Peripheral nerve blocks play an important role in the anesthetic plan for patients undergoing many types of surgical procedures. A peripheral nerve block is accomplished by injecting a local anesthetic near the nerve, or nerves, that control sensation and movement to a specific part of the body. This injection will temporarily numb the area in question, resulting in a number of benefits.
Peripheral nerve blocks are typically performed for surgeries of the upper or lower extremities but can also be used for surgeries around the neck (e.g. carotid artery endarterectomy) or groin (hernia).
Aternative, when appropriate, to general anesthesia and central nerve blocks
Peripheral nerve blocks give us an alternative to general anesthesia and central nerve blocks for surgery. In some cases, especially for patients with more serious medical issues, peripheral nerve blocks are safer than general or spinal anesthesia. In many cases, NEA prefers to administer peripheral nerve blocks because of their distinct advantages-they significantly reduce the risk of post-operative fatigue/confusion, as well as dramatically reduce the incidences of nausea and vomiting. Additionally, the use of peripheral blocks, in comparison to central blocks, restricts the numbed area to the specific site of the surgery, or to one extremity, as opposed to numbing both legs. Further advantages include better post-operative pain control (limiting the need for strong pain medications, which have complications of their own), earlier discharge from the recovery room and hospital and improved patient satisfaction. Patients who have had peripheral nerve blocks tell NEA doctors they sleep better after leaving the hospital and recover more quickly from surgery.
Peripheral nerve blocks allow for reduced medication during surgery
In many cases, even when another anesthetic (general or regional) is necessary for adequate surgical anesthesia, a peripheral nerve block performed pre-operatively will allow us to give a greatly reduced dosage of medications during the operation itself. NEA anesthesiologists time the injection so that by the end of the surgical procedure, the peripheral nerve block is in full effect. This allows the patient to go home sooner than would otherwise be possible and with excellent pain relief since the numbness that results from the block will generally last from 12-24 hours, and in some cases, up to several days.
Peripheral nerve blocks, or local anesthetics, and the duration of pain relief
The duration of pain relief from peripheral nerve blocks is related both to the choice of medication used, as well as to how it is delivered. Some local anesthetics have longer duration than others and your NEA anesthesiologist will be able to tell you what to expect depending on specific factors related to your individual case. Another factor influencing the duration of pain relief is the decision to administer a single shot injection of local anesthetic or place a catheter next to the nerve, which will deliver numbing medicine continuously for a period of days.
The combination of drugs, working in concert, to control surgical pain
Whether your NEA anesthesiologist gives you a single shot or a catheter, you will probably be told that there are other medications that will be used in conjunction with the block in order to optimally control any pain related to surgery. The use of these other medications, along with a block, is frequently referred to as multi-modal analgesia. Basically, it means NEA has chosen to use a combination of drugs, which work in different ways to fight pain. No single intervention can fully control all pain and all pain medicines can have side effects. Combining different medicines, which work at different points in the pain pathway, decreases the amount of each medicine needed. Working in concert, they provide better pain relief than would otherwise be possible. Typically, the medicines NEA doctors add to the peripheral nerve block might include acetaminophen (Tylenol) and an NSAID (Motrin-type medicine), as well as an opiod (like codeine) and possibly a medicine designed specifically for pain of nerve origin (Lyrica or Neurontin). Generally, you'll be asked to continue on these medications only for a period of days.
Complications from local anesthesia, or peripheral nerve blocks, extremely rare
Complications from peripheral nerve blocks occur rarely. The incidence of permanent nerve injury is reported to be somewhere in the range of 1/5000 to 1/10,000. Approximately 1-3% of patients will report some tingling sensation in some portion of the area that was blocked, which may persist longer than a week. For some reason, these complications seem to occur more frequently for upper extremity blocks than lower extremity blocks. It should be noted that these statistics were compiled for blocks done with less sophisticated techniques than are now available to NEA. We use ultrasound technology not previously available (and still not available to the vast majority of anesthesiologists in this country) in order to actually see the nerves and needle through the skin. This allows NEA to watch the medicine spread around the targeted nerves. This is a safer approach and should lower NEA's complication rates even further.
For questions concerning peripheral nerve blocks, please contact Northeastern Anesthesia Services.