Preoperative hemoglobin A1c and perioperative blood glucose in patients with diabetes mellitus undergoing spinal cord stimulation surgery: A literature review of surgical site infection risk.

AIMS: The aim of our study was to review the surgical literature regarding the relationship between hemoglobin A1c (HbA1c), diagnosis of diabetes mellitus (DM), and risk of postoperative surgical site infection (SSI). METHODS: A librarian-assisted literature search was performed with two goals: (1) identify surgical publications related to SSI and HbA1c values, and (2) identify publications reporting infection risk with DM in spinal cord stimulation (SCS), intrathecal drug delivery systems (IDDS), and cardiovascular implantable electronic device (CIED) implantation surgeries. Published guidelines on perioperative management of DM are reviewed. RESULTS: We identified 30 studies reporting SSI and HbA1c values. The literature review indicated that for many surgical procedures, elevated HbA1c is not correlated to rate of SSI. We identified 16 studies reporting infection rates within DM cohorts following SCS, IDDS, and CIED implantation surgeries. The data reviewed did not indicate DM as an independent risk factor for SSI. CONCLUSION: Preoperative HbA1c levels in patients with a history of DM is not a singularly sufficient tool to estimate risk of perioperative infection in SCS implantation surgery. Published guidelines on perioperative management of DM do not suggest a specific HbA1c above which surgery should be delayed; intentional perioperative glycemic control is recommended.

Explantation of 10 kHz Spinal Cord Stimulation Devices: A Retrospective Review of 744 Patients Followed for at Least 12 Months.

OBJECTIVES: High-frequency 10 kHz spinal cord stimulation (10 kHz-SCS) has achieved analgesia superior to traditional SCS in a number of studies. However, there is concern regarding long-term outcomes of 10 kHz-SCS. Prior work has suggested that explant rates are higher with 10 kHz-SCS. Our primary objective was to determine the explant rate of 10 kHz-SCS in a large patient cohort from multiple centers followed for at least 12 months after implant surgery. MATERIALS AND METHODS: We performed a retrospective chart review of all patients who received a 10 kHz-SCS implant before July 1, 2019. We abstracted patient demographics, implant date, primary site of pain, implant indication, explant date, and reason for explant. A total of 744 patients were included in the study analysis. RESULTS: Average age of the overall cohort was 65.53 years and 407 (54.7%) were women. Average follow-up for all patients was 793 days. There were a total of 76 explants (10.2%). The most common reason for explant was loss of efficacy, which accounted for 39 explants (51.3% of total explants, 5.2% of overall cohort). Female sex and radiculopathy as the SCS indication were associated with statistically significant decreased risk of 10 kHz-SCS explant. CONCLUSIONS: We found 10 kHz-SCS explant rates to be similar to prior reported explant rates for traditional SCS devices. Patient-related factors including female sex and radiculopathy as the primary SCS indication may be protective factors against explantation.

Utilization of Leads After Permanent Implant in Spinal Cord Stimulator Systems.

OBJECTIVE: The goal of this study was to determine the frequency and clinical indications associated with implantation of single vs. dual percutaneous lead spinal cord stimulator (SCS) systems and to look further into how these leads are utilized for treatment. MATERIALS AND METHODS: A retrospective cohort analysis of all patients undergoing SCS implantation between January 2001 and December 2013 with a minimum of 2 years of clinical follow-up was performed. Number of trial leads and implanted leads was recorded. For patients with dual-lead systems, it was noted if and when the second lead was used, along with the clinical indication for lead activation. RESULTS: In the 259-patient cohort, 15.8% (n = 41) patients underwent placement of a single-lead system, 83.0% (n = 215) underwent placement of a dual-lead system, and 1.2% (n = 3) underwent placement of 3-lead systems. Placement of dual-lead systems was similar among all indication groups. Of those patients with a dual-lead system in place, 88.1% utilized both leads and average time to programming of the second lead was 2.3 months. The most common reason to activate the second lead was inadequate stimulation coverage. Five of the 41 patients with single-lead systems underwent an additional surgery to implant a second lead due to inadequate stimulation with 1 lead. CONCLUSIONS: To our knowledge this is the first descriptive analysis of the frequency of single- and dual-lead SCS systems. This report indicates that dual-lead systems are most often placed and both leads are required for optimal patient therapy.

Surgical Site Infections in Cancer Patients with Intrathecal Drug Delivery Devices.

Objectives: Our purpose was to determine the incidence of surgical site infection (SSI) in cancer patients receiving an intrathecal drug delivery system (IDDS) and compare that rate with the incidence of SSI in the general population receiving an IDDS or spinal cord stimulator. We attempted to describe risk factors for SSIs in cancer patients treated with IDDS in terms of exposure to cancer treatments. Design: Retrospective review. Setting: Large tertiary care center. Patients: Cancer patients receiving an IDDS in 2006-2013. Methods: The incidence of SSI was determined according to the US Centers for Disease Control and Prevention definition. Medication regimens and current cancer treatment were investigated to identify immunocompromised patients during IDDS placement. Microbacteriology, treatment, and overall outcomes were investigated. Results: Sixty-four patients had an IDDS implanted in 2006-2013. SSI developed in four patients (6.2%). All four patients had received chemotherapy or radiotherapy within three months before implantation. Three of the three were receiving dexamethasone, and three of the four required explantation of the IDDS. Conclusion: The incidence of SSI was at the upper end of the published infection rates for IDDS. The risk of SSI may be increased in this population because of factors that alter the patient's immune status, including concomitant corticosteroid use, radiotherapy near the SSI, and presence of immunomodulators. The identification and mitigation of certain risk factors for this population may prevent infection in future patients.

Bleeding Complications in Patients Undergoing Intrathecal Drug Delivery System Implantation.

INTRODUCTION: Intrathecal drug delivery systems (IDDSs) have dramatically improved analgesia and the functional status of cancer patients and those with chronic pain states. However, given the close proximity to the neuraxis and frequent concomitant use of antiplatelet or anticoagulant medications, this intervention is not without risk. The goal of this investigation was to determine the incidence of bleeding complications following IDDS placement. METHODS: This is a retrospective review from 2005 through 2014 of adult patients undergoing IDDS implantation or revision at a tertiary care center. The primary outcome was a bleeding-related neurological complication requiring emergency medicine, neurology, or neurosurgical evaluation within 31 days. RESULTS: A total of 247 procedures were performed on 216 unique patients. Patients received aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) within seven days of needle placement for 64 procedures (25.9%). A preprocedural platelet count or international normalized ratio (INR) was available within 30 days for 138 procedures (55.9%). Of these, two patients had a platelet count lower than 100 x 109/L and one patient had an INR of 1.5 or higher at the time of the procedure. One neurological complication was identified (0.4%) that was not related to procedural bleeding. Similarly, three patients (1.2%) received a periprocedural red blood cell transfusion, none of which were related to procedural bleeding. CONCLUSION: No cases of bleeding-related neurological complications were identified following IDDS placement or revision, including in those receiving aspirin or NSAIDs. Future investigations with larger numbers are needed to further explore the safety of antithrombotic therapy continuation or discontinuation periprocedurally.

Spinal Cord Stimulator Implant Infection Rates and Risk Factors: A Multicenter Retrospective Study.

OBJECTIVES: Spinal cord stimulation is an evidence-based treatment for a number of chronic pain conditions. While this therapy offers improvement in pain and function it is not without potential complications. These complications include device failure, migration, loss of therapeutic paresthesia, and infection. This article looked to establish a modern infection rate for spinal cord stimulators, assess the impact of known risk factors for surgical site infections and to determine the impact of certain preventative measures on the rate of infection. METHODS: After institutional review board approval, a multisite, retrospective review was conducted on 2737 unique implants or revisions of SCS systems. Patient demographics, risk factors including diabetes, tobacco use, obesity, revision surgery, trial length, implant location, implant type, surgeon background, prophylactic antibiotic use, utilization of a occlusive dressing, and post-operative antibiotic use were recorded and analyzed. RESULTS: The overall infection rate was 2.45% (n = 67). Diabetes, tobacco use, and obesity did not independently increase the rate of infection. Revision surgeries had a trend toward higher infection rate; however, this did not meet statistical significance. There was no difference in the rate of infection between implants performed by physicians of different base specialties, cylinder leads vs. paddle leads, or between different prophylactic antibiotics. Implants performed at academic centers had a higher rate of infection when compared to implants performed in nonacademic settings. When patients received an occlusive dressing or post-operative antibiotics they had a lower rate of infection. CONCLUSIONS: The infection rate (2.45%) reported in this study is lower than the previously reported rates (3-6%) and are on par with other surgical specialties. This study did not show an increased rate of infection for patients that used tobacco, had diabetes or were obese. It's possible that given the low overall infection rate a larger study is needed to establish the true impact of these factors on infection. In addition, this study did not address the impact of poorly controlled diabetes mellitus (elevated hemoglobin A1c) vs. well-controlled diabetes. It can be concluded from this study that utilizing an occlusive dressing over the incision in the post-operative period decreases the rate of infection and should become the standard of care. This study also demonstrated the positive impact of post-operative antibiotics in decreasing the rate of infection. Studies in other surgical specialties have not shown this impact which would suggest that further research is needed.

Spinal Cord Stimulator Related Infections: Findings From a Multicenter Retrospective Analysis of 2737 Implants.

INTRODUCTION: Surgical site infection is a potential complication of spinal cord stimulator (SCS) implantation. Current understanding of the epidemiology, diagnosis, and treatment of these infections is based largely on small clinical studies, many of which are outdated. Evidence-based guidelines for management of SCS-related infections thus rely instead on expert opinion, case reports, and case series. In this study, we aim to provide a large scale retrospective study of infection management techniques specifically for SCS implantation. METHODS: A multicenter retrospective study of SCS implants performed over a seven-year period at 11 unique academic and non-academic institutions in the United States. All infections and related complications in this cohort were analyzed. RESULTS: Within our study of 2737 SCS implant procedures, we identified all procedures complicated by infection (2.45%). Localized incisional pain and wound erythema were the most common presenting signs. Laboratory studies were performed in the majority of patients, but an imaging study was performed in less than half of these patients. The most common causative organism was Staphylococcus aureus and the IPG pocket was the most common site of an SCS-related infection. Explantation was ultimately performed in 52 of the 67 patients (77.6%). Non-explantation salvage therapy was attempted in 24 patients and was successful in resolving the infection in 15 patients without removal of SCS hardware components. DISCUSSION: This study provides current data regarding SCS related infections, including incidence, diagnosis, and treatment.

High-Frequency Spinal Cord Stimulation in a Patient with an Implanted Cardiac Device.

BACKGROUND: New advances in spinal cord stimulation have led to improved treatment of patients suffering from chronic pain. While the overall safety of newer stimulation devices has been established, no published reports exist regarding safety considerations when these devices are implanted in patients with a preexisting cardiac device. CASE REPORT: An 83-year-old man with a history of out-of-hospital cardiac arrest secondary to an episode of ventricular fibrillation underwent automated implantable cardiac defibrillator placement. Concomitantly, he suffered from intractable chronic low axial back pain and was deemed a candidate for high-frequency (10 kHz) spinal cord stimulation (SCS). Cardiac monitoring during SCS trial and implantation was performed with no interference noted. Following high-frequency SCS implantation, the patient was observed to have significant pain relief with functional improvement. DISCUSSION: While others have reported safety during traditional SCS in patients with implanted cardiac devices, this is the first case report to describe safe and effective use of high-frequency SCS in a patient with an implanted cardiac device.

Safety of Lumbar Spine Radiofrequency Procedures in Patients Who Have Posterior Spinal Hardware.

OBJECTIVE: The purpose of this study was to determine whether the energy generated by an active radiofrequency (RF) cannula adjacent to lumbar spine hardware could result in heating of the hardware. DESIGN: Prospective study. SETTING: Tertiary care medical center. SUBJECTS: Six patients with lumbar facet joint pain at the level adjacent to lumbar spine fusion hardware were studied. METHODS: A total of 10 lumbar medial branch nerve radiofrequency lesion procedures were performed on six patients. A temperature probe was placed on the fusion hardware to continuously monitor the temperature of the hardware throughout the RF procedure. RESULTS: The temperature of the fusion hardware increased in six of the 10 RF lesion procedures. During two of the procedures, the temperature rose rapidly to 42°C, at which time the procedure was ceased at that level. CONCLUSION: This study demonstrated that radiofrequency lesioning to treat symptomatic facet joint pain in patients who have adjacent posterior lumbar fusion hardware may result in heat energy being transferred to the adjacent hardware. This may increase the risk of injury to the patient. Monitoring for a temperature increase is easily accomplished by inserting a temperature probe onto the surface of the hardware.

Bleeding Complications in Patients Undergoing Percutaneous Spinal Cord Stimulator Trials and Implantations.

INTRODUCTION: Spinal cord stimulators (SCS) are indicated for the management of multiple pain states with strong evidence. Recent guidelines recommend discontinuing aspirin or non-steroidal anti-inflammatory drugs (NSAIDs) for the described procedures. The goal of this investigation is to assess the rate of bleeding and neurologic sequelae in patients undergoing SCS trials and implantation. METHODS: This is a retrospective review from 2005 through 2014 of all patients 18 years or older undergoing the following procedures: Percutaneous SCS implantations, SCS revisions, and SCS trials. Baseline characteristics, antiplatelet and anticoagulation medications, coagulation parameters, and procedural details were extracted. The primary outcome was the presence of a bleeding complication within 31 days of the procedure requiring emergency medicine, neurology, or neurosurgical evaluation. The neurological complication was independently categorized for its potential relationship to procedural bleeding, and periprocedural red blood cell transfusion requirements were analyzed as a secondary outcome. RESULTS: A total of 642 percutaneous SCS procedures were performed on 421 unique patients, including 346 SCS trials, 255 SCS implantations, and 41 revision surgeries. Patients had received aspirin or NSAIDs within 7 days of needle placement for 101 procedures (15.7%). There were no bleeding or neurological complications identified in this cohort. CONCLUSION: Although the incidence of epidural hematoma is low, the development of bleeding complications following SCS lead placement can be devastating. In the present investigation, we identified no cases of epidural hematoma following percutaneous SCS lead placement, including more than 100 patients receiving aspirin or NSAIDs. Future investigations with larger numbers are needed to better define the relationships between periprocedural aspirin and NSAID utilization and bleeding complications.

Patient Outcomes and Spinal Cord Stimulation: A Retrospective Case Series Evaluating Patient Satisfaction, Pain Scores, and Opioid Requirements.

INTRODUCTION: Spinal cord stimulators (SCS) are used to treat various chronic pain states. Establishing patient outcomes in terms of pain control, opioid medication use, and overall satisfaction is vital in maintaining SCS's role in clinical practice. METHODS: All patients who underwent SCS implantation between January 2001 and December 2011 at a tertiary academic pain medicine center were included if he or she underwent permanent cervical or thoracolumbar dorsal column SCS implantation and age was 18 or greater. For the 199 patients who met inclusion criteria, data were collected retrospectively. Preimplant information included indication for implantation, Numeric Rating Scale (NRS) score, and dose in oral morphine equivalents (OME). Postimplant NRS score was recorded at 6 months and 1 year. OME requirement and patient satisfaction were determined at 1 year postimplantation. RESULTS: This data set showed an overall decrease in OME requirements and NRS scores at both 6 months and 1 year. These differences were statistically significant (P < 0.01) compared to preimplantation values. Additionally, 84.27% of patients were satisfied with their implants at 1 year. Patient outcomes were analyzed further in respect to implant indication; groups included failed back surgery syndrome (FBSS), complex regional pain syndrome (CRPS), angina, and other. For all groups, there were statistically significant (P < 0.01) decreases in NRS scores at 6 months and 1 year. In the FBSS and CRPS groups, statistically significant (P < 0.02) decreases in OME usage existed. CONCLUSION: Retrospective review of patients with spinal cord stimulators revealed OME reduction at 1 year for those patients in the FBSS and CRPS groups; patient satisfaction at 1 year and NRS score reduction at 6 months and 1 year were statistically significant for all groups.

Using simulation and standardized patients to teach vital skills to pain medicine fellows.

INTRODUCTION: Simulation is an evolving aspect of medical education. The role of simulation in training programs is variable, however, in technical specialties such as surgery and anesthesiology its role is quickly becoming a standard part of training programs. Pain fellowship programs must teach clinical diagnostic skills, pharmacology and pathophysiology, in addition to interventional skills to fellows with varying residency backgrounds. METHODS: The implementation of a hybrid simulation course into the pain fellowship curriculum allows for active learning as fellows experience challenging patient scenarios, stressful periprocedural events, and cases gone awry that require emergency algorithm recall and action. CONCLUSION: This report describes the incorporation of simulation and crucial conversations into a pain fellowship curriculum.

Misrepresentation in multidisciplinary pain medicine fellowship applications to a single academic program.

BACKGROUND AND OBJECTIVES: Publication misrepresentation by residency applicants has been well documented, but fewer studies have investigated it in fellowship applicants, specifically in pain medicine. We therefore sought to evaluate the demographics of pain medicine fellowship applicants and the type, number, and accuracy of referenced publications they reported. METHODS: Applications to the Multidisciplinary Pain Medicine fellowship program in the Mayo School of Graduate Medical Education, Rochester, Minnesota were reviewed for three consecutive academic years (2009-2012). Demographic information and publications claimed by applicants were compiled, and publications were scrutinized by a medical librarian for accuracy. RESULTS: Over a 3-year period, 179 fellowship applications were received. Of the 179 applicants, more than half (106 [59%]) listed at least one publication. Of 324 listed publications, 263 were verifiable; of these, 14 (5.3%) were deemed fraudulent, and six (2.3%) contained an inaccuracy possibly conferring a competitive advantage. In our small sample size, we found no difference in the rate of publications or in the accuracy of listed publications across subspecialties, or between US medical graduates and international medical graduates. CONCLUSIONS: The lack of national data, specifically on applicant misrepresentation, due to the heretofore absence of a universal application process or match, impedes assessment of the extent to which these findings are representative of the national applicant pool. We observed notable trends (few female applicants; numerous international medical graduate applicants) different from those reported by other specialties. Despite the low rate (5.3%) of fraudulent publications, fellowship program directors and selection committees should be aware of this possibility to ensure selection of fellows with the highest degree of professional and ethical integrity.

Spinal cord stimulator explantation for magnetic resonance imaging: a case series.

INTRODUCTION: Spinal cord stimulator (SCS) systems are implanted to treat pain conditions such as neuropathic, radicular, and ischemic pain syndromes. Prior to July 2013, SCS systems were not magnetic resonance imaging (MRI) compatible due to the risk of thermal injury at the site of the leads and generator. Although there are some case reports of patients undergoing MRI studies with SCS systems in place, these stimulators are frequently explanted when clinical care has necessitated an MRI. The purpose of this case series is to discuss the role of SCS explantation in order to acquire an MRI. METHODS: This study was performed at a tertiary academic pain medicine clinic. After exempt status was obtained via the institutional review board, patients were identified via the use of Common Procedural Terminology codes for implantable devices. A chart review was performed to identify all patients >18 years of age who had a lumbar or thoracic dorsal column SCS implanted during January 2001-December 2011. The charts were then followed to identify any patients who underwent a surgery for explantation of the device. Data collection included the total number of patients undergoing permanent SCS implantation, the total number of explantation of these devices, patient demographic factors, indication for SCS implantation, incidence of revisions and the indication, duration between implantation and explant of the device, and indication for explantation. RESULTS: During the time between 2001 and 2011, 199 patients were identified who underwent a thoracic or lumbar SCS implant after a successful trial. Among 199 implants, 33 devices were explanted, and of these, four were explanted due to the primary need for an MRI scan.

Incidence of clinically significant percutaneous spinal cord stimulator lead migration.

OBJECTIVE: To examine the incidence of percutaneous spinal cord stimulator lead migration, given current hardware and surgical technique. MATERIALS AND METHODS: We retrospectively reviewed records of patients who underwent spinal cord stimulator implantation with percutaneous leads at our institution from 2008 through 2011. We determined the number of patients who required surgical revision for clinically significant lead migration. RESULTS: Clinically significant lead migration requiring surgical revision occurred in three of 143 patients (2.1%) with primary SCS system implants utilizing percutaneous-type leads. CONCLUSIONS: The rate of lead migration observed in our practice was considerably lower than previously published estimates of clinically significant lead migration or revision for lead migration (13%-22%). However, our study did not determine the reason for the decreased rate, which may be influenced by current hardware and implant techniques.

Pain Management in Four-Limb Amputation: A Case Report.

Acute pain following amputation can be challenging to treat due to multiple underlying mechanisms and variable clinical responses to treatment. Furthermore, poorly controlled preoperative pain is a risk factor for developing chronic pain. Evidence suggests that epidural analgesia and peripheral nerve blockade may decrease the severity of residual limb pain and the prevalence of phantom pain after lower extremity amputation. We present the perioperative analgesic management of a patient with gangrene of the bilateral upper and lower extremities as a result of septic shock and prolonged vasopressor administration who underwent four-limb amputation in a single procedure. A multimodal analgesic regimen was utilized, including titration of preoperative opioid and neuropathic pain agents, perioperative intravenous, epidural and peripheral nerve catheter infusions, and postoperative oral medication titration. More than 8 months postoperatively, the patient has satisfactory pain control with no evidence for phantom limb pain. To our knowledge, there have been no publications to date concerning analgesic regimens in four-limb amputation.

Fibrin glue to treat spinal fluid leaks associated with intrathecal drug systems.

Intrathecal drug delivery systems (IDDSs) are used to treat resistant pain states as well as intractable spasticity via medication delivery into the spinal fluid. Risks associated with implantation of these devices include infection, bleeding, intrathecal granuloma formation, and neurologic sequelae similar to other neuraxial procedures. Intrathecal catheter placement creates the additional risk of persistent spinal fluid leak, which can lead to postdural puncture headaches as well as seroma formation and may require subsequent surgical exploration or explantation. This retrospective case series examines 3 patients at a single institution with persistent spinal fluid leak after IDDS placement (and explantation in one case) resulting in headache and/or seroma formation that were treated with epidural fibrin glue. Three patients underwent IDDS implantation with baclofen for spasticity. In 1 patient, a cerebral spinal fluid leak developed at 1-week postoperatively. After several unsuccessful epidural blood patches and surgical exploration with a catheter revision, she was ultimately treated successfully with a fibrin glue patch. The second patient received an IDDS and did well until a seroma developed 1 year later. He was likewise treated with an epidural fibrin glue patch after 2 failed blood patches. In a third patient, a spinal fluid leak developed after explantation of an IDDS and was treated with an epidural fibrin glue patch as initial therapy.

Tobacco control in patients treated for chronic pain: a survey of pain fellowship program directors.

BACKGROUND AND OBJECTIVES: Previous studies have established the relationship between tobacco use and pain severity among patients suffering from chronic pain. Unfortunately, many physicians feel underprepared to counsel patients on smoking cessation. The purpose of this study was to identify the attitudes, beliefs, and practices of pain medicine fellowship directors in regard to tobacco control interventions and trainee education. METHODS: Program directors of ACGME-accredited pain medicine fellowships were surveyed via a web-based form to assess current practices in tobacco intervention and to gauge interest in incorporating tobacco control into their current fellowship training curriculum. RESULTS: Of the respondents, the majority indicated that they frequently asking their patients about tobacco use and advise them to quit. In addition, most agreed that presenting tobacco control is a responsibility of pain physicians. However, few consistently provided any assistance with quitting. Finally, the majority of program directors felt that pain medicine fellowships should include tobacco control training and were interested in incorporating an educational module about smoking and pain into their training program. CONCLUSIONS: This survey of pain medicine fellowship program directors indicates that although smoking cessation interventions are not being consistently applied in academic pain practices, there is a strong interest in doing so. Furthermore, the majority of program directors recognized the importance of incorporating tobacco control training into pain medicine fellowships. This recognition may provide an opportunity to develop a web-based training module that could be easily incorporated into the upcoming milestones in pain medicine training.

Indirect Comparison of 10 kHz Spinal Cord Stimulation (SCS) versus Traditional Low-Frequency SCS for the Treatment of Painful Diabetic Neuropathy: A Systematic Review of Randomized Controlled Trials.

Spinal cord stimulation (SCS) is increasingly used to treat painful diabetic neuropathy (PDN). At the time of a recent meta-analysis in this field, data were only available from randomized controlled trials (RCTs) of traditional low-frequency SCS (LF-SCS). However, outcomes from high-frequency 10 kHz SCS treatment are now available. Our study aimed to systematically review the contemporary evidence for SCS in patients with lower limb pain due to PDN and include an indirect comparison of the high- and low-frequency modalities. We searched the PubMed/CENTRAL databases up to 18 August 2022, for peer-reviewed RCTs of SCS that enrolled PDN patients with lower limb pain symptoms. The quality of the evidence was assessed with the Cochrane Risk of Bias tool. Using SCS treatment arm data from the RCTs, we indirectly compared the absolute treatment effect of 10 kHz SCS and LF-SCS. Results are presented in tables and forest plots. This systematic review was reported according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 guidelines. Three RCTs met our eligibility criteria, including the recent 10 kHz SCS RCT (N = 216, 90 implanted) and 2 others that examined LF-SCS (N = 36, 17 implanted; N = 60, 37 implanted). Our analysis of 6-month data found clinically meaningful pain relief with each SCS modality. However, significantly greater pain reduction was identified for 10 kHz SCS over LF-SCS: average pain reduction in the 10 kHz SCS cohort was 73.7% compared with 47.5% in the pooled LF-SCS group (p < 0.0001). In the permanent implant subset, the 50% pain reduction responder rate was 83.3% in the 10 kHz SCS cohort versus 63.0% in the pooled LF-SCS group (p = 0.0072). The overall risk of bias of each included RCT was deemed high, mainly due to the absence of patient blinding. Our analysis indicates that paresthesia-free 10 kHz SCS can provide superior pain relief and responder rate over LF-SCS for managing PDN patients refractory to conventional medical management.

An exploratory pilot study of palliative medicine compared to anesthesia-pain consultation for pain in patients with cancer.

Oncologists often manage cancer-associated symptoms including pain. When symptoms are severe, anesthesia-pain medicine (APM) and/or palliative medicine (PM) can effectively treat symptoms. Nevertheless, symptom management may be suboptimal, leading to diminished quality of life (QOL). We assessed the value of PM vs. APM consultation in cancer patients referred for pain management alone. Patients referred to an APM-based Cancer Pain Clinic (CPC) over an 8-month period were evaluated by PM or APM based on the first available appointment. Symptoms and QOL were assessed by the MD Anderson Symptom Inventory and Linear Analog Self-Assessment at baseline and 4-6 weeks after initial encounter. Data were analyzed on an available-case basis. Sixty-two patients (37 PM, 25 APM) completed the initial survey, with 48 patients (31 PM, 17 APM) completing followup. Mean pain score improved from 7.97 to 5.47 in the PM group (P < 0.0001) and from 7.1 to 4.5 (P = 0.29) in the APM group. The PM group demonstrated a clinically significant improvement in 8/19 symptoms vs. 3/19 in the APM group and in 3/5 QOL parameters in the PM group vs. 1/5 in the APM group. Our small sample size weakens our power and ability to detect significant differences between the groups. Only one follow-up symptom-assessment point was obtained. PM consultation is as effective as APM in improving cancer pain but may be more effective with symptom management and improving QOL.