Ketanserin in reflex sympathetic dystrophy. A double-blind placebo controlled cross-over trial

Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews

BACKGROUND

Complex regional pain syndrome (CRPS) is a chronic pain condition that usually occurs in a limb following trauma or surgery. It is characterised by persisting pain that is disproportionate in magnitude or duration to the typical course of pain after similar injury. There is currently no consensus regarding the optimal management of CRPS, although a broad range of interventions have been described and are commonly used. This is the first update of the original Cochrane review published in Issue 4, 2013.

OBJECTIVES

To summarise the evidence from Cochrane and non-Cochrane systematic reviews of the efficacy, effectiveness, and safety of any intervention used to reduce pain, disability, or both, in adults with CRPS.

METHODS

We identified Cochrane reviews and non-Cochrane reviews through a systematic search of Ovid MEDLINE, Ovid Embase, Cochrane Database of Systematic Reviews, CINAHL, PEDro, LILACS and Epistemonikos from inception to October 2022, with no language restrictions. We included systematic reviews of randomised controlled trials that included adults (≥18 years) diagnosed with CRPS, using any diagnostic criteria.  Two overview authors independently assessed eligibility, extracted data, and assessed the quality of the reviews and certainty of the evidence using the AMSTAR 2 and GRADE tools respectively. We extracted data for the primary outcomes pain, disability and adverse events, and the secondary outcomes quality of life, emotional well-being, and participants' ratings of satisfaction or improvement with treatment.  MAIN RESULTS: We included six Cochrane and 13 non-Cochrane systematic reviews in the previous version of this overview and five Cochrane and 12 non-Cochrane reviews in the current version. Using the AMSTAR 2 tool, we judged Cochrane reviews to have higher methodological quality than non-Cochrane reviews. The studies in the included reviews were typically small and mostly at high risk of bias or of low methodological quality. We found no high-certainty evidence for any comparison.  There was low-certainty evidence that bisphosphonates may reduce pain intensity post-intervention (standardised mean difference (SMD) -2.6, 95% confidence interval (CI) -1.8 to -3.4, P = 0.001; I2 = 81%; 4 trials, n = 181) and moderate-certainty evidence that they are probably associated with increased adverse events of any nature (risk ratio (RR) 2.10, 95% CI 1.27 to 3.47; number needed to treat for an additional harmful outcome (NNTH) 4.6, 95% CI 2.4 to 168.0; 4 trials, n = 181).  There was moderate-certainty evidence that lidocaine local anaesthetic sympathetic blockade probably does not reduce pain intensity compared with placebo, and low-certainty evidence that it may not reduce pain intensity compared with ultrasound of the stellate ganglion. No effect size was reported for either comparison. There was low-certainty evidence that topical dimethyl sulfoxide may not reduce pain intensity compared with oral N-acetylcysteine, but no effect size was reported. There was low-certainty evidence that continuous bupivacaine brachial plexus block may reduce pain intensity compared with continuous bupivacaine stellate ganglion block, but no effect size was reported. For a wide range of other commonly used interventions, the certainty in the evidence was very low and provides insufficient evidence to either support or refute their use. Comparisons with low- and very low-certainty evidence should be treated with substantial caution. We did not identify any RCT evidence for routinely used pharmacological interventions for CRPS such as tricyclic antidepressants or opioids.

AUTHORS' CONCLUSIONS

Despite a considerable increase in included evidence compared with the previous version of this overview, we identified no high-certainty evidence for the effectiveness of any therapy for CRPS. Until larger, high-quality trials are undertaken, formulating an evidence-based approach to managing CRPS will remain difficult. Current non-Cochrane systematic reviews of interventions for CRPS are of low methodological quality and should not be relied upon to provide an accurate and comprehensive summary of the evidence.

Effectiveness of complex regional pain syndrome treatment: A systematic review

Complex regional pain syndrome (CRPS) is a descriptive term for a complex of symptoms and signs typically occurring following trauma of the extremity. Typical symptomatology includes severe pain, swelling, vasomotor instability and functional impairment of the affected limb. At present there is no one, effective method of treatment of the condition. A large number of treatments have been investigated but major multicentre randomized controlled trials are lacking. This study presents the results of a systematic review of the evidence on effectiveness of treatment methods in CRPS. It is a follow-up to earlier reviews of randomized controlled trials on CRPS treatment published between 1966 and 2016.

RESULTS

The review of randomized controlled trials showed that only bisphosphonates were found to give uniformly positive effects, statistically significantly better than placebo. Improvement has been reported with topical dimethyl sulfoxide, systemic steroids, spinal cord stimulation and graded motor imagery/mirror therapy programmes. The available evidence does not support the use of other treatments in CRPS, however they are frequently used in clinical practice.

CONCLUSION

Available evidence, although numerous, does not necessarily reflect what is truly effective and what is sham in the management of CRPS.

Intravenous Therapies for Complex Regional Pain Syndrome: A Systematic Review

Complex regional pain syndrome (CRPS) remains a challenging clinical pain condition. Multidisciplinary approaches have been advocated for managing CRPS. Compared with spinal cord stimulation and intrathecal targeted therapy, IV treatments are less invasive and less costly. We aimed to systemically review the literature on IV therapies and determine the level of evidence to guide the management of CRPS. We searched PubMed, Embase, Scopus, and the Cochrane databases for articles published on IV therapies of CRPS up through February 2015. The search yielded 299 articles, of which 101 were deemed relevant by reading the titles and 63 by reading abstracts. All these 63 articles were retrieved for analysis and discussion. We evaluated the relevant studies and provided recommendations according to the level of evidence. We conclude that there is evidence to support the use of IV bisphosphonates, immunoglobulin, ketamine, or lidocaine as valuable interventions in selected patients with CRPS. However, high-quality studies are required to further evaluate the safety, efficacy, and cost-effectiveness of IV therapies for CRPS.

Interventions for treating pain and disability in adults with complex regional pain syndrome

BACKGROUND

There is currently no strong consensus regarding the optimal management of complex regional pain syndrome although a multitude of interventions have been described and are commonly used.

OBJECTIVES

To summarise the evidence from Cochrane and non-Cochrane systematic reviews of the effectiveness of any therapeutic intervention used to reduce pain, disability or both in adults with complex regional pain syndrome (CRPS).

METHODS

We identified Cochrane reviews and non-Cochrane reviews through a systematic search of the following databases: Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects (DARE), Ovid MEDLINE, Ovid EMBASE, CINAHL, LILACS and PEDro. We included non-Cochrane systematic reviews where they contained evidence not covered by identified Cochrane reviews. The methodological quality of reviews was assessed using the AMSTAR tool.We extracted data for the primary outcomes pain, disability and adverse events, and the secondary outcomes of quality of life, emotional well being and participants' ratings of satisfaction or improvement. Only evidence arising from randomised controlled trials was considered. We used the GRADE system to assess the quality of evidence.

MAIN RESULTS

We included six Cochrane reviews and 13 non-Cochrane systematic reviews. Cochrane reviews demonstrated better methodological quality than non-Cochrane reviews. Trials were typically small and the quality variable.There is moderate quality evidence that intravenous regional blockade with guanethidine is not effective in CRPS and that the procedure appears to be associated with the risk of significant adverse events.There is low quality evidence that bisphosphonates, calcitonin or a daily course of intravenous ketamine may be effective for pain when compared with placebo; graded motor imagery may be effective for pain and function when compared with usual care; and that mirror therapy may be effective for pain in post-stroke CRPS compared with a 'covered mirror' control. This evidence should be interpreted with caution. There is low quality evidence that local anaesthetic sympathetic blockade is not effective. Low quality evidence suggests that physiotherapy or occupational therapy are associated with small positive effects that are unlikely to be clinically important at one year follow up when compared with a social work passive attention control.For a wide range of other interventions, there is either no evidence or very low quality evidence available from which no conclusions should be drawn.

AUTHORS' CONCLUSIONS

There is a critical lack of high quality evidence for the effectiveness of most therapies for CRPS. Until further larger trials are undertaken, formulating an evidence-based approach to managing CRPS will remain difficult.

Interventions for treating pain and disability in adults with complex regional pain syndrome

BACKGROUND

There is currently no strong consensus regarding the optimal management of complex regional pain syndrome although a multitude of interventions have been described and are commonly used.

OBJECTIVES

To summarise the evidence from Cochrane and non-Cochrane systematic reviews of the effectiveness of any therapeutic intervention used to reduce pain, disability or both in adults with complex regional pain syndrome (CRPS).

METHODS

We identified Cochrane reviews and non-Cochrane reviews through a systematic search of the following databases: Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects (DARE), Ovid MEDLINE, Ovid EMBASE, CINAHL, LILACS and PEDro. We included non-Cochrane systematic reviews where they contained evidence not covered by identified Cochrane reviews. The methodological quality of reviews was assessed using the AMSTAR tool.We extracted data for the primary outcomes pain, disability and adverse events, and the secondary outcomes of quality of life, emotional well being and participants' ratings of satisfaction or improvement. Only evidence arising from randomised controlled trials was considered. We used the GRADE system to assess the quality of evidence.

MAIN RESULTS

We included six Cochrane reviews and 13 non-Cochrane systematic reviews. Cochrane reviews demonstrated better methodological quality than non-Cochrane reviews. Trials were typically small and the quality variable.There is moderate quality evidence that intravenous regional blockade with guanethidine is not effective in CRPS and that the procedure appears to be associated with the risk of significant adverse events.There is low quality evidence that bisphosphonates, calcitonin or a daily course of intravenous ketamine may be effective for pain when compared with placebo; graded motor imagery may be effective for pain and function when compared with usual care; and that mirror therapy may be effective for pain in post-stroke CRPS compared with a 'covered mirror' control. This evidence should be interpreted with caution. There is low quality evidence that local anaesthetic sympathetic blockade is not effective. Low quality evidence suggests that physiotherapy or occupational therapy are associated with small positive effects that are unlikely to be clinically important at one year follow up when compared with a social work passive attention control.For a wide range of other interventions, there is either no evidence or very low quality evidence available from which no conclusions should be drawn.

AUTHORS' CONCLUSIONS

There is a critical lack of high quality evidence for the effectiveness of most therapies for CRPS. Until further larger trials are undertaken, formulating an evidence-based approach to managing CRPS will remain difficult.

Inhibition of SNL-induced upregulation of CGRP and NPY in the spinal cord and dorsal root ganglia by the 5-HT(2A) receptor antagonist ketanserin in rats

Our previous study has demonstrated that topical and systemic administration of the 5-HT(2A) receptor antagonist ketanserin attenuates neuropathic pain. To explore the mechanisms involved, we examined whether ketanserin reversed the plasticity changes associated with calcitonin gene-related peptides (CGRP) and neuropeptide Y (NPY) which may reflect distinct mechanisms: involvement and compensatory protection. Behavioral responses to thermal and tactile stimuli after spinal nerve ligation (SNL) at L5 demonstrated neuropathic pain and its attenuation in the vehicle- and ketanserin-treated groups, respectively. SNL surgery induced an increase in CGRP and NPY immunoreactivity (IR) in laminae I-II of the spinal cord. L5 SNL produced an expression of NPY-IR in large, medium and small diameter neurons in dorsal root ganglion (DRG) only at L5, but not adjacent L4 and L6. Daily injection of ketanserin (0.3 mg/kg, s.c.) for two weeks suppressed the increase in CGRP-IR and NPY-IR in the spinal cord or DRG. The present study demonstrated that: (1) the expression of CGRP was enhanced in the spinal dorsal horn and NPY was expressed in the DRG containing injured neurons, but not in the adjacent DRG containing intact neurons, following L5 SNL; (2) the maladaptive changes in CGRP and NPY expression in the spinal cord and DRG mediated the bioactivity of 5-HT/5-HT(2A) receptors in neuropathic pain and (3) the blockade of 5-HT(2A) receptors by ketanserin reversed the evoked upregulation of both CGRP and NPY in the spinal cord and DRG contributing to the inhibition of neuropathic pain.

Complex regional pain syndrome type I as a consequence of trauma or surgery to upper extremity: management with intravenous regional anaesthesia, using lidocaine and methyloprednisolone

Complex regional pain syndrome type I (CRPS-I) is a known complication after surgery or trauma to the upper extremity and is difficult to treat. A simple and easily tolerated method of treatment that includes intravenous regional anaesthetic block with lidocaine and methyloprednisolone is presented. One hundred and sixty-eight patients with CRPS-I of the upper extremity were treated in a 5-year period. At the end of treatment 88% of the patients reported minimal or no pain. After a mean follow-up of 5 years (range 28 months to 7 years) complete absence of pain was reported by 92% of patients. The symptoms of the acute phase of the syndrome were reversed. Early recognition and prompt initiation of treatment is very important for the course of the disease as symptoms can be reversible when treatment starts early. Permanent results with a functional upper extremity and very satisfactory pain relief can be anticipated.

Complex regional pain syndrome: state of the art update

OPINION STATEMENT

Although the pathophysiology of complex regional pain syndrome (CRPS) is not fully understood, it appears to reflect multiple interacting mechanisms. In addition to altered autonomic function, a role for inflammatory mechanisms and altered somatosensory and motor function in the brain is increasingly suggested. Several possible risk factors for development of CRPS, including genetic factors, have been identified. Few treatments have been proven effective for CRPS in well-designed clinical trials. However, recent work suggests that bisphosphonates may be useful in CRPS management and that the N-methyl-D: -aspartate receptor antagonist ketamine significantly reduces CRPS pain when administered topically or intravenously at subanesthetic dosages. Extended use of ketamine at anesthetic dosages ("ketamine coma") remains a controversial and unproven treatment for CRPS. Spinal cord stimulation may be effective for reducing pain in approximately two thirds of CRPS patients not responding to other treatments, but its efficacy appears to diminish over time.

Evidence-based interventional pain medicine according to clinical diagnoses. 16. Complex regional pain syndrome

Complex regional pain syndrome (CRPS), formerly known as reflex sympathetic dystrophy is a pain syndrome with an unclear pathophysiology and unpredictable clinical course. The disease is often therapy resistant, the natural course not always favorable. The diagnosis of CRPS is based on signs and symptoms derived from medical history and physical examination. Pharmacological pain management and physical rehabilitation of limb function are the main pillars of therapy and should be started as early as possible. If, however, there is no improvement of limb function and persistent severe pain, interventional pain management techniques may be considered. Intravenous regional blocks with guanethidine did not prove superior to placebo but frequent side effects occurred.Therefore this technique receives a negative recommendation (2 A-). Sympathetic block is the interventional treatment of first choice and has a 2 B+ rating. Ganglion stellatum (stellate ganglion) block with repeated local anesthetic injections or by radiofrequency denervation after positive diagnostic block is documented in prospective and retrospective trials in patients suffering from upper limb CRPS. Lumbar sympathetic blocks can be performed with repeated local anesthetic injections. For a more prolonged lumbar sympathetic block radiofrequency treatment is preferred over phenol neurolysis because effects are comparable whereas the risk for side effects is lower (2 B+). For patients suffering from CRPS refractory to conventional treatment and sympathetic blocks, plexus brachialis block or continuous epidural infusion analgesia coupled with exercise therapy may be tried (2 C+). Spinal cord stimulation is recommended if other treatments fail to improve pain and dysfunction (2 B+). Alternatively peripheral nerve stimulation can be considered, preferentially in study conditions (2 C+).

Validation of proposed diagnostic criteria (the "Budapest Criteria") for Complex Regional Pain Syndrome

Current IASP diagnostic criteria for CRPS have low specificity, potentially leading to overdiagnosis. This validation study compared current IASP diagnostic criteria for CRPS to proposed new diagnostic criteria (the "Budapest Criteria") regarding diagnostic accuracy. Structured evaluations of CRPS-related signs and symptoms were conducted in 113 CRPS-I and 47 non-CRPS neuropathic pain patients. Discriminating between diagnostic groups based on presence of signs or symptoms meeting IASP criteria showed high diagnostic sensitivity (1.00), but poor specificity (0.41), replicating prior work. In comparison, the Budapest clinical criteria retained the exceptional sensitivity of the IASP criteria (0.99), but greatly improved upon the specificity (0.68). As designed, the Budapest research criteria resulted in the highest specificity (0.79), again replicating prior work. Analyses indicated that inclusion of four distinct CRPS components in the Budapest Criteria contributed to enhanced specificity. Overall, results corroborate the validity of the Budapest Criteria and suggest they improve upon existing IASP diagnostic criteria for CRPS.

Evidence based guidelines for complex regional pain syndrome type 1

Background

Treatment of complex regional pain syndrome type I (CRPS-I) is subject to discussion. The purpose of this study was to develop multidisciplinary guidelines for treatment of CRPS-I.

Method

A multidisciplinary task force graded literature evaluating treatment effects for CRPS-I according to their strength of evidence, published between 1980 to June 2005. Treatment recommendations based on the literature findings were formulated and formally approved by all Dutch professional associations involved in CRPS-I treatment.

Results

For pain treatment, the WHO analgesic ladder is advised with the exception of strong opioids. For neuropathic pain, anticonvulsants and tricyclic antidepressants may be considered. For inflammatory symptoms, free-radical scavengers (dimethylsulphoxide or acetylcysteine) are advised. To promote peripheral blood flow, vasodilatory medication may be considered. Percutaneous sympathetic blockades may be used to increase blood flow in case vasodilatory medication has insufficient effect. To decrease functional limitations, standardised physiotherapy and occupational therapy are advised. To prevent the occurrence of CRPS-I after wrist fractures, vitamin C is recommended. Adequate perioperative analgesia, limitation of operating time, limited use of tourniquet, and use of regional anaesthetic techniques are recommended for secondary prevention of CRPS-I.

Conclusions

Based on the literature identified and the extent of evidence found for therapeutic interventions for CRPS-I, we conclude that further research is needed into each of the therapeutic modalities discussed in the guidelines.

Increased plasma serotonin in complex regional pain syndrome type 1

BACKGROUND

In patients with complex regional pain syndrome type 1 (CRPS1), some improvement can be achieved by the administration of ketanserin, a 5-HT(2A) receptor antagonist. We measured plasma levels of serotonin (5-HT) during CRPS1 and correlated these levels with disease characteristics.

METHODS

Plasma 5-HT was measured in 35 patients who had CRPS1 for 3 yr and compared with 35 age-matched healthy controls.

RESULTS

The plasma 5-HT levels were 411 +/- 263 nmol/L and 29 +/- 18 nmol/L, respectively (P < 0.001). No correlations with disease characteristics were observed.

CONCLUSIONS

The markedly elevated levels of plasma 5-HT in CRPS1 patients suggest a role for 5-HT during the course of this disease. However, because of the lack of correlations with distinct disease characteristics, 5-HT is probably one of a number of mediators in CRPS1.

Report of a focus group survey of current practice in the therapeutic treatment of Complex Regional Pain Syndrome in the United Kingdom

Complex Regional Pain Syndrome (CRPS) typically affects the hand following trauma. It is characterised by pain, altered sensation, motor disturbance, oedema, functional limitation and psychological disturbance. There is no definitive curative treatment for CRPS and controversy exists regarding the most effective combination of interventions for the treatment of this syndrome (Siddiqui et al 2001).

A study was commissioned in 2006 to explore the therapeutic interventions being implemented with patients with CRPS in the UK. Sixty therapists at the British Association of Hand Therapists annual conference consented to participate in focus group discussions. Categories were established to identify all therapeutic modalities currently used by participants. Therapists utilised the following therapeutic techniques: functional activity, exercise, education, support, sensory re-education, desensitisation, stress loading, pressure garments, mirror visual feedback, splints and psychological strategies, amongst others.

The identified interventions were then reviewed against evidence in the recent literature. There is insufficient evidence to support the use of a single set of multidisciplinary interventions (Stanton-Hicks et al 2002) to address the primary long-term goals of functional restoration and pain relief. This study has, however, highlighted that this is achieved through the treatment of individual symptoms, using multiple therapeutic interventions and algorithms in a multidisciplinary approach.

Pharmacologic management of complex regional pain syndrome

Few randomized controlled trials of oral pharmacotherapy have been performed in patients with complex regional pain syndrome (CRPS). The prevalence of CRPS is uncertain. Severe and advanced cases of CRPS are easily recognized but difficult to treat and constitute a minority compared with those who meet minimum criteria for the diagnosis. Unsettled disability or liability claims limit pharmaceutical industry interest in the disorder. Many studies are small or anecdotal, or are reported on only via posters at meetings. Targeting the process of bone resorption with bisphosphonate-type compounds such as calcitonin, clodronate, and alendronate has shown efficacy in three published randomized controlled trials. Intravenous phentolamine has been studied both alone and in comparison to intravenous regional blockade or stellate ganglion block. Steroids continue to be administered by multiple routes without large-scale placebo-controlled trials. Topical medications have received little attention. There has been considerable interest in the use of thalidomide and TNF-alpha blockers for CRPS, but no published controlled trials as of yet. Numerous other oral drugs, including muscle relaxants, benzodiazepines, antidepressants, anticonvulsants, and opioids, have been reported on anecdotally. Some therapies have been the subject of early controlled studies, without subsequent follow-up (eg, ketanserin) or without an analogous well-tolerated and equally effective oral treatment (eg, intravenous ketamine). Gabapentin, tricyclic antidepressants, and opioids have been proven effective for chronic pain in disorders other than CRPS. Each has shown a broad enough spectrum of analgesic activity to be cautiously recommended for treatment of CRPS until adequate randomized controlled trials settle the issue. The relative benefit of oral medications compared with the widely used treatments of intensive physical therapy, nerve blocks, sympathectomy, intraspinally administered drugs, and neuromodulatory therapies (eg, spinal cord stimulation) remains uncertain. In summary, treatment of CRPS has received insufficient study and remains largely empirical.

Treatment of complex regional pain syndrome type I of the hand with a series of intravenous regional sympathetic blocks with guanethidine and lidocaine

The aim of this study was to evaluate the efficacy of guanethidine and lidocaine in the treatment of complex regional pain syndrome (CRPS) type I of the hand. Seventeen patients, aged between 33 and 72 years, suffering from CRPS type I of the hand received two series of intravenous regional sympathetic block (Bier's block) sessions with guanethidine and lidocaine according to the following therapeutic protocol: (1) 5 sessions (once every second day) composed of intravenous regional administration of 15 mg guanethidine and 1 mg lidocaine/kg body weight each and (2) 20 sessions (twice a week) composed of intravenous regional administration of 10 mg guanethidine and 1 mg lidocaine/kg body weight each. Complete disappearance of pain and return of the normal function and movement of the extremity were achieved. No side effects were observed. The above-described therapeutic protocol method resulted in excellent pain relief and full restoration of both function and range of movement of the affected extremity in 17 patients suffering from CRPS type I of the hand.

Contribution of the peripheral 5-HT2A receptor to mechanical hyperalgesia in a rat model of neuropathic pain

We investigated the effect of 5-HT receptor antagonists on mechanical hyperalgesia observed in a neuropathic pain rat model prepared by chronic constriction injury of the sciatic nerve. NAN-190, a 5-HT 1A receptor antagonist, (-)-pindolol, a 5-HT 1A/1B receptor antagonist, and tropisetron, a 5-HT(3/4) receptor antagonist, did not affect the pain threshold in the hyperalgesic hind limb to the same extent as in the normal hind limb. However, sarpogrelate and ketanserin, 5-HT 2A receptor antagonists, significantly elevated the pain threshold in the hyperalgesic hind limb, but not in the normal hind limb. In spite of its high affinity for the 5-HT 2A receptor, methysergide only slightly elevated the pain threshold in the hyperalgesic hind limb. Pre-treatment with methysergide significantly antagonized the inhibitory effect of sarpogrelate on hyperalgesia. Furthermore, the 5-HT 2A receptor specific binding activity of 3H-ketanserin determined for the hyperalgesic hind limb did not differ from that of the normal hind limb. From these results, we propose that the 5-HT 2A receptor in the hyperalgesic hind paw function as an agonist-independent active receptor following constriction of the sciatic nerve, and that sarpogrelate and ketanserin act as inverse agonists of this receptor and suppress its activation. Methysergide may act as a neutral antagonist that blocks the effect of inverse agonists on the 5-HT 2A receptor.

Surgery on the affected upper extremity of patients with a history of complex regional pain syndrome: the use of intravenous regional anesthesia with clonidine

STUDY OBJECTIVES

To evaluate the efficacy of intravenous regional anesthesia (IVRA) with clonidine in patients with a previous history of complex regional pain syndrome (CRPS) who are undergoing upper extremity hand surgery.

DESIGN

Prospective, randomized, double-blind study.

SETTING

Operating suites and Pain Management Center of a large university-affiliated medical center.

PATIENTS

84 patients with a previous history of upper extremity CRPS undergoing surgery on the affected extremity. All signs and symptoms of CRPS had resolved prior to the time of surgery.

INTERVENTIONS

Patients were randomized to receive IVRA with 0.5 % lidocaine with either 1 mL normal saline (n=42) or clonidine 1 microg/kg (n=42) added to the lidocaine solution.

MEASUREMENTS

Recurrence of CRPS symptoms at 1 year following surgery were recorded.

MAIN RESULTS

The recurrence rate of CRPS was significantly lower (p <0.001) in those patients receiving IVRA with lidocaine and clonidine (10%, n=4) compared with those patients receiving IVRA lidocaine only (74%, n=31).

CONCLUSIONS

Intraoperative IVRA with lidocaine and clonidine on patients with a history of CRPS can significantly reduce the recurrence rate of this disease process.

Management of neuropathic pain following treatment for breast cancer in the absence of recurrence: A challenge for the radiation oncologist

This report reviews various management options for treatment-induced neuropathic pain in breast cancer. First-line options include tricyclic antidepressants and anticonvulsant drugs. Opioids should be prescribed according to published guidelines. Second-line treatments include lignocaine, mexiletine and ketamine. Sympatholytic therapies are available to patients with features of chronic regional pain syndrome. Anti-inflammatory agents are used for neurogenic inflammation. Surgical interventions are considered for refractory neuropathic pain. Interdisciplinary management is appropriate when persisting pain causes physical and psychosocial disabilities.

Regional antibiotic prophylaxis in elbow surgery

In this study we describe a technique for the delivery of regional antibiotic prophylaxis in patients undergoing elbow surgery and compare tissue antibiotic concentrations achieved by this technique with those achieved by standard systemic intravenous prophylaxis. We collected bone and fat samples from patients undergoing elective elbow surgery who had received regional antibiotic prophylaxis and measured the tissue antibiotic concentration. For comparison, we measured the antibiotic concentration in bone and fat samples taken from patients undergoing elective shoulder surgery who had received systemic prophylaxis. Mean tissue antibiotic concentrations were significantly higher in the regional antibiotic group (bone, 1484 microg/g vs 35.8 microg/g; fat, 1422.7 microg/g vs 10.7 microg/g; P <.05). No adverse effects were encountered with regional antibiotic delivery. The delivery of regional antibiotic prophylaxis in elbow surgery achieves higher tissue antibiotic concentrations than those achieved with standard systemic delivery. This technique may help reduce the risk of perioperative infection in elbow surgery.

Complex regional pain syndrome

Complex regional pain syndrome (CRPS) is a heterogeneous disorder that falls in the spectrum of neuropathic pain disorders. It is maintained by abnormalities throughout the neuraxis (the peripheral, autonomic, and central nervous systems). The pathophysiology of CRPS is not fully known. There are no scientifically well-established treatments. The diagnostic criteria for CRPS at this time are purely clinical, and the use of diagnostic tests has not been demonstrated. The most appropriate management of CRPS uses a multidisciplinary approach, with the inclusion of medical and psychologic intervention, and physical and occupational therapy. The key is gradual, persistent, functional improvement. The rational use of pain therapies must be grounded in a thorough knowledge of the neurobiology of pain, its endogenous modulation, and the clinical presentation. Potential peripheral pathophysiologic targets (and possible treatments) include increased spontaneous firing and responsiveness of peripheral afferent fibers mediated by inflammatory and other algogenic substances (somatosensory blocks, corticosteroids), altered levels of expression and functioning of multiple ion channels (local anesthetics, calcium channel blockers, anticonvulsants), abnormal interneuronal communication, and increased peripheral expression of adrenergic receptors and sympathetic excitation (sympathetic blocks, alpha-adrenergic antagonists, alpha-2 agonists). CRPS is also perpetuated by central mechanisms, with pathophysiologic targets (and possible treatments) including reorientation of dorsal horn terminals (desensitization techniques), functional reduction in inhibitory interneuron activity (tricyclic antidepressants, gabapentin, opioids), central sensitization and increased central excitability (gabapentin, topiramate, spinal cord stimulation, somatosensory blocks), impaired descending nociceptive inhibition (tricyclic antidepressants, opioids), and adaptive changes in the cortical centers underlying the sensory-discriminative and affective-motivational dimensions of pain (psychologic, physical, and occupational therapies). The treatment choices should be aimed at remodulating, normalizing, disrupting, or preventing the progression of abnormalities in pain processing. Sympathetic nerve blocks should be performed at least once to assess if sympathetically maintained pain is present. To the extent that peripheral somatosensory nerve blocks can diminish nociceptive input to the central nervous system, these techniques may help reduce the nociceptive sensitization of spinal neurons. Pain relief, however it is achieved and however temporary it is, is intended to facilitate participation in functional therapies to normalize use and to improve motion, strength, and dexterity. Psychologic therapies, such as biofeedback and cognitive-behavioral techniques targeting pain, stress, and mood disorders, are valuable adjunctive treatments for pain control and can facilitate functional improvement.

What is a meaningful pain reduction in patients with complex regional pain syndrome type 1?

OBJECTIVE

To investigate the degree of pain reduction in patients with complex regional pain syndrome type 1 (CRPS 1) that can be defined as "successful."

DESIGN

All patients rated their pain on a visual analog scale (VAS; 0-10) before treatment and on three occasions after treatment, at 6 months, 1 year, and 2 years. Patients also rated a Global Perceived Effect (GPE) for their pain relief at the same time periods. The GPE items were classified as "successful" or "unsuccessful." The mean absolute and relative pain reduction (using the VAS) was calculated for both "successful" and "unsuccessful" GPE classifications for each time period. Sensitivity and specificity analyses were performed.

PATIENTS

Sixty-one patients with CRPS 1.

RESULTS

The patients defined a relative pain reduction of 58% (SD, 23.4) or more as "successful," whereas in "successful" and "unsuccessful" patient groups the pain was reduced significantly on the VAS. Furthermore, sensitivity and specificity analyses showed that a cut-off point of 50% relative pain reduction and a 3-cm absolute pain reduction on the VAS have the highest likelihood that patients will report their treatment "successful" on the GPE.

CONCLUSIONS

Relative pain reduction of 50% or more and an absolute pain reduction of at least 3 cm on the VAS are accurate in predicting a successful pain reduction after a given treatment.

Treatment of complex regional pain syndrome type I

Reflex sympathetic dystrophy (RSD), also known as complex regional pain syndrome type I (CRPS I), is a disabling neuropathic pain syndrome. Controversy exists about the effectiveness of therapeutic interventions for the management of RSD/CRPS I. In order to ascertain appropriate therapies we conducted a review of existing randomized controlled trials of therapies for this disabling disease. Eligible trials were identified from the Cochrane, Pubmed, Embase and MEDLINE databases from 1966 through June 2000, from references in retrieved reports and from references in review articles. Twenty-six studies concerning treatment modalities were identified. Eighteen studies were randomized placebo-controlled trials and eight studies were randomized active-controlled trials. Three independent investigators reviewed articles for inclusion criteria using a 15-item checklist. Seventeen of the trials were of high quality according to the 15-item criteria. There was limited evidence for the effectiveness of these interventions because of the heterogeneity of treatment modalities. The search for trials concerning prevention of RSD/CRPS I resulted in two eligible studies. Both were of high quality and dealt with different interventions. There is limited evidence for their preventive effect.

Complex regional pain syndrome type I in cancer patients

Complex regional pain syndrome type I (CRPS-I) is infrequently associated with various malignancies, and may lead to severe pain in already debilitated patients. The causal relationship between CRPS-I and paraneoplastic syndrome, controversies in diagnosis and treatment, and new treatment modalities are presented.

Treatment of reflex sympathetic dystrophy (CRPS type 1): a research synthesis of 21 randomized clinical trials

A blinded meta analysis was performed on randomized clinical trials (RCT) on the medicinal treatment of reflex sympathetic dystrophy (complex regional pain syndrome type I) to assess the methodological quality and quantify the analgesic effect of treatments by calculating individual and summary effect sizes. The internal validity of 21 RCTs was investigated and the quality weighted summary effect size was calculated using a fixed effect model (Glass Delta). The methodological quality ranged from moderate to good (average 46%). Differences were found between the trials in inclusion/exclusion criteria, treatment methods, duration of treatments and trials, and measurement instruments. Statistical analysis was possible for four subgroups; one evaluating the analgesic effects of sympathetic suppressors in general (n = 12), one subgroup concerning the analgesic effects of guanethidine (n = 6), one investigating the analgesic effect of intravenous regional sympathetic blocks (n = 9), and one subgroup (n = 5) evaluating the analgesic effect of calcitonin. Except for the calcitonin subgroup (P = 0.002), the quality-weighted summary effect size of these subgroups were not significant. No significant analgesic effect by sympathetic suppressing agents could be established. Calcitonin seems to provide effective pain relief in reflex sympathetic dystrophy patients. The results of the present study show that weighting methodological quality influences the magnitude of the effect sizes of specific treatment methods. Future studies should control for methodological quality.

Soft tissue complications of orthopedic emergencies

The emergency physician encounters a diversity of potentially devastating and disabling soft tissue maladies. This article reviews the literature and approach to the compartment syndrome and Volkmann contracture, reflex sympathetic dystrophy and causalgia, fracture blisters, and gas gangrene.

Bone atrophy in complex regional pain syndrome patients measured by microdensitometry

PURPOSE

To determine the usefulness of quantitative measurement of bone atrophy in the diagnosis and the long-term follow-up of patients with complex regional pain syndrome (CRPS). The bone-sparing effect of a 5-hydroxytriptamine (5-HT2) antagonist was also studied.

METHODS

Bone mass was measured by computerized micro-densitometry at the middle position of the second metacarpal. The effect of repeated stellate ganglion blocks (SGBs) three times per week with mepivacaine (n = 11), administration of a 5-HT2 antagonist (sarpogrelate hydrochloride, 300 mg a day po) (n = 12), and combined therapy (n = 10) were compared by micro-densitometry and conventional visual analogue scale (VAS) for analgesia after three months of treatment.

RESULTS

In CRPS patients, metacarpal index (cortical bone thickness), maximum bone density (cortical bone density), minimum bone density (trabecular bone density), and average bone density were reduced on the affected side (14.1%, 12.1%, 25.0% and 19.3% respectively). The rate of reduction in bone mass correlated with the duration of the disease (P < 0.05). Therapy with the 5-HT2 receptor antagonist (with or without repeated SGBs) decreased pain intensity (from 6.10 to 3.81 with SGB, from 6.30 to 2.91 without SGB, respectively; P < 0.01) and bone atrophy evaluated by micro-densitometry (P < 0.05). In contrast, repeated SGBs alone reduced pain intensity (from 6.30 to 2.91; P < 0.01) but did not ameliorate bone atrophy.

CONCLUSION

Bone micro-densitometry is useful in the assessment and follow-up of CRPS and for evaluation of treatment. The 5-HT2 antagonist, sarpogrelate hydrochloride, is a promising treatment for CRPS patients.

Complex regional pain syndromes: including "reflex sympathetic dystrophy" and "causalgia"

"Reflex sympathetic dystrophy" and "causalgia" are now classified by the International Association for the Study of Pain as Complex Regional Pain Syndromes I and II. Sympathetically maintained pain is a frequent but variable component of these syndromes, as the sympathetic and somatosensory pathways are no longer functionally distinct. Pain is the cardinal feature of CRPS, but the constellation of symptoms and signs may also include sensory changes, autonomic dysfunction, trophic changes, motor impairment and psychological changes. Diagnosis is based on the clinical picture, with additional information regarding the presence of sympathetically maintained pain or autonomic dysfunction being provided by carefully performed and interpreted supplemental tests. Clinical experience supports early intervention with sympatholytic procedures (pharmacological or nerve block techniques), but further scientific data is required to confirm the appropriate timing and relative efficacy of different procedures. Patients with recurrent or refractory symptoms are best managed in a multi-disciplinary pain clinic as more invasive and intensive treatment will be required to minimize ongoing pain and disability.

Reflex sympathetic dystrophy

Reflex sympathetic dystrophy presents with pain out of proportion to the cause, loss of function, and significant evidence of an autonomic disorder. These findings are often accompanied by psychological disturbances, which can dominate the condition. There are differences in the symptoms and signs during childhood. It is more frequent among girls than boys, and the legs are more often affected than the arms; and trophic changes may be absent. There may be no history of trauma, and the response to treatment is often satisfactory. There are a number of theories on etiology. A disorder of the sympathetic nervous system with increased activity has been suggested, but on the evidence available super-sensitivity to neurotransmitters is more likely. Also there may be a spinal, as well as a peripheral, component to the sensitivity. Other suggestions include the release of a pain substance, a disturbance of natural opioid metabolism, and an exaggerated inflammatory response. The diagnosis is mainly clinical, supported by X-ray examination, bone scans with Technetium 99m labelled diphosphonates, and a characteristic scintograph pattern. Laser Doppler flowmetry can also, be useful. The most effective preventative measure is control of pain and early mobilisation. Many treatments have been tried, but the response is variable. Drugs include analgesics, non-steroid anti-inflammatory drugs, anti-depressants, and steroids. Betablockers, with gradually increasing doses may help; as may vasodilators. Calcitonin, by intramuscular injection has been given a particularly favourable report. Physiotherapy is of prime importance. Some treatments are only likely to be considered in older children. Blocking of sympathetic pathways can be tried with paravertebral or epidural injections of local anesthetics. Regional intravenous injections of alpha adrenergic blocking agents distal to a tourniquet can relieve pain, but usually only transiently; and ketanserin may act favourably as a serotonin antagonist. Surgical sympathectomy can also be considered.

Prevalence and associated features of the cold hemiplegic arm

BACKGROUND AND PURPOSE

Some stroke patients complain of an unpleasant sensation of coldness in the hemiplegic arm. This study aimed to determine the prevalence of this symptom and any associated features.

METHODS

A questionnaire about symptoms in the arms was sent to patients at least 12 months after stroke. Reflex sympathetic dystrophy (RSD) was diagnosed if four typical symptoms were present in the arm.

RESULTS

One hundred patients were recruited and 75 complete replies received. The mean age of the patients was 74 years, and the mean time since the stroke was 19 months. Forty patients (53%) experienced unilateral coldness in the hemiplegic arm. In 14 this sensation was constant, and 10 rated the symptom as troublesome. The symptom developed at a median time of 1 month after stroke, but only 13 patients (32%) sought advice from a doctor. Sensory symptoms and arm and shoulder pain were common, but the only symptoms associated with coldness were numbness (P < .001) and color change (P < .05). Fifteen patients fulfilled the diagnostic criteria for RSD, 13 of whom had coldness only in the hemiplegic arm.

CONCLUSIONS

A sensation of coldness in the hemiplegic arm is common and distressing. It is associated with numbness and color changes in the arm. Some cases are caused by RSD, but other patients have coldness that may be due to other causes such as a vasomotor abnormality.

Reflex sympathetic dystrophy

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Intravenous regional sympathetic blockade for pain relief in reflex sympathetic dystrophy: a systematic review and a randomized, double-blind crossover study

The first aim was a systematic review of intravenous regional sympathetic blocks (IRSBs) in patients with reflex sympathetic dystrophy (RSD). Randomized controlled trials (RCTs) of IRSBs in patients with RSD were identified by MEDLINE search (1966 to May 1993) and by hand search of 30 journals (1950 to May 1993). Authors of eligible trials were asked for information on additional trials and for unpublished data. Seven RCTs of IRSBs in RSD were found. Four used guanethidine; none showed significant analgesic effect in IRSBs to relieve pain due to RSD. Two reports, one using ketanserin and one bretylium, with 17 patients in total, showed some advantage of IRSBs over control. RCT results were not combined because of the variety of different drugs and outcome measures and because of methodological deficiencies in most of the reports. The second aim was a randomized, double-blind, crossover study to assess the effectiveness of IRSBs with guanethidine. Patients fulfilling diagnostic criteria for RSD and who had reported pain relief after an open IRSB with guanethidine received IRSBs with guanethidine high dose, guanethidine low dose, and normal saline. Pain intensity and relief, adverse effects, mood, duration of analgesia, and global scores were recorded. Sixteen patients with diagnosis of RSD were recruited, but only nine entered the double-blind phase. The trial was stopped prematurely because of the severity of the adverse effects. No significant difference was found between guanethidine and placebo on any of the outcome measures.(ABSTRACT TRUNCATED AT 250 WORDS)

The Use of Acupuncture in Reflex Sympathetic Dystrophy Syndrome

Reflex sympathetic dystrophy syndrome, also known as causalgia or algodystrophy, clinically presents with pain, swelling, muscle dysfunction and skin changes to a limb. It is usually the result of trauma to the affected limb, which may be quite minor. Three stages of the syndrome are described, associated with increasingly severe symptoms and deterioration of prognosis. Sympathetic blockade is probably the treatment of choice, although acupuncture can be beneficial in the early stages. To be effective, treatment must be started early as the physical changes may become irreversible.

Reflex sympathetic dystrophy of the hand: an excessive inflammatory response?

In 23 patients with reflex sympathetic dystrophy (RSD) of the hand, scintigraphy with indium-111 labeled human non-specific polyclonal immunoglobulin G (In-111-IgG) was performed to investigate whether inflammatory characteristics are present in RSD. Both blood flow and accumulation over 48 h were assessed. Nineteen patients had increased flow to the affected hand, and 3 had decreased flow. One patient had bilateral RSD. Exercise provoked aggravation of complaints and signs in all patients. The affected/non-affected hand ratio (target-to-background, T/B) immediately before and after exercise did not change significantly. The T/B ratios 48 h after In-111-IgG injection were significantly higher in patients with RSD less than 5 months than in patients with RSD existing 5 months or longer. The T/B ratios 24 and 48 h after In-111-IgG injection were not correlated with the flow T/B ratios. In fact, 2 of the 3 patients with a decreased flow showed excess accumulation on the late images. Significantly more patients with early RSD, existing less than 5 months, had a positive In-111-IgG scintigraphy (14 of 17) than the patients with late RSD (1 of 6). Increased vascular permeability for macromolecules, an important characteristic of inflammation, appears to play a role in the development of RSD. This phenomenon is not flow-dependent.

Signs and symptoms of reflex sympathetic dystrophy: prospective study of 829 patients

The pathogenesis of reflex sympathetic dystrophy--variously known as Sudeck's atrophy, causalgia, algodystrophy, and peripheral trophoneurosis--is not yet understood, and diagnosing and treating patients is difficult. We have prospectively studied 829 patients, paying particular attention to early signs and symptoms. In its early phase, reflex sympathetic dystrophy is characterised by regional inflammation, which increases after muscular exercise. Pain was present in 93% of patients, and hypoaesthesia and hyperpathy were present in 69% and 75% respectively. With time, tissue atrophy may occur as well as involuntary movements, muscle spasms, or pseudoparalysis. Tremor was found in 49% and muscular incoordination in 54% of patients. Sympathetic signs such as hyperhidrosis are infrequent and therefore have no diagnostic value. We found no evidence consistent with the presence of three consecutive phases of the disease. Early symptoms are those of an inflammatory reaction and not of a disturbance of the sympathetic nervous system. These data support the concept of an exaggerated regional inflammatory response to injury or operation in reflex sympathetic dystrophy.