They are regional anesthesia techniques that are sometimes administer as an alternative to a general anesthesia for surgery of the hand, wrist, forearm, arm, or shoulder. A local anesthetic is injected close to the brachial plexus which will temporarily block the ability and sensation to move the upper extremity. The brachial plexus if the nerve that supplies most of the sensation to the upper part of the body and is responsible for its function.
A useful alternative to general anesthesia is a regional anesthesia which this method employs. A nerve stimulator can be used to enhance the effectiveness and safety of the procedure. Most upper limb procedures can be performed by the interscalene block or the axillary block. To be successful the appropriate local anesthetic agent and block and to be chosen and the procedure has to be conducted by someone who has had a significant amount of practice.
The patient does not have to be put under and can stay awake during the procedure which lessens the risk of adverse reactions to the anesthesia. In some cases the patient may be completely sedated or under full anesthesia.
There are several procedures that will work for this type of pain management. The different levels deals with where the catheter or needle is inserted: on the neck, interscalene, above the clavicle, supraclavicular block, and below the clavicle, infraclavicular block. A peripheral nerve stimulator may be used to facilitate the performance of many regional blocks. It can identify nerves effectively without needing the patient to participate in the process. It may also prevent nerve damage by accidental injection or incidental penetration of that nerve.
It can result in lower blood pressure, depression of the central nervous system, decreases in cardiac output, loss of airway reflexes like coughing, respiratory depression, need for tracheal intubation, and mechanical ventilation. This procedure can be done without a general anesthetic.
If the procedure is done without a general anesthetic, the side effects are reduced. However, if a general anesthetic is used, there are possible side effects.
There are several criteria that should be met before deciding on this option:
Al-Hadda, MF & Coventry, DM. Brachial Plexus Blockage. Continuing Education in Anesthesia, Critical Care & Pain Oxford Journals. Volume 2, Issue 2. P 33-36. Retrieved from http://ceaccp.oxfordjournals.org/content/2/2/33.abstract
Brockway MS, Wildsmith JAW. (1990). Axillary brachial plexus block: method of choice? 64: 224-231.