EFFICACY AND SAFETY OF PULSED RADIOFREQUENCY TREATMENT IN
CHRONIC PAIN SYNDROMES
Introdução à Medicina II | Teacher Luís Filipe Azevedo | Class 14
Summary
Introdução à Medicina II | Teacher Luís Azevedo | Class 14
1. Introduction
2. Methods
3. Results
4. Discussion
5. Conclusion
6. Website
7. References
1.Introduction Research question and aims
What is the efficacy and safety of Pulsed Radiofrequency treatment in chronic pain
syndromes?
Aim:
To systematically review the evidence about efficacy and safety of pulsed radiofrequency in patients with chronic pain syndromes.
Introdução à Medicina II | Teacher Luís Azevedo | Class 14
1.Introduction
What is pain?
PAIN
Acute Chronic
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]
Introdução à Medicina II | Teacher Luís Azevedo | Class 14[1] Abu-Saad Huijer H. Chronic pain: a review. J Med Liban 2010 Jan-Mar;58(1):21-7
1.Introduction
Introdução à Medicina II | Teacher Luís Azevedo | Class 14[2] Van Zundert J, Huntoon M, Patijn J, Lataster A, Mekhail N, van Kleef M. Cervical Radicular Pain. Pain Pract. 2009 Oct 5.4
Relaxation
techniques
• Helps reduce stress levels
Phisical Terapy
• Relieves pain and improves movement and function
Electrical Stimulati
on Therapies
• Alters pain signals as they travel to the brain
Different treatments for chronic
pain [2]
Radiofrequency treatment [3]
1.Introduction
Introdução à Medicina II | Teacher Luís Azevedo | Class 14[3] Byrd D, Mackey S. Pulsed radiofrequency for chronic pain. Curr Pain Headache Rep. 2008 Jan;12(1):37-41
Is a recently developed treatment modality for pain syndromes such as chronic pain.
It uses brief pulses of high voltage to produce controlled tissue destruction, reducing pain by modulating its transmission.
Importance of this treatment
Its apparent lack of side effects which is appealing for those who suffer from chronic pain which has detrimental effects on physical and mental health. [1]
Project Development Phases
1. Research question formulation
2. Definition of selection criteria (inclusion and exclusion)
3. Definition and implementation of literature search methods and resources
4. Study selection using defined selection criteria
5. Data extraction from included studies
6. Critical appraisal and quality assessment of included studies
7. Data analysis and synthesis from included primary studies
8. Writing and disseminating final report
2. Methods
Introdução à Medicina II | Teacher Luís Azevedo | Class 14
Type of studySystematic Review
Units of analysis
Articles Data Search
PubMedISI Web of KnowledgeScopusCentral
2. Methods
Introdução à Medicina II | Teacher Luís Azevedo | Class 14
Key-wordsPainChronicPulsedRadiofrequency
Query
PubMed:pulsed[All Fields] AND radiofrequency[All Fields] AND (("pain"[MeSH Terms] OR "pain"[All Fields]) AND chronic[All Fields])Scopus:TITLE-ABS-KEY(radiofrequency) AND TITLE-ABS-KEY(pulsed) AND TITLE-ABS-KEY(pain) AND TITLE-ABS-KEY(chronic)ISITS=(Radiofrequency SAME pulsed) AND TS=pain AND TS=chronicCentral#1 MeSH descriptor Pain explode all trees#2 (Chronic): ti, ab, kw#3 (Radiofrequency Near Pulsed): ti, ab, kw
2. Methods
MeSH Term: Pain
Introdução à Medicina II | Teacher Luís Azevedo | Class 14
Research Limits
2. Methods
Inclusion Criteria Exclusion Criteria1. Articles that mention the radiofrequency treatment in chronic pain
1. Theme does not match the expected
2. Articles that have, at least, two comparative groups
2. Treatment is not used for chronic pain
3. Articles that mention the issue of efficacy and safety of pulsed radiofrequency
3. Type of article is not the desired
4. Study is not conducted in humans
5. Article does not mention the methods used and results
Introdução à Medicina II | Teacher Luís Azevedo | Class 14
2. MethodsArticles found
78
PUBMED48
ISI Web32
SCOPUS65
CENTRAL3
65 excluded
13 included
Introdução à Medicina II | Teacher Luís Azevedo | Class 14
5 included articles
2nd selection stage
3. Results Articles Excluded
Exclusion Criteria Articles1. Theme does not match the expected 22. Treatment is not used for chronic pain 13. Type of article is not the desired. 594. Study is not conducted in humans 35. Article does not mention the methods used and results
0
Introdução à Medicina II | Teacher Luís Azevedo | Class 14
3. Results Articles Excluded
Exclusion Criteria Articles1. Theme does not match the expected 22. Treatment is not used for chronic pain 13. Type of article is not the desired. 674. Study is not conducted in humans 35. Article does not mention the methods used and results
0
Introdução à Medicina II | Teacher Luís Azevedo | Class 14
3. Results
Introdução à Medicina II | Teacher Luís Azevedo | Class 14
Publication year
3. Results
4 times was necessary a 3rd reviewer74 times wasn’t necessary
Introdução à Medicina II | Teacher Luís Azevedo | Class 14
Inclusion/Exclusion: 8 disagreements
Reason for exclusion:4 disagreements
Agreement / Disagreement
3. Results Included Articles:
Study and Methods
Patients and
treatments
Results Study limitations
Number of patients in each group
SettingAdverse reactions or events
Van Zundert et al
Prospective, randomised,
sham-controlled,
double blind trial
23 patients with cervical
radicular syndrome,PRF of DRG compared with sham
intervention
3 months follow-up: PRF
group with better
outcome – GPE and VAS
(20%)
Only 23 patients,
short-term follow up, high pre-treatment
VAS of sham treated group
11 patients – PRF group; 12
patients – sham treated
group
Netherland -
Cohen et al, Retrospective data analysis
49 patients with post surgical thoracic
pain, PRF of DRG and PRF
of ICN compare
d with pharmacother
apy
Both 6 weeks and 3
months follow up: PRF of DRG group with better outcome
Retrospective, Only 49 patients,
short-term maximum follow up (3 months)
PRF of DRG (n=13)
PRF of ICN (n=15)
Pharmacotherapy (n=21)
USA
Only in the pharmacotherapy group, 7
of the 21 patients revealed
adverse side effects
3. Results Included Articles:
Study and Methods
Patients and
treatments
Results Study limitations
Number of patients in each group
SettingAdverse reactions or events
Simopoulos et al
Prospective, randomised,
sham-controlled,
double blind trial
76 patients with chronic lombo-sacral
pain randomly assigned to one of two types of
treatment: PRF of the
DRG or PRF followed by continued
radiofrequency.
2 months follow up: success (2
groups); non statistically difference
between the two treatment
groups.
The efficacy of PRF is not tested on the comparative
group
37 - PRF39 - PRF
followed by continues
radiofrequency
USAIsrael -
Lindner et al. Retrospective
study
48 patients with low back
pain and >50% pain
relief following a diagnostic
medial branch block.:
PRF treatment of the medial
branch
21/29 nonoperated patients and
5/19 operated patients,
successful outcome.
The setup of our study does not permit a
comparison with the results of
continuous radiofrequency (CRF) for the
same procedure
19 patients operated
29 patients non-operated
Switzerland -
3. Results Included Articles:
Study and Methods
Patients and
treatments
Results Study limitations
Number of patients in each group
SettingAdverse reactions or events
Tekin I et alProspective, randomized, double-blind, sham lesion
controlled trial
60 patients with
continuous low back pain
with no radicular
syndrome. 80ºC CRF
compared to 2Hz PRF and
to local anesthetic.
VAS and ODI scores of PRF
and CRF groups were
lower than the control group. In the follow up period the scores were lower in the CRF group
than those of the PRF.
Risk of ending the blinding process after
3 month follow-up. Few
support studies.
Risk of false positive blocks
20 patients- Control Group20 patients- PRF Group
20 patients- CRF Group
Turkey -
3. ResultsQuantitative results: VAS – Visual Analogue Scale
VASControl or alternative intervention
groupVAS
PRF group
Article Intervention Primary outcome
Secondary outcome Intervention Primary
outcomeSecondary outcome
Cohen et al, 2006
Medical managemen
t group
6 weeks:27.3%
reported ≥50% pain
relief
3 months: 19.9%
reported ≥50% pain
relief
PRF group
6 weeks: 61.5%
reported ≥50% pain
relief
3 months: 53.8%
reported ≥50% pain
relief
Lindner et al, 2006
Operated patients
1 month:-
4 months: 5/19
reported ≥60% pain
relief
Nonoperated patients
1 months:-
4 months: 21/29
reported ≥60% pain
reliefVan
Zundert et al, 2007
Sham group: 76,2
3 months: 3/12 (25%) improvemen
t
6 months: < improvemen
tPRF group:
55,7
3 months: 9/11 (82%) improvemen
t
6 months: > improvemen
t
Tekin et al, 2007
Control group:Similar
6 months: Higher
1 year:Similar
PRF group:Similar
6 months: Lower
1 year:Similar
Simopoulos et al,
2008
PRF + CRF group:
7.1 ± 1.98 weeks:2.3 ± 2.2 - PRF group:
7.8 ± 1.68 weeks:3.5 ± 3.4 -
3. ResultsChecklist for randomized controlled trials
• CONSORT checklist
3. ResultsChecklist for observational studies
• STROBE checklist
3. Results
Article Checklist evaluation
Van Zundert et al, 2007 100%
Lindner et al, 2006 93,75%
Cohen et al, 2006 75%
Tekin et al, 2007 56,25%
Simopoulos et al, 2008 43,75%
3. ResultsSide-effects and complications of PRF:
• Although a potential for bleeding, nerve damage, infection and burns from
incorrect needle or grounding pad placement have been suggested [4], none of the
studies reviewed reported any noticeable complications of PRF application.
[4] Cohen S, Foster A. Pulsed radiofrequency as treatment for groin pain and orchialgia. Urology. 2003, 61:645
4. Discussion• The majority of the clinical studies of PRF reported its clinical efficacy.
• There are many articles about PRF, which report small un-controlled prospective trials,
retrospective studies with only one group or reviews.
• The articles refer almost uniform beneficial effects of PRF.
• It is possible that therapeutic failures with PRF were not reported.
• The randomized, controlled clinical data available on PRF is limited and the articles about them
are recent.
• There probably exists a significant margin of safety because no neurological deficits were
found in patients treated with PRF and CRF. [5]
[5] Simopoulos TT, Kraemer J, Nagda JV, Aner M, Bajwa ZH; Pain Physician; 2008
5. Conclusion
• The controlled clinical data on pulsed radiofrequency is limited and provide a level
2 or 3 of evidence of its efficacy.
• Despite the weakness of the controlled clinical data, the apparent lack of
complications and the wider applicability of PRF call for further RCTs.
… in order to achieve a clear understanding about PRF’s role in the treatment of different and various chronic pain syndromes.
6. Website
7. References
Introdução à Medicina II | Teacher Luís Azevedo | Class 14
[1] Abu-Saad H. Chronic pain: a review. J Med Liban. 2010; 58(1):21-7[2] Van Zundert J, Huntoon M, Patijn J, Lataster A, Mekhail N, van Kleef M. Cervical Radicular Pain. Pain Pract. 2009 Oct 5.4[3] Byrd D, Mackey S. Pulsed radiofrequency for chronic pain. Curr Pain Headache Rep. 2008 Jan;12(1):37-41.[4] Cohen S, Foster A. Pulsed radiofrequency as treatment for groin pain and orchialgia. Urology. 2003, 61:645[5] Simopoulos TT, Kraemer J, Nagda JV, Aner M, Bajwa ZH; Response to pulsed and continuous radiofrequency lesioning of the dorsal root ganglion and segmental nerves in patients with chronic lumbar radicular pain; Pain Physician; 2008;11(2):137-44.[6] Sackett DL, Strauss SE, Richardson WS, et al. Evidence-Based Medicine: How to Practice and Teach EBM. Philadelphia, Pa: Churchill-Livingstone; 2000.[7] Malik K. Pulsed radiofrequency: a critical review of its efficacy. Anaesthesia and Intensive Care; 2007; 35:6[8] Green, S. Systematic reviews and meta-analysis; Singapore Med J. 2005; 46: 270[9] Moher, D., Schulz, KF., Altman, DG.; CONSORT Group. The CONSORT statement: revised recommendations for improving the quality of reports of parallel-group randomised trials. Clin Oral Investig 2003; 7:2–7[10] Bidstrup, B. Who Reviews the Reviewers?. Asian Cardiovasc Thorac Ann. 2006; 14:357-358[11] Jadad, A.R., Moore, R.A., Carroll, D., Jenkinson, C., Reynolds, D.J.M., Gavaghan, D.J., Carroll, D.C., McQuay, H.J. Assessing the quality of reports of randomized clinical trials: is blinding necessary?. Contr Clin Trials. 1996; 17:1-12[12] von Elm, E., Altman, D., Egger, M., Pocock, S., Gøtzsche, P., Vandenbroucke, J.; STROBE Initiative. Strengthening the reporting of observational studies in epidemiology (STROBE) statement: guidelines for reporting observational studies. BMJ. 2007; 335:806-808[13] Gan, W., Man, S., Senthilselvan, A., Sin, D. Association between chronic obstructive pulmonary disease and systemic inflammation: a systematic review and a meta-analysis. Thorax. 2004; 59:574-580