Wednesday, November 22, 2006

Epidural (Cont-1)


Question:
What are the indications for epidural anaesthesia?

Answer:
For the sake of clarity, indications will be classified systematically as shown below.

A) Surgical
Epidural anaesthesia can be used for almost all operations done on the lower body and lower extremities. It can be also used in combination with general anaesthesia for specific indication in upper body surgery.

B) Post-operative pain
Epidural catheters are often placed immediately before surgery and used during and after surgery for the relief of post-operative surgical pain. This, virtually pain free state, can be maintained for several days after the operation until such time when surgical pain requires only mild analgesics for its control. Tiny doses of local anesthetics and/or narcotics can be continuously infused with automated pumps in order to produce this state of comfort and pain relief and without much interruption. Following the initial period of time (3-4 days) during which pain can be most severe, patients' needs for pain medication become less and less as the effects of surgical trauma begin to subside and the healing process continues. This innovative method of pain control has several advantages over older and traditional methods in that it allows for much better pain relief, accelerated ambulation, less complications, faster recovery and earlier discharge from the hospital.

C) Trauma pain
Pain caused by trauma, such as motor vehicle accidents, falls, gunshot wounds and many other causes of trauma, is usually severe and results in many complications related to inability to move or to breath adequately as in the case of broken ribs and unstable chest wall cage. If untreated, it can result in severe disabilities and complications. Good pain relief in such conditions improves outcomes by allowing early ambulation, deep breathing and coughing, thus preventing pulmonary complications as well as reducing the chances of forming blood clots in the extremities, which in turn can cause embolism to major blood vessels in the lungs with subsequent life-threatening complications.

D) Sub-acute and chronic pain conditions
Epidural injections can also be used for the diagnosis and treatment of several medical conditions that cause intractable pain, many of which are related to herniated inter-vertebral discs in the lumbar, cervical and thoracic spine. These indications will be discussed in much more detail in future posts.

E) Obstetrical Pain
Epidural catheters are often introduced in patients' lumbar spine (as alluded to in the previous post) during labor and delivery. Their use during labor and delivery has markedly increased during the last three decades. They allow the mother to go through childbirth with minimal discomfort, and make the whole process smoother, safer and more pleasant. Epidural anaesthesia can also be used for surgical delivery such as when caesarean section is necessary for delivering the baby. More will be written on this in future posts.


(Intrathecal means inside the spinal fluid)

F) Cancer related pain

Epidural catheters can be implanted and tunneled under the skin for long term use in the treatment of intractable, severe cancer pain. These catheters can be left in place for months and even years if necessary. They facilitate the ability to continuously infuse small amounts of pain relieving medications, such as morphine, directly into the spine, thus allowing the drug to be infused as close as possible to the central nervous system. Normally when narcotics are administered orally or by injection (intramuscular, under the skin or intravenous), they will have to cross a barrier between the blood and the brain in order to reach their target receptors in the central nervous system. By injecting these drugs directly into the spinal canal, close to the nerves and the spinal fluid, much smaller doses are required in order to accomplish the degree of pain relief that is possible with much higher doses of the drug when given systemically. The quality of pain relief is also far more superior when the drugs are delivered closer to the sites of their action. In other words, this method of administration allows us to get to the receptors in the central nervous system "by the back door." There will be more details on this particular subject in future posts.

To be Continued....

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