Peripheral Nerve Stimulation for Back Pain in Patients With Multiple Myeloma as Bridge Therapy to Radiation Treatment: A Case Series.

OBJECTIVES: Patients with spinal lesions or vertebral compression fractures from multiple myeloma often present with back pain that restricts their ability to lie flat and prevents them from undergoing cancer treatment. Temporary, percutaneous peripheral nerve stimulation (PNS) has been described for cancer pain secondary to oncologic surgery or neuropathy/radiculopathy from tumor invasion. The purpose of this case series is to show the use of PNS as an analgesic bridge therapy to treat myeloma-related back pain and allow patients to complete their course of radiation. MATERIALS AND METHODS: Temporary, percutaneous PNS was placed under fluoroscopic guidance for four patients with unremitting low back pain secondary to myelomatous spinal lesions. Before PNS, the patients had pain refractory to medical management and were unable to tolerate radiation mapping and treatment owing to low back pain while supine. Patients were followed with routine clinic visits to monitor pain and progression through cancer therapy. PNS was removed after approximately 60 days or after completion of radiation. RESULTS: This case series presents four successful cases of PNS to treat low back pain from myelomatous spinal lesions and associated vertebral compression fractures. PNS targeted the medial branch nerves to treat both nociceptive and neuropathic low back pain. All four patients successfully completed radiation therapy with PNS in place. CONCLUSIONS: PNS can effectively treat low back pain secondary to myeloma-related spinal lesions as a bridge therapy to radiation. The use of PNS is a promising option for back pain from other primary or metastatic tumors. Further research is needed into the use of PNS for cancer-related back pain.

Dorsal root ganglion stimulation for chemotherapy-induced peripheral neuropathy.

BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) is a common consequence of cancer treatment that can be persistent and difficult to manage. Dorsal root ganglion stimulation (DRG-S) is a recently introduced but understudied treatment modality. This study explored the effect of DRG-S on pain and symptom burden associated with CIPN. METHODS: Patients with CIPN who underwent a DRG-S trial between January 2017 and August 2022 were identified through chart review after IRB approval was obtained. Demographic data, procedure details, pre-and postoperative scores, including the Numerical Rating Scale (NRS) and Edmonton Symptom Assessment System (ESAS), and duration of follow-up were recorded. Statistical analysis included descriptive statistics and paired t-tests to compare pre-and postoperative scores. RESULTS: Nine patients with an even mix of solid and hematologic malignancies underwent DRG-S trial and had a statistically significant decrease in NRS scores, with a mean reduction of 2.3 in their average pain (p = 0.014), 2.6 in worst pain (p = 0.023), and 2.1 in least pain (p = 0.018). Eight patients (88.9%) underwent permanent DRG-S implantation. Mean NRS scores remained lower than preoperative baselines through the first year of follow-up. Statistically significant reductions were noted at 3 months in average (2.1, p = 0.006) and least pain scores (1.9, p = 0.045), which further decreased after 6-12 months (average: 3.6, p = 0.049; least: 3.4, p = 0.023). Only the pain component of ESAS scores showed a significant reduction with DRG-S (2.0, p = 0.021). All patients endorsed improved sensation, 75% decreased their pain medication usage, and 37.5% reported complete pain relief by 2 years. CONCLUSION: Dorsal root ganglion stimulation can be an effective treatment for pain related to CIPN and deserves further investigation.

Normal Saline Trigger Point Injections vs Conventional Active Drug Mix for Myofascial Pain Syndromes.

BACKGROUND: Myofascial pain syndrome (MPS) originates in the muscle and fascia. MPS presents with referred pain specific for each muscle and a trigger point that reproduces the symptoms. Trigger-point-injection (TPI) is an effective approach to treating MPS. Some TPI agents, however, are associated with systemic and local side effects. OBJECTIVE: The aim of this study was to evaluate the effectiveness of TPI with a conventional active drug mixture (CADM) vs. that with normal saline solution (NS) alone in patients with MPS presenting to the emergency department (ED). METHODS: Adults with MPS diagnosed in the ED, participants were randomly assigned to receive TPI with NS or with CADM. Pain intensity was scored using a 0-10 numeric rating scale prior to and after TPI, before discharge and 2 weeks after TPI. RESULTS: Among 48 patients analyzed, 23 received TPI with NS. The mean pain scores were as follows: immediately before TPI, 7.59 (NS) and 7.44 (CADM); immediately after TPI, 2.22 (NS) and 1.76 (CADM); prior to discharge, 1.52 (NS) and 1.76 (CADM). At 2-week follow up, the mean pain scores were 4.29 (NS) and 4.14 (CADM). Pain was significantly reduced after TPI in both groups. At 2 weeks, the mean pain scores were similar between the groups. No adverse events were reported. CONCLUSION: In cases of MPS in the ED, pain can be controlled with TPI independent of the injectate. TPI with NS may be preferred over CADM because of its lower cost and more favorable side effect profile.

The effect of clonidine pretreatment on epidural resiniferatoxin in a neuropathic pain rat model.

Resiniferatoxin (RTX) is an ultrapotent synthetic TRPV1 (transient receptor potential vanilloid subtype 1) agonist with significant initial transient hyperalgesia followed by a prolonged analgesic effect in response to thermal stimulus. Using a rat model of neuropathic pain, we evaluated the effect of pretreatment with clonidine-which has been shown to relieve intradermal capsaicin-induced hyperalgesia-on the initial hyperalgesic response and the thermal analgesic property of RTX. Thirty-six male rats were divided into 6 treatment groups (n=6 each):RTX 500 ng, RTX 1 µg, clonidine 20 µg (Cl), Cl＋RTX 500 ng, Cl＋RTX 1 µg, or normal saline 20 µL (control). We evaluated the short-term (180 min) and long-term (20 days) analgesic effects of RTX after thermal stimulation and mechanical stimulation. RTX had significant initial transient hyperalgesia followed by a prolonged analgesic effect in response to the thermal stimulus, but the RTX 500 ng and RTX 1 µg groups showed no initial short-term thermal hyperalgesic responses when pretreated with clonidine. The Cl＋RTX 1 µg rats' behavior scores indicated that they were more calm and comfortable compared to the RTX 1 µg rats. Even though we cannot precisely confirm that pretreatment with clonidine potentiates or adds to the analgesic effect of RTX, clonidine pretreatment with epidural RTX eliminated the initial RTX-associated hyperalgesic response and systemic toxicity in this neuropathic pain rat model.

Acute rhabdomyolysis in a patient with long-term exposure to intrathecal ziconotide: a case report.

INTRODUCTION: Ziconotide is an intrathecally administered nonopioid analgesic for the treatment of severe chronic pain. Previous reports have noted rhabdomyolysis in patients receiving ziconotide during the initial single-shot trial or due to concurrent medical problems. We present a case of an acute rhabdomyolysis following an intrathecal bolus injection of ziconotide on a patient who had long-term exposure to the drug. CASE REPORT: The patient suffered from chronic neuropathic pain with diagnosis of failed back surgery syndrome and received intrathecal ziconotide for 2 years. Moderate side effects resulting from dose escalation led to a discontinuation of the drug. The pump medication was changed to morphine, which failed to provide adequate analgesia even with dose titration. A single intrathecal bolus of ziconotide, as an adjunctive therapy, resulted in good pain control. Two months later, the patient received a second ziconotide injection. Sixteen hours after the injection, she presented to local emergency center with nausea, vomiting, diarrhea, and myalgia. She had significantly increased CK levels and was admitted for intravenous hydration and close observation. Her serum CK level peaked at 4940 IU/L. The patient was discharged on hospital day 3 with a CK level of 808 IU/L. Her symptoms resolved without renal impairment. DISCUSSION: The clinical scenario described is a case of acute rhabdomyolysis from an intrathecal bolus injection of ziconotide in a patient with prior long-term exposure to the drug. The decrease in CK levels coincided well with the average half-life of ziconotide; however, the rhabdomyolysis may have been potentiated by hypokalemia.

Peripheral nerve stimulation for the treatment of primary headache.

A headache is a common neurological disorder, and large numbers of patients suffer from intractable headaches including migraine, tension headache and cluster headache, etc., with no clear therapeutic options. Despite the advances made in the treatment of headaches over the last few decades, subsets of patients either do not achieve adequate pain relief or cannot tolerate the side effects of typical migraine medications. An electrical stimulation of the peripheral nerves via an implantable pulse generator appears to be good alternative option for patients with treatment-refractory headaches. A number of clinical trials show considerable evidence supporting the use of peripheral nerve stimulator (PNS) for headaches not responding to conservative therapies. However, the mechanism by which PNS improves headaches or predicts who will benefit from PNS remains uncertain. The decision to use PNS should be individualized based on patient suffering and disability. Hence, further work is imperative. Here, we discuss the mechanism, indication, efficacy, implant technique, and complications of PNS.

Insurance disparities in the outcomes of spinal cord stimulation surgery.

OBJECTIVES: The Affordable Care Act aims to expand health insurance and to help narrow existing health care disparities. Medicaid patients have previously been noted to be at an increased risk for impaired access to health care, delayed medical treatment, and the receipt of substandard care. Conversely, those with commercial insurance may be subject to overtreatment. The goal of this study was to evaluate how Medicaid versus commercial insurance status affects outcomes following spinal cord stimulation (SCS) surgery. MATERIALS AND METHODS: A retrospective cohort study of 13,774 patients underwent either percutaneous or paddle permanent SCS implantation, selected from the Thomson Reuter's MarketScan database between 2000 and 2009. Patients were characterized by age at initial procedure, gender, baseline comorbidity burden, procedure-associated diagnosis code, follow-up, and type of insurance (Medicaid vs. commercial insurance). Outcome measures included probability of reoperation, timing and type of reoperation, presence of postoperative complications (immediate, 30 days, and 90 days), and overall utilization of health resources postoperatively. Multivariate analysis was performed comparing the relative effect of insurance status on outcomes following initial surgery. RESULTS: Medicaid patients had greater healthcare resource utilization as measured by medications prescribed, emergency department visits, and length of stay; however, commercially insured patients had significantly higher overall costs ($110,908 vs. $64,644, p < 0.0001). Commercial and Medicaid patients did not significantly differ in their complication rates during the index hospitalization or at 30 days or 90 days postoperatively. The group were also not significantly different in their two-year reoperation rates (7.32% vs. 5.06%, p = 0.0513). CONCLUSIONS: There are substantial insurance disparities that affect healthcare utilization and overall cost following SCS. Efforts for national healthcare reform should examine system factors that will reduce socioeconomic disparities in outcomes following SCS.

Case report: use of high-intensity laser therapy for treatment of trigeminal neuralgia.

Trigeminal neuralgia represents a form of chronic facial pain that is characterized by its incapacitating nature. The current therapeutic approaches encompass pharmacological agents with carbamazepine or non-pharmacologic options including utilization of percutaneous rhizotomy, Gamma knife radiosurgery or microvascular decompression may be indicated in certain cases. While the interventions may be effective, medications have negative side effects and procedures are invasive which can pose challenges for patients with various comorbidities. High-intensity laser therapy (HILT) has demonstrated safety and efficacy for many types of chronic pain such as musculoskeletal, autoimmune and neuropathic. Herein, we demonstrate the benefits of HILT therapy in the management of trigeminal neuralgia in a 72 year-old patient with a complex history of facial surgery and radiation who had failed pharmacological treatments and denied any invasive procedures.

Trigeminal neuralgia causes severe facial pain, often requiring medications or invasive procedures. High-intensity laser therapy (HILT), known for treating many chronic pains, was explored for a 72 year-old patient with a complex medical history. Previous treatments had failed, and alternatives carried risks. HILT, a safe approach improving blood flow, was given for 3 days, targeting the painful area in the face. The patient experienced improved tissue oxygen supply and pain relief. The follow-up visit at 4 weeks showed sustained relief, enhanced jaw movement and no side effects. Although promising, further research is needed to confirm HILT's effectiveness for trigeminal neuralgia on a larger scale.

Risk factors for surgical site infection in advanced neuromodulation pain procedures: a retrospective study.

Aim: To assess the effects of diabetes mellitus (DM) and related variables on surgical site infection (SSI) risk in neuromodulation. Methods: This retrospective study followed patients who underwent neuromodulation procedures for at least 9 months to identify postoperative infections. Demographics, clinical characteristics and surgical outcomes were compared. Results: Of 195 cases included, 5 (2.6%) resulted in SSIs. Median HbA1c was significantly higher for the cases with SSIs (8.2 vs 5.6%; p = 0.0044). The rate of SSI was significantly higher among patients with DM (17.9 vs 0%; p = 0.0005), HbA1c≥7% (37.5 vs 0%; p = 0.0009), and perioperative glucose ≥200 mg/dl (40 vs 2.3%; p = 0.0101). Conclusion: DM, elevated HbA1c and perioperative hyperglycemia may all contribute to increased risk of SSIs with neuromodulation procedures.

Infections are feared complications of surgery. It is important to identify factors that increase the risk of infection to prevent these complications. This study looked at the effects of diabetes and high blood sugar on the risk of infection associated with pain procedures. The researchers followed patients who had these procedures and looked for any infections that occurred afterward. They found that patients with diabetes and high blood sugar levels before surgery were more likely to develop infections after these procedures. More research can help establish blood sugar targets so that physicians can better manage this risk for their patients.

Clinical practice guidelines for the management of patients with complex regional pain syndrome: a systematic appraisal using the AGREE II instrument.

Aim: Complex regional pain syndrome (CRPS) is a debilitating, painful condition of limbs that often arises after an injury and is associated with significant morbidity. Materials & methods: The Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument, used to assess the quality of clinical practice guidelines (CPGs), was used to evaluate seven CRPS management guideline. Results: Out of the seven CPGs evaluated using the AGREE II instrument, only one from Royal College of Physicians was found to have high-quality consensus guidelines for diagnosis and management of CRPS. Conclusion: Future CPGs should be backed by systematic literature searches, focus on guidelines clinical translation into clinical practice and applicability to the desired patient population.

Radiation dose exposure for lumbar spine epidural steroid injections: a comparison of conventional fluoroscopy data and CT fluoroscopy techniques.

OBJECTIVE: The purpose of this article is to compare the radiation dose of conventional fluoroscopy-guided lumbar epidural steroid injections (ESIs) and CT fluoroscopy (CTF)-guided lumbar ESI using both clinical data and anthropomorphic phantoms. MATERIALS AND METHODS: We performed a retrospective review of dose parameters for 14 conventional fluoroscopy ESI procedures performed by one proceduralist and 42 CTF-guided ESIs performed by three proceduralists (14 each). By use of imaging techniques similar to those for our clinical cohorts, a commercially available anthropomorphic male phantom with metal oxide semiconductor field effect transistor detectors was scanned to obtain absorbed organ doses for conventional fluoroscopy-guided and CTF-guided ESIs. Effective dose (ED) was calculated from measured organ doses. RESULTS: The mean conventional fluoroscopy time for ESI was 37 seconds, and the mean procedural CTF time was 4.7 seconds. Calculated ED for conventional fluoroscopy was 0.85 mSv compared with 0.45 mSv for CTF. The greatest contribution to the radiation dose from CTF-guided ESI came from the planning lumbar spine CT scan, which had an ED of 2.90 mSv when z-axis ranged from L2 to S1. This resulted in a total ED for CTF-guided ESI (lumbar spine CT scan plus CTF) of 3.35 mSv. CONCLUSION: The ED for the CTF-guided ESI was almost half that of conventional fluoroscopy because of the shorter fluoroscopy time. However, the overall radiation dose for CTF-guided ESIs can be up to four times higher when a full diagnostic lumbar CT scan is performed as part of the procedure. Radiation dose reduction for CTF-guided ESI is best achieved by minimizing the dose from the preliminary planning lumbar spine CT scan.

Kerma area product method for effective dose estimation during lumbar epidural steroid injection procedures: phantom study.

OBJECTIVE: The purpose of this study was to derive from the kerma area product the dose conversion coefficient for estimating the effective dose for lumbar epidural steroid injection procedures. MATERIALS AND METHODS: A mobile fluoroscopy system was used for fluoroscopic imaging guidance of lumbar epidural steroid injection procedures. For acquisition of organ dose measurements, 20 diagnostic metal oxide semiconductor field effect transistor detectors were placed at each organ in an anthropomorphic phantom of a man, and these detectors were attached to four mobile metal oxide semiconductor field effect transistor wireless bias supplies to obtain the organ dose readings. The kerma area product was recorded from the system console and independently validated with an ion chamber and therapeutic x-ray film. Fluoroscopy was performed on the phantom for 10 minutes for acquisition of the dose rate for each organ, and the average clinical procedure time was multiplied by each organ dose rate for acquisition of individual organ doses. The effective dose was computed by summing the product of each organ dose and the corresponding tissue weighting factor from International Commission on Radiologic Protection publication 60. RESULTS: The effective dose was computed as 0.93 mSv for an average lumbar epidural steroid injection procedure (fluoroscopic time, 40.7 seconds). The corresponding kerma area product was 2.80 Gy.cm(2). The dose conversion coefficient was derived as 0.33 mSv/(Gy.cm(2)). CONCLUSION: The effective dose for lumbar epidural steroid injection can be easily estimated by multiplying the derived dose conversion coefficient by the console-displayed kerma area product.

Collateral meridian acupressure therapy effectively relieves postregional anesthesia/analgesia backache.

Epidural and spinal aesthesia may cause backache. In fact, the overall incidence of postneuraxial block backache is 9% to 50% and the incidence of back pain on the third postoperative day ranges from 5.91% to 22% after spinal anesthesia. Five patients suffering from postneuraxial block backache after regional anesthesia or analgesia are reported. Despite administering conventional treatment modalities including bed rest, cold/warm packing, physical therapy, and medications with nonsteroidal anti-inflammatory drugs (NSAIDs), strong analgesics, and opioids, the backache persisted and disturbed the patients' daily life. Surprisingly, utilization of a new acupressure technique, collateral meridian acupressure therapy (CMAT), relieved the backache dramatically.

Sacroiliac joint pain following iliac-bone marrow aspiration and biopsy: a cohort study.

Background: Sacroiliac joint (SIJ) pain is a common source of lower back pain; the factors associated have not been studied in cancer patients. Observing patients with bone marrow aspiration and biopsy (BMAB) who subsequently developed SIJ-pain led to this investigation. Aim: To investigate this possible relationship. Methods: A cohort study of cancer patients diagnosed with SIJ pain. The association of BMAB with SIJ pain was evaluated, as were variables that differed between the groups. Results: The prevalence of SIJ pain was 4.95% (231/4669). Among 231 patients with SIJ pain, 34% (78/231) did not have prior history of lower back pain and had undergone BMAB prior to their diagnosis of SIJ pain. A statistically significant association between BMAB-SIJ-pain was found (p < 0.01). Conclusion: We found linear correlation between BMAB and subsequent SIJ pain.

Topical amitriptyline versus lidocaine in the treatment of neuropathic pain.

OBJECTIVE: Oral amitriptyline, a tricyclic antidepressant, is effective for treating neuropathic pain. We conducted a double-blind, randomized, placebo-controlled crossover study to evaluate the efficacy of topical 5% amitriptyline and 5% lidocaine in treating patients with neuropathic pain. METHODS: Thirty-five patients with postsurgical neuropathic pain, postherpetic neuralgia, or diabetic neuropathy with allodynia or hyperalgesia were assigned to receive 3 topical creams (5% amitriptyline, 5% lidocaine, or placebo) in random sequence. The primary outcome measure was change in pain intensity (baseline vs. posttreatment average pain) using a 0 to 100 mm Visual Analog Scale. Secondary outcome measures included the McGill Pain Questionnaire, requirement for rescue medication, and patient satisfaction. Primary statistical comparisons were made with paired t tests or signed-rank tests. RESULTS: A reduction in pain intensity was observed with topical lidocaine (P<0.05). No significant change in pain intensity was found with topical amitriptyline or placebo. In pairwise comparison of treatments, topical lidocaine and placebo each reduced pain more than topical amitriptyline (P<0.05). DISCUSSION: This randomized, placebo-controlled crossover study examining topical 5% amitriptyline and 5% lidocaine in the treatment of neuropathic pain showed that topical lidocaine reduced pain intensity but the clinical improvement is minimal and that topical 5% amitriptyline was not effective.

Shoulder tip pain after laparoscopic surgery analgesia by collateral meridian acupressure (shiatsu) therapy: a report of 2 cases.

OBJECTIVES: This article describes 2 cases of collateral meridian acupressure (shiatsu) therapy (CMAT) for treatment of shoulder tip pain after laparoscopic cholecystectomy (LC). Both cases showed marked pain relief with reduction of skin temperature (1 degrees C) of the affected shoulder after CMAT. CLINICAL FEATURES: A 32- and a 53-year-old female presented with right shoulder tip pain after LC surgery. The repeated dose of intravenous ketorolac 30 mg and meperidine 50 mg did not improve the pain. Because of persistent pain and episodes of nausea and vomiting after intravenous nonsteroidal anti-inflammatory drugs and opioid medications, patients refused to take more analgesics, and we were consulted for pain management. INTERVENTION AND OUTCOME: After informed written consent obtained, CMAT was performed using acupoints located on the contralateral (left) kidney meridian to treat affected (right) shoulder pain. Postoperatively, patients' pain intensity was measured using a numeric pain scale. The infrared thermography of shoulder tip was obtained before and after the CMAT. Both patients reported immediate pain relief after the CMAT, with pain scores decreased from 5 to 1 of 10 and 5 to 0 of 10, respectively. Moreover, the local skin temperature of affected shoulders were significantly decreased in both patients after the CMAT. Similarly, the temperature difference between patients' affected and nonpainful shoulders were also significant after the CMAT. CONCLUSION: The results of these 2 cases suggest that the CMAT may be effective in reducing patients' post-LC shoulder tip pain without medication. An associated reduction of skin temperature of the painful shoulder with CMAT warrants further investigation.

Can oliceridine (TRV130), an ideal novel µ receptor G protein pathway selective (µ-GPS) modulator, provide analgesia without opioid-related adverse reactions?

All drugs have both favorable therapeutic and untoward adverse effects. Conventional opioid analgesics possess both analgesia and adverse reactions, such as nausea, vomiting, and respiratory depression. The opioid ligand binds to µ opioid receptor and non-selectively activates two intracellular signaling pathways: the G protein pathway induce analgesia, while the ß-arrestin pathway is responsible for the opioid-related adverse reactions. An ideal opioid should activate the G protein pathway while deactivating the ß-arrestin pathway. Oliceridine (TRV130) has a novel characteristic mechanism on the action of the µ receptor G protein pathway selective (µ-GPS) modulation. Even though adverse reactions (ADRs) are significantly attenuated, while the analgesic effect is augmented, the some residual ADRs persist. Consequently, a G protein biased µ opioid ligand, oliceridine, improves the therapeutic index owing to increased analgesia with decreased adverse events. This review article provides a brief history, mechanism of action, pharmacokinetics, pharmacodynamics, and ADRs of oliceridine.

Epidural clonidine for postoperative pain after total knee arthroplasty: a dose-response study.

BACKGROUND: Combinations of epidural clonidine, local anesthetics, and opioids have improved postoperative analgesia after total knee arthroplasty. In this study we sought to determine the optimal epidural bolus dose of clonidine, which provides the best analgesia and fewest side effects. METHODS: Eighty ASA I-III patients, who underwent total knee arthroplasty were randomly assigned to one of four groups of 20 patients each. Identical epidural anesthesia procedures were used for all groups. After surgery, groups C0, C1, C2, and C4 received patient-controlled epidural analgesia (PCEA) with clonidine (0, 1.0, 2.0, or 4.0 mug/mL, respectively) and morphine (0.1 mg/mL) in 0.2% ropivacaine. The analgesia effect was estimated by PCEA consumption volume and visual analog pain scale at rest and with movement at 1, 2, 4, 12, 24, 48, and 72 h after surgery. Systolic blood pressure, heart rate, sedation, and sensory and motor blockade were also recorded for 72 h after surgery. RESULTS: The PCEA consumption volume for groups C0, C1, C2, and C4 were 71.8 +/- 19.5 mL, 49.6 +/- 12.3 mL, 48.1 +/- 9.3 mL, and 39.4 +/- 9.0 mL, respectively. The clonidine groups experienced less postoperative pain (P = 0.002). In the C4 group, four patients had prolonged sensory blockade and one patient had both severe sedation and prolonged sensory motor blockade. No significant statistical difference in analgesic consumption (P = 0.78) and pain intensity (P = 0.66) between groups C1 and C2 were noted. CONCLUSIONS: The optimal amount of epidural clonidine in a solution of morphine and ropivacaine for postoperative pain management is 1.0 microg/mL.

Premedication with intravenous low-dose ketamine suppresses fentanyl-induced cough.

STUDY OBJECTIVE: To evaluate the effect of low-dose ketamine on fentanyl-induced cough. DESIGN: Prospective, randomized, double-blind, placebo-controlled clinical trial. SETTING: Medical center hospital. PATIENTS: 360 ASA physical status I-II patients aged 18 to 65 years, weighing between 40 and 80 kg, and scheduled for elective surgery during general anesthesia. INTERVENTIONS AND MEASUREMENTS: Patients were randomly assigned to receive either ketamine 0.15 mg/kg or placebo (equal volume of 0.9% saline) given intravenously over 10 seconds, one minute before administration of fentanyl (1.5 microg/kg IV, injected within 5 seconds), during induction of general anesthesia. Any episode of cough was classified as coughing and the onset time of cough (the time of the first episode of cough) was observed for one minute after fentanyl administration by a blinded observer. Severity of coughing was graded based on the number of episodes of coughing (mild, 1-2; moderate, 3-5; and severe, >5). Blood pressure, heart rate, and pulse oximetry oxygen saturation (Spo2) were recorded before giving ketamine or 0.9% saline and 1 minute after fentanyl injections. MAIN RESULTS: After the intravenous injection of fentanyl bolus, patients in the placebo group showed significantly higher frequency cough than those in the ketamine pretreatment group (21.6% vs 7.2%, P<0.05), and onset time of the ketamine group was significantly longer than that of the control group (20+/-8 vs 15+/-10 seconds, P<0.01). However, no difference in cough severity was observed between the two groups. CONCLUSION: Low-dose ketamine (0.15 mg/kg IV) effectively reduces fentanyl-induced cough and delays the onset time of cough.

Iliocostalis Thoracis-Lumborum Myofascial Pain: Reviewing a Subgroup of a Prospective, Randomized, Blinded Trial. A Challenging Diagnosis with Clinical Implications.

BACKGROUND: Pain of myofascial origin is a well-recognized pathology characterized by the presence of two components: referred pain; which is often distant from its source and specific to each muscle, and the trigger point, a localized hyperirritable band present in the affected muscle and able to reproduce the referred pain when stimulated. Myofascial pain (MP) commonly coexists in patients with acute or chronic pain of other etiologies. The uniqueness of the clinical presentation of some MPs and the lack of training of most specialties represent a clinical challenge. Thus, many patients with MPS receive less than optimal management of this condition. OBJECTIVE: Pain at the anterior torso, originating at the posterior torso, can mimic common pathologies that correlate with the same anatomical area such as cardiac and intra-abdominal conditions. These clinical characteristics could be caused by MP of the iliocostalis thoracis-lumborum (ITL) muscle. However, this entity has not been well addressed in the medical literature. In this report we characterize the manifestations, diagnosis, and clinical implications of ITL MP. STUDY DESIGN: Observational assessment. SETTING: Two university-based academic emergency medicine departments (ED) in an urban setting in the United States. METHODS: A convenience sample of 43 patients who presented to the ED with pain at the anterior aspect of the torso (chest, abdomen, or pelvis) and clinical evidence of MP originated in the ITL muscle.Of a clinical trial of patients with MP, we describe a subgroup of patients with MP of the ITL which was clinically evident by the presence of a trigger point (TP) in its ability to reproduce the referred pain present at the anterior aspect of the torso. Patients received a TP injection. In this trial we intend to demonstrate that TP injections using particulate steroids mixed with a local are no more effective than saline alone to treat MP. The primary outcome was pain control (decrease in intensity of 50% or more below baseline numeric pain rating). A follow-up telephone interview was performed by third-party abstractors. RESULTS: Forty-three patients presented with pain of the anterior torso and ipsilateral back, both correlating with the level of the TP of the ITL muscle. The pain had been present from 2 days to 7 years. The most common locations of pain were the right-lower quadrant and the left side of the chest. In many of them a pattern of missed diagnosis was evident despite extensive workups and consultations. Only 17 patients were able to identify the precipitating event; the most common was coughing. Two weeks after TP injection, all patients still had satisfactory pain control. After treatment, no missed pathology or returns to the ED were reported. LIMITATIONS: This descriptive portion of the ongoing study does not affect the integrity of the trial itself but could be subject to the introduction of subject selection and selective reporting bias. Similarly, this convenience sample does not establish the incidence of this pathology and challenges the external validity to other clinical settings. CONCLUSIONS: Anterior torso pain often resulted in extensive workups before ITL myofascial pain was diagnosed. TP injections were diagnostic and therapeutic of ITL myofascial pain.