaving the catheter in place. To ensure that the catheter remains in place, a liquid adhesive and bandage are used to secure the catheter in place. A small container with medication can then be connected with the catheter to provide a continuous stream of medication to the nerve.
Needle, and subsequent catheter placement can be guided by electrical nerve stimulation catheters which can identify and confirm needle placement near nervous tissue, however ultrasound is increasingly gaining acceptance as an alternative for real-time imaging guidance of the needle (Jeng & Rosenblatt, 2011). Both guidance methods can be combined for even greater assurance that the targeted peripheral nerve has been reached.
The primary benefit of CCNB is as an alternative to more traditional methods for the management of chronic pain, including intravenous opioid administration. These methods tend to be sedative and produce undesirable, and in some cases life-threatening, side effects. Studies consistently show that continuous infusion groups reported a reduced need for supplemental oral pain relievers eliminating much of the risk for experiencing these side effects. Secondarily, in many studies, patients report improved pain relief with CCNB when compared to placebo or alternative pain management options.
As with any medical procedure, CCNB placement carries some risk, albeit minimal. Potential complications include bleeding, infection, nerve injury, or inadequate nerve coverage due to improper catheter placement.
Potentially the most significant, and usually delayed, complication of catheter placement is infection, which may or may not present with abscess formation (Kaplan & Portenoy, 2011). Catheter placement into a nerve leaves an open channel from outside the body to the internal tissues until the catheter is removed and the placement site healed. Because of this increased risk of infection, it is imperative that patients properly sanitize the catheter and medication connection, and keep it dry. Patients should keep an eye out for hallmarks of infection, including fever and redness or draining at the implantation site, and seek immediate medical attention should these symptoms occur.
It is essential for patients to follow a proper protocol following the procedure as delineated by the interventional pain specialist. The protocol will include written and verbal instructions on care of the placement site, physician-patient communication within 24 hours, and a 24 hour/day patient contact for anesthesia-related questions and concerns (Jeng & Rosenblatt, 2011). Catheters are generally only left in place for approximately 5-7 days before removal to minimize the risk of infection.
Studies in support of CCNB are bountiful according to one systematic review (Fowler & al., 2008). In one study amongst 540 patients undergoing knee surgery, patients receiving continuous medication infusions had equivalent pain relief with fewer side effects. Another study compared CCNB with single injection blockade, IV morphine and epidural analgesia in patients undergoing total knee replacement surgery, in which patients receiving CCNB reported improved pain control, less cardiovascular instability during the procedure, and reduced nausea and vomiting following the procedure. Another study of CCNB on the lumbar plexus noted improved outcomes when compared to control groups. Finally, a large study conducted with children suffering from CRPS evaluated the use of CCNB for pain management (Dadure al., 2005). The study authors found CCNB to be an innovative treatment approach that allowed for significant pain relief, early mobilization and a rapid return home.
CCNB represents an effective treatment modality for the inpatient and outpatient treatment of chronic pain.
References/ Journal Articles
- Dadure, C., et al. (2005). Continuous peripheral nerve blocks at home for treatment of recurrent complex regional pain syndrome I in children. Anesthesiology , 252-255.
- Fowler, S., et al. (2008). Epidural analgesia compared with peripheral nerve blockade after major knee surgery: a systematic review and meta-analysis of randomized trials. Br. J. Anaesth. , 154-164.
- Hansen, J. (2010). Back. Retrieved April 7, 2012, from MD Consult. Netter’s Clinical Anatomy.
- Jeng, C., & Rosenblatt, M. (2011). Overview of peripheral nerve blocks. Retrieved April 23, 2012, from UpToDate: http://www.uptodate.com.ezproxy1.library.arizona.edu/contents/overview-of-peripheral-nerve-blocks?source=see_link&anchor=H12#H12
- Kaplan, R., & Portenoy, R. (2011). Cancer pain management: Interventional therapies. Retrieved April 23, 2012, from UpToDate: http://www.uptodate.com.ezproxy1.library.arizona.edu/contents/cancer-pain-management-interventional-therapies?source=search_result&search=continuous+catheter+nerve+blocks&selectedTitle=3~150
- Sheon, R., & Abdi, S. (2011). Prevention and management of complex regional pain syndrome in adults. Retrieved April 20, 2012, from UpToDate: http://www.uptodate.com.ezproxy1.library.arizona.edu/contents/prevention-and-management-of-complex-regional-pain-syndrome-in-adults?source=search_result&search=cervical+sympathetic+nerve+block&selectedTitle=2~150