Efficacy of Stellate Ganglion Blockade for the Management of Type 1 Complex Regional Pain Syndrome

Efficacy of stellate ganglion interventions for complex regional pain syndrome in the upper limb-A systematic review and meta-analysis

Background and Aims

Stellate ganglion (SG) interventions for treating upper limb complex regional pain syndrome (CRPS) have been reported in studies. However, more substantial evidence is required to reach a consensus on its analgesic efficacy. To the best of our knowledge, no systematic review demonstrating the effectiveness of SG intervention for upper limb CRPS has been reported. Hence, this meta-analysis was done to ascertain the efficacy of SG intervention in managing patients with upper limb CRPS.

Methods

A database search of PubMed, Cochrane, Embase, Scopus and Google Scholar was done for articles published between January 2001 and December 2021. Two independent reviewers extracted data from the included studies, and the studies were evaluated for any potential risk of bias, and a meta-analysis was performed.

Results

Eight studies were included in the qualitative synthesis, four were randomised controlled trials (RCTs), and the rest were non-RCTs. Six studies were assessed quantitatively. A significant reduction in pain scores post-intervention, up to two weeks, and four to 28 weeks after the procedure was observed, although the included studies exhibited marked heterogeneity. Qualitative analysis of these studies revealed an overall improvement in disability scores and functionality as assessed by an improved range of motion. Most studies reported no complications or only short-term minor complications after the procedure.

Conclusion

Stellate ganglion interventions improve pain and disability scores with self-limiting short-term complications and no long-term complications. However, further studies with a large sample size are required to validate this treatment modality.

Sympathetic Modulation in Cardiac Arrhythmias: Where We Stand and Where We Go

The nuance of autonomic cardiac control has been studied for more than 400 years, yet little is understood. This review aimed to provide a comprehensive overview of the current understanding, clinical implications, and ongoing studies of cardiac sympathetic modulation and its anti-ventricular arrhythmias' therapeutic potential. Molecular-level studies and clinical studies were reviewed to elucidate the gaps in knowledge and the possible future directions for these strategies to be translated into the clinical setting. Imbalanced sympathoexcitation and parasympathetic withdrawal destabilize cardiac electrophysiology and confer the development of ventricular arrhythmias. Therefore, the current strategy for rebalancing the autonomic system includes attenuating sympathoexcitation and increasing vagal tone. Multilevel targets of the cardiac neuraxis exist, and some have emerged as promising antiarrhythmic strategies. These interventions include pharmacological blockade, permanent cardiac sympathetic denervation, temporal cardiac sympathetic denervation, etc. The gold standard approach, however, has not been known. Although neuromodulatory strategies have been shown to be highly effective in several acute animal studies with very promising results, the individual and interspecies variation between human autonomic systems limits the progress in this young field. There is, however, still much room to refine the current neuromodulation therapy to meet the unmet need for life-threatening ventricular arrhythmias.

Agents Used for Nerve Blocks and Neurolysis

The recognition of pain and the treatments used for it are vital for all practitioners. Many types of pain can be treated in a locoregional fashion, which has significant implications not just for any individual patient but for society as a whole. These treatments are most effective when performed in a minimally invasive, image-guided fashion. Interventional radiologists should play a central role in providing these lifestyle-limiting treatments. This article describes the medications most typically used for spinal and extra-axial treatments in the management of patients in pain.

The Tourniquet Ischemia Test Effectively Predicts the Efficacy of Lumbar Sympathetic Block in Patients with Lower Extremity Complex Regional Pain Syndrome Type 1

Background

Neuropathic pain is the most common clinical sign of complex regional pain syndrome (CRPS). Currently, lumbar sympathetic block (LSB) is commonly utilized in lower extremity CRPS that has failed to respond to medication therapy and physical therapy, but its effectiveness is unknown. The tourniquet ischemia test (IT) can distinguish between two types of CRPS: IT-positive CRPS and IT-negative CRPS.

Objective

The aim of the study was to investigate whether LSB improves pain scores in patients with lower extremity CRPS-1 and to screen factors to predict its efficacy.

Study Design

Prospective clinical observational study.

Setting

Pain management center.

Subjects

Forty-three patients diagnosed with lower extremity CRPS-1 using the Budapest criteria were included as participants.

Methods

Forty-three CRPS-1 patients were treated with LSB therapy, and all of them underwent a tourniquet ischemia test (IT) before undergoing LSB therapy. LSB therapy was performed using a combination of ultrasonography and fluoroscopy. Then, numeric rating scale (NRS) scores and the symptom relief rates of patients were evaluated at 1, 4, and 12 weeks. Finally, peripheral blood inflammatory cytokine samples were collected before and after the LSB treatment.

Results

At 4 weeks after the treatment, the total effective symptom relief rate of LSB on CRPS-1 was 25.6% (11/43), with 52.6% (10/19) of IT(+) patients and 4.2% (1/24) of IT(-) patients. There was a significant difference between the IT(-) and IT(+) groups (P = 0.001). The multivariate binary logistic regression analysis revealed that the response to the tourniquet IT was the only significant independent predictor of sympathetic block success (p = 0.007).

Conclusion

Tourniquet IT is a simple, safe and effective test to distinguish patients with lower extremity CRPS-1. The response to the tourniquet IT is a reliable predictor of LSB effectiveness in lower extremity CRPS-1 patients.

Epidural unilateral stimulation with "adaptive stim" option in treatment of type II CRPS

CRPS is a type of severe pain syndrome and can be triggered by previous surgery or trauma. CRPS involves vasomotor changes such as changes in color and temperature of the skin, edema, increased sensitivity to touch, and a limited range of movement. Depending on the presence of nerve damage, CRPS is divided into two types. CRPS type II is associated with a confirmed peripheral nerve injury, while CRPS type I is not associated with an apparent peripheral nerve injury. Despite the ongoing therapy, sometimes, patients still have persistent, burning pain. Intractable CRPS that fail more conservative treatments may undergo neuromodulation. We want to present to your attention a case report of the successful treatment of a patient with CRPS type II using epidural unilateral stimulation. The 44-year-old woman came to us with complaints of burning pain and numbness of 1-3 fingers of the right hand, the lateral surface of the right wrist, and lower quarter of the forearm, and shooting pain in the projection of the right median nerve from the shoulder to the wrist. A clinical diagnosis was made-CRPS type II. During the stimulation trial, the most effective pain relief was obtained when the electrode was located in the right side of epidural space at the C4-Th1 level. The implantation of a pulse generator was performed, and the final selection of the stimulation parameters was carried out (Pulse width: 60 ms, Rate: 210 Hz, and Amplitude: 0.9-1.6 V). The severity of pain syndrome was measured using validated scales in the preoperative period (VAS: 8-9, Pain Detect: 22, NTSS-9: 4.62, and DN4: 8), in the early postoperative period (VAS: 0-1, Pain Detect: 6, NTSS -9: 0.66, and DN4: 1), and after 12 months (VAS: 0-2, Pain Detect: 6, NTSS-9: 0.99, and DN4: 1). Observation during 12 months showed that a stable analgesic effect of neurostimulation was achieved using standard neuromodulation regimens and the adaptive stim option. Unilateral stimulation is an effective type of SCS in the treatment of pain syndromes. adaptive stim is usually not applicable for lead implantation at the cervical level. Nevertheless, the rational use of stimulation at threshold values allowed our patient to use adaptive stim in a non-standard situation.

Moderate and deep procedural sedation-the role of proper monitoring and safe techniques in clinical practice

PURPOSE OF REVIEW

Interventional pain management procedures provide significant improvement to patient quality of life and functionality. In-office procedures are becoming an increasingly more common site of pain management intervention for patients with minimal risk of harm.

RECENT FINDINGS

Moderate and deep sedation techniques can be used in patients with high anxiety, complex pharmacotherapy, or a low pain threshold. Proper guidance and oversight by an attending anesthesiologist, in addition to appropriate monitoring, are key. Epidural steroid injection complications rates have been cited at 2.4%, with the most common complications noted as persistent pain and flushing.

SUMMARY

Serious complication errors can be avoided with proper supervision and monitoring. The adherence to published societal recommendations and guidelines for indications of when to use moderate to deep sedation techniques, and appropriate supervision and monitoring methods, can avoid errors in interventional pain management procedures.

Complex Regional Pain Syndrome and Distal Radius Fracture: Etiology, Diagnosis, and Treatment

Complex regional pain syndrome (CRPS) is a chronic pain condition characterized by a constellation of signs and symptoms including pain out of proportion to the injury or insult, autonomic dysfunction, trophic changes, and impaired function. CRPS may occur following either conservative or surgical management of distal radius fractures and can significantly complicate the trajectory of a patient's recovery. Although the incidence, diagnosis, prevention, and treatment of this condition have been extensively studied, optimal methods to identify, prevent, and treat this condition remain controversial. This article reviews the available literature on the diagnosis and treatment of CRPS in distal radius fractures.

Complex regional pain syndrome: an evolving perspective

BACKGROUND

Complex regional pain syndrome (CRPS) is a heterogenous and poorly understood condition that can be provoked by quite minor injuries. The symptoms and signs of CRPS persist, long after the patient has recovered from the inciting event. In some cases, there is a clear association with a peripheral nerve injury. The degree of disability produced by CRPS is often out of proportion to the scale of the original insult and the condition is associated with protracted recovery times and frequent litigation.

METHODS

We have performed a PubMed literature search, referenced landmark papers in the field and included a national expert in peripheral nerve injury and repair in our team of authors.

RESULTS AND CONCLUSIONS

The diagnostic criteria for CRPS have changed repeatedly over the last two centuries and much of the historical literature is difficult to compare with more recent research. In this review article, we consider how our understanding of the condition has evolved and discuss its pathogenesis, its apparent heterogenicity and the various investigations and treatments available to the clinician.

Management of CRPS secondary to preganglionic C8 nerve root avulsion: A case report and literature review

Background:

Cervical nerve root avulsion is a well-documented result of high-velocity motor vehicle accidents (MVAs). In up to 21% of cases, preganglionic cervical root avulsion can result in a complex regional pain syndrome (CRPS) impacting the quality of life for patients already impaired by motor, sensory, and autonomic dysfunction. The optimal treatment strategies include repeated stellate ganglion blocks (SBGs).

Case Description:

A 43-year-old male sustained a high-velocity MVA resulting in the left C8 nerve root avulsion. This resulted in weakness in the C8 distribution, tactile allodynia, and dysesthesias. The magnetic resonance imaging demonstrated an abnormal signal ventral to the C8–T1 level. As the patient was not considered a candidate for surgical intervention secondary to the attendant brachial plexus injury, a C7–C8 epidural steroid injection was performed; this did not provide improvement. Before placing a spinal cord stimulator, the patient underwent a series of six ultrasound-guided SBGs performed 2 weeks apart; there was 75% improvement in pain and strength. Six years later, the patient continues to do well while receiving SBGs 4 times a year.

Conclusion:

A preganglionic cervical nerve root avulsion should not be a contraindication for a stellate ganglion block in a patient with established CRPS.

Use of Oral Prednisolone and a 3-Phase Bone Scintigraphy in Patients with Complex Regional Pain Syndrome Type I

To compare the treatment effects of a high-dose and low-dose oral steroid regimen based on changes in the radioisotope uptake ratio (RUR) observed from three-phase bone scintigraphy (TPBS) in patients with complex regional pain syndrome type I (CRPS I), we retrospectively analyzed data of 34 patients with CRPS I from traumatic brain injury and stroke. Depending on the dose of steroid administered, patients were divided into high-dose (n = 14) and low-dose steroid groups (n = 20). We compared the severity scores, Kozin's classification scores, and RUR observed from TPBS between the two groups. There were significant changes in the severity scores and Kozin's classification between the baseline and 2 weeks from baseline (p < 0.05), however, there were no significant differences in terms of changes in the scores, classification, or the RUR observed from TPBS at 2 weeks from baseline (p > 0.05). There were no treatment-emergent adverse events (TEAEs) such as blood pressure elevation, impaired glycemic control, or gastrointestinal disturbances. Our results indicate that the efficacy profile of a low-dose oral steroid regimen is comparable to that of a high-dose regimen in alleviating symptoms in CRPS I patients. However, additional prospective, large-scale, multi-center studies are warranted to confirm our results.

Outcomes of Sympathetic Blocks in the Management of Complex Regional Pain Syndrome

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

Sympathetic dysfunction may be present in complex regional pain syndrome, and sympathetic blocks are routinely performed in practice. To investigate the therapeutic and predictive values of sympathetic blocks, the authors test the hypotheses that sympathetic blocks provide analgesic effects that may be associated with the temperature differences between the two extremities before and after the blocks and that the effects of sympathetic blocks may predict the success (defined as achieving more than 50% pain reduction) of spinal cord stimulation trials.

Methods

The authors performed a retrospective study of 318 patients who underwent sympathetic blocks in a major academic center (2009 to 2016) to assess the association between pain reduction and preprocedure temperature difference between the involved and contralateral limbs. The primary outcome was pain improvement by more than 50%, and the secondary outcome was duration of more than 50% pain reduction per patient report. The authors assessed the association between pain reduction and the success rate of spinal cord stimulation trials.

Results

Among the 318 patients, 255 were diagnosed with complex regional pain syndrome and others with various sympathetically related disorders. Successful pain reduction (more than 50%) was observed in 155 patients with complex regional pain syndrome (155 of 255, 61%). The majority of patients (132 of 155, 85%) experienced more than 50% pain relief for 1 to 4 weeks or longer. The degree and duration of pain relief were not associated with preprocedure temperature parameters with estimated odds ratio of 1.03 (97.5% CI, 0.95–1.11) or 1.01 (97.5% CI, 0.96–1.06) for one degree decrease (P = 0.459 or 0.809). There was no difference in the success rate of spinal cord stimulation trials between patients with or without more than 50% pain relief after sympathetic blocks (35 of 40, 88% vs. 26 of 29, 90%, P &gt; 0.990).

Conclusions

The authors conclude that sympathetic blocks may be therapeutic in patients with complex regional pain syndrome regardless of preprocedure limb temperatures. The effects of sympathetic blocks do not predict the success of spinal cord stimulation.

Efficacy of the Stellate Ganglion Block Through the Lateral Approach Using Ultrasonogram and Fluoroscopy

OBJECTIVE

Stellate ganglion (SG) block can provide pain relief in sympathetically mediated painful conditions. SG block at the sixth cervical (C6) vertebra level through lateral approach under the ultrasonogram (USG) guidance is very safe but may spare the fibres supplying the upper limb. When the drug is given at the C6 subfascially, it spreads along the cervical sympathetic chain, blocking the head/neck and upper limb. In this study, we assessed the efficacy of the SG block given at the C6 level after confirming the subfascial needle position under USG and downward spread of dye under fluoroscopy.

METHODS

Ten patients with sympathetically mediated painful conditions belonging to the American Society of Anesthesiologists (ASA) Class I and II and aged between 18 and 60 years were included in the study. The SG was approached laterally under the USG guidance, and the dye was injected after confirming the subfascial needle position. A downward spread of dye was confirmed on fluoroscope, and 4 mL of 0.25% of bupivacaine with 40 mg of methylprednisolone was injected. Patients were assessed in terms of the pain relief, an increase in axillary temperature and adverse events after 30 minutes. A statistical analysis was done with Student's t-test and paired samples t-test.

RESULTS

There was a statistically significant reduction in the post-block pain scores with the rise in temperature in the ipsilateral arm (p=0.000). The dye spread was observed from the fourth cervical vertebra to the first thoracic vertebra in all patients. Transient hoarseness was seen in 20% of patients, and the sensation of a lump was seen in 10% of patients.

CONCLUSION

We conclude that SG can be blocked effectively and safely through the lateral approach at the C6 level under ultrasonogram and fluoroscopic guidance.

Use of stellate ganglion block for treatment of recurrent syncope followed by chest pain

Syncope is defined as a transient loss of consciousness and postural tone, characterized by rapid onset, short duration, and spontaneous recovery. Stellate ganglion block (SGB) is a nerve block method that is used for treatment of neuropathic pain in the head, neck and upper extremities, especially trigeminal neuralgia, postherpetic neuralgia and complex regional pain syndrome. SGB can modulate and stabilize the sympathetic nervous system, which prevents it from overexcitation and improves symptoms of syncope. The authors report a patient who was treated for pain and edema of both upper extremities with SGB, then showed improvement in recurrent syncope followed by chest pain and overall quality of life.

Ganglion blocks as a treatment of pain: current perspectives

The inputs from sympathetic ganglia have been known to be involved in the pathophysiology of various painful conditions such as complex regional pain syndrome, cancer pain of different origin, and coccygodynia. Sympathetic ganglia blocks are used to relieve patients who suffer from these conditions for over a century. Many numbers of local anesthetics such as bupivacaine or neurolytic agents such as alcohol can be chosen for a successful block. The agent is selected according to its duration of effect and the purpose of the injection. Most commonly used sympathetic blocks are stellate ganglion block, lumbar sympathetic block, celiac plexus block, superior hypogastric block, and ganglion Impar block. In this review, indications, methods, effectiveness, and complications of these blocks are discussed based on the data from the current literature.

Does Temperature Increase by Sympathetic Neurolysis Improve Pain in Complex Regional Pain Syndrome? A Retrospective Cohort Study

BACKGROUND

Lumbar sympathetic neurolysis (LSN) is a treatment option for complex regional pain syndrome (CRPS). We examined whether LSN-related temperature changes are associated with clinical outcome and investigated relationships between the outcome of LSN and clinical variables in patients with CRPS-I.

METHODS

We included 95 patients with CRPS-I affecting a single lower extremity, by the Budapest criteria, and who underwent LSN after successful lumbar sympathetic blocks, in this retrospective study. Fluoroscopy-guided LSN was conducted with 1.5 mL of 99% alcohol at L2 and L3 vertebral levels. Positive outcome was defined as a reduction of ≥50% on a numeric rating scale pain score at 6 months after LSN. The relationship between successful outcome and clinical variables was analyzed.

RESULTS

Positive LSN outcome occurred in 49.5% of patients, and it was suggested that Sympathetically maintained pain may accompany CRPS-I in 28% of patients. The overall temperature in the affected limb was increased after LSN, without contralateral limb temperature changes, but did not differ significantly between the positive and negative outcome groups (P = 0.590). Temperature after LSN in warm-type CRPS was reduced in the affected limb, without contralateral limb temperature changes. The absolute temperature change was significantly greater in cold-type than in warm-type CRPS (P = 0.026). In multivariate analysis, a short duration of pain and concurrent cold intolerance were significant factors predicting a positive outcome after LSN.

CONCLUSIONS

LSN may be effective in some patients with CRPS, irrespective of temperature changes and temperature asymmetry pattern. A short duration of pain and concurrent cold intolerance significantly predict successful LSN.

Effects of Linearly Polarized Near-Infrared Irradiation Near the Stellate Ganglion Region on Pain and Heart Rate Variability in Patients with Neuropathic Pain

Background

Neuropathic pain associated with sympathetic overactivity can be effectively relieved by light irradiating the region near stellate ganglion (SGI), applied as an alternative to a conventional sympathetic blockade. The clinical effect of SGI on heart rate variability (HRV) and its association with pain outcomes require investigation.

Objective

This study attempted to identify the effects of SGI on pain outcomes and HRV indices and to determine the association between pain and HRV outcomes.

Design

A prospective double-blind, randomized study.

Setting

An outpatient pain medicine clinic.

Subjects and Methods

A total of 44 patients were enrolled and randomized into the experimental group ( n = 22) and control group ( n = 22). The experimental group received 12 sessions (twice weekly) of standard SGI, whereas the control group received the same protocol with sham irradiation. Pain and HRV were measured before and after each irradiation session. All outcome measures used in the first- and second-half treatment courses were analyzed.

Results

Pain and HRV outcome measures of the experimental group significantly improved after SGI when compared with the control group in both courses. Considering time and frequency domains, the changes in HRV in the second-half treatment course exceeded those in the first-half treatment course. Pain was significantly associated with postirradiated HRV indices ( P < 0.001).

Conclusions

Twelve sessions of SGI exerted time-dependent positive effects on pain and sympathovagal imbalance. HRV outcomes, including time and frequency domains, were an independent indicator of the clinical efficiency of SGI for treating pain in patients with neuropathic pain.

Transition from Deep Regional Blocks toward Deep Nerve Hydrodissection in the Upper Body and Torso: Method Description and Results from a Retrospective Chart Review of the Analgesic Effect of 5% Dextrose Water as the Primary Hydrodissection Injectate to Enhance Safety

Deep nerve hydrodissection uses fluid injection under pressure to purposely separate nerves from areas of suspected fascial compression, which are increasingly viewed as potential perpetuating factors in recalcitrant neuropathic pain/complex regional pain. The usage of 5% dextrose water (D5W) as a primary injectate for hydrodissection, with or without low dose anesthetic, could limit anesthetic-related toxicity. An analgesic effect of 5% dextrose water (D5W) upon perineural injection in patients with chronic neuropathic pain has recently been described. Here we describe ultrasound-guided methods for hydrodissection of deep nerve structures in the upper torso, including the stellate ganglion, brachial plexus, cervical nerve roots, and paravertebral spaces. We retrospectively reviewed the outcomes of 100 hydrodissection treatments in 26 consecutive cases with a neuropathic pain duration of 16 ± 12.2 months and the mean Numeric Pain Rating Scale (NPRS) 0-10 pain level of 8.3 ± 1.3. The mean percentage of analgesia during each treatment session involving D5W injection without anesthetic was 88.1%  ±  9.8%. The pretreatment Numeric Pain Rating Scale score of 8.3 ± 1.3 improved to 1.9 ± 0.9 at 2 months after the last treatment. Patients received 3.8 ± 2.6 treatments over 9.7 ± 7.8 months from the first treatment to the 2-month posttreatment follow-up. Pain improvement exceeded 50% in all cases and 75% in half. Our results confirm the analgesic effect of D5W injection and suggest that hydrodissection using D5W provides cumulative pain reduction.

Efficacy of Stellate Ganglion Blockade Applied with Light Irradiation: A Systemic Review and Meta-analysis

OBJECTIVE

Stellate ganglion block has mostly been used to relieve symptoms of neuropathic pain; several potential complications have been reported. Noninvasive stellate ganglion block application using light irradiation (SG-LI) can be used as an alternative to conventional injection blockades. Based on the variety of application protocols among previous studies, it was needed to further identify the clinical efficacy of SG-LI in managing neuropathic pain or other disorders associated with sympathetic hyperactivity.

DESIGN

A comprehensive search of online databases was performed to identify experimental or observational studies reporting the efficacy of SG-LI in treating patients with disorders requiring sympatholytic management. The included studies were subjected to a meta-analysis and risk-of-bias assessment.

RESULTS

Twenty-one experimental studies with a Physiotherapy Evidence Database score of 6/10 and 5 observational studies with a Newcastle-Ottawa scale score of 7/9 were included in the analysis. A significant effect on pain relief favoring SG-LI was identified at a standard mean difference (SMD) of -2.05 [95% confidence interval (CI), -2.49 to -1.61; P < 0.00001]. Similar effects favoring SG-LI were found in peripheral blood flow (SMD, 1.26; 95% CI, 0.26-2.25; P = 0.01) and skin temperature (SMD, 1.31; 95% CI, 0.55, 2.08; P = 0.0007).

CONCLUSIONS

Stellate ganglion block application using light irradiation effectively relieves pain of various etiologies and successfully induces a sympatholytic response. Stellate ganglion block application using light irradiation may be a valuable addition to the contemporary pain management armamentarium.

Efficacy of Noninvasive Stellate Ganglion Blockade Performed Using Physical Agent Modalities in Patients with Sympathetic Hyperactivity-Associated Disorders: A Systematic Review and Meta-Analysis

BACKGROUND

Stellate ganglion blockade (SGB) is mainly used to relieve symptoms of neuropathic pain in conditions such as complex regional pain syndrome and has several potential complications. Noninvasive SGB performed using physical agent modalities (PAMs), such as light irradiation and electrical stimulation, can be clinically used as an alternative to conventional invasive SGB. However, its application protocols vary and its clinical efficacy remains controversial. This study investigated the use of noninvasive SGB for managing neuropathic pain or other disorders associated with sympathetic hyperactivity.

MATERIALS AND METHODS

We performed a comprehensive search of the following online databases: Medline, PubMed, Excerpta Medica Database, Cochrane Library Database, Ovid MEDLINE, Europe PubMed Central, EBSCOhost Research Databases, CINAHL, ProQuest Research Library, Physiotherapy Evidence Database, WorldWideScience, BIOSIS, and Google Scholar. We identified and included quasi-randomized or randomized controlled trials reporting the efficacy of SGB performed using therapeutic ultrasound, transcutaneous electrical nerve stimulation, light irradiation using low-level laser therapy, or xenon light or linearly polarized near-infrared light irradiation near or over the stellate ganglion region in treating complex regional pain syndrome or disorders requiring sympatholytic management. The included articles were subjected to a meta-analysis and risk of bias assessment.

RESULTS

Nine randomized and four quasi-randomized controlled trials were included. Eleven trials had good methodological quality with a Physiotherapy Evidence Database (PEDro) score of ≥6, whereas the remaining two trials had a PEDro score of <6. The meta-analysis results revealed that the efficacy of noninvasive SGB on 100-mm visual analog pain score is higher than that of a placebo or active control (weighted mean difference, -21.59 mm; 95% CI, -34.25, -8.94; p = 0.0008).

CONCLUSIONS

Noninvasive SGB performed using PAMs effectively relieves pain of various etiologies, making it a valuable addition to the contemporary pain management armamentarium. However, this evidence is limited by the potential risk of bias.

Palliative Interventional Oncology

Interventional oncologists are playing an ever greater role in improving the quality of life of their patients through minimally invasive procedures, many of which can be performed on an outpatient basis. Some of the most common palliative procedures currently performed will be discussed including management of intractable ascites and pleural effusions, neurolytic plexus blocks, and palliation of pain and bleeding associated with metastatic tumors.

Local anaesthetic sympathetic blockade for complex regional pain syndrome

BACKGROUND

This review is an update of a previously published review in the Cochrane Database of Systematic Reviews, 2005, Issue 4 (and last updated in the Cochrane Database of Systematic Reviews, 2013 issue 8), on local anaesthetic blockade (LASB) of the sympathetic chain to treat people with complex regional pain syndrome (CRPS).

OBJECTIVES

To assess the efficacy of LASB for the treatment of pain in CRPS and to evaluate the incidence of adverse effects of the procedure.

SEARCH METHODS

For this update we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 9), MEDLINE (Ovid), EMBASE (Ovid), LILACS (Birme), conference abstracts of the World Congresses of the International Association for the Study of Pain, and various clinical trial registers up to September 2015. We also searched bibliographies from retrieved articles for additional studies.

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) that evaluated the effect of sympathetic blockade with local anaesthetics in children or adults with CRPS compared to placebo, no treatment, or alternative treatments.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. The outcomes of interest were reduction in pain intensity, the proportion who achieved moderate or substantial pain relief, the duration of pain relief, and the presence of adverse effects in each treatment arm. We assessed the evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation) and created a 'Summary of findings' table.

MAIN RESULTS

We included an additional four studies (N = 154) in this update. For this update, we excluded studies that did not follow up patients for more than 48 hours. As a result, we excluded four studies from the previous review in this update. Overall we included 12 studies (N = 461), all of which we judged to be at high or unclear risk of bias. Overall, the quality of evidence was low to very low, downgraded due to limitations, inconsistency, imprecision, indirectness, or a combination of these.Two small studies compared LASB to placebo/sham (N = 32). They did not demonstrate significant short-term benefit for LASB for pain intensity (moderate quality evidence).One small study (N = 36) at high risk of bias compared thoracic sympathetic block with corticosteroid and local anaesthetic versus injection of the same agents into the subcutaneous space, reporting statistically significant and clinically important differences in pain intensity at one-year follow-up but not at short term follow-up (very low quality evidence).Of two studies that investigated LASB as an addition to rehabilitation treatment, the only study that reported pain outcomes demonstrated no additional benefit from LASB (very low quality evidence).Eight small randomised studies compared sympathetic blockade to various other active interventions. Most studies found no difference in pain outcomes between sympathetic block versus other active treatments (low to very low quality evidence).One small study compared ultrasound-guided LASB with non-guided LASB and found no clinically important difference in pain outcomes (very low quality evidence).Six studies reported adverse events, all with minor effects reported.

AUTHORS' CONCLUSIONS

This update's results are similar to the previous versions of this systematic review, and the main conclusions are unchanged. There remains a scarcity of published evidence and a lack of high quality evidence to support or refute the use of local anaesthetic sympathetic blockade for CRPS. From the existing evidence, it is not possible to draw firm conclusions regarding the efficacy or safety of this intervention, but the limited data available do not suggest that LASB is effective for reducing pain in CRPS.

Work-Related Complex Regional Pain Syndrome: Diagnosis and Treatment

Complex regional pain syndrome can be a debilitating disorder, which, in its earliest stages, can be prevented by aggressive rehabilitation based on reactivation. It is critical to follow international criteria on making the diagnosis; overdiagnosis can lead to inappropriate interventions and further disability. When present, early recognition with reactivation is the cornerstone of treatment. This article presents a phased approach to treatment that suggests movements of nonresponders quickly to more integrated levels of care. Some commonly used invasive interventions, such as sympathectomy and spinal cord stimulation, have not been proved effective; these unproven and potentially harmful therapies should be avoided.

Evaluation of new approach to ultrasound guided stellate ganglion block

BACKGROUND

Ultrasound imaging is an ideal tool for stellate ganglion block (SGB) due to clarity, portability, lack of radiation, and low cost. Ultrasound guided anterior approach requires the application of pressure to the anterior neck and is associated with more risk of injury to inferior thyroid artery, vertebral artery, and esophagus. The lateral approach does not interfere with nerve or vascular structures. Blockade at the C6 vertebral level results in more successful sympathetic blockade of the head and neck with less sympathetic blockade of the upper extremity compared to sympathetic blockade at C7 vertebral level, which produces successful sympathetic blockade of upper extremity. This is helpful in patients of complex regional pain syndrome of the upper limb. Hence, we conducted a study using the lateral approach at C7 level.

MATERIALS AND METHODS

Ultrasound guided SGBs using lateral in-plane technique at C7 level were given in 20 patients suffering from chronic pain patients of upper extremity, head, and neck using 4 ml of 0.25% bupivacaine and 1 ml of 40 mg triamcinolone. The patients were assessed for a numeric pain intensity score (NPIS), the rise in axillary temperature, the range of motion of joints of upper extremity, and resolution of edema at various time intervals up to 3 months.

RESULTS

NPIS showed a statistically significant decrease from baseline at 30 min, which was sustained till 3(rd) month. The rise in axillary temperature after the block was statistically significant, which was sustained till 2(nd) week. The edema score decreased significantly at all-time intervals (P ≤ 0.001). The restriction of motion in all joints of upper limb decreased from 13 to 3 patients.

CONCLUSION

There is a significant variation in the anatomy of stellate ganglion at the level of C6 and C7. Ultrasound guided lateral approach increases the efficacy of SGB by deposition of drug subfascially with real-time imaging.

Effectiveness of Stellate Ganglion Block Under Fuoroscopy or Ultrasound Guidance in Upper Extremity CRPS

INTRODUCTION

Stellate Ganglion Block (SGB) is an effective technique which may be used to manage upper extremities pain due to Chronic Regional Pain Syndrome (CRPS), in this study we tried to evaluate the effectiveness of this procedure under two different guidance for management of this syndrome.

AIM

The purpose of this study was to evaluate the effectiveness of ultrsound guide SGB by comparing it with the furoscopy guided SGB in upper extermities CRPS patients in reducing pain & dysfuction of the affected link.

MATERIALS AND METHODS

Fourteen patients with sympathetic CRPS in upper extremities in a randomized method with block randomization divided in two equal groups (with ultrasound or fluoroscopic guidance). First group was blocked under fluoroscopic guidance and second group blocked under ultrasound guidance. After correct positioning of the needle, a mixture of 5 ml bupivacaine 0.25% and 1 mL of triamcinolone was injected.

RESULTS

These data represent no meaningful statistical difference between the two groups in terms of the number of pain attacks before the blocks, a borderline correlation between two groups one week and one month after the block and a significant statistical correlation between two groups three month after the block. These data represent no meaningful statistical difference between the patients of any group in terms of the pain intensity (from one week to six months after block), p-value = 0.61. These data represent a meaningful statistical difference among patients of any group and between the two groups in terms of the pain intensity (before the block until six months after block), p-values were 0.001, 0.031 respectively.

CONCLUSION

According the above mentioned data, in comparison with fluoroscopic guidance, stellate ganglion block under ultrasound guidance is a safe and effective method with lower complication and better improvement in patient's disability indexes.

Augmentation of cardiac sympathetic tone by percutaneous low-level stellate ganglion stimulation in humans: a feasibility study

Modulation of human cardiac mechanical and electrophysiologic function by direct stellate ganglion stimulation has not been performed. Our aim was to assess the effect of low-level left stellate ganglion (LSG) stimulation (SGS) on arrhythmias, hemodynamic, and cardiac electrophysiological indices. Patients undergoing ablation procedures for arrhythmias were recruited for SGS. A stimulating electrode was placed next to the LSG under fluoroscopy and ultrasound imaging; and SGS (5-10 Hz, 10-20 mA) was performed. We measured hemodynamic, intracardiac and ECG parameters, and activation recovery intervals (ARIs) (surrogate for action potential duration) from a duodecapolar catheter in the right ventricular outflow tract. Five patients underwent SGS (3 males, 45 ± 20 years). Stimulating catheter placement was successful, and without complication in all patients. SGS did not change heart rate, but increased mean arterial blood pressure (78 ± 3 mmHg to 98 ± 5 mmHg, P < 0.001) and dP/dt max (1148 ± 244 mmHg/sec to 1645 ± 493 mmHg/sec, P = 0.03). SGS shortened mean ARI from 304 ± 23 msec to 283 ± 17 msec (P < 0.001), although one patient required parasympathetic blockade. Dispersion of repolarization (DOR) increased in four patients and decreased in one, consistent with animal models. QT interval, T-wave duration and amplitude at baseline and with SGS were 415 ± 15 msec versus 399 ± 15 msec (P < 0.001); 201 ± 12 msec versus 230 ± 28 msec; and 0.2 ± 0.09 mV versus 0.22 ± 0.08 mV, respectively. At the level of SGS performed, no increase in arrhythmias was seen. Percutaneous low-level SGS shortens ARI in the RVOT, and increases blood pressure and LV contractility. These observations demonstrate feasibility of percutaneous SGS in humans.

Interventional management of neuropathic pain: NeuPSIG recommendations

Neuropathic pain (NP) is often refractory to pharmacologic and noninterventional treatment. On behalf of the International Association for the Study of Pain Neuropathic Pain Special Interest Group, the authors evaluated systematic reviews, clinical trials, and existing guidelines for the interventional management of NP. Evidence is summarized and presented for neural blockade, spinal cord stimulation (SCS), intrathecal medication, and neurosurgical interventions in patients with the following peripheral and central NP conditions: herpes zoster and postherpetic neuralgia (PHN); painful diabetic and other peripheral neuropathies; spinal cord injury NP; central poststroke pain; radiculopathy and failed back surgery syndrome (FBSS); complex regional pain syndrome (CRPS); and trigeminal neuralgia and neuropathy. Due to the paucity of high-quality clinical trials, no strong recommendations can be made. Four weak recommendations based on the amount and consistency of evidence, including degree of efficacy and safety, are: 1) epidural injections for herpes zoster; 2) steroid injections for radiculopathy; 3) SCS for FBSS; and 4) SCS for CRPS type 1. Based on the available data, we recommend not to use sympathetic blocks for PHN nor radiofrequency lesions for radiculopathy. No other conclusive recommendations can be made due to the poor quality of available data. Whenever possible, these interventions should either be part of randomized clinical trials or documented in pain registries. Priorities for future research include randomized clinical trials, long-term studies, and head-to-head comparisons among different interventional and noninterventional treatments.

Local anaesthetic sympathetic blockade for complex regional pain syndrome

BACKGROUND

This is an update of the original Cochrane review published in The Cochrane Library, 2005, Issue 4, on local anaesthetic blockade (LASB) of the sympathetic chain used to treat complex regional pain syndrome (CRPS).

OBJECTIVES

To assess the efficacy of LASB for the treatment of pain in CRPS and to evaluate the incidence of adverse effects of the procedure.

SEARCH METHODS

We updated searches of the Cochrane Pain, Palliative and Supportive Care Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) on the Cochrane Library (Issue 11 of 12, 2012), MEDLINE (1966 to 22/11/12), EMBASE (1974 to 22/11/12), LILACS (1982 to 22/11/12), conference abstracts of the World Congresses of the International Association for the Study of Pain (1995 to 2010), and various clinical trial registers (inception to 2012). We also searched bibliographies from retrieved articles for additional studies.

SELECTION CRITERIA

We considered for inclusion randomised controlled trials (RCTs) that evaluated the effect of sympathetic blockade with local anaesthetics in children or adults with CRPS.

DATA COLLECTION AND ANALYSIS

The outcomes of interest were reduction in pain intensity levels, the proportion who achieved moderate or substantial pain relief, the duration of pain relief, and the presence of adverse effects in each treatment arm.

MAIN RESULTS

We included an additional 10 studies (combined n = 363) in this update. Overall we include 12 studies (combined n = 386). All included studies were assessed to be at high or unclear risk of bias.Three small studies compared LASB to placebo/sham. We were able to pool the results from two of these trials (intervention n = 23). Pooling did not demonstrate significant short-term benefit for LASB (in terms of the risk of a 50% reduction of pain scores).Of two studies that investigated LASB as an addition to rehabilitation treatment, the only study that reported pain outcomes demonstrated no additional benefit from LASB.Eight small randomised studies compared sympathetic blockade to another active intervention. Most studies found no difference in pain outcomes between sympathetic block and other active treatments.Only five studies reported adverse effects, all with minor effects reported.

AUTHORS' CONCLUSIONS

This update has found similar results to the original systematic review. There remains a scarcity of published evidence to support the use of local anaesthetic sympathetic blockade for CRPS. From the existing evidence it is not possible to draw firm conclusions regarding the efficacy or safety of this intervention but the limited data available do not suggest that LASB is effective for reducing pain in CRPS.

CT-guided stellate ganglion blockade vs. radiofrequency neurolysis in the management of refractory type I complex regional pain syndrome of the upper limb

OBJECTIVE

To describe and evaluate the feasibility and efficacy of CT-guided radiofrequency neurolysis (RFN) vs. local blockade of the stellate ganglion in the management of chronic refractory type I complex regional pain syndrome (CRPS) of the upper limb.

METHODS

Sixty-seven patients were included in this retrospective study between 2000 and 2011. All suffered from chronic upper limb type I CRPS refractory to conventional pain therapies. Thirty-three patients underwent stellate ganglion blockade and 34 benefited from radiofrequency neurolysis of the stellate ganglion. CT guidance was used in both groups. The procedure was considered effective when pain relief was ≥50 %, lasting for at least 2 years.

RESULTS

Thirty-nine women (58.2 %) and 28 men (41.8 %) with a mean age of 49.5 years were included in the study. Univariate analysis performed on the blockade and RFN groups showed a significantly (P < 0.0001) higher success rate in the RFN group (67.6 %, 23/34) compared with the blockade group (21.2 %, 7/33) with an odds ratio of 7.76.

CONCLUSION

CT-guided radiofrequency neurolysis of the stellate ganglion is a safe and successful treatment of chronic refractory type I CRPS of the upper limb. It appears to be more effective than stellate ganglion blockade.

KEY POINTS

• Complex regional pain syndrome is painful, disabling and often refractory to treatment. • Sixty-seven percent of patients had lasting pain relief (2 years) after radiofrequency neurolysis. • Retrospective study showed a significantly higher success rate for radiofrequency neurolysis. • CT guidance is mandatory for a successful and safe procedure.

Revalidation of a modified and safe approach of stellate ganglion block

Stellate ganglion block (SGB) is very effective in management of chronic regional pain syndrome (CRPS-1). However, serious complication may occur due to accidental intravascular (intra-arterial) injection of local anaesthetic agents. Abdi and others, has suggested a modified technique in which fluoroscopy-guided block is given at the junction of uncinate process and body of vertebra at C7 level. In this approach vascular structures remain away from the trajectory of needle and thus avoid accidental vascular injection. We have used this technique of SGB in nine patients who were treated for CRPS-I. The blocks were effective in all the patients all the time without any vascular or other serious complication.

Stellate ganglion blockade (SGB) for refractory index finger pain - a case report

OBJECTIVE

To identify through case study the presentation and possible pathophysiological cause of complex regional pain syndrome and its preferential response to stellate ganglion blockade.

SETTING

Complex regional pain syndrome can occur in an extremity after minor injury, fracture, surgery, peripheral nerve insult or spontaneously and is characterised by spontaneous pain, changes in skin temperature and colour, oedema, and motor disturbances. Pathophysiology is likely to involve peripheral and central components and neurological and inflammatory elements. There is no consistent approach to treatment with a wide variety of specialists involved. Diagnosis can be difficult, with over-diagnosis resulting from undue emphasis placed upon pain disproportionate to an inciting event despite the absence of other symptoms or under-diagnosed when subtle symptoms are not recognised. The International Association for the Study of Pain supports the use of sympathetic blocks to reduce sympathetic nervous system overactivity and relieve complex regional pain symptoms. Educational reviews promote stellate ganglion blockade as beneficial. Three blocks were given at 8, 10 and 13 months after the initial injury under local anaesthesia and sterile conditions. Physiotherapeutic input was delivered under block conditions to maximise joint and tissue mobility and facilitate restoration of function.

CONCLUSION

This case demonstrates the need for practitioners from all disciplines to be able to identify the clinical characteristics of complex regional pain syndrome to instigate immediate treatment and supports the notion that stellate ganglion blockade is preferable to upper limb intravenous regional anaesthetic block for refractory index finger pain associated with complex regional pain syndrome.

The contribution of sympathetic mechanisms to postamputation phantom and residual limb pain: a pilot study

Postamputation pain (PAP) affects over 60% of major limb amputees. One of the main challenges in treating PAP is the difficulty involved in identifying pain mechanism(s), which pertains to both residual limb pain (RLP) and phantom limb pain (PLP). In this study, sympathetic blocks were performed on 17 major limb amputees refractory to treatment, including 2 placebo-controlled blocks done for bilateral amputations. One hour postinjection, mean RLP scores at rest declined from 5.2 (SD 2.8) to 2.8 (SD 2.6) (P = .0002), and PLP decreased from 5.3 (SD 3.1) to 2.3 (SD 2.1) (P = .0009). By 1 week, mean pain scores for RLP and PLP were 4.3 (SD 2.9) and 4.2 (SD 3.0), respectively. Overall, 8 of 16 (50%) patients experienced ≥50% reduction in RLP 1-hour postinjection, with the beneficial effects being maintained at 1 and 8 weeks in 4 and 1 patient(s), respectively. For PLP, 8 of 15 (53%) patients obtained ≥50% decrease in pain 1-hour postblock, with these numbers decreasing to 2 patients at both 1 and 8 weeks. In the 2 bilateral amputees who received controlled injections, mean PLP and RLP at rest scores went from 4.0 and 3.3 to 4.0 and 2.5 1-hour postblock, respectively, on the placebo side. On the treatment side, mean PLP and RLP scores decreased from 7.5 and 6.5, respectively, to 0.

PERSPECTIVE

The results of this study suggest that sympathetic mechanisms play a role in PLP and to a lesser extent, RLP, but that blocks confer long-term benefits in only a small percentage of patients.

Physical therapy and rehabilitation of complex regional pain syndrome in shoulder prosthesis

We report a 66-year-old woman with complex regional pain syndrome (CRPS) 1 treated with combined medical and active physical therapy. She was diagnosed with CRPS 1 following partial shoulder prosthesis due to proximal humerus fracture. Despite continuous medication and physical therapy, there was no improvement in her pain and functional outcome. Her overall pain was decresed by stellate ganglion block 3 times in two weeks conducted during the second month of the follow-up period. Following the ganglion blockades, pain and the other symptoms were decreased intermittently but range of motion (ROM) and functional status were not satisfied as much as expected. After the third month of follow-up, her passive and active ROM of the shoulder joint was increased after application of manipulation under general anesthesia. In conclusion, because CRPS 1 remains one of the most difficult pain syndromes, early diagnosis and treatment are important to have adequate functional results from physical therapy. Manipulation under general anesthesia may be an additional effective treatment tool to obtain functional improvement in some patients diagnosed with CRPS 1.

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+).

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.

Complex regional pain syndrome type I: efficacy of stellate ganglion blockade

Background

This study was performed to evaluate the treatment of complex regional pain syndrome (CRPS) type I with stellate ganglion blockade.

Materials and methods

We performed three blockades at weekly intervals in 22 patients with CRPS type I in one hand. The patients were divided into two groups depending on the time between symptom onset and treatment initiation. Group 1and 2 patients had short and long symptom-onset-to-treatment intervals, respectively. Pain intensity, using a visual analog score (VAS), and range of motion (ROM) for the wrist joint were assessed before and 2 weeks after treatment and were compared using nonparametric statistical analysis.

Results

Treatment produced a statistically significant difference in wrist ROM for all patients (P < 0.001). VAS values showed an overall decrease from 8 ± 1 to 1 ± 1 following treatment, and there was a significant difference in VAS value between groups 1 and 2 (P < 0.05).

Conclusions

We concluded that stellate ganglion blockade successfully decreased VAS and increased ROM of wrist joints in patients with CRPS type I. Further, the duration between symptom onset and therapy initiation was a major factor affecting blockade success.

Effects of bilateral stellate ganglion block on autonomic cardiovascular regulation

BACKGROUND

Stellate ganglion block (SGB) is performed for the diagnosis and treatment of sympathetic dependent pain in the head, neck and upper limbs. However, the effects of bilateral SGB on cardiovascular and autonomic regulation remain unknown. The aim of this study was to assess the effects of bilateral SGB on cardiovascular and autonomic function by measuring heart rate variability (HRV), systolic blood pressure variability (SBPV) and spontaneous baroreflex sensitivity (SBRS).

METHODS AND RESULTS

Twenty healthy volunteers were randomly allocated to receive right or left SGB with 8 ml 1% lidocaine solution; after 20 min, the contralateral side SGB was performed. Changes in the RR interval (RRI), systolic blood pressure (SBP), HRV, SBPV and SBRS were assessed before and after bilateral SGB. The low-frequency (LF, 0.04-0.15 Hz) and high-frequency (HF, 0.15-0.4 Hz) components of HRV and SBRS decreased significantly; however, no significant changes were found in RRI, SBP and the LF and HF components of SBPV after bilateral SGB. In subjects with symptoms of vagal blockade, HRV, SBP and SBRS were significantly affected by bilateral SGB.

CONCLUSIONS

Bilateral SGB should be performed cautiously because it can reduce cardiac vagal modulation and BRS, especially for those with symptoms of vagal blockade after bilateral SGB.

Referral and treatment patterns for complex regional pain syndrome in the Netherlands

BACKGROUND

Patients with complex regional pain syndrome (CRPS) are seen and treated by a variety of physicians. The present study aims to describe referral and treatment patterns for CRPS patients in the Netherlands.

METHODS

Patients, who were selected (1996-2005) from an electronic general practice (GP) database (Integrated Primary Care Information Project), were invited for study participation, involving diagnosis verification (International Association for the Study of Pain criteria) and assessment of referrals and treatment through information retrieved from GP journals, patients' questionnaires, pharmacy dispensing lists and specialist letters if available.

RESULTS

One hundred and two patients were included. Sixty-one percent had presented first at the GP, while 80% subsequently consulted one or more medical specialists, most frequently an anesthetist (55% of the cases) or a specialist in rehabilitation medicine (41%). Over 90% of the patients received oral or topical pharmacotherapy, 45% received intravenous therapy, 89% received non-invasive therapy (i.e. physiotherapy) and 18% received nerve blocks. Analgesics and free radical scavengers were administered early during CRPS, while vasodilating drugs and drugs against neuropathic pain (antidepressants and anti-epileptics) were administered later on. Pharmacotherapy was usually initiated by a medical specialist.

CONCLUSION

The Dutch treatment guidelines, issued in 2006, recommend free radical scavenger prescription (plus physiotherapy) as the initial treatment step for CRPS. Until 2005 only half of the patients received a scavenger within 3 months after disease onset, and the majority presents first at the GP, in particular GPs may be encouraged to initiate treatment with scavengers, while waiting for the results of further specialist consultation.