EFFICACY AND SAFETY OF Pulsed radiofrequency treatment in CHRONIC pain syndromes

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.


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


Type of studySystematic Review

Units of analysis

Articles Data Search

PubMedISI Web of KnowledgeScopusCentral

2. Methods


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


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


2. MethodsArticles found

78

PUBMED48

ISI Web32

SCOPUS65

CENTRAL3

65 excluded

13 included


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


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


3. Results


Publication year

3. Results

4 times was necessary a 3rd reviewer74 times wasn’t necessary


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


Study and Methods

Patients and

treatments




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 -


Study and Methods

Patients and

treatments




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%


relief

PRF group

6 weeks: 61.5%


relief

3 months: 53.8%


relief

Lindner et al, 2006

Operated patients

1 month:-

4 months: 5/19


relief

Nonoperated patients

1 months:-

4 months: 21/29


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


[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

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EFFICACY AND SAFETY OF Pulsed radiofrequency treatment in CHRONIC pain syndromes