2009/2010
PULSED RADIOFREQUENCY TREATMENT IN CHRONIC PAIN SYNDROMES
WHAT IS THE EVIDENCE?
PROTOCOL
Class 14:
Ana Luis Faria, Ines Pinto, Jorge Pinto, Jorge Soares, José Barreto, José Vicente Formoso, Luís Pinho, Mafalda Pinto, Mafalda Pais Carrington, Maria Teresa Silveiro, Miguel Valente, Paula Teixeira e Pedro Monteiro.
Teacher: José Gustavo Martins
1. Introduction
1.1 Background and Justification
1.1.1 Motivation of the research
There are many different opinions about pulsed radiofrequency treatment, so it is considered a controversial subject in scientific community, as it can be seen by reading these examples:
“Pulsed radiofrequency treatment adjacent to the cervical dorsal root ganglion is a recommended treatment for chronic cervical radicular pain” (1)
“Suprascapular nerve PRF lesioning was effective in chronic shoulder pain of rotator cuff lesion, and this effect was maintained in the long-term period.” (1)
“PRF of spermatic cord appears to be a safe minimally invasive outpatient procedure that should be investigated further with placebo-controlled trials.” (3)
“Although much anecdotal evidence exists in favor of PRF, there are few quality studies substantiating its utility.” (4)
It is also a treatment that is used in various types of chronic pain syndromes, which is seen as a very interesting point.
1.1.2 What is pain?
The International Association for the Study of Pain defines pain as "an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage."
1. Pain is subjective in nature and is defined by the person experiencing it. The medical community's understanding of chronic pain now includes the impact that the mind has in processing and interpreting pain signals.
2. Pain has both physical and emotional components. The physical part of pain results from nerve stimulation. Pain may be contained to a discrete area, as in an injury, or it can be more diffuse. Pain is mediated by specific nerve fibers that carry the pain impulses to the brain where their conscious appreciation may be modified by many factors.
It is useful to distinguish between two basic types of pain: acute and chronic. Acute pain is severe and lasts a relatively short time. It is usually a signal that body tissue is being injured in some way, and the pain generally disappears when the injury heals. Chronic pain may range from mild to severe, and it is present to some degree for long periods of time.
3. There are many ways to treat pain such as pharmaceuticals, commonly analgesics, anaesthesia and appropriate techniques for removing the cause and for controlling the pain sensation, acupuncture or nutritional supplements.
1.1.3 Pain Problem (in the world and in Portugal)
It is known that pain is the second leading cause of hospitalization and also concluded that currently the early treatment of chronic pain enhances its control.
However, in Portugal, a large proportion of cases of pain syndromes are not addressed as early as recommended, making the full recovery of the patient more difficult. Considering that a high percentage of people have experienced at least once in their lives, back pain and that when suffering from this type of pain for more than 6 months, the majority abandons permanently their jobs, it has become urgent to create a plan to combat the pain.
Plano Nacional de Luta Contra a Dor seeks to improve the treatment of patients with pain syndromes.
• Pain is the second leading cause of hospitalization
• Early treatment of chronic pain enhances its control
• In Portugal, a large proportion of cases are not addressed as early as recommended
• A high percentage of people have experienced back pain
• Plano Nacional de Luta Contra a Dor seeks to improve the treatment of patients with pain syndromes.
1.1.4 Chronic Pain
Chronic pain has been defined as pain that persists longer than the temporal course of natural healing and it is associated with a particular type of injury or disease process.
Pain is subjective because it needs to be defined by the person who is experiencing it. The medical community's understanding of chronic pain actually includes the impact that the mind has in processing and interpreting pain signals.
There are many types of chronic pain such as, general somatic pain (pain from the outer body), visceral pain (pain from the internal organs), bone pain, muscle spasm (muscle cramps), peripheral neuropathy (pain arising in the nerves leading from the head, face, trunk, or extremities to the spinal cord), circulatory problems and even headaches.
1.1.5 Different treatments for chronic pain
In many cases the reason behind chronic pain is not clear, so the patient may need various complementary treatments. Over time, treatment should reduce the pain and increase your ability to function.
Pain may be controlled at home by:
-Making exercise
-Having a healthy diet
-Getting enough sleep
-Using pain relievers
If the pain can’t be controlled at home, there are a series of treatments:
- The patient can be recommended to reduce stress levels with relaxation techniques.
- Physical therapy, to relieve pain and improve movement and function
- Electrical stimulation therapies, such as TENS, transcutaneous electrical nerve stimulation, to alter pain signals as they travel to the brain.
The most importance is to build a clear treatment plan for chronic pain and part of it should be identifying ways for patients to manage their pain.
There are also medicines which can be administrated to relieve pain and inflammation, such as corticosteroids, acetaminophen, cooling sprays, opioid analgesics, or a therapy called nerve block therapy which is an anaesthetic that is injected into the affected nerve to relieve pain.
Chronic pain may affect personal life, interfere with work and relationships. The best way to deal and relieve the pain is a combination of treatment that can include healthy habits and consulting a psychiatrist for example.
If the condition gets worse and prolonged patients could try a pain management clinic. Some strategies used are physical therapy, transcutaneous electric nerve stimulation (TENS) and professional counselling.
In extreme cases it could be consider surgical options:
-The intrathecal drug delivery is a method that regularly delivers some medicine in the spinal canal;
-Spinal cord stimulation where a electrical generator is put under the skin and send a electrical pulse to the affected area;
-Radiofrequency ablasion.
1.1.6 Radiofrequency Treatment
Pulsed radiofrequency is a development of heat basedradiofrequency denervation. Both procedures areused in medicine to treat especially chronic pain. Unlike heat based radiofrequency treatment, pulsed radiofrequency does no direct damage to the nerve.
Pulsed radiofrequency treatment is based on the principle that when a nerve is constantly subject to pain stimulus, it becomes more efficient transmitting that painmessage to the brain, which will make that patient experience more pain. The treatment itself consists of creating an electromagnetic field through a catheter inserted near the nerve that will take the nerve back to its original state before "learning" how to transmit the pain signal so efficiently withoutdamaging the nerve.
Before the treatment is necessary to identify the nerve that is causing the trouble.
The clinical procedure is not simple and requires some expertise. The first step is the placing of the insulated needle in the vicinity of the nerve to be lesioned. The needle position is checked through multiple fluoroscopic X-ray views. Then there needs to be done a motor and sensory nerve stimulation testing. At this point, the grounded electrode is passed through the insulated needle to the tip. Finally, the electrical current created by the electrode heats up the surrounding tissue.
The major side effect is not logical sinceit isthat the pain is greaterthe days after the treatment. The other side effects are relatedto pain during the procedure due tothe insertion of the catheter near a nerve and related toanesthetics as local anestheticis not applicable because it would interfere with the procedure.
Besides the side effects, there are some dangers immediate to the procedure as it can damage blood vessels or other nerves close to the area where the catheter needs to be inserted.
Pulsed radiofrequency has been in clinical used for 30 years and has demonstrated success in reducing pain in several chronic pain condition, proving to be a useful tool in the overall management of refractory neuropathic pain.
Even so, its use in neuropathic pain is under debate because success in randomized control trials has not yet been achieved.
1.2 Research question and Aims
The question that drives our research is: Pulsed radiofrequency treatment in chronic pain syndromes – What is the evidence?
We chose this question because we think that it is a good summary of our systematic review. It shows our main goal.
Our aims are:
1. To do a critical aproval about published articles about the evidence of pulsed radiofrequency treatment in chronic pain syndromes;
2. To know more about different types of chronic pain syndromes;
3. To know more about Pulsed radiofrequency treatment;
4. To understand why there is controversy about this subject.
2. References
1. RACZ, G.B, RUIZ-LOPEZ, R. Radiofrequency Procedures: Review Article, Pain Practice, 2006; p.46-50
2. KESKINBORA K, AYDINLI I. Long-term results of suprascapular pulsed radiofrequency in chronic shoulder pain, Jan. 2009; p.16-21
3. Misra S, Ward S, Coker C.Pain. Pulsed radiofrequency for chronic testicular pain-a preliminary report, 19/03/2009, p.673-8
4. Byrd D, Mackey S. Curr Pain Headache Rep. Pulsed radiofrequency for chronic pain. 2008 Jan, p.37-41.
5. Kornick, C., Meng, F.C., Xu, S.J., Liu, Y.G., Wang, H.W. Selective percutaneous radiofrequency thermocoagulation in the treatment of trigeminal neuralgia:report on 1860 cases. Chinese Medical Journal 2004; 117:467-470
6. Van Zundert J, Huntoon M, Patijn J, Lataster A, Mekhail N, van Kleef M. Cervical Radicular Pain, 05/05/2009.
7. http://www.hospicenet.org/html/what_is_pain.html [Consultado a 23/10/2009]
8.http://arthritis.about.com/od/arthqa/g/whatispain.htm [Consultado a 23/10/2009]
9. http://www.nlm.nih.gov/medlineplus/pain.html [Consultado a 23/10/2009]
10. http://en.wikipedia.org/wiki/Chronic_pain [Consultado a 24/10/2009]
11. http://www.pain-management-info.com/definition-of-pain.htm [Consultado a 24/10/2009]
12. http://www.medterms.com/script/main/art.asp?articlekey=4723 [Consultado a 25/10/2009]
13. http://www.emedicinehealth.com/chronic_pain/page2_em.htm [Consultado a 25/10/2009]
14. http://www.webmd.com/pain-management/tc/chronic-pain-treatment-overview?page=2 [Consultado a 25/10/2009]
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