Thursday, November 23, 2006

Happy Thanksgiving!


Getting ready for Thanksgiving meal....

A good laugh is worth a thousand shots!

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....

Saturday, November 18, 2006

Epidural

Question:
What is an epidural?

Answer:
An epidural is a procedure done to either provide a painless state in order to perform surgery and to have childbirth without significant pain, or is used for the diagnosis & treatment of certain chronic pain conditions.

Anatomy: there is a potential space (epi- or extra-dural) located outside the dura which is a thick membrane surrounding the spinal cord and its terminal nerve structures that are called cauda equina. The spinal cord and all these nerve structures are bathed in a watery fluid medium called cerebrospinal fluid which provides the central nervous system with protection, pressure balance, suspension and nutrition. The spinal fluid is contained in between an internal membrane called pia mater and two external coverings (membranes), the first of which is called arachnoid mater and the second and outermost layer is called dura mater.

Just outside the dura mater there is a narrow space containing veins, fat, lymphatics, and through which the nerves travel on their way exiting the spinal canal towards their target sites in the body. This narrow space is termed Epidural Space, and is surrounded on the outside with strong ligaments, periosteum (a strong layer of tissue on the surface of bone) and bony structures that form the spine.

When a person receives an "epidural" it implies the placement of a needle into that space (epidural space), and through that needle a catheter is introduced into the epidural space, then the needle is removed and the catheter is secured in place so that medications can be delivered over extended periods of time. For other specific indications, the medications can be injected directly through the needle as a "one shot" technique, and the needle is then removed.


To be continued....

Wednesday, November 8, 2006

Acute & Chronic Pain


Question:

What are the main differences between acute and chronic pain?

Answer:

Acute pain, even though is not a pleasant sensation, serves a useful function. Without the sensation of pain we could easily injure or burn ourselves without knowing it. Another example: if we do not feel the pain caused by a disease condition, such as acute appendicitis, we would not know that we suffer from a serious medical condition and neglect to seek medical help; so in this case pain acts as a warning signal telling us that something is wrong with our body. Acute pain is usually associated with other signs of increased sympathetic nervous system activity, such as increase in blood pressure, rise in heart rate, sweating, pallor, anxiety, fear and restlessness.

On the other hand, chronic pain is the sensation of pain that continues after the complete healing of the initial cause of pain and might last for months, weeks or years. It no longer serves a useful function, and becomes a disease on its own. It is not associated with rise in blood pressure or heart rate, but is rather accompanied with significant changes in personality and behavior. It leads to depression, anxiety and anger. In some cases it can be accompanied with manifestations of hypochondriasis and hysteria as well as certain personality disorders. it leads to employment difficulties, job loss, socio-economic consequences, drug dependence and abuse, as well as family difficulties and divorce. In severe and intractable cases, it can even lead to suicide.

One of the examples of chronic pain conditions is shingles (herpes zoster), an extremely painful condition caused by the reactivation of a dormant varicella-zoster virus which infects young people--mostly children--causing the disease known as chickenpox. After the resolution of this disease, the virus becomes dormant (goes to sleep) and remains in the body hidden in the brain and the spinal cord in certain nerve tissue relay structures called ganglia.

Later on in life the virus can reactivate as a result of a variety of factors, such as decreased immunity, cancer, HIV infection, trauma to the nervous system, toxic exposure, severe illness and many other conditions. When the virus reactivates (wakes up) it spreads along the individual nerves connected to these ganglia. causing severe nerve pain and rash. The older the person the more likelihood of continuation of pain after the complete healing of the rash, which is the result of permanent nerve damage.

This is a perfect example of differences between acute and chronic pain and it illustrates how an acute condition could turn into a chronic disease.

Sunday, November 5, 2006

Purpose Of This Blog & Disclaimer

The main purpose of this blog, as a public service, is to provide the readers with information regarding all questions related to anaesthesia and resuscitation for surgical operations, including pre-operative preparation, intra-operative care and post-operative management. It will also address issues related to pain management in the acute setting--such as in trauma and obstetrics--as well as in chronic pain conditions, with special emphasis on cancer-related pain.

In order to assess the needs of the readers, questions and comments are strongly encouraged.

The content of this blog is not intended as a substitution for advice you receive from your personal physician, and is provided to help improve awareness and education of the public. Therefore the blog's author does not assume any legal responsibility for any content, information or advice given on this blog.

This blog does not represent or imply the practice of medicine in any form.