Treatment of Low Back Pain with SpecificAcupoint. A Double-Blind  Placebo-Controlled Trial

Marco Aurelio Dornelles, MD 





Freire  Alemao,۶۱۶/۳۰۳ 





۹۰۴۵۰-۰۶۰ - Porto Alegre



RS - Brazil 



e-mail: dornelle@mozart.ulbra.tche.br

SUMMARY

Low back pain is acommon disease that injury a lots of people, causing  physical impairment,pain and disability. It’s treatment is long lasting and  expensive topatient and society. The purpose of this trial is to offer a new  modelfor acupuncture treatment to low back pain Acupuncture treatment of achronic low back pain was studied in a placebo-controlled double-blindcrossover  trial completed by ۱۸ patients. Their pain were measured byVASP (Visual Analog  Pain Scale ). These patients were randomly selectedin two Groups : A and B. The  A group received acupuncture needle atpoints K۳ ; UB۲۳ ; UB۵۲ ; UB۵۸ during  first phase of treatment which lastedfour weeks, and placebo acupoint during  the second phase of trial. The BGroup ( also ۴ weeks ) that started with  placebo acupoint ( S۴۱, L۹, L۱۳and BAXIE ) was changed during the second phase  of treatment to specificacupoints and lasted four weeks, too. A significant  reduction of ۴۳% inthe "VASP" occurred in the first phase of treatment for the  AGroup. On the other hand, the reduction of only ۱۷% in the B Group wasnot  significant. During the second phase of treatment the reduction was۵۲ % for the  A Group and ۷۱ % for the B Group . Finally when both groupswere receiving  acupuncture in specific points the reduction wassignificant only Group B . This  trial was completed with success using agroup of points needling was  theoretically; irrelevant sites as placebogroup and showed that is necessary  specific acupoints for the treatmentof low back pain.

INTRODUCTION

Numerous studies reportthe ability of acupuncture to reduce the pain in  acute and chronic cases(Pommeranz,۱۹۸۷), but most of there are either anecdotal  or employinappropriate methodologies. In fact, scientific data for acupuncturesafety and efficacy based on well-controlled studies utilizing acceptablemethodologies and pain models is limited (MacDonald,۱۹۸۳).

A key problem withacupuncture research has been the difficulty in designing  appropriatecontrol groups (Campbell,۱۹۹۱). In some cases elaborate physicalprocedures such as mock transcutaneous nerve stimulation ( mTENS ) havebeen  employed (Lewith,۱۹۸۳). However, despite its frequency in theliterature, this  practice is problematic because TENS in not acupuncture,and its use as a  control is questionable. Very few studies used anadequate placebo procedure  (Moore,۱۹۷۶). Another control commonlyemployed is "sham " acupuncture, in which  needles are insertedat variables distances from the "real " acupuncture points,  andwith variable depth (Edlist et al, ۱۹۷۶). One argument suggest that painattenuation by sham acupuncture may be due to diffuse noxious inhibitorycontrol  (Takeshige,۱۹۸۹), and his may confound efforts to testacupuncture effects.  Another difficult to choose sham acupuncture is thefact that to show  statistical significance in the differences betweensham-point needling and  true-points needling requires huge numbers ofpatients ( at least ۱۲۲ per study  ), in accordance with Vicent andRichardson´s (۱۹۸۶) point of view. In this way,  sham acupuncture is notan appropriate control.

Other common problems inacupuncture studies include ambiguous inclusion or  diagnostic criteria,non-standard outcome measures, and insufficient follow-up  periods(Patel,۱۹۸۷) . In many studies, patients, evaluation procedures, andstatistical analyses are often inadequately described (Patel,۱۹۸۹).

STIMULATION POINT SPECIFICITY

Acupuncture can beapplied to any of several hundred known acupuncture points  all over thebody. It has been reported that the application of acupuncture to aparticular point is critical for analgesia to develop in a region of body (Crozeet al,۱۹۷۶) . Although the old Chinese acupuncture theory of ahypothetical  system of energy channels or meridians was considered thebasis for acupuncture  specificity (Chang,۱۹۷۹), the current scientificexplanation over this  specificity is conflicting. Chung(۱۹۸۹) demonstrateno evidence for stimulation  point specificity for the production ofanalgesia, although other papers has  been showed that acupuncture pointstimulation is not effective in causing  analgesia in all animals, classifyingrats in two types, the responders and  nonresponders to acupuncture points(Takeshige,۱۹۸۳) and acupuncture points and  nonacupuncture points aredistinguished by differing central pathway  (Takeshige,۱۹۸۹).

In order to resolve someof the methodological problems apparent in the  literature and develop amodel for appropriate acupuncture evaluation of low  back pain, we havecompleted a pilot study.

The present study isplacebo-controlled and double-blind, which objectives  are:

۱ - to observe if theuse of a group of acupoint selected without effect over  the low back painis an appropriate control group; and

۲ - if there areacupoint specific to treat low back pain.

METHOD

PATIENT SELECTION

Twenty acupuncture naivepatients with chronic low back pain without  rhizopathy and had beenfailed to derive sufficient relief from appropriate  conventional methodsof treatment were included after they accepted the study  design. Allpatient were referred to us before they were examined by a clinical  assistantwho blinded regarding what treatment group the patient belonged to.  Thepatients were informed that we studying the effect of two differentmethods  equally efficient against their low back pain. Thus, the patientswere informed  that placebo treatment will be an efficient new acupuncturetreatment.

Before the patients wereexamined a random process was used to divide the  sexes and age equally aspossible between the two groups. The acupuncture group  had ۷ females and۳ males and placebo group ( nonspecific acupuncture points )  had ۶females and ۴ males, whith ۵۲ years old of mean age for first group and۵۴  years old for the last group.

PROCEDURE

The treatments weregiven twice a week for eight weeks. All patients were  randomly allocatedto either of two groups. Group A received specific  acupuncture needles atpoints K۳, UB۲۳, UB۵۲ and UB۵۸ bilaterally, and one  needle at DU۳ and DU۴as described by Traditional Chinese Medicine ( TCM )  (Pommeranz,۱۹۸۷) totreat low back pain during first phase of treatment lasting  four weeks.Group B received placebo acupoints defined like acupoints without  effectsover low back pain, in accordance with TCM at points S۵۱, L۹ and LI۳,bilaterally and two needles at Baxie acupoints, lasting four weeks as in theGroup A. Then after that period the patients crossed over and receivedthe  alternate for four weeks. The maximum number of treatments betweenthe two  phases was arbitrarily defined as ۱۰ ( ten ).

PAIN ASSESSMENT

Huskisson (۱۹۷۴)described an visual analogue scales for subjective  measurement of pain. Ahorizontal line ۱۰۰ mm in length, with ۰, "no pain at all  "and۱۰ ", pain as severe as it could possibly be’’ at the left and rightextremes, respectively, scored by measuring the distance of patient’smark  before each treatment phase by an independent Clinical Assistant.Initial  assessment was followed by a one-week baseline observation periodduring which  the patients recorded pain severity using the Visual AnalogueScale of Pain (  VASP ) and that assessment had served for control in eachgroup.(TABLE I ).

ACUPUNCTURE TECHNIQUE AND PLACEBO

Acupuncture wasperformed according to TCM (Pommeranz,۱۹۸۷) by a physician  trained at theChinese Traditional medical Research Institute in Pekin (Author).  Withthe patient in lateral decubitus, ۱۰ (ten) needles were inserted closethe  spinal at tenderness points and at distance acupoints defined asefficient to  complete the treatment. The needles were left in situ for ۳۰minutes with no  further stimulation.

The placebo groupconsisted in the use of local and distant acupuncture  points withouthrelation with low back pain, in accordance with TCM. Ten needles  wereused at each treatment session and left in situ for ۳۰ minutes with nofurther stimulation in the same way like acupuncture group.

STATISTICAL ANALYSIS

The t-Test, atsignificant level for p < .۰۵ , was used to compare the  specificacupoints against nonspecific acupoints and whether that nonspecificacupoints may be considered an adequated placebo procedure.

RESULTS

Results are presentedfor the ۱۸ patients who completed the trial. Two  patients failed tocomplete the first phase of group B ( placebo ). The patients  reportedthat the pain was the same at beginning of treatment and they notcontinue the trial.

Table I comparesdecrease in Visual Analogue Scales of Pain ( VASP ) in the  patientsgroups before and after treatment sessions and the pain reductionobserved and the baseline observation. A significant reduction in theVASP  occurred in the first treatment phase for Group A and, inversely, inthe Group B  the reduction was not significant. The reduction was ۴۳% forGroup A receiving  acupuncture, and ۱۷ % for Group B receiving placebo.Further reduction in the  VASP occurred in both groups during the secondphase of treatment. The reduction  was ۵۲ % for Group A, now receivingplacebo, and ۷۱ % for Group B, now receiving  acupuncture. This reductionwas significant for only Group B .

TABLE I . . DECREASE IN VISUAL ANALOGUE SCALESOF PAIN [VASP]

SCORE DURING TREATMENT SESSIONS

S = Significant ( p<.۰۵ )

NS = Not Significant

DISCUSSION

Because patients enteredthe study on voluntary basis, the group was  self-selected and randomisedtrial was defined. This may be important because  the patient’s expectantattitude to acupuncture could affect the response to  treatment (Mendelsonet al,۱۹۸۳) . The same way, the clinical observer that  assessed allpatients at the beginning and the end of each course of treatment  and thephysician that applied the needles were blinded one each other.  Therapistexpectant effects upon patient assessement and other methodologicalartifacts may equally well create the appearance of trends in data(Patel,۱۹۸۷;Patel,۱۹۸۹) which do not deserve to be with this design. Thistrial  was double-blind as it was not possible to be sure that the patientswould not  describe, during the second assessment, the methods oftreatment that had been  employed.

Although, in this trialwas not used a rest period between the phases this is  not important,because the follow-up periods have been variable with the effects  ofacupuncture persisting since ۴۰ hours (Fox,۱۹۷۶) until ۱۲ months(Carlson,۱۹۹۳). The relative long-term follow-up data is especiallydisappointing with chronic pain patients where the need to demonstratelasting  benefits from any new treatment is of paramount importance(Richardson,۱۹۸۶).

The overall significanceof point location is unclear as yet. The majority of  studiesinvestigating this question have compared acupuncture at classical siteswith needle insertion at random or theoretically irrelevant locations(Patel,۱۹۸۷). Of eleven controlled clinical trials in this category fivefind  classical acupuncture to be significantly more effective than thecontrol group  and the remaining find non-significant differences infavour of acupuncture. In  this trial were tested with success the use ofa group of points needling at  theoretically irrelevant sites as a placebogroup.

Satisfactory pain reliefwas defined by Beecher (۱۹۵۵) as a ۵۰ percent or  greater reduction ofpain severity. More recently, a reduction of ۳۳ percent in  pain severityhas been accepted as significant (Moertel,۱۹۷۶). Based on this  criterion,in the first phase of the trial acupuncture led to satisfactory painrelief (۴۳ % ), whereas placebo did not ( ۱۷ % ). This was reversed duringthe  second phase, with the placebo group reporting ۵۲ % pain reductionagainst with  ۷۱ % for the acupuncture group. However, the both groups hadreduction on VASP  during the trial, when the acupuncture was used theresults were more  significant than placebo acupuncture group. Group Ashowed a significant  reduction on the first phase of trial and althoughthat effect can be observed  on the second phase of the trial this waslesser than Group B, now using  acupuncture points. Possibly, this effectsis attributed to a physiological or  psychological states induced by thefirst treatment and persisting during the  second phase of the trial(Price et al,۱۹۸۴) or an increase in the endorphin  level in thecerebrospinal fluid (Sjolund et al,۱۹۷۷), caused for any  stimulation onthe body skin (Han, ۱۹۸۹).

This study have beenconcluded the following :

a- this pilot studyprovides an effective model for evaluation of efficacy on  low back pain.

b- the present trialsuccessfully established a valid nonspecific group of  acupoints as acontrol group (placebo ).

c- specific acupoints totreat low back pain, in accordance with TCM, is more  effective thannonspecific acupoints used like placebo.

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