Epidural steroids for low back pain syndromes

Abstracts

JUSTIFICATIVA E OBJETIVOS: As síndromes dolorosas lombares constituem uma grande causa de morbidade e incapacidade. A terapêutica destas doenças é normalmente baseada em medidas conservadoras como repouso, analgesia, fisioterapia, até medidas cirúrgicas e de reabilitação. O objetivo deste trabalho é demonstrar a possibilidade do uso de corticosteróides por via peridural no tratamento das síndromes dolorosas lombares. CONTEÚDO: Técnicas e indicações adequadas do uso de infiltração peridural de corticosteróides em dores lombares de diferentes etiologias serão apresentadas nesta revisão de literatura, como uma opção viável e eficaz, assim como serão descritas suas indicações, contra-indicações, complicações e eficácia. CONCLUSÕES: O uso de corticosteróide por via peridural pode ser uma alternativa ao tratamento, desde que respeitando-se suas corretas indicações.

DOR, Aguda, Crônica; DROGAS; TÉCNICAS ANESTÉSICAS, Regional

REVIEW ARTICLE

Epidural steroids for low back pain syndromes^*

Uso de corticoesteroides por vía peridural y en las síndromes dolorosas lumbares

Alexander Ferrari Cocicov, M.D.^I; Hercilia Laura Ferrari Cocicov, TSA, M.D.^II; Marília Barreto G da Silva, M.D.^III; Thelma Larocca Skare, M.D.^IV

^IAcadêmico (6º ano) da Faculdade Evangélica do Paraná

^IIEx-Responsável pelo CET do HC da UFPr no período 1992-1995

^IIIProfessora Assistente da Disciplina de Reumatologia da Faculdade Evangélica do Paraná

^IVProfessora Assistente e Responsável pela Disciplina de Reumatologia da Faculdade Evangélica do Paraná

^{Correspondence}

SUMMARY

BACKGROUND AND OBJECTIVES: Low back pain syndromes are major causes of morbidity and disability. Their therapeutic management is often based on conservative measures, such as rest, analgesia, physical therapy, and even surgical and rehabilitation procedures. This study aimed at describing the use of epidural steroids to treat low back pain syndromes.

CONTENTS: Adequate techniques and indications for epidural steroid injections to treat low back pain of different etiologies are presented in this literature review as feasible and effective options, as well as their indications, counterindications, complications and efficacy.

CONCLUSIONS: Epidural steroids may be an alternative treatment, provided adequate indications are respected.

Key Words: ANESTHETIC TECHNIQUES, Regional: epidural; DRUGS: steroid; PAIN, Acute, Chronic: low back pain

RESUMEN

JUSTIFICATIVA Y OBJETIVOS: Las síndromes dolorosas lumbares constituyen la grande causa de morbididad e incapacidad. La terapéutica de estas enfermedades es normalmente fundamentada en medidas conservadoras como reposo, analgesia, fisioterapia, inclusive hasta medidas quirúrgicas y de rehabilitación. El objetivo de este trabajo es demostrar la posibilidad del uso de corticosteroides por vía peridural en el tratamiento de las síndromes dolorosas lumbares.

CONTENIDO: Técnicas e indicaciones adecuadas del uso de infiltración peridural de corticosteroides en dolores lumbares de diferentes etiologías serán mostradas en esta revisión de literatura, como una opción viable y eficaz, así como serán descritas sus indicaciones, contra-indicaciones, complicaciones y eficiencia.

CONCLUSIONES: El uso de corticosteroide por vía peridural puede ser una alternativa al tratamiento, desde que se respeten sus indicaciones correctas.

INTRODUCTION

Throughout the history of mankind, pain has been a major concern and is the reason of being of Medicine ¹.

Low back pain syndromes are still a public health problem, although humanity suffers from it for centuries. Low back pain is a major cause of morbidity and disability, being only second to headache in the scale of painful disorders affecting men. Approximately 80% of people, in some stage of their lives, suffer from low back pain. Regardless of the progress of ergono- mics applied to the spine and the use of sophisticated diagnostic methods in the 70s, 80s and 90s, low back pain and lumbar sciatic pain have increased 14 times more than the growth of population. Difficulties to study and approach low back pain and lumbar sciatic pain are a consequence of several factors, among them: lack of true correlation between clinical and imaging findings, the lumbar segment is innervated by a diffuse and interlaced nervous network making difficult the precise location of the pain origin, frequent and painful contractures are not followed by apparent histological injury, few and inadequate information on anatomic and physiologic findings of structures potentially involved and difficulties in interpreting pain ².

Etiologic low back pain syndrome characterization is predominantly clinical and additional tests are indicated to confirm the diagnostic hypothesis.

It is necessary to define the terminology to understand the differences ².

Low back pain - all pain conditions, with or without stiffness, located in the low dorsal region in an area between the last costal arch and the gluteus fold. Lumbar sciatic pain - pain irradiating from the lumbar region to one or both lower limbs. Sciatic pain - uni or bilateral pain originating from the root of the thigh, crossing the knee(s) and most of the times reaching the ipsilateral foot, followed or not by motor and/or sensory deficit. As to evolution, all syndromes may be characterized as acute or lumbago, sub-acute and chronic. The treatment involves conservative measures such as bed rest, oral, topic or parenteral drugs, infiltrations and surgical and rehabilitation procedures ².

This study describes the use of epidural steroids to control lumbar sciatic pain which, by following adequate techniques and precise indications, aims at relieving pain, especially in the acute phase, being a low risk procedure as compared to surgical approaches ^3-5.

HISTORY

The use of the vertebral route to introduce drugs in the body was firstly described by L. Corning in 1885. His first idea was to inject the drug as close as possible to perimedullary blood circulation, but soon his experiments have evolved to the subdural route, after confirming the impossibility of reaching perimedullary blood circulation ¹.

In 1901, De Pasquier and Leri have used lumbar spinal injections with 5 mg cocaine to induce toxicity on bulbar and brain centers, to observe the effects ⁶.

Cathelin, in 1901, has proposed that the epidural space would be less dangerous to prevent direct medullary puncture, injecting drugs on spinal roots, where they would act. He has described, then, the sacral hiatus as the access pathway to the epidural space ¹.

Winer, in 1928, has reported the use of novocaine in Ringer's solution to treat sciatic pain, phantom limb pain, and even rectal carcinoma, with successful results. Evans, in 1930, has stated that pain relief was independent of the nature of the injected solution and that, in his opinion, the most important factor for cure was mechanical nervous roots distension. Paulino A, in 1930, has reported pain relief in three patients with sacral epidural saline solution injection, and has observed that it generated the same results as anesthetic drugs ¹.

There are controversies on the first epidural steroid injection report, being sometimes described as having been performed in 1951 by Robecchi et al. ⁴, and sometimes described as having been firstly performed by Lievre in 1953 ^5,6, using hydrocortisone. The first North-American (USA) case reports were published by Goebert et al., who believed that nervous root compression syndrome was associated to inflammation and edema. Epidural procaine and hydrocortisone have achieved satisfactory results in 72% of patients ⁶. From then on, several studies have been carried out to prove the efficacy of this method.

In a 10-year period (1958-1968), Swerdlow et al. have treated 325 cases of lumbar sciatic pain with sacral epidural injection of saline solution, local anesthetics and methylprednisolone acetate; as from 1963, they have exclusively used lumbar epidural steroids. Cases were divided in acute, chronic and recurrent. In general, the steroid treatment has resulted in better results as compared to local anesthetics or saline solution, especially in the chronic patients groups. There was an impression that saline solution or anesthetics were better for acute cases, but data were not statistically significant ¹.

EPIDURAL STEROIDS

Steroids have analgesic and anti-inflammatory effects by preventing arachidonic acid release from injured cells membrane. Epidural steroids have several effects, among them: ability to decrease edema, decrease fibrin deposits, decrease capillary dilatation, decrease leucocytes migration, decrease disease activity, decrease capillary and fibroblast proliferation, decrease collagen deposition and improve healing ⁵. Studies have also shown that steroids decrease nervous cell hyperexcitability by directly affecting cell membrane conduction ⁷.

This way, nervous roots and even adjacent tissues edema is decreased. One may say that the curative effect of epidural steroids does not result from the effect of volume in adherences lysis, but rather from the anti-inflammatory effect of those steroids ¹.

Saal et al. have observed the high potency of phospholipase A₂ produced by herniated disks which, together with prostaglandins and leucotriens would induce direct injury to cell membrane causing edema. The hypothesis was then raised that steroids could decrease inflammation around herniated disks by decreasing phospholipase A₂ synthesis, a phenomenon that would decrease the production of multiple inflammatory markers and, as a consequence, would decrease pain ⁴.

Some steroids described for epidural injection are ⁷:

Methylprednisolone Acetate - the most common steroid. It is used in 80 mg doses, varying from 40 mg to 120 mg per injection;

Triamcinolone Salts - used by some authors, such as Doloney et al., who have elected it for having minor sodium retention effect and for remaining in suspension for a longer period at injection site;

Betamethasone and Dexamethasone - seldom used;

Hydrocortisone - used in the past, has been replaced by current drugs with longer duration and higher potency.

Most professionals use methylprednisolone or triamcinolone. Hydrocortisone and prednisolone have less anti-inflammatory potency as compared to methylprednisolone and triamcinolone, have higher mineralocorticoid effects resulting in higher sodium retention and, as a consequence, blood pressure increase. Dexamethasone has higher anti-inflammatory potency as compared to methylprednisolone and triamcinolone, but has also more and severe adverse effects. It is worth highlighting that methylprednisolone and triamcinolone have satisfactory anti-inflammatory potency with minor mineralocorticoid and adverse events as compared to other steroids. Both ended being drugs preferably used for epidural injections ⁷.

Diluent

Steroids may be administered diluted or not in local anesthetics and/or isotonic saline solution. Yates has reported that the association with local anesthetics has resulted in better comfort for patients during epidural injection ⁵.

In theory, local anesthetics used as diluents are advantageous due to the possibility of disrupting the spasm- ischemia-pain cycle, thus favoring muscle relaxation. Their use also helps checking whether the solution is being adequately applied for generating sensory block ^4,5.

Vehicles used in epidural steroids are highly questioned as to the risk of neurotoxicity, especially non-ionic polyethylene glycol and the bactericide agent associated to solutions such as methylprednisolone and triamcinolone ⁶.

Solution Volume

Volume used widely and there are no studies aiming at standardizing the most adequate and correct volume to be used.

Bryan et al. have performed a fluoroscopy and contrast study where they have observed that only 31% of injections reach the dorsal portion of the epidural space, that is, do not reach the ventral portion ⁴.

Steroid effects seem to be independent of total injected vo- lume, but volume should be at least enough to "take" the steroid to the site where its effect is needed. There is a theory advocating that the higher the volume the "farthest" the steroid reaches, but the closer to the affected side the solution is applied, the lower is the volume needed to reach the desired effect.

Harley believes that 10 ml are more than enough to involve the affected area. For sacral blocks, however, higher vo- lumes have been suggested, around 20 to 25 ml ⁵.

Low volumes (1 to 3 ml) are not encouraged, due to the potential toxicity of polyethylene glycol used in the preparations. Higher volumes would provide lower concentrations of this irritating substance directly on tissues. Low volumes are also not recommended due to the possibility of not reaching the "surroundings" of the inflamed region ⁴.

Number of Injections

If one steroid epidural injection is enough to totally relief pain symptoms, this is a potential indication not to repeat the procedure ¹. It seems that some patients have responded to the second or third steroid epidural injection, although not responding to previous ones ⁴.

Brown has not found benefits in using more than three injections, but has also not explained whether it would be counterindicated to go beyond three attempts. The repetitive use may bring noxious local and systemic effects to patients ^5,8.

Swerdlow et al. suggest that steroids remain at epidural injection site for more than two weeks. Green et al. have observed symptomatic improvement in 37% of patients in two days, and in 63% of patients in four to six days. A second attempt before the sixth day of the previous attempt is not indicated for those who had no satisfactory response. A second injection may be indicated due to the possibility of technical error during previous attempt. There are strong evidences that solutions injected in the epidural space not only reach spinal nerves, but also cross the dura to the spinal space, reaching roots and even the spinal cord ¹.

Injection Site

Epidural space identification with a needle is based on the perception of the moment in which ligamentum flavum is crossed. The most common method consists in using the loss of resistance to air technique. Loss of resistance is more easily detected when large needles are used, being 16G, 17G and 18G the most commonly used ⁹.

Sacral epidural injection requires the needle to be introduced through the sacrococcygeus hiatus, and the ability to advance the needle 1 or 1 ½ cm in the cephalad direction confirms the right position. Access may vary and may be lumbar median, lumbar paramedian or caudal (sacral) ⁹.

Several factors favor lumbar application (both median and paramedian) as compared to sacral: lumbar region has less anatomic variations, is easier to locate and the solution is deposited closer to the inflamed area ⁹.

When applied in the sacral hiatus, steroids are "spread" to a wide area before reaching the area where they should act. It is advantageous when the patient has already been submitted to lumbar region surgery ⁹. It should also be considered that the sacral region is at lower risk for accidental dural puncture because in adults, the dural sac in general ends below the inferior border of the second sacral vertebra and the solution is injected in the sacral hiatus, that is, three vertebral segments below ⁹.

Some investigators recommend the associated use of fluoroscopy to guide epidural steroid injections to assure better results. A study by Bryan et al. has shown that from 100 epidural steroid injections using contrast fluoroscopy, only 31% have reached the dorsal epidural space. Other studies using contrast fluoroscopy have shown 18% to 52% route deviations, depending on the route and the professional's experience ⁴.

In spite of what has been said, some professionals advocate the use of a correct and adequate technique which, associated to cooperative patients and qualified professionals, assure efficiencies close to 95% without contrast fluoroscopy ^5,10.

INDICATIONS

Epidural steroids are primarily indicated to relieve inflammation-induced pain which affects neural elements in the epidural and epineural spaces ⁴, being indicated for sciatic pain, lumbar pain, sacral pain, radicular pain, lumbar sciatic pain, radiculopathy, nervous compression, protrusion, herniated disk or disc prolapse, lumbar sciatic syndrome and lumbar canal stenosis. Nervous roots irritation and inflammation seem to be common mechanisms for such disorders where epidural steroids have effect ⁵.

Multifactorial pain genesis and local inflammation are factors to be considered. It is known that nervous root compression alone does not justify symptoms. Inflammation site pH evaluation by Nachemson has evidenced that in the presence of inflammation there is a change in pH and this determines reaction in epidural and epineural tissues, favoring inflammation. As from these data, it is possible to charge inflammation as a major contributor to pain genesis ⁵. Herniated disk determines a direct nervous root trauma and clinical symptoms tend to decrease when there is inflammatory edema decrease, even without herniation correction. After epidural steroid injection, inflammation and pain would decrease with no need for surgery or herniation correction. Nucleus pulposos material is also an irritative source for nervous roots; steroids, then, decrease this inflammatory response when there is fibrous annulus rupture and consequent nucleus pulposos leakage ⁵. Bobechko et al. have observed an auto-immune response to nucleus pulposos which has proteoglycan antigenic properties, fact that also contribute to evidence steroids local therapeutic effects ^4,7.

These findings explain epidural steroid beneficial effects on nervous root inflammatory process ^5,7. A more favorable response has been observed in acute pain. There is a lower response for chronic pain as compared to acute pain response because chronic inflammation may progress to nervous fibrosis, which is an irreversible condition ⁵. Patients with herniated disk or spinal cord canal stenosis have higher improvement chances than patients with instability, chronic pain, trauma and scoliosis ^3,11.

COUNTERINDICATIONS

Epidural steroid counterindications are ^3-5,11: local or systemic infection, use of anticoagulants, recent use of AAS ⁵ (some do not consider it a counterindication) ⁴, exacerbated allergic reaction to drugs, allergy to one formula component and pregnancy; the latter may have absolute counterindication for fluoroscopy ⁴.

Patients with diabetes mellitus, congestive heart failure and gastric ulcer may react with exacerbation of underlying disease symptoms ³.

Cases involving pseudoarthrosis, infection, tumor or chronic pain are considered less precise indications for epidural steroids. There is a higher risk for associated complications in patients with multiple co-morbidities ¹¹.

COMPLICATIONS

There is no risk-free treatment and the risks of this technique are associated both to technique and drugs used ^4-7,10,12.

Minor complications are: dural perforation, post-procedure headache, accidental subdural injection, accidental spinal injection, accidental intravascular injection, salt and water retention, diabetes mellitus exacerbation, congestive heart failure exacerbation, increased pain during procedure, vasovagal reflex and facial erythema. When local anesthetics are associated, minor complications are also: arterial hypotension, motor block and markedly longer sensory block duration.

Major complications are those involving the development of: systemic infection, bacterial meningitis, chemical meningitis, Cushing and pseudo-Cushing, cauda equina syndrome, cataract, fistula, abscess, epidural hematoma, arachnoiditis, epidural lipomatosis and neurotoxicity.

Neurotoxicity is a well studied complication which does not seem to be determined by the steroid itself, but in many cases it seems to be attributed to solutions containing different substances ^7,12. Dewey, since 1973, as well as Margolis et al., Hurst, Chino et al. and Selby, have described the development of arachnoiditis determined by toxic effects of polyethylene glycol in which some steroids are diluted ¹³.

Cooper et al., in 1996, have reported a case where the patient has developed increased pain after the second injection, followed by temperature increase being afterward diagnosed as sepsis by Staphylococcus aureus. After 13 days of hospitalization, patient has developed left leg weakness, urinary and fecal incontinency with further development of meningitis by Staphylococcus aureus and cauda equina syndrome ¹⁴.

EFFICACY

It is difficult to determine epidural steroids efficacy due to the large number of variables found when different studies are compared. Since lumbar sciatic pain is determined by several factors, which may be associated or not, there are several difficulties to perform studies and especially to propose suggestions and treatment standardization ^3,11,15.

In non-controlled studies, approximately 65% of patients improved their pain symptoms after epidural steroid injection, but these are difficult to interpret results due to their variations, such as: diagnostic criteria for patients selection and inclusion, type of steroid and diluent, dose, volume, number of injections, interval between injections, establishment of improvement patterns, follow-up duration, and also the fact that pain cannot be technically measured and is subjectively described by patients ^5,6,15.

There are data showing pain improvement varying from 0% to 75% of patients ¹¹.

The first prospective controlled study on epidural steroid injections was published by Beliveau in 1971. The study involved 2 groups of 24 patients; the first received procaine and methylprednisolone acetate, and the second procaine alone. The injection would only be repeated if there was improvement after the first application. After one to three-month follow-up, no statistically significant difference was found in symptoms and clinic between both groups. It is believed that this was due to the combination of acute and chronic pain patients. Investigations have shown that different responses depend on symptoms duration and this aspect was not clear in this paper for each group ^5,7.

Winnie et al. have shown in 1972 that steroids administered in low isotonic saline solution or anesthetic volumes determine a significant improvement (almost 80%), when injected in the closest site to the affected area, because the closer to the pathological process the solution is administered, the better will be its therapeutic effect ^4,6.

Prospective, randomized and double blind studies with epidural steroids were firstly published by Dilke et al. in 1973, who have evaluated 100 patients. The treated group received 80 mg methylprednisolone acetate in 10 ml isotonic saline solution, and the control group received 1 ml isotonic saline solution. Both groups had the same number of patients with acute or chronic pain and most of them referred symptoms for less than 6 months. Two weeks later there was pain relief in 46% of treated patients and 11% of control group patients. Three months later pain was mild or absent in 98% of treated patients and 82% of control group patients ^4,6,7.

Breivik et al., in 1976, have evaluated 35 patients, 16 of whom received 20 ml of 0.25% bupivacaine with 80 mg methylprednisolone acetate in caudal block. The remaining 19 patients received 20 ml of 0.25% bupivacaine followed by 100 ml isotonic saline solution. A total of 3 injections were administered at 1-week intervals. Follow-up varied from 3 to 20 months. The steroid group presented significant improvement in 65% of patients while the control group had only 25% improvement ^5,7.

Snoek et al., in 1977, have evaluated 51 acute pain patients. One group received caudal 2 ml isotonic saline solution and the other 80 mg methylprednisolone acetate. Short-term follow-up lasted 24 to 48 hours and no significant differences were found between groups. Long-term follow-up consisted of a medical questionnaire applied 8 to 20 months later. There were no statistically significant differences between groups. Several are the biases of this study which may have determined the absence of significant differences, among them: very short-term or very long-term follow-up which did not consist of a medical revaluation but rather of a letter or fax with a questionnaire, and the low volume injected which could lead to administration in the wrong site ^4,6,7.

Yates has performed in 1978 a prospective randomized study with 4 different epidural injections: 50 ml isotonic saline solution, 50 ml of 0.5% lidocaine, 47 ml isotonic saline solution with 3 ml of triamcinolone and 47 ml of 0.5% lidocaine with 3 ml triamcinolone. The study was limited to a short-term follow-up (1 week), in which improvements were observed in patients receiving steroids as compared to those not receiving steroids ^5,7.

Klenerman et al., in 1984, have performed a prospective, randomized and double blind study with 63 acute pain patients referring symptoms for less than 6 months. The treatment group received 80 mg methylprednisolone acetate in 20 ml isotonic saline solution. The remaining groups received 20 ml isotonic saline solution, 20 ml of 0.25% bupivacaine and the last group was submitted to needle prick only without drug administration. Patients were evaluated 2 weeks and 2 months later. Through a visual pain scale, 75% of patients have reported improvement however without distinction among different injection types. Major bias of this study was the small number of patients in each group ^4-7.

Cuckler et al., in 1985, have performed a prospective, randomized and double blind study involving 73 patients. The treatment group received 80 mg methylprednisolone acetate and 5 ml of 1% procaine in the epidural space between L₃ and L₄; the control group received 2 ml saline solution with 5 ml of 1% procaine in the same site. Short-term follow-up was 24 hours and long-term follow-up was 20 months. Improvement criteria were estimated in percentages by patients themselves. There have been no statistically significant differences between groups in any follow-up. As in other controlled studies (Snoek et al. and Yates), several biases may be found in those studies, such as: no medium-term follow-up, lack of similar criteria for patients selection, and follow-up method which did not include medical evaluation ^6,7.

A study by Ridley et al. in 1988 has shown beneficial effects of epidural steroids in medium-term follow-ups. This study has evaluated 35 patients; the treated group received 10 ml lumbar epidural isotonic saline solution with 80 mg methylprednisolone acetate and the control group received 2 ml isotonic saline solution in the interspinal ligament region. Injections were repeated one week later if no pain improvement was observed. The treatment group referred improvement in 1 to 2 weeks as compared to the control group, but this improvement was maintained for 12 weeks with pain returning to baseline values 24 weeks later in the treatment group. As with other studies, conclusions are limited due to the small number of patients in each group (19 and 16) ^4,7.

Bush et al. in 1991 have evaluated 23 patients receiving 2 injections of each evaluated solution, being 25 ml isotonic saline solution with 0.25% procaine and 80 mg triamcinolone in the treatment group and 25 ml isotonic saline solution in the control group. Follow up was at 4 weeks and 1 year and in 4 weeks there has been statistically significant improvement in the treatment group. One year follow up has not shown statistically significant differences between groups. This result might be explained by the fact that long-term follow-up (6 months to 1 year) in the treatment group may be difficult to compare to control group, due to the trend toward natural resolution of symptoms during this period. Bush et al. results are consistent with Dilke et al., who have observed improvement in the treatment group when evaluated at the medium term (3 months). Unfortunately, both studies are limited due to the small number of patients ^4,7.

Langmayr et al., in 1994, have carried out a prospective, controlled, double-blind study on spinal steroids in the intraoperative period of lumbar herniated disk and have concluded that such procedure has considerably decreased postoperative pain, but with transient effect ¹⁶.

Yung-Liang Wang et al., in 1997, have carried out a prospective, randomized and double-blind study on epidural steroids (5 mg dexametazone in 1 ml saline solution) in the immediate postoperative period of surgeries under epidural anesthesia and have observed a significant decrease in postoperative low back pain in non-obstetric surgeries ¹⁷.

Carette, in 1997, has carried out a study with two groups. The treatment group has received 8 ml isotonic saline solution with 80 mg methylprednisolone acetate and the control group has received 1 ml isotonic saline solution. There has been statistically significant difference in the treatment group as compared to the control group in the first three months, and after this period improvement scores were equivalent for both groups ^4,6.

Different results found in all those studies may be explained by differences in patients selection, diagnostic criteria, symptoms duration, methods, time and type of post-procedure follow-up ⁵. A major problem is the lack of documentation of injections applied in the correct site because none of those studies have used contrast fluoroscopy to document administration. Studies with contrast fluoroscopy aiming at observing the correct administration of epidural solutions have found 18% to 52% administration errors, depending on the route and physicians' experience. Of these, only Snoek et al. have mentioned correct administration or not ⁴.

Riew et al. ⁴ have carried out a prospective randomized and double-blind study using contrast fluoroscopy to guide lumbar transforaminal injection in 55 patients divided in two groups. The first group, with 28 patients, has received bupivacaine with dexamethasone and the other group, with 27 patients, has received bupivacaine alone. Follow-up was 13 to 36 months. This study has found a statistically significant difference in the need for post-treatment surgery indication because in the steroid group, 71.4% decided for non-surgery while 33.3% in the bupivacaine group have decided for non-surgery ⁴.

Buchner et al., in 1999, have carried out a prospective and randomized study with 36 patients divided in two groups, the first with 17 patients and the second with 19 patients. Both groups have received conservative treatment techniques involving analgesics, anti-inflammatories, rest, physical therapy, hydrotherapy and other conservative methods. The first group received 3 epidural injections of 100 mg methylprednisolone in 10 ml of 0.25% bupivacaine. Follow-up was at 2 weeks, 6 weeks and 6 months and pain relief, functional aspect and the ability to stretch the leg were evaluated. At 2 weeks, the steroid group was statistically different from control group in the ability to stretch the leg, but was not statistically different in pain relief and mobility. At 6 weeks and 6 months there were no longer statistically significant differences in all parameters between groups. The conclusion was that epidural steroids may be recommended as additional conservative therapy to control lumbar sciatic pain only during the acute phase of pain ⁸.

CONCLUSIONS

Some conclusions were drawn from the combination of results of these controlled studies:

A) In long-term follow-ups, there were no statistically significant differences in pain relief between patients receiving epidural steroids and control groups. This might be explained by the fact that long-term prognosis of non-surgical patients is improvement of symptoms;

B) Therapeutic effects seem to be present especially in the short and medium-term follow-up, from 2 weeks to 3 months. It is believed that beneficial effects of epidural steroids, even if only for a short or medium period, justify this treatment due to the potential of decreasing pain duration, movement limitations and loss of labor ability from weeks or months, to only a few days.

C) Contrast fluoroscopy enables to identify whether the steroid was correctly administered in the right site, thus allowing better control of the technique, and studies to evaluate the beneficial effects of epidural steroids associated to contrast fluoroscopy to control lumbar sciatic pain may become an excellent method to prove, with statistically significant data, the real efficacy of this procedure;

D) Undoubtedly, most patients prefer a treatment to relief pain much faster than if they waited for its natural resolution, even when informed of possible procedure-related risks.

REFERENCES

Submitted for publication March 25, 2003

Accepted for publication June 12, 2003

• 01. Gonçalves BMV - Sobre o Uso de Corticosteróide por Via Peridural no Tratamento de Radiculopatias. Rio de Janeiro, Tese (Livre Docência). Faculdade de Medicina. Universidade Federal do Rio de Janeiro, 1976;44.
• 02. Cecin HA - Consenso Brasileiro sobre Lombalgias e Lombociatalgias. Sociedade Brasileira de Reumatologia. Comitê de Coluna Vertebral. Uberaba, Faculdade de Medicina do Triângulo Mineiro, 2000;60.
• 03. Abram SE - Factors that influence the decision to treat pain of spinal origin with peridural steroid injections. Reg Anesth Pain Med, 2001;26:2-4.
• 04. Cannon DT, Aprill CN - Lumbosacral peridural steroid injections. Arch Phys Med Rehabil, 2000;81:87-98.
• 05. Spaccarelli KC - Lumbar and caudal peridural corticosteroid injections. Mayo Clin Proc, 1996;71:169-178.
• 06. Nelson DA, Landau WM - Intraspinal steroids: history, efficacy, accidentally, and controversy with review of United States Food and Drug Administration reports. J Neurol Neurosurg Psychiatry, 2001;70:433-443.
• 07. Tonkovich-Quaranta LA, Winkler SR - Use of peridural corticosteroids in low back pain. Ann Pharmacother, 2000;34: 1165-1172.
• 08. Buchner M, Zeifang F, Brocai DRC et al - M. Epidural corticosteroid injection in the conservative management of sciatica. Clin Orthop, 2000;375:149-156.
• 09. Scott DB - Bloqueio Peridural, em: Rogers MC, Tinker JH, Covino BC et al - Princípios e Prática de Anestesiologia. Rio de Janeiro: Guanabara Koogan, 1993;955-971.
• 10. Johnson BA, Schellhs KP, Pollei SR - Epidurography and therapeutic peridural injections: technical considerations and experience with 5334 cases. AJNR Am J Neuroradiol, 1999;20: 697-705.
• 11. Fanciullo GJ, Hanscom B, Seville J et al - An observational study of the frequency and pattern of use of peridural steroid injection in 25.479 patients with spinal and radicular pain. Reg Anesth Pain Med, 2001;26:5-11.
• 12. Borenstein D - Epidemiology, etiology, diagnostic evaluation, and treatment of low back pain. Current Opinion in Rheumatology, 1998;10:104-109.
• 13. Gronow DW, Mendelson G - Epidural injection of depot corticosteroids. The Med J Australia, 1992;157:417-420.
• 14. Cooper AB, Sharpe MD - Bacterial meningitis and cauda equina syndrome after epidural steroid injections. Can J Anaesth, 1996;43:43-45.
• 15. Deyo RA - Drug therapy for back pain. Which drugs help which patients? Spine, 1996;21:2840-2850.
• 16. Langmayr JJ, Obwegeser AA Schwarz AB et al - Intrathecal steroids to reduce pain after lumbar disc surgery: double-blind, placebo-controlled prospective study. Pain, 1995;62:357-361.
• 17. Wang YL, Tan PPC, Yang CH - Epidural dexamethasone reduces the incidence of backache after lumbar peridural anesthesia. Anesth Analg, 1997;84:376-378.

Correspondence to

Dr. Alexander Ferrari Cocicov

Address: Rua Carmelo Rangel, 580 Batel

ZIP: 80440-050 City: Curitiba, Brazil

*

Received from Departamento de Clínica Médica da Faculdade Evangélica do Paraná, Curitiba, PR

Publication Dates

• Publication in this collection
  06 May 2004
• Date of issue
  Feb 2004

History

• Received
  25 Mar 2003
• Accepted
  12 June 2003