Nerve Stimulator-Guided Repetitive Paravertebral Block for Thoracic Myofascial Pain Syndrome

▪ Abstract:   Myofascial pain syndrome (MPS) may persist for many years and is often refractory to traditional therapeutic approaches including pharmacotherapy, focal tenderness infiltration by local anesthetic and corticosteroids, physical therapy and behavioral modification. This report describes three cases of MPS following coronary artery bypass graft, inadequate positioning during abdominal hysterectomy, and excessive physical effort refractory to conventional therapeutic approaches. Three patients were successfully treated with repeated nerve stimulator-guided paravertebral block using a mixture of bupivacaine and clonidine.
Physical examinations including a complete neurological assessments were unremarkable. Relevant diagnostic imaging (X-ray, magnetic resonance imaging, computed tomography) and laboratory evaluations also failed to demonstrate any significant structural disorders or systemic diseases that might have been responsible for their pain. Nerve stimulator-guided paravertebral block was performed at the dermatomes corresponding to the thoracic myofascial pain region. Each point was injected with 4 mL of the local anesthetic solution. If the pain returned, a second paravertebral block was performed. The three patients were pain-free over a follow-up period up to 2 years. Our report suggests that nerve stimulator-guided paravertebral blockade could be a useful treatment for MPS refractory to traditional therapeutic approaches. ▪     

Ultrasonography in Pain Medicine: A Critical Review

▪ Abstract:   Recently, ultrasonography has been increasingly used in the field of regional anesthesia to assure reliable blockade of peripheral nerves and to visualize neuroaxial structures. As its popularity is steadily increasing, it may become a standard of care for both intraoperative analgesia and postoperative pain control. The application of ultrasound in chronic pain management, however, remains underutilized. Multiple reasons can be suggested to explain this situation. Nonetheless, numerous articles have been published and some interventionalists have gained experience and started to spread their knowledge through hands-on workshops and medical meetings.
It, therefore, seems timely to describe the techniques of ultrasound-guided injections for chronic pain, to review accumulated experience in this field, to reappraise the scientific and clinical value of this method, and to outline potential future developments. ▪     

The Ultrasound-Guided Supraclavicular-Interscalene (UGSCIS) Block: A Case Report

▪ Abstract:   Providing complete anesthesia to the entire upper extremity remains challenging. We present the use of a novel, updated, regional anesthetic technique—an ultrasound-guided supraclavicular-interscalene block (UGSCIS)—to provide anesthesia and analgesia to a patient with end-stage liver disease who required fixation of a pathologic fracture of the humerus. ▪     

Defining the therapeutic role of local anesthetic sympathetic blockade in complex regional pain syndrome: a narrative and systematic review

OBJECTIVE: There is growing controversy on the value of blocking the sympathetic nervous system for the treatment of complex regional pain syndromes (CRPS). The authors sought to evaluate the efficacy of sympathetic blockade with local anesthetic in these syndromes. In addition, they performed a comprehensive review of the pathophysiology and other treatments for CRPS. DESIGN: Systematic review of the literature was performed. MEDLINE was searched from 1966 through 1999. The authors identified only three randomized controlled trials (RCTs) that evaluated sympathetic blockade with local anesthetic, but because of differences in study design they were unable to pool the study data. The authors therefore included nonrandomized studies and case series. INTERVENTIONS: Studies were included if local anesthetic sympathetic blockade was used in at least 10 patients. Studies were excluded if continuous infusion techniques, somatic nerve blocks, or combined sympatholytic therapies were evaluated. OUTCOME MEASURES: Pain relief was classified as full, partial, or absent. The lack of a comparison group in the studies allowed only the calculation of distribution of the response categories, and the sum of the pooled rates does not equal 100%. RESULTS: Twenty-nine studies were included that evaluated 1,144 patients. Nineteen studies were retrospective, 5 prospective case series, 3 RCTs, and 2 nonrandomized controlled studies. The quality of the publications was generally poor. Twenty-nine percent of patients had full response, 41% had partial response, and 32% had absent response. It was not possible to estimate the duration of pain relief. CONCLUSIONS: This review raises questions as to the efficacy of local anesthetic sympathetic blockade as treatment of CRPS. Its efficacy is based mainly on case series. Less than one third of patients obtained full pain relief. The absence of control groups in case series leads to an overestimation of the treatment response that can explain the findings.     

Treatment of Complex Regional Pain Syndrome Type I With Oral Phenoxybenzamine: Rationale and Case Reports

▪ Abstract:   The nonselective α-adrenergic antagonist, phenoxybenzamine, has been used in the treatment of neuropathic pain syndromes, specifically, complex regional pain syndrome (CRPS) types I and II. This agent has also previously been used in intravenous regional peripheral blocks for treatment of CRPS I; however, an intravenous preparation of phenoxybenzamine is not currently available in the U.S.A. In this case series, systemic administration was more appropriate for three of the four patients, as their syndromes had spread beyond the initial area of surgery or trauma. We report an apparent clinical benefit in three of the four patients following oral administration. We postulate that this may be due to the noncompetitive (irreversible) blockade of α₁- and α₂-adrenergic receptors. We further hypothesize that this blockade could reduce stimulation of an increased population of adrenergic receptors in hyperalgesic skin, blunt the stimulation by norepinephrine of α₂-adrenergic receptors on macrophages, and ultimately reduce the release of proinflammatory cytokines from cellular elements. ▪     

Neural Modulation by Blocks and Infusions

Abstract:   Neural blockade is widely used in clinical practice to alleviate acute or chronic pain, including neuropathic pain. However, to date there is little controlled evidence to confirm the efficacy of nerve blocks in neuropathic pain. The most common indication for nerve blocks, especially sympathetic blockade, is complex regional pain syndrome, in which success rates of up to 38% have been achieved, depending on the type of the block used. Greater efficacy has been achieved by combining a nerve block with patient-controlled analgesia. Sympathectomy is recommended for the treatment of neuropathic pain only after careful consideration of its usefulness, effectiveness, and risk of adverse effects. Current evidence and clinical experience suggest that neural blockade could be a useful adjunct in the management of refractory neuropathic pain, but further well-controlled studies would be of great benefit to support this type of therapy.     

Complicated Pain Management in a CYP450 2D6 Poor Metabolizer

▪ Abstract:   We describe the case of a patient with significant adverse effects from posttraumatic analgesic therapy with opioid analgesics who was found by microarray analysis to have a CYP2D6 genotype predictive of a poor metabolizer phenotype. In addition to her poor tolerance and limited response to opioid analgesics, she developed further discomfort when the antiemetic promethazine was administered to treat her gastrointestinal adverse effects. In our discussion we review the literature about the clinical impact of CYP450 2D6 polymorphisms in treatment with the commonly used opioid analgesics codeine, oxycodone, hydrocodone, hydromorphone, and morphine, as well as the antiemetic promethazine. The case we present, as well as the literature we review, demonstrates the clinical utility of CYP2D6 genotyping in patients with adverse effects from analgesia therapy. ▪     

Botulinum Toxin Occipital Nerve Block for the Treatment of Severe Occipital Neuralgia: A Case Series

▪ Abstract:   Persistent occipital neuralgia can produce severe headaches that are difficult to control by conservative or surgical approaches. We retrospectively describe a series of six patients with severe occipital neuralgia who received conservative and interventional therapies, including oral antidepressants, membrane stabilizers, opioids, and traditional occipital nerve blocks without significant relief. This group then underwent occipital nerve blocks using the botulinum toxin type A (BoNT-A) BOTOX® Type A (Allergan, Inc., Irvine, CA, U.S.A.) 50 U for each block (100 U if bilateral). Significant decreases in pain Visual Analog Scale (VAS) scores and improvement in Pain Disability Index (PDI) were observed at four weeks follow-up in five out of six patients following BoNT-A occipital nerve block. The mean VAS score changed from 8 ± 1.8 (median score of 8.5) to 2 ± 2.7 (median score of 1), while PDI improved from 51.5 ± 17.6 (median 56) to 19.5 ± 21 (median 17.5) and the duration of the pain relief increased to an average of 16.3 ± 3.2 weeks (median 16) from an average of 1.9 ± 0.5 weeks (median 2) compared to diagnostic 0.5% bupivacaine block. Following block resolution, the average pain scores and PDI returned to similar levels as before BoNT-A block. In conclusion, BoNT-A occipital nerve blocks provided a much longer duration of analgesia than diagnostic local anesthetics. The functional capacity improvement measured by PDI was profound enough in the majority of the patients to allow patients to resume their regular daily activities for a period of time. ▪     

Perioperative Management in Reverse Total Shoulder Arthroplasty

Purpose of ReviewA successful reverse total shoulder arthroplasty requires careful preoperative planning and perioperative management. Preoperative comorbidity risks, perioperative pain management, and postoperative rehabilitation are all critical components of this arthroplasty. The current review examines available literature to guide the perioperative care of the reverse total shoulder arthroplasty patient.Recent FindingsOne of the most important advances for shoulder arthroplasty in recent years has been heightened awareness of various modalities for perioperative pain management. A number of recent studies have focused on the options for regional blockade as a critical tool for postoperative pain relief and the use of either continuous interscalene blocks or single shot blocks are supported. Additional studies are necessary to define the best local anesthetic agent and delivery mechanism to provide appropriate pain relief with a low side effect profile.SummaryManagement of the patient throughout the perioperative course is a critical component in achieving better patient outcomes delivering high quality patient care. An orthopedic surgery team focused on perioperative management is better positioned to decrease adverse events and improve patient outcomes after reverse total shoulder arthroplasty.     

Facet joint pain and the role of neural blockade in its management

Chronic spinal pain is a common medical problem with serious financial and social consequences. Among the various structures with potential for producing pain in the spine, facet joints as sources of chronic spinal pain have attracted considerable attention and controversy. Significant progress has been made in precision diagnosis of spinal pain with neural blockade, in the face of less than optimal diagnostic information offered by imaging and neurophysiologic studies. Research into the role of facet joints in spinal pain has shown that cervical facet joints are the cause of chronic neck pain in 54% to 60% of patients, whereas lumbar facet joints cause pain in 15% to 40% of patients with chronic low back pain. Local anesthetic blocks of medial branches have proven to be a reliable diagnostic test; they are target-specific when used appropriately with control blocks, either with two local anesthetics with different durations of action or with the addition of an inactive placebo injection. The literature is replete with reports on uncontrolled studies, case reports, and documentation from a few controlled studies, all of which offer supporting information on the rationale and effectiveness of facet blocks and neurotomy. Facet joint injections and medial branch blocks are considered to be of equal value. Lumbar intra-articular steroid injections have been proven effective to a certain extent, but evidence indicates that cervical intra-articular steroids are ineffective. The role of repeat medial branch blocks is not known. Radiofrequency neurotomy remains the only practical and validated treatment for cervical facet joint pain; however, its role in management of either lumbar or thoracic facet joint pain awaits validation.     

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

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

Trans-facet Joint Approach to Pulsed Radiofrequency Ablation of the L5 Dorsal Root Ganglion in a Patient with Degenerative Spondylosis and Scoliosis

▪ Abstract:   Mechanical low back pain secondary to degenerative facet joint changes is a common reason for referral to pain clinics. When these changes cause encroachment into the intervertebral foramen, radicular pain may result. While pulsed radiofrequency of the dorsal root ganglion can be used in this setting, the anatomic deformity may make the transforaminal approach difficult. We report a case where a trans-facet approach was used successfully and describe the technique. ▪     

Continuous peripheral nerve blocks

A continuous peripheral nerve block—also termed “perineural local anesthetic infusion”—involves the percutaneous insertion of a catheter adjacent to a peripheral nerve, followed by local anesthetic administration via the catheter, providing anesthesia/analgesia for a prolonged period of time. The most-common indication for continuous peripheral nerve blocks is analgesia following painful surgical procedures; but, they are also used for inducing a sympathectomy and vasodilation following digit transfer/replantation, a vascular accident, limb salvage, or peripheral embolism; treating intractable hiccups; alleviating the vasospasm of Raynaud’s disease; and treating chronic pain such as phantom limb pain, cancer-induced pain, complex regional pain syndrome, and trigeminal neuralgia. Continuous peripheral nerve blocks may also provide pain control during medical transport, or awaiting surgical correction. The most common catheter insertion techniques include electrical stimulation and ultrasound-guidance. Long-acting local anesthetic is usually the sole infusate, and is optimally delivered with a continuous basal infusion with available patient-controlled bolus doses. Benefits are dependent upon analgesia improvement, and include decreasing pain, supplemental analgesic consumption, opioid-related side effects, sleep disturbances, patient dissatisfaction, time until discharge readiness, and actual hospitalization duration. Additional possible benefits include improvements in ambulation/functioning and an accelerated resumption of passive joint range-of-motion. Most benefits occur during the infusion itself, but a few studies suggest prolonged benefits following catheter removal in some cases. Minor complications occur at approximately the incidence as for single-injection peripheral nerve blocks; but, major risks including nerve injury are extraordinary uncommon.     

A Randomized Double-Blind Comparison of a Morphine–Fentanyl Combination vs. Morphine Alone for Patient-Controlled Analgesia Following Bowel Surgery

▪ Abstract:   An ideal patient-controlled analgesia (PCA) opioid would have both a rapid onset and a long duration of action, attributes, which are not available in currently existing opioids including morphine, the most widely used agent. A mixture of rapid onset and long-acting opioids may potentially achieve both these qualities. In a randomized, double-blind study, we compared a fentanyl–morphine combination with morphine alone for PCA, in 54 patients undergoing bowel surgery. The combination solution was prepared according to a 1:75 fentanyl to morphine potency ratio. The mixture contained fentanyl 13.33 μg/mL and morphine 1 mg/mL. The morphine alone solution contained 2 mg/mL. Patients were randomly allocated to one of the regimens and were then evaluated 4 times during the first 48 hours following surgery. Time to effect, visual analog pain scores, opioid consumption, demands, deliveries, and side effects on an opioid-related symptom distress scale were recorded. Groups were well matched for age, weight, and sex. There were no significant differences between groups in time to effect, PCA usage, pain scores or side effects other than the occurrence of nausea, which was lower for the combination group in 1 visit. Further studies are needed to explore the potential of different potency ratios and opioid combinations to achieve rapid and long-lasting pain control. ▪     

Necrotic arachnidism and intractable pain from recluse spider bites treated with lumbar sympathetic block: a case report and review of literature

Brown recluse (Loxosceles reclusa) spider bites mainly occur in the southern and Midwestern United States. The clinical manifestation of brown recluse spider bites varies from skin irritation, a small area of tissue damage to neuropathic pain, necrotic arachnidism and severe systemic reactions such as acute renal failure and even death. Treatment is controversial and nonspecific. We describe a case of extensive right lower extremity tissue necrosis and intractable neuropathic pain treated with lumbar sympathetic block in a patient with a documented brown recluse spider bite. Both his pain and tissue necrosis improved significantly with lumbar sympathetic block with local anesthetic. After a series of lumbar sympathetic blocks, his symptoms resolved and lower extremity wound healed rapidly. We discuss the benefit of sympathetic blockade not only for neuropathic pain but also possibly as a treatment for necrotic arachnidism from a brown recluse spider bite.     

Pulsed Radiofrequency Treatment of Articular Branches of the Obturator and Femoral Nerves for Management of Hip Joint Pain

▪ Abstract:   Groin and thigh pain are frequently the major symptoms of hip joint pathology. The hip joint is innervated by articular branches of the obturator, femoral, superior gluteal, and sciatic nerves. The nerve responsible for hip joint pain can be determined by a diagnostic nerve block. Radiofrequency ablation of the identified articular branches of the hip was demonstrated to provide relief of hip pain. However, continuous radiofrequency denervation by thermal coagulation carries the potential risk of neuritis. We report on two patients with groin and thigh pain related to hip joint pathology treated with a novel technique for hip pain relief, pulsed radiofrequency treatment (PRF) of articular branches of the obturator and femoral nerves. At the time this case was written, both patients demonstrated at least 50% pain relief 3 to 4 months after the intervention along with improved function (increased ambulation and ability to participate in physical therapy). Our clinical observation suggests that PRF of articular branches of the hip joint may be an alternative treatment for patients with intractable hip pain. ▪     

Scorpion sting pain: which way to treat?

The objective of reporting this case is to highlight the clinical usefulness of chloroquine in the management of scorpion sting pain with the hope of stimulating interest and research, especially in areas where local anesthetic agents may not be available. In this case reported here, lidocaine failed to provide sustained analgesia for pain relief following scorpion sting. Two milliliters of parenteral chloroquine was injected intradermally around the bite site. Chloroquine provided immediate pain relief within 3 minutes of injection. The pain relief was sustained beyond 24 hours. The use of local anesthetic agents should be continued while other agents such as chloroquine, which may also have relevant clinical usefulness, should be considered.     

Principles of safety for ultrasound-guided single injection blocks in the emergency department

Ultrasound-guided nerve blocks (UGNBs) allow emergency physicians an opportunity to provide optimal pain management for acute traumatic conditions. Over the past decade, a growing body of literature has detailed the novel ways clinicians have incorporated UGNBs for analgesia and an alternative to procedural sedation. UGNBs are considered a relatively safe procedure, and have been shown to increase rates of success and reduce complications (as compared to older techniques). Ultrasound allows the operator needle visualization and a clear anatomic overview. Even with the presumed level of increased safety, we recommend that any clinician who performs ultrasound-guided nerve blocks be aware of complications that could arise during and after the procedure. Peripheral nerve injury (PNI) post block, local anesthetic systemic toxicity (LAST) and the role of single peripheral nerve blocks in patients with a risk for compartment syndrome are common safety issues discussed when performing ultrasound-guided nerve blocks.     

Successful emergency pain control for acute pancreatitis with ultrasound guided erector spinae plane blocks

Pain control for patients in the Emergency Department (ED) with acute pancreatitis (AP) can be difficult and is often limited to intravenous opioids. The acute side effects from opioids are well known and their use in the treatment of AP is associated with prolonged length of hospitalization. Additionally, up to 10% of patients hospitalized for acute pancreatitis are still receiving opioids 6 months after discharge. Ultrasound-guided regional anesthesia by emergency physicians has increasingly proven to be an integral part of a multi-modal opioid sparing pain control strategy for patients in the ED. The ultrasound guided erector spinae plane block may be an ideal adjunct or alternative to opioids for analgesia from AP in the ED. The erector spinae plane block has already been successfully utilized by emergency physicians for pain control from rib fractures, herpes zoster, and more recently, acute appendicitis A lower thoracic erector spinae plane block targets sympathetic nerve fibers in addition to the dorsal and ventral rami via local anesthetic spread to the paravertebral space to provide both visceral and somatic analgesia. Herein, we present the first reported case of acute pancreatitis pain successfully managed by emergency physicians with the ESPB.