Long-term epidural ketamine, morphine and bupivacaine attenuate reflex sympathetic dystrophy neuralgia

Purpose

There is considerable evidence that NMDA receptor antagonists can abolish nociceptor hypersensitivity in animals. In the present case report, two patients with reflex sympathetic dystrophy were treated with ketamine, a NMDA antagonist, morphine and bupivacaine.

Clinical features

Two patients were referred suffering from severe pain, allodynia, hyperaesthesia, swelling and disability over their right lower legs, diagnosed as reflex sympathetic dystrophy. They had received conventional treatments with non-steroid anti-inflammatory drugs (NSAIDs), steroids, anticonvulsant, antidepressant, epidural lidocaine sympathetectomy and rehabilitation which failed to provide satisfactory pain relief. We administered subanalgesic doses of ketamine (7.5 mg), morphine (0.75 mg) and 6 ml bupivacaine 0.1% via a lumbar epidural catheter three times per day. After several courses of treatment over three and six months, satisfactory pain relief was achieved in each patient. Both are now able to walk with slight weight bearing with the assistance of crutch. The treatment is continuing with further improvement of symptoms and signs.

Conclusion

Epidural coadministration of low doses of morphine, ketamine and bupivacaine provided effective pain relief in two patients. This suggests synergy from this combination that provides an alternative treatment for reflex sympathetic dystrophy.     

Compression syndromes in reflex sympathetic dystrophy

Over an 8-year period we treated 93 cases of reflex sympathetic dystrophy. The initial treatment consisted of long-acting intramuscular corticosteroids and active exercises. Twenty-two patients who did not respond significantly to this treatment had carpal tunnel syndrome. In addition, five had cubital tunnel syndrome, one had ulnar tunnel syndrome, and one had a herniated disk of the cervical spine. All nerves were decompressed with significant improvement in the patient's condition. Pain was relieved in all except three who had mild pain. Motion of the proximal interphalangeal joint improved from an average of 35 degrees before operation to 76 degrees after operation. Grip strength improved from an average of 4 pounds to 27 pounds.     

The sequelae of reflex sympathetic dystrophy

This paper presents the results of a retrospective analysis of 94 patients who were assessed at a mean of 11 months after successful treatment of reflex sympathetic dystrophy (RSD) of the hand. Fifty-four percent still complained of pain related to the weather, and many complained of cold intolerance (44%), slight pain after use (34%), nail and hair growth changes (34%), sensory disturbances (34%) and stiffness of fingers in the morning (28%). There were also complaints of reduced finger extension, pain and loss of movement in the shoulder joint and hand swelling after use, and 78% of patients had significantly reduced grip strength. These results suggest that, in spite of resolution of the acute RSD problem, significant long term sequelae of RSD continue to impair function of the hand in a proportion of patients.     

What is reflex sympathetic dystrophy?

In the literature there is no unanimity with respect to the diagnosis of reflex sympathetic dystrophy (RSD). Frequently, the diagnosis is established on mere clinical grounds. In our opinion, however, bone scintigraphy is of major importance for the diagnosis. Using this examination, true RSD can be clearly differentiated from other conditions which are incorrectly diagnosed and treated as RSD. If the bone scan is not suggestive of RSD, the clinical picture, radiological examination and vascular scan may lead to the correct diagnosis. This may be a pseudodystrophy, in which a hypovascularization is found right from the start, while in true RSD there is initially a hypervascularization. Other conditions which may be confused with RSD are causalgia, neurotic compulsive postures, hysterical conversion, malingering and even self-mutilation. In the spontaneous course of RSD three phases can be distinguished. Stage I is the warm or hypertrophic phase, stage II the cold or atrophic phase. Per definition the third phase corresponds to stabilization or, in rare instances, to healing. By means of the vascular scan the correct stage can be determined, and the results of treatment evaluated. Finally it should be noted that in children the condition is completely different from true RSD, as it concerns a pseudodystrophy or disuse-related dystrophy. This condition may also be seen in adults and adolescents, usually females. The bone scan is always negative. In this way bone scintigraphy constitutes the means to answer the question as to what RSD is and what it is not. An algorithm for the differential diagnosis is presented.     

Continuous versus intermittent epidural analgesia

A randomised study of 381 women was carried out to compare the obstetric outcome after epidural analgesia maintained by an intermittent top-up regimen or with a continuous infusion. The two groups were well matched with respect to age, parity, mode of onset of labour and indication for epidural. Maintenance of epidural analgesia by continuous infusion resulted in a significantly decreased need for top-up doses. A reduction in the incidence of hypotension, cardiotocographic evidence of intrapartum fetal hypoxia and Caesarean section was associated with this. It is concluded that the maintenance of epidural analgesia by continuous infusion is a safe and reliable method and may be more advantageous and less labour intensive than the traditional intermittent regimen.     

Continuous infusion epidural analgesia in obstetrics

The effects of 0.08% (Group A) and 0.25% (Group B) solutions of bupivacaine were compared in a random manner, to assess continuous pump infusion epidural analgesia in labour. Both solutions were infused at a dose rate of 20 mg bupivacaine/hour. The results in all the mothers who had received infusions lasting more than 4 hours were studied. There were 25 in Group A and 28 in Group B. Any treatment during the infusion epidural for inadequate analgesia, hypotension, etc., was recorded as an intervention. The mean of the intervention-free intervals was significantly greater in Group A than in Group B, and significantly fewer top-up injections were required in Group A. The results show that the administration of a 0.08% solution of bupivacaine into the epidural space by continuous pump infusion is more labour saving than the infusion of a 0.25% solution. The concept that a greater volume infusion rate maintains a more extended liquid sleeve of local anaesthetic in the epidural space is supported.     

Intravenous guanethidine in patients with reflex sympathetic dystrophy

Background : Intravenous regional guanethidine Bier block (IVRGBB) has been used predominantly in Europe for treating reflex sympathetic dystrophy (RSD). Our experience in the United States, where its use has been limited, is reported. Methods: Fifty-five patients received IVRGBB for RSD. Upper extremities received 20 mg (10 mg/ml) of guanethidine in 30–50 ml of 0.5% lidocaine; lower extremities received 40 mg in 40–75 ml of lidocaine (volume adjusted for size, weight, or prior adverse effect). Pain severity (mild, moderate, severe, excruciating) was obtained pretreatment. Pain severity and a global clinical assessment (GCA) (resolved, improved, no change, worse) were obtained following each treatment. The final GCA was analyzed vs: pretreatment score; age; sex; pain duration; number of treatments; and precipitating event. Adverse effects were documented. Results : Of 55 enrolled patients, 2 were lost to follow-up, and 2 returned 1 and 4 years later for repeat treatment. Therefore, 53 patients were evaluated for 55 treatments. Age: 38.2 ? 14.8 (SD) (range 10–77) years. Sex: 11 males, 44 females. Average pain duration: 2.0 ? 1.7 years (3 days - 7 years). Final assessment occurred at 3.88 ? 5.21 months (6 days - 2 2/3 years). Effect on pain: resolution-9.1%; improved-14.5%; no change-61.8%; worsening-14.5%. No significant relationship was found between GCA and the factors evaluated. There was a significant positive linear association between pretreatment pain and post treatment GCA (P = 0.032). Fifty-six adverse effects occurred in 19 (34.5%) patients (nausea, vomiting, orthostatic hypotension, dizziness, diarrhea, weakness). Conclusions : IVRGBB does not provide long-term pain relief and is associated with adverse effects in over 1 / 3 of patients.     

Late-onset spondyloarthropathy mimicking reflex sympathetic dystrophy syndrome

Atypical presentations are common when spondyloarthropathy develops in older patients. We report two cases initially mistaken for reflex sympathetic dystrophy syndrome (RSDS). Both the patients were men, aged 62 and 75 years, respectively, with marked painful edema of a foot. One patient reported a moderate-energy trauma as the triggering event. Severe diffuse demineralization was noted on radiographs and diffuse hyperactivity on bone scans starting at the early vascular phase. These findings suggestive of RSDS led to treatment with calcitonin, griseofulvin, and pamidronate, all of which were ineffective. Laboratory tests showed severe inflammation, promoting investigations for other conditions. Spondyloarthropathy was diagnosed based on oligoarthritis with sacroiliitis, presence of HLA B27, and a favorable response to non-steroidal antiinflammatory therapy. In older patients, edema of the foot with severe demineralization and the laboratory evidence of inflammation should suggest a spondyloarthropathy.     

Surgical sympathectomy for reflex sympathetic dystrophy syndromes

PURPOSE: The purpose of this study was the assessment of the efficacy of thoracoscopic cervicodorsal and open lumbar sympathectomy for the reduction of pain severity and disability associated with reflex sympathetic dystrophy (RSD). METHODS: From 1992 to 2000, 73 patients with RSD underwent 46 video-assisted thoracoscopic (first to fourth thoracic ganglion) or 37 surgical lumbar (first to fourth lumbar ganglion) sympathetic chain resections. The patients were referred from multidisciplinary pain clinics with documented sympathetically maintained pain syndrome on the basis of reproducible more than 50% reduction in pain severity score (0, no pain; 10, most severe pain imaginable) for more than 2 days after sympathetic block therapy. The mean duration of the RSD symptoms before sympathectomy was 26 plus minus 14 months (range, 6 to 100 months). Postoperative pain severity score, limb disability, and overall patient satisfaction were assessed by an independent third-party observer at a mean follow-up period of 30 months. RESULTS: No operative mortality or serious morbidity (Horner's syndrome, bleeding that needed transfusion, wound infection) occurred. Transient (<3-month) postprocedural sympathalgia developed in one third of the patients for cervicodorsal sympathectomy and 20% of the patients for lumbar sympathectomy and was treated effectively with trigger point/proximal ganglion block therapy or transcutaneous electrical nerve stimulation. At 3 months after sympathectomy, 10% of the patients had conditions that were judged treatment failures with no reduction in pain severity or limb disability. The remaining patients testified to more than 50% pain reduction, with pain severity scores decreasing from a mean of 8.7 before surgery to 3.4 after sympathectomy. At 1 year, one quarter of the patients had continued significant pain relief (pain severity score, <3) and an additional 50% of the patients indicated continued but reduced pain severity and an increase in daily/work activities. Overall, patient satisfaction (willingness to have procedure again, benefit from sympathectomy) was 77% and was not significantly influenced by patient age, RSD duration/stage, or extremity involvement (lumbar, 84%; cervicodorsal, 72%). CONCLUSION: Patients with RSD with a confirmed sympathetically maintained pain syndrome can realize long-term benefit from surgical sympathectomy. Procedural efficacy was similar for both upper limb and lower limb RSD syndromes, although the level of pain reduction did deteriorate with time. After sympathectomy, the patients with RSD had a low incidence rate (7%) of "new" complex regional pain or disabling compensatory sweating syndromes.