Post provided by Kevin Turezyn, Drexel University College of Medicine Class of 2013:
While the overall risks of undergoing a procedure involving general anesthesia have decreased dramatically over the last 25 years, there is one phenomenon that still puzzles both anesthesiologists and surgeons: post-operative peripheral neuropathies.
Why a patient undergoing an appendectomy would wake up with weakness in their arm is still in large part a mystery. Luckily most patients recover fully, but a small subset suffer from permanent damage.
While relatively infrequent, peripheral nerve injury after anesthesia is one of the largest sources of professional liability for anesthesiologists. Estimates of its frequency range from .03% to .11% of patients who undergo anesthesia.
Interestingly, despite numerous attempts to decrease its incidence, anesthesiologists have had little success.
While the exact cause is unknown, many believe that it relates to patient positioning. There are several points in the body where nerves run very close to the surface leaving them vulnerable to injury. For example, the most commonly injured nerve is the Ulnar nerve of the arm. When this nerve goes through the elbow, it is very close to the surface where it has little body tissue for protection. People commonly hit this nerve in daily life, giving them a painful sensation called hitting your “funny bone”. Other commonly injured nerves include the radial nerve (compression in the spiral groove against the humerus), brachial plexus from traction on the arm, sciatic nerve in the buttock and peroneal nerve against the fibula head.
The American Society of Anesthesiologists has published guidelines for prevention of perioperative peripheral neuropathies. The guidelines focus on pre-operative assessment for patients who are at higher risk ( diabetics, alcoholics, patients with peripheral vascular disease) as well as proper positioning of the extremities and adequate padding.
Click here for the full guidelines.
When peripheral nerve injury does occur, it frequently resolves on its own, although this can take take several months. During this time, there is little that can done to speed recovery. Physical therapy is often recommended to prevent muscle contractures and atrophy during this time period.
If a patient feels that they suffered a nerve injury during surgery, it is important that they be evaluated right away by a trained neurologist. Testing such as an electromyogram (EMG) can be done to determine the location of the injury and prognosis for recovery.