September, 2004
An elderly man needs total shoulder replacement, but he is fearful. One of his friends had this procedure and suffered severe pain and confusion due to both the procedure and the pain treatment. A woman requires mastectomy for cancer. Previously, she has suffered severe nausea and vomiting after undergoing general anesthesia. How would you proceed?
Patients like these point up the deficiencies of relying on general anesthesia alone for surgery. Although general anesthesia is excellent at making patients unaware (possibly by generally expanding membranes in the brain and decreasing neural traffic), it has many significant disadvantages.
Most important, it does not stop pain impulses from bombarding the spinal cord throughout surgery. In fact, these signals may actually “mount up,” leading to intense post-op pain or even hyperalgesia, and possibly chronic pain later on.
We can give intramuscular or IV opioids to relieve the pain, but in the process we may trigger unwanted side effects, including nausea and vomiting, ileus, urinary retention, respiratory depression, cognitive dysfunction, and more.
Unimpeded stress from surgery can induce sympathetic overactivity, which decreases gastric motility. Opioids can intensify this effect.
Both general anesthesia and opioids also temporarily suppress killer cells, reducing protection from infection and cancer.
Fortunately, there is an excellent alternative for these and other patients: Regional anesthesia. By localizing the anesthetic to the site of surgery, we can achieve:
- Dramatic reduction in post-op pain. Regional anesthetic techniques “trick” the body, preventing painful impulses from reaching the spinal cord. As the great American surgeon George Crile recognized back in the 1920s, “local anesthesia prevents poisonous substances/messages from reaching the brain during surgery.”
- Improved outcomes. Particularly in orthopedic cases, post-op pain can interfere with recovery. When general anesthesia is used for surgery on exquisitely innervated areas such as the shoulder, severe post-op pain can result. If opioids are ineffective, as they often are, physiotherapy stops, and the patient may develop adhesive capsulitis, requiring reoperation or more manipulation. Continuous regional anesthesia, consisting of an interscalene catheter inserted preoperatively, allows surgical deafferentiation, minimizing post-op pain. Physiotherapy works better and patients often attain therapeutic milestones early.
- Speedier discharge. Regional anesthesia blocks the reflex sympathetic arc, enhancing peristalsis, allowing earlier return of bowel function, and earlier feeding.
- Improved circulation. As opposed to general anesthesia, regional anesthesia is unlikely to cause hypercoagulable states. Instead, it enhances microcirculatory flow, decreases leukocyte adhesion to endothelial cells, and increases vasodilator release.
- Flexibility. An inquisitive physiotherapist who wants to observe her knee surgery can do so under regional anesthesia with minimal sedation. An extremely apprehensive patient can have a regional block, then have an IV anesthetic as a supplement.
- Profitability. Implemented properly, regional anesthesia can save surgical facilities time and money. For example, a femoral catheter plus sciatic block for a total knee allows for very specific analgesia/anesthesia without the need for placing a urinary catheter. The patient will typically use far fewer opioids, have more successful physiotherapy and a faster convalescence. Indeed, many centers are now receiving referrals not only for surgical expertise but for anesthesia care, thanks to regional blocks.
Regional anesthesia is increasingly demonstrating outstanding clinical results, minimizing recovery room stays, saving money and enhancing patient satisfaction. If you have not yet investigated its benefits for your facility, the time in my view is now.
Dr. Greengrass has lectured nationally and internationally on regional anesthesia. He is Associate Professor of Anesthesiology at the Mayo Medical School.
