Percentage Pain Reduction Research Articles

A single-center real-world review of 10 kHz high-frequency spinal cord stimulation outcomes for treatment of chronic pain

ObjectiveTo compare pragmatic real-world 10-kHz high-frequency spinal cord stimulation (HF-SCS) outcomes at a single academic center to the industry-sponsored SENZA-RCT and Stauss et al. study. MethodsThis single-center retrospective study included patients with refractory back or limb pain trialed and/or permanently implanted with the Nevro HF-SCS system from 2016 to 2021. Demographic and outcome data were obtained from the electronic medical record (EMR) and real-world global database maintained by Nevro Corp. Data obtained from the global database were confirmed using the EMR. Main outcome measures included positive responder status (≥50% patient-reported percentage pain reduction (PRPPR)), improvement in function, improvement in sleep, and reduction in pain medication usage. Comparison groups included patient outcomes from the SENZA-RCT and Stauss et al. study. ResultsPatients (N = 147) trialed with HF-SCS were reviewed, with data available for 137. Positive trialed patient responder rate (≥50% PRPPR) was 77% (106/137, 95CI 70–84%) vs. 87% (1393/1607, 95CI 85–89%) Stauss et al. vs. 93% (90/97, 95CI 88–98%) SENZA-RCT HF-SCS. At the last available follow-up, positive implanted patient responder rate was 73% (58/80, 95CI 63–82%) vs. 78% (254/326, 95CI 73–82%) Stauss et al. vs. 79% (71/90, 95CI 70–87%) SENZA-RCT HF-SCS. Sixty-seven percent (59/88, 95CI 57–77%) reported improved function vs. 72% (787/1088, 95CI 70–75%) Stauss et al.; 45% (31/69, 95CI 33–57%) reported improved sleep vs. 68% (693/1020, 95CI 65–71%) Stauss et al. and 16% (9/56, 95CI 6–26%) reported decrease in medication use vs. 32% (342/1070, 95CI 29–35%) Stauss et al. ConclusionPatient responder rates in this retrospective pragmatic real-world study of HF-SCS are consistent with previous industry-sponsored studies. However, improvements in quality-of-life measures and reduction in medication usage were not as robust as reported in industry-sponsored studies. The findings of this non-industry-sponsored, independent study of HF-SCS complement those of previously published studies by reporting patient outcomes collected in the absence of industry sponsorship.

Discrepancy Between Reported and Calculated Pain Reduction in Patients With Spinal Cord Stimulation Therapy and Lack of Agreement Between Patient Satisfaction and Degree of Pain Relief

ObjectivesThis study aimed to determine agreement between reported percentage pain reduction (RPPR) and calculated percentage pain reduction (CPPR) in patients with percutaneous spinal cord stimulation (SCS) implants, and to correlate RPPR and CPPR with patient satisfaction. We also sought to determine which patient-reported outcome measures are most improved in patients with SCS. Materials and MethodsFifty patients with percutaneous spinal cord stimulator implants with a mean follow-up of 51.1 months were interviewed and surveyed to assess their pain level, impression of degree of pain relief, satisfaction with the therapy, and desire to have the device again. Baseline pain level was obtained from their preimplant records. ResultsOverall, RPPR was found to be 53.3%, whereas CPPR was 44.4%. Of all patients, 21 reported <50% pain reduction; however, most of these (12/21, 57%) were satisfied with the outcome of therapy. In terms of individual improvement in outcomes, activities of daily life was the most improved measure at 82%, followed by mood, sleep, medication use, and health care utilization at 74%, 62%, 50%, and 48%, respectively. ConclusionsRPPR appears to be a complex outcome measure that may not agree with CPPR. Overall RPPR is greater than the CPPR. On the basis of our data, these independently valid measures should not be used interchangeably. A 50% pain reduction threshold is not a requisite for patient satisfaction and desire to have the device again. Activities of daily living was the most improved measure in this cohort, followed by mood, sleep, medication usage, and decrease in health care utilization.

Peripheral Nerve Stimulation in Chronic Knee Pain: A Case Series.

Introduction Chronic knee pain is increasing in prevalence and is associated with substantial limitations in functional mobility. Peripheral nerve stimulation (PNS) has been increasingly used to treat various chronic pain conditions. However, there is a paucity of research exploring the potential therapeutic benefit of PNS for chronic knee pain. Methods This research is a retrospective case series of all patients who received PNS for the treatment of chronic knee pain performed at a single-center academic medical institution between March 2021 and June 2022. The primary outcome was percent pain reduction six months after implantation. Outcome data was obtained via chart review and phone calls to patients. Secondary outcomes included percent pain reduction two weeks and two months after implantation and adverse medical events related to the procedure and nerve stimulation. Results Fourteen individual patients received PNS for chronic knee pain during the study period. Three of these patients received bilateral PNS for a total of 17 cases. The mean percent pain reduction six months after implantation was 52% (SD=28.2) (N=12). A total of 75.0% of participants (9/12) reported≥50% reductions in pain six months after implantation. No adverse events were reported relating to the implantation procedure and/or nerve stimulation. Conclusion PNS is a safe and efficacious treatment modality for chronic knee pain with demonstrated long-term benefit. Further research should clarify patient factors associated with improved treatment response.

Poster 374: Patient knowledge of and willingness to pay for platelet-rich plasma injections: A prospective survey study on orthopedic sports medicine patients

Objectives: The efficacy of platelet-rich plasma (PRP) injections for sports-related injuries is a hotly- debated topic. PRP is a cash-pay procedure that is not covered by insurance, and it is actively advertised for a number of different indications, some without supporting evidence. Yet, an increasing number of patients are asking their physicians for PRP injections. The aim of this study is to better understand patients’ knowledge of PRP and willingness to pay out of pocket. Methods: This ongoing Institutional Review Board-approved prospective study included patients presenting with a new chief complaint at a sports medicine orthopedic office in a large urban academic health system. Patients completed an anonymous survey prior to evaluation by an orthopedic surgeon. The survey collected demographic information, clinical information, knowledge of PRP, willingness to pay for PRP based on expected percentage pain reduction, and motivators behind willingness to pay. Two cohorts included: 1) patients who had heard of PRP and 2) patients who had not. The latter group was given a short educational excerpt on PRP. Two-tailed Mann-Whitney U and Kruskal-Wallis tests evaluated pain scores and willingness to pay for PRP between the cohorts. Spearman rank correlation tests evaluated correlations between household income and willingness to pay. Results: To date, we have enrolled 32 patients of which 37.5% had previous orthopedic surgery, 43.75% had seen another medical provider for their current symptoms and 37.5% had previously heard of PRP. Patients who had heard of PRP (versus those that had not) reported lower median pain scores (median 4.75 versus 5.0 out of 10), the same hindrance of daily activities (median 3.0 out of 5), and longer duration of symptoms (median 5.0 months versus 1.0 month), although not statistically significant. Patients were willing to pay more for a greater anticipated reduction in pain: median of $50, $250, and $500 for 25%, 50% and 100% reduction in pain, respectively (Table 1) (p&lt;0.05). Patients who had heard of PRP were willing to pay more for PRP (median $500 versus $200; Table 1); this was not statistically significant. There was no correlation between patients’ income and willingness to pay. Finally, regarding willingness to pay for a given percent reduction in pain, patients reported their top three motivators to be symptoms affecting their day-to-day life, desire to try non-surgical interventions, and desire to return to normal activity (Table 1). For patients who had not heard of PRP, after being informed of PRP these patients reported physician trust as the greatest motivator behind their willingness to pay (Table 1). Conclusions: This ongoing study demonstrates the correlation between willingness to pay and perceived effectiveness of PRP while also noting motivators to pay. Moreover, we were also able to demonstrate some differences between patients who had heard of PRP versus those that had not. These data may be further refined with ongoing enrollment and will provide important insights into patients’ knowledge and how this impacts decision-making in the context of PRP injections. [Table: see text]

Efficacy of IV Valproic Acid and Oral Valproic Acid Tapers for the Treatment of Pediatric Headaches in the Emergency Department.

Pediatric headaches, including migraine, are a common reason for emergency department (ED) presentation. IV valproic acid (VPA) followed by oral VPA tapers are often used to abort pediatric headache and reduce recurrence, though limited data exist regarding this approach. This study evaluated the effectiveness of IV VPA and oral VPA tapers for the treatment of acute pediatric headaches in the ED in preventing return encounters. This is a retrospective cohort study of patients aged 5-21 years presenting to a tertiary-care pediatric ED from 2010 to 2016 who received IV VPA for headache or migraine. Primary outcomes were ED disposition, percent pain reduction (initial vs 2-hour patient-reported pain score [10-point scale]), and return for acute headache treatment within 1 month. A total of 486 ED encounters were included with a median patient age of 15 years; most of them were females (76%, 369/486). Of available pain scores within 2 hours of IV VPA administration, 41% (173/425) had ≥50% pain reduction. Fifty-two percent (254/486) were discharged without additional treatment, 14% (69/486) were discharged after additional treatment, and 33% (163/486) were admitted to the hospital. Initial pain score, number of preceding home treatments, and number of preceding ED treatments were not associated with ED disposition. Oral VPA tapers were prescribed in 39% (94/253) of encounters when the patient was discharged after IV VPA. Oral VPA tapers produced a transient decrease in recurrence at 72 hours, which was no longer present at 1 week nor 1 month. There was no difference in the time to recurrence or total number of return visits within 1 month. IV VPA was efficacious in treating pediatric headaches evaluated in the ED, with nearly two-thirds of patients discharged home after administration. Oral VPA tapers did not reduce total headache recurrence nor time to recurrence. Given the limited benefit of oral VPA tapers, this practice should be re-examined. This study provides Class IV evidence that for children with headache seen in the ED, IV VPA reduces head pain and Class III evidence that following this with an oral VPA taper is of no benefit.

ID: 220996 Use of Remote Physiological Monitoring to Track Patient Well-Being During the SCS Trial

Spinal cord stimulation (SCS) for chronic intractable back pain is often prescribed after a successful trial period in which a patient demonstrates a sufficient reduction in pain intensity. Currently, the decision of whether to recommend a patient for permanent implant relies upon one or two snapshots from a subjective rating scale (e.g., Numerical Rating Scale, Percent Pain Reduction, Visual Analog Scale). However, subjective rating scales are subject to variability from un-controlled external sources [1]. Additionally, chronic pain is a complex multi-dimensional struggle, and resolution of symptoms may also be manifest via improvements to mental, physical, and social well-being [2]. This research demonstrates proof-of-concept for a remote monitoring system to track and report patient well-being using objective physiologic data collected before, during, and after the SCS trial period.

The Discrepancy and Agreement between Patient-Reported Percentage Pain Reduction and Calculated Percentage Pain Reduction in Chronic Pain Patients

Two derivatives of the numeric rating scale (NRS) and visual analog scale (VAS), namely patient-reported percentage pain reduction (PRPPR) and calculated percentage pain reduction (CPPR), are commonly used when evaluating pain reduction. A small number of studies have attempted to assess the agreement between PRPPR and CPPR. However, they have been limited in their scope by a focus on specific types of pain, or by their focus on specific treatment modalities. As far as the authors of this article are aware, this is the first study to assess the agreement between PRPPR and CPPR in chronic pain patients, as well as the first to assess how the duration of treatment affects the correlations between PRPPR and CPPR. The aim of this retrospective analysis was to determine whether the duration of treatment affects CPPR and PRPPR, and the discrepancy and agreement between the two. Additionally, the study assessed whether individual treatment modalities, or the lack there of, impacted the discrepancy and correlation between PRPPR and CPPR. The mean PRPPR and CPPR for the entire patient population were 59.98 and 40.71, respectively. The mean discrepancy between the two parameters was 19.27. The agreement between PRPPR and CPPR, as measured by the concordance correlation coefficient, was 0.984 (95% C.I., 0.982-0.986).

PP110 An External Combined Occipital And Trigeminal Neurostimulation Device For Migraine Treatment

IntroductionMigraine is a multifactorial pathology that affects 12 percent of the world’s population. Relivion® MG (Neurolief Inc., USA) is a non-invasive self-administered device for external combined occipital and trigeminal nerve stimulation that has been recently approved for marketing in Europe and the USA. The objective of this study was to conduct an early assessment of the efficacy and safety of Relivion for the treatment of migraine episodes.MethodsRelivion was identified by the early awareness and alert system, SINTESIS- nuevas tecnologías, of the Agencia de Evaluación de Tecnologías Sanitarias at the Instituto de Salud Carlos III. An early assessment of the technology was conducted by reviewing relevant clinical studies published to 29 September 2021. The literature was identified by searching PubMed, Embase, the International Clinical Trials Registry Platform, ClinicalTrials.gov, and the Cochrane Library.ResultsTwo randomized, sham-controlled double-blind trials were found. They assessed side effects and pain relief, response rate, and pain freedom two hours after treatment. One study included 55 patients and the other (the RIME study) included 131 patients. The rate of pain relief two hours after treatment ranged from 60 to 76 percent in the treatment group and from 31 to 37 percent in the control group (p&lt;0.01). The response rate, defined as at least 50 percent pain reduction two hours after treatment, was significantly higher in the treatment group (67 to 70% versus 32 to 42%). The percentage of patients free of pain two hours after treatment ranged from 42 to 46 percent in the treatment group, compared with 11 to 12 percent in the control group (p&lt;0.0001). No notable adverse events were recorded.ConclusionsPreliminary results indicated that Relivion effectively and safely relieves or eliminates acute migraine pain. However, more comparative studies are needed. The use of Relivion could improve the control of symptoms and improve quality of life in patients with migraine.

IF IM in a crisis: Intranasal fentanyl versus intravenous morphine in adult vaso-occlusive crisis

ImportanceStudies have demonstrated the benefits of INF in reducing pain scores in pediatric patients with VOC due to sickle cell disease (SCD) and in adult patients with chronic pain conditions other than VOC, such as cancer. However, there is limited literature that exists describing the role of INF in adult patients with VOC due to SCD. Current literature demonstrates that the use of IV morphine for VOC patients leads to reduced pain. Therefore, comparing the use of INF with IV morphine will establish the degree of effectiveness of INF for VOC patients. ObjectiveTo determine if intranasal fentanyl is equally as effective as IV morphine for treating VOC-associated pain in adult SCD patients. DesignThis study was a retrospective non-inferiority cohort study. Electronic health records were utilized to identify eligible patients between January 1, 2021 to February 28, 2022. Patients who received INF as an initial opioid upon presentation to the ED where allocated to the intervention group. On the other hand, individuals who received IV morphine as an initial opioid upon presentation to the ED were allocated to the control group. SettingA multi-site healthcare system containing five hospitals. ParticipantsPatients 18 years of age or older, admitted to the ED with VOC due to SCD, and received INF or IV morphine as an initial opioid upon presentation to the ED. Main outcomes and measuresThe primary outcome was to evaluate the percent change in pain reduction after the initial dose of opiate between groups. Secondary outcomes include time to first rescue medication, total morphine milligram equivalent (MME) of IV opiates, hypotension, bradycardia, respiratory distress requiring opiate reversal within 6 h post- study drug administration, readmission within 48 h, and ED disposition. ResultsA total of 230 patients were reviewed within the study period, 95 subjects met inclusion criteria, 31 subjects were included in the INF arm and 64 subjects in the IV morphine arm. The primary outcome showed an average percent pain reduction of 17.25% in the INF arm and 17.15% in the IV morphine arm. The point estimate difference was 0.1% (95% CI −9.3%–9.5%; non-inferiority (p < 0.0001). The median dose of IV opiates was 8 MME in the INF group, and 6 MME in the IV morphine group (p = 0.0268). The time from study drug to first rescue medication administration was 22.4 min and 27.3 min in the INF and IV morphine groups, respectively (p = 0.2231). There was no incidence of hypotension or respiratory distress requiring opiate reversal in either arm. Bradycardia occurred in 12.9% and 7.7% (p = 0.2042), readmission rates within 48 h due to VOC was 6.5% and 20.9% (p = 0.0553), and discharge from the ED to home was 16% and 66% (p = 0.0196) in INF and IV morphine arms, respectively. ConclusionINF provided similar pain reduction compared to IV morphine in the treatment of adults with VOC presenting to the ED. IV morphine arm showed a statistically significant difference in discharge to home from the ED, however there was a trend in readmission within 48 h. The study showed no significant difference in hypotension, respiratory distress, or bradycardia between the groups. The INF group had no significant impact on time to drug administration compared to IV morphine, however it was within 1 h of patient presentation which complies with American Society of Hematology (ASH) guidelines. In conclusion, our study showed that INF was non-inferior when compared to IV morphine in reducing pain scores after drug administration. Therefore, INF is an effective alternative to IV morphine for pain management in adults presenting to the ED for VOC particularly in those with limited IV access.

Caudal Pulsed Radiofrequency for Distal Symmetrical Polyneuropathy

Background: Numbness, tingling, discomfort, and/or weakness in the toes are symptoms of distal symmetrical polyneuropathy (DSP), which proceeds in a stocking-glove pattern proximally. There is still no particular therapy available. Objective: CPRF (caudal pulsed radiofrequency) is used to treat people who have sensory symptoms. Study Design: This is a prospective study at Alsdr teaching hospital in Iraq-Basra. Methods: CPRF, Boston Scientific G4™ RF Generator, Twenty-four subjects with DSP who were stimulated reported sensory complaints that did not respond to therapy. Under fluoroscopy at S2-3 level, inserted a caudal 21 gauge, 20-mm active tip RF cannula into the epidural space through the sacral hiatus. After the sensory and motor RF, give PRF at 5 Hz for 600 seconds at 45 V. Within the first week of the operation, the impact of activation was examined using a numeric rating scale, which was repeated every three months for the next three months. Patient satisfaction levels were assessed three months following treatment; patients who scored "7" (very good) or "6" (good) on the treatment satisfaction scale were rated fulfilled. Results: Neuropathic pain was effectively diminished after four visits (P&lt; 0.001, test one-factor analysis). Furthermore, three months after receiving CPRF, more than half of the patients had an effective reaction (≥60 percent pain reduction) and were comfortable with the therapeutic outcomes. Limitations: The research included a small number of patients and was only for a brief time. Conclusion: CPRF is a safer, less expensive, and more effective way to treat symptoms.

Music alleviates pain perception in depression mouse models by promoting the release of glutamate in the hippocampus of mice to act on GRIK5

Objective: To explore the effect of music in pain perception and the molecular mechanism. Methods: Mice were separated to control, music, music + inhibitor, and saline group. Percentage pain reduction of mice in each group was determined. The contents of 5-HT, Glu, and NE in cerebrospinal fluid of mice in the four groups were determined by HPLC. FISH was used to analyze the distribution characteristics of GRIK5 in hippocampal tissues. The protein expressions of GRIK5, NMDA 1, and TRPC1 in the hippocampal tissues were determined via western blot. Results: Mice exposed to music showed a higher percentage of pain reduction compared to model animals, while injection of GRIK5 inhibitor weakened the effect of music. It increased the contents of 5-HT, Glu, and NE in mouse models of depression. The fluorescence signal in music group was significantly stronger than saline group. Music remarkably increased the expression of GRIK5, DLG4, NMDA 1, and TRPC1 proteins when compared with saline group. Conclusion: Music promoted the secretion of Glu. The glutaminergic pathway sensed Glu, subsequently activated GRIK5, DLG4, and NMDA 1 proteins to excite dopaminergic neurons, and finally promoted the production of 5-HT.

Multicenter Retrospective Review of Safety and Efficacy of a Novel Minimally Invasive Lumbar Interspinous Fusion Device.

IntroductionSeveral treatment options exist for those with spinal stenosis, as well as degenerative changes. This series evaluates the use of an interspinous fixation (ISF) device as performed by interventional pain physicians.MethodsThis is a retrospective analysis identifying 32 patients with the diagnosis of lumbar degenerative disc disease with secondary diagnosis of lumbar spinal stenosis being treated with ISF with Aurora Spine Zip Interspinous Spacer. Serious adverse events, specifically nerve injury, hematoma, infection, and death, were analyzed quantitatively for reported complications within 90 days from the procedure. In addition, VAS was analyzed for patient reported outcomes.ResultsAdverse event rate was 0% with no incidences of reoperation, or device removal. Estimated blood loss was recorded as less than 50 cc for all patients. The preoperative pain assessment demonstrated an average pain score of 8.1 and a postoperative pain score of 2.65 equating to a percentage pain reduction of 67%.ConclusionThis case series demonstrates the success and safety of ISF being performed by interventional pain physicians in an outpatient setting. It is a valuable tool in the treatment of moderate to severe lumbar spinal stenosis and degenerative disc disease that has decreased morbidity and significant efficacy.

175. Discrepancy in patient-reported pain using the numeric pain scale and a percentage change to quantify treatment effectiveness after pain injections

BACKGROUND CONTEXT The Numeric Pain Rating Scale (NRPS) may not match with patient-reported percentage pain reduction (PRPPP) at 1 to 4 weeks follow-up, as these patients may be reporting a higher estimated percentage improvement compared to the value calculated from their pain scores PURPOSE The objective of this study was to calculate patients’ pain level prior to and after various fluoroscopic injections using the NRPS. The calculated percent change was then compared to a patient-reported percent change. Our hypothesis was that there is a statistically significant difference in calculated NRPS vs patient-reported percentage change. The discrepancy between calculated percent change compared to the patient reported percent change was studied since accurately assessing patient reported pain impacts clinical management of patients with chronic musculoskeletal pain STUDY DESIGN/SETTING This is a retrospective study using patient reported pre- and postinjection NRPS value were used to calculate a percent change in overall pain ([pre-post)/post] x 100). The calculated percent change was rounded to the nearest degree. This calculated percent change in pain was compared to the patient reported percent change (calculated % - reported %). An overall average change in calculated minus reported percent change was obtained for all the injections. A t-test was also performed to determine if there was a significant difference between the calculated percent change and the reported percent change. PATIENT SAMPLE A total of 135 patients were included. OUTCOME MEASURES The patient reported pre- and postinjection NRPS value were used to calculate a percent change in overall pain ([pre-post)/post] x 100). This calculated percent change in pain was compared to the patient reported percent change (calculated % - reported %). METHODS A total of 135 patients who underwent spinal corticosteroid injections under fluoroscopic-guidance between 2015 and 2017 were retrospectively reviewed. The patient reported pre- and postinjection NRPS value were used to calculate a percent change in overall pain ([pre-post)/post] x 100). This calculated percent change in pain was compared to the patient reported percent change (calculated % - reported %). An overall average change in calculated minus reported percent change was obtained for all the injections. Univariate analysis was utilized to compare the calculated percent change and the reported percent change. RESULTS Data from 135 patient charts was analyzed with a total of 144 injections. This study included 36 males and 99 females. The average patient age was 63.0 years. A total of 42 patients had a BMI >30 and 7 patients had a prior surgical history in the same joint which was injected. Various injections included sacroiliac joint (SI J, n=15), medial branch blocks (MBB, n=21), lumbar transforaminal epidural steroid injections (LTFESI, n=65), lumbar and cervical epidural steroid injections (LESI and CESI, n=25), radiofrequency ablations (RFA), genicular nerve block of the knee, and various shoulder joint injections. The average difference in calculated percent change vs the patient-reported percent change in pain prior to and after the injections was -18.37% (p CONCLUSIONS Effective management of chronic musculoskeletal pain is important due to its physical, social, and financial burden on patients and the healthcare system. Management of chronic pain is heavily impacted by the meaningful use of various patient reported outcome measures. Health insurance companies use variable percent change in pain level to determine effectiveness of treatment. Our data reflects the existence of a statistically significant difference between calculated percent change in pain using the NRPS as compared to patient reported percent change. Based on this analysis it may be valuable to use other functional and psychosocial outcome measures for chronic pain management. Further studies are needed to assess the combined use of the different outcome measures. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Effectiveness of Emergency Department Treatment of Pediatric Headache and Relation to Rebound Headache.

This study aimed to assess the association between the degree of headache relief obtained in the pediatric emergency department (PED) with abortive treatment and unscheduled return visits to the PED for a recurrent or persistent headache within 72 hours. This was a retrospective observational study with 369 patients, all younger than 18 years, who presented to the PED with a primary complaint of either a headache or migraine. Patient and visit details were collected from the medical chart, along with presenting and discharge pain score. Percent pain reduction at discharge was determined through the following calculation: (Presenting Pain Score - Discharge Pain Score)/Presenting Pain Score. Associations were assessed using multivariable logistic regression. No significant association was found between the percent pain reduction and return to the PED (P = 0.49). Mean presenting pain score at the index visit was statistically higher for those who ended up returning to the PED versus those who did not (8.1 vs 7.4; P = 0.02). A trend toward increase in return visits was seen among patients who had a headache duration greater than 3 days (odds ratio, 1.99) and patients who experienced less than 50% pain reduction in the PED (odds ratio, 1.77). Complete resolution in the PED may not be necessary, given the lack of association between the degree of pain relief and revisit rates. Perhaps, the goal should be to achieve at least 50% pain reduction before discharge.

Ultrasound-Guided Microwave Ablation for the Management of Inguinal Neuralgia: A Preliminary Study with 1-Year Follow-up

PurposeTo evaluate the feasibility and efficacy of ultrasound-guided microwave ablation for the treatment of inguinal neuralgia. Materials and MethodsA retrospective review of 12 consecutive ultrasound-guided microwave ablation procedures was performed of 10 consecutive patients (8 men, 2 women; mean age, 41 years [range, 15–64 years]), between August 2012 and August 2016. Inclusion criteria for inguinal neuralgia included clinical diagnosis of chronic inguinal pain (average, 17.3 months [range, 6–46 months]) refractory to conservative treatment and a positive nerve block. Pain response—reduction of pain level and duration and percent pain reduction using a 10-point visual analog scale (VAS) at baseline and up to 12 months after the procedure—was measured. Nine patients had pain after the inguinal hernia repair, and 1 patient had pain from the femoral artery bypass procedure. The microwave ablation procedure targeted the ilioinguinal nerve in 7 cases, the genitofemoral nerve in 4 cases, and the iliohypogastric nerve in 1 case. ResultsAverage baseline VAS pain score was 6.1 (standard deviation, 2.5). Improved pain levels immediately after the procedure and at 1, 6, and 12 months were statistically significant (P = .0037, .0037, .0038, .0058, respectively). Also, 91.7% (11/12) of the procedures resulted in immediate pain relief and at 1 month and 6 months. At 12 months, 83.3% (10/12) of patients had an average of 69% ± 31% pain reduction. Percent maximal pain reduction was 93% ± 14% (60%–100%), and the average duration of clinically significant pain reduction was 10.5 months (range, 0–12 months.). No complications or adverse outcomes occurred. ConclusionsUltrasound-guided microwave ablation is an effective technique for the treatment of inguinal neuralgia after herniorrhaphy.

Comparative analgesic efficacy of ultrasound-guided nerve blocks induced by three anesthetics with different duration of action in the treatment of resistant neuropathic pain in the lower extremities

Background/Aim. The neuropathic pain (NP) treatment is a big medical and socioeconomical problem. The new sorts of the NP treatment was developed and are applied in case of a medical treatment failure. The aim of this work was to investigate the efficacy of the ultrasound-assisted treatment of the resistant and chronic peripheral neuropathic pain with the local anesthetic nerve blocks. Due to the inefficacy of conventional treatment, three local anesthetics (shortacting, medium-term and long-acting) were administered in a series of the same minimal dose on a daily basis. Complications, side effects, the execution time of procedure and the onset time of local anesthetic were also investigated. Methods. In this prospective, randomized and doubleblinded study, 108 patients (of which 53 were diagnosed with diabetes and 55 with radiculopathy) with the resistant and chronic peripheral neuropathic pain in the lower extremities were treated with a series of ultra-sound assisted peripheral nerve blocks. The conventional treatment was exhausted. The presence of this neuropathic pain was confirmed by, at least, one of the three scales ? the Leeds Assesment of Neuropathic Simptoms and Signs (LANSS) scale, the Dolour Neuropathic 4 questions (DN4) scale and the pain DETECT(PD-Q) scale. Other therapies were not applied. The nerve blocks were administered on a daily basis until the relief of pain (visual analogue scale ? VAS &lt; 30), and after that, two additional nerve blocks were given. The three local anesthetics of the different duration of therapeutic effect were given at the same minimal dose: the schortacting (1% procaine-chloride solution), medium-term (1% lidocaine-chloride solution) and long-acting (0.25% levobupivacaine-chloride solution) local anesthetics were used. The therapeutic efficacy was measured with the percentage reduction in the pain intensity on the VAS scale before and after the therapy and one month after the treatment: &gt; 50% ? excellent results; 31?49% ? good results; &lt; 30% the therapy did not work. The side effects, complications, the execution duration of procedure, the onset time of numbness, the number of corrections of the needle direction were recorded as well. Results. For all three groups: nerve blocks took 5.4 ? 1.48 minutes to do (withouth difference among the groups), the onset of numbness occured, on average, within 3.75 ? 2.62 minutes (withouth differences among the groups), and the need for corrections of needle direction was minimal (1.03 ? 0.17 corrections). All the patients experienced a loss of pain sensation (VAS &lt; 30); when a long-acting anesthetic was used, the number of required nerve blocks was significant (p &lt; 0.001) smallest (4.33 ? 0.63 blocks), than in other two groups, and the percentage pain reduction was highest (73.13%) (p &lt; 0.001). The pain relief lasted one month after the therapy without the application of any other therapy. Neither complications nor side effects were observed. Conclusion. The procedure dercibed is a safe, efficient and easy-to-perform and does not lead to any complications and side effects. The pain relief is achieved most effectively and rapidly with the longacting local anesthetics, and maintained even for one month without the introduction of any additional therapy.

Intrathecal betamethasone for cancer pain: A study of its analgesic efficacy and safety.

BackgroundA preliminary study has shown effective cancer pain relief by intrathecal betamethasone (ITB). However, further evidence is needed to support this new approach.MethodsCancer patients with opioid‐resistant pain received lumbar intrathecal administration of betamethasone 2 or 3 mg once a week for 28 days. Immediate and short‐term analgesia (using a percentage pain reduction scale and a numerical rating scale, NRS) and long‐term analgesia (using NRS) were assessed. Patients were classified into two groups according to the most painful site of metastasis: vertebral column and/or surrounding nerve plexus metastases (group A) and other metastases distal from the vertebral column (group B).ResultsA total of 104 patients received ITB. Pain relief was observed not only in the lower half but also in the upper half of the body. The proportion of group A patients who experienced immediate analgesia was 81% (47/58), which was significantly greater than that of group B (P < 0.001). A decrease in NRS scores 1 day after ITB administration was observed in significantly more patients in group A than in group B (P < 0.001). Long‐term analgesia was also recorded in a greater proportion of patients in group A than in group B in the 7‐day (59%, 38/64 vs 6%, 2/33) and 28‐day periods (71%, 40/56 vs 31%, 8/26) (P < 0.001). No adverse effects related to neurotoxicity were recorded.ConclusionIntrathecal injection of betamethasone produced analgesia for opioid‐resistant cancer pain, and may be a potent therapeutic option for intolerable pain from vertebral column and/or surrounding nerve plexus metastases.

Single-Blind Placebo-Controlled Response Test with Phenytoin 10% Cream in Neuropathic Pain Patients.

Background: Phenytoin cream applied topically has been explored in neuropathic pain conditions. In several case series, phenytoin 5% and 10% cream could reduce pain in a clinically relevant way with a fast onset of action within 30 min, and with positive effects on sleep. Objective: To evaluate a single-blind placebo-controlled response test (SIBRET) for use in clinical practice. Materials and Methods: Patients with localized neuropathic pain, having an equal pain intensity in at least 2 areas (e.g., both feet), and a pain intensity of at least 4 on the 11-point numerical rating scale (NRS), were selected to perform the SIBRET. In one area, placebo cream consisting of the base cream was applied, and on the other area, phenytoin 10% cream was applied with separate hands to avoid contamination. Responders were defined as patients who experienced within 30 min at least 2-points difference as scored on the NRS, between the phenytoin 10% and the placebo cream applied areas, in favor of the former. Responders were subsequently prescribed phenytoin 10% cream. Results: Of the 21 patients, 15 patients (71.45%) were classified as responders. The mean pain reduction after 30 min as measured with the NRS in the phenytoin 10% cream area was 3.3 (SD: 1.3) and in the placebo cream area 1.2 (SD: 1.1). The difference of the mean percentage pain reduction between phenytoin 10% cream and placebo cream was 33.2% (SD: 17.6, p < 0.001). Using a 50% reduction on the NRS as a full response criterion, we could identify 57.1% of responders on phenytoin 10% cream and only 9.5% responders on placebo cream. Conclusions: The SIBRET helps patients and clinicians to quickly identify the appropriate treatment and can thus be seen as an important contributor to the domain of personalized medicine in pain. These results can also be regarded as a proof of principle for the analgesic activity of 10% phenytoin cream.

Botulinum Toxin A: A Novel Therapeutic Modality for Upper Extremity Chronic Regional Pain Syndrome.

Background:Complex regional pain syndromes (CRPS) is a disease that is poorly understood. It is a chronic pain syndrome characterized by sympathetic disruptions as well as CNS sensitization. Botulinum Toxin-A has been shown to have efficacy in Raynaud's as well as other neuropathic pain disorders. Perhaps BTX-A warrants experimentation in the treatment of CRPS.Methods:Patients with CRPS refractory to 2 or more regional sympathetic nerve blocks in 2007 were included in the study. Patient's were asked to rank their initial pain on a visual analog scale of 0 to 10 (10 being the worst pain). "Tenderness maps" were marked on patient's areas of most pain in 1 by 1 centimeter grids. Each box on the grid was injected with 10 IU of BTX-A after nerve blocks with 1% lidocaine. Treatment sessions occured on a monthly basis with VAS pain scores being re-assessed immediately before the new treatment. t Test, linear regression, and Cohen's D-test were used to analyze the correlation of the data.Results:Study sample was 20 patients. Etiology of CRPS was 6 amputations, 4 crush injuries, 4 penetrating injuries, and 2 lacerations. Average pain reduction on VAS scale achieved was 2.05 points. Average percentage pain reduction was 22.94%. Cohen's D Test also showed a meaningful difference with a score of 1.01. Linear regression R2 = 0.491. Maximum pain reduction, on average, was achieved by treatment 9.Conclusion:Despite the esoteric etiology of CRPS, BTX-A has a well-demonstrated mechanism of effect. BTX-A should be further explored as a treatment modality for CRPS.

Edema caused by continuous epidural hydromorphone infusion: A case report and review of the literature

Intraspinal drug delivery (IDD) therapy has been increasingly employed in patients with intractable, nonmalignant pain. Before implantation of permanent intraspinal pump, an intraspinal opioid screening trial is conducted to demonstrate the efficacy. The patient-controlled continuous epidural opioid infusion trail, performed in an outpatient setting, is widely accepted by many interventional pain specialists. To report a case of severe edema observed during the continuous epidural hydromorphone infusion trial. An otherwise healthy 68-year-old lady with a 5-year history of severe low back pain and bilateral leg pain because of failed back surgery syndrome was referred to our clinic for IDD therapy. A tunneled lumbar epidural catheter was placed at L2-L3 with catheter tip advanced to L1 under fluoroscopic guidance. Satisfactory catheter placement was confirmed by epidurogram. The catheter was then tunneled subcutaneously and connected to a Microject patient-controlled epidural analgesia (PCEA) pump (Codman, Raynham, MA). The pump was programmed to deliver hydromorphone (0.1 mg/ml) at basal rate of 0.3 ml/h. The bolus dose was 0.1 ml with a 60-minute lockout interval. The patient was instructed how to operate the infusion pump. During the following infusion trial, she reported satisfactory analgesia (> 70 percent pain reduction) and was able to wean off her other systemic opioids. However, she developed diffuse edema and gained over 16 pounds during the 5-day infusion trial. Her edema finally resolved 3-4 days after termination of the epidural infusion. Edema may occur and persist during epidural hydromorphone infusion. This report represents the first case report, to the best of our knowledge, describing severe edema in a patient on continuous epidural hydromorphone administration during an outpatient epidural infusion trial.