What is a CPNB?
A CPNB (Continuous Peripheral Nerve Block) is a procedure that is performed by your anesthesiologist to control pain due to surgery. Local anesthetic (numbing medicine, like a dentist might use) is placed near a bundle of specific nerves, and a thin catheter is left by the nerve bundle and bandaged in place. This catheter allows the numbing medicine to be continually infused over several days or more through an electronic pump (in the hospital) or through a disposable “balloon-like” pump that can be taken home by the patient. This allows the area affected by surgery to remain numb while the worst amount of surgical pain is present. The infusion rate can be adjusted up or down by the patient as their individual needs vary. A CPNB will significantly cut down on the amount of opioids (narcotic) that will be needed after surgery.
How can a CPNB improve my outcome after surgery?
In addition to having the most effective form of pain control available, the infusion will minimize (and sometimes eliminate) the need for “traditional” pain pills or IV pain medicines (opioids, or narcotics). This will allow you to be dramatically more alert after surgery and avoid or minimize the other side–effects of those medicines during your recovery. Common side-effects of narcotics include nausea and vomiting, constipation, itching, respiratory depression (breathing poorly) and drowsiness. As well, for abdominal surgery, significantly reducing the amount of opioids that are required allows bowel function to return more quickly.
Using a nerve block (CPNB as well as single injection nerve blocks), there are some surgeries where we can avoid the need for a general anesthetic (putting you “all the way to sleep” and inserting a breathing tube). There are various circumstances where avoiding a general anesthetic is a convenience to the patient, and there are some circumstances where this will increase the level of safety for the patient. Matters of convenience include awakening more quickly and more fully with less likelihood of nausea. Matters of safety include avoiding the negative blood pressure and breathing changes, confusion and airway issues that can occur with general anesthesia.
Minimizing pain and the effects of opioids will allow you to participate more fully with the goals of recovery, physical therapy and returning to your regular daily activities. We see regularly that patients are able to go home more quickly and far exceed our recovery and physical therapy goals.
Using a CPNB as the cornerstone of your pain control plan, the exposure to narcotics during your recovery will be minimized or possibly eliminated. The potential for addiction to narcotics following surgery or trauma due to narcotic exposure has created awareness on a national scale, and this problem has continued to grow. This is one of the central aims at expanding the utilization of CPNB’s in this country. Again, the continuous infusion is numbing medicine only.
There is also a great deal of evidence in the literature that controlling pain well and for long enough immediately following surgery significantly reduces the likelihood of developing chronic pain syndromes that could last months, years or a lifetime. Surgeries most consistently associated with chronic pain syndromes after surgery include those for chest, breast, inguinal hernia and amputations. One in three patients that have a chronic pain syndrome can trace the origin of it to a surgical procedure.
Recent literature is beginning to show the possibility of reducing the likelihood of cancer returning or spreading after surgery when CPNB’s are used for breast cancer surgery. The evidence is only preliminary, but the mechanism appears to be related to slowing the immune suppression that occurs after surgery that occurs due to pain, opioids (narcotics), anesthetic gases and the surgery itself.
Is it painful to have the procedure?
No. Patients commonly tell me the procedure is less bothersome than having their IV started, was “no big deal” or was no pain at all. You will be given some sedation, and sometimes, a short-acting pain medicine through the IV that will help you relax during the few minutes it will take to perform your nerve block. Though you will be able to communicate with us, the sedation medicine you receive may allow you not to remember the time during the procedure at all.
Certainly, if anything we do is uncomfortable, you will be able to communicate that to us to allow us to remedy the situation. I usually tell patients that I may cause a small amount of discomfort in order to remove an enormous amount of discomfort, but your safety and comfort throughout the procedure are very important to us.
Because the procedure is almost always well-tolerated by patients, and it is safer for us to be able to communicate with you during it, it is only in certain circumstances that we choose to perform nerve blocks with you under a general anesthetic, or “all the way asleep.”
In what types of surgery are CPNB’S commonly used?
Generally, CPNB’s are reserved for moderately or severely painful procedures or for patients particularly intolerant to or otherwise unable to take traditional pain medicines (opioids, or ‘narcotics’) that are required after smaller surgeries. Orthopedic procedures for the shoulder, arm, hip and leg are common as are many chest, breast and abdominal surgeries.
Common surgeries that receive CPNB’s include the following: Rotator Cuff Repair, Total Shoulder Arthroplasty, Fractures of the Upper and Lower Arm, Total Hip Arthroplasty, Hip Fracture, Upper and Lower Leg Fracture, Total Knee Arthroplasty, Various Surgeries of the Ankle and Foot, Thoracotomy (incision between the ribs for Lung Surgery), Mastectomy, Exploratory Laparotomy (incision down the middle of the abdomen), Colon Resection, Abdominal and Inguinal Hernia Repairs, and Nephrectomy (removal of a kidney).
Do I have to stay in the hospital to have a CPNB?
No. In fact, having the continuous infusion of numbing medicine will likely help you get home sooner or may even help you avoid having to stay in the hospital at all. When you go home with a CPNB and a disposable pump, the anesthesia department will contact you by phone regularly to make sure you are doing well and that any ongoing questions or concerns are addressed. You will also have 24/7 access to the anesthesia department during your infusion.
The infusion can be adjusted as needed by the patient or simply left on the rate initially ordered by the anesthesiologist. When the infusion is complete, you do not need to return to the hospital to have it removed either. The catheter is simply removed by the patient (or family member) and thrown away along with the disposable pump. It is as simple as removing a large bandage.
Are there risks I should know about?
As with any medical procedure, there are always risks. Fortunately, the likelihood of serious complications with a CPNB is extremely low. We take every measure to ensure that the CPNB is performed as safely as possible, including real-time ultrasound visualization of the structures below the skin and the proper spread of the local anesthetic as it is injected. The likelihood of complication is similar to (or lower than) the complication rate for single injection nerve blocks. The rate of complications of real medical consequence is so low, in fact, that it is nearly impossible to design a study that is large enough to detect the actual complication rate using techniques and supplies that we use today. Minor complications or side-effects, such as a patch of skin that remains numb for longer than a week, may occur up to 8% of the time as sited in the literature.
Any time these procedures are performed, you must know that there is the risk of bleeding, infection, damaging structures under the skin (blood vessels, lung, or nerves) or having a reaction to the local anesthetic (numbing medicine) that is injected. We will make sure all of your questions and concerns are addressed prior to your procedure.
Am I a candidate for a CPNB?
Most patients are candidates to receive a CPNB for an appropriate surgical procedure. There are medical conditions, however, that can increase the complication rate for patients, so you will be individually evaluated by your anesthesiologist to ensure that you are a candidate for a CPNB and that the benefits still outweigh the risk.
What do I do now?
If you have surgery that is already planned or expect to have surgery soon, the best place to start is to have a conversation with your surgeon at your next visit. If you have not selected a surgeon yet, you can call their office to find out if they do surgery at a facility that has experienced anesthesiologists who have an established CPNB Program.
If you have surgery planned at MY facility, Regional Hospital of Jackson, you will be asked to come to our Pre-testing Clinic, or you will visit our Joint Camp if you are planning a Total Joint Replacement. At either of these, you will become more familiar with our CPNB Program. Your questions will be addressed, and you will be sent home with written material that you can look through at your convenience. If your surgeon has particular concerns about whether or not you are a candidate or if certain medical conditions are present, someone from the Anesthesia Department will interview you personally.
What if I have more questions?
You are more than welcome to send your questions to me through this website, and I will answer them ASAP. Some of these questions will be posted for the benefit of other patients. Also, make yourself aware of local presentations in your community, or check the internet for more information on CPNB’s. I would also recommend asking around your community to find out from friends or family that may have had the surgery that you are planning to learn about their experience. Find out if they had a CPNB and if they would want to have one again or not.