Infectious Complications of Dorsal Root Ganglion Stimulation: A Systematic Review and Pooled Analysis of Incidence.

BACKGROUND AND OBJECTIVES: Dorsal root ganglion stimulation (DRGS) is a newer form of neuromodulation that targets the dorsal root ganglion. DRGS has superior efficacy in complex regional pain syndrome compared to spinal cord stimulation (SCS) and may have efficacy in other forms of chronic pain. While decades of safety data are available for SCS, there is less available safety information for DRGS. The objectives of this systematic review and pooled analysis of incidence are to determine the overall incidence of DRGS infections, incidence at each stage (trial vs implant vs revision), infection characteristics, and outcomes. MATERIALS AND METHODS: A comprehensive search of databases from January 1980 to January 2021 was conducted. RESULTS: Ten studies met inclusion criteria. Eight studies reported patients with trial data (n = 291), ten studies reported patients with implant data (n = 250), and seven studies reported data with revisions (n = 26). The pooled incidence of trial infections was 1.03% (95% CI 0.35-2.99%), implant infections was 4.80% (95% CI 2.77-8.20%), revision infections was 3.85% (95% CI 0.20-21.59%), and overall infections was 2.82% (95% CI 1.62-4.54%). There was a statistically significant difference in infection rates between the trial, implant, and revision stages, X2 (2, N = 567) = 8.9839, p = 0.01. CONCLUSIONS: This is the first systematic review and pooled analysis that followed PRISMA guidelines to report infectious complications of DRGS by stage (trial vs implant vs revision). DRGS trial appears to be low risk for infection but that risk is significantly increased with DRGS implant. Our findings highlight the need for further study of infectious complications, their risks, and optimal prophylaxis.

A Systematic Review and Meta-analysis of Unguided Electronic and Mobile Health Technologies for Chronic Pain-Is It Time to Start Prescribing Electronic Health Applications?

OBJECTIVE: Electronic (eHealth) and mobile (mHealth) technologies may be a useful adjunct to clinicians treating patients with chronic pain. The primary aim of this study was to investigate the effects of eHealth and mHealth interventions that do not require clinician contact or feedback on pain-related outcomes recommended by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) guidelines in adults with chronic pain. METHODS: We searched four databases and included English language randomized controlled trials of ambulatory adults with chronic pain from January, 1 2000, to January 31, 2018, with interventions that are independent of clinician contact or feedback. In the meta-analysis, outcomes were assessed at short- (three months or less), intermediate- (four to six months), and long-term (seven or more months) follow-up. RESULTS: Seventeen randomized controlled trials (N = 2,496) were included in the meta-analysis. Both eHealth and mHealth interventions had a significant effect on pain intensity at short- and intermediate-term follow-up. Similarly, a significant but small effect was observed for depression at short- and intermediate-term follow-up and self-efficacy at short-term follow-up. Finally, a significant effect was observed for pain catastrophizing at short-term follow-up. CONCLUSIONS: eHealth and mHealth interventions had significant effects on multiple short- and intermediate-term outcome measures recommended in the IMMPACT guidelines. Given widespread availability and low cost to patients, clinicians treating patients with chronic pain could consider using eHealth and mHealth interventions as part of a multidisciplinary pain treatment strategy.

Preoperative Epidural Steroid Injections and Postoperative Infections After Lumbar or Cervical Spine Surgery: A Systematic Review and Meta-Analysis.

Objective: To determine the risk difference and 95% prediction intervals (PIs) for postoperative infections (POIs) associated with preoperative epidural steroid injections (ESIs) in adults undergoing lumbar or cervical spine surgery. Methods: Comprehensive database searches were conducted from inception dates through December 2023. Inclusion criteria included all study designs involving adults receiving a preoperative ESI before lumbar or cervical decompression or fusion spine surgery. Risk of bias was assessed using a modified tool developed for uncontrolled studies. The summary estimates of risk difference and the corresponding PIs were reported. Results: A total of 12 studies were included in the systematic review, of which 9 were included in the meta-analysis. Preoperative ESIs within 1 month of lumbar spine decompression or fusion surgery were associated with a 0.6% and 2.31% greater risk of a POI, respectively. In adults ≥65 years of age, ESIs within 1 or 1-3 months of lumbar spine decompression or fusion surgery were associated with a 1.3% and 0.6% greater risk of a POI, respectively. Preoperative ESIs within 3 months of cervical spine fusion were not associated with an increased risk of a POI. The bounds of all corresponding 95% PIs were nonsignificant. Conclusion: The observations of this study provide summary estimates of risk difference and 95% PIs, which could be used to support shared decision-making about the use of ESIs before cervical or lumbar spine surgery.

Heparin Versus Bivalirudin for Anticoagulation in Adult Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Analysis.

Extracorporeal membrane oxygenation (ECMO) poses unique thrombotic and hemorrhagic risks, and the optimal anticoagulant choice is unknown. We systematically searched Ovid EBM Reviews, Ovid Embase, Ovid Medline, Scopus, and Web of Science Core Collection for randomized-, crossover-, retrospective cohort-, or parallel-designed clinical studies of adult patients receiving ECMO that compared heparin recipients with bivalirudin recipients. Meta-analysis was performed with random-effects models. The ROBINS-I tool was used to assess the risk of bias. Six retrospective observational studies met the inclusion criteria for the qualitative summary. Five studies were suitable for meta-analysis. Those who received heparin were more likely to experience circuit-related thrombosis (odds ratio [OR] 2.05, 95% confidence interval [CI] 1.25-3.37, p = 0.005, I2 = 0%) and die (OR 1.62, 95% CI 1.19-2.21, p = 0.002, I2 = 0%) compared with those who received bivalirudin. There were no differences in major bleeding events between heparin and bivalirudin recipients (OR 1.83, 95% CI 0.55-6.09, p = 0.33, I2 = 82.7%). In retrospective settings compared with heparin anticoagulation, bivalirudin was associated with less circuit-related thrombotic events and greater survival in adults supported on ECMO, without contributing to more bleeding complications. Prospective controlled studies comparing heparin and bivalirudin in adult ECMO patients are warranted to corroborate these findings.

Ultrasound-guided lumbar medial branch blocks and intra-articular facet joint injections: a systematic review and meta-analysis.

There is great interest in expanding the use of ultrasound (US), but new challenges exist with its application to lumbar facet-targeted procedures. The primary aim of this systematic review and meta-analysis was to determine the risk of incorrect needle placement associated with US-guided lumbar medial branch blocks (MBB) and facet joint injections (FJI) as confirmed by fluoroscopy or computerized tomography (CT). An a priori protocol was registered, and a database search was conducted. Inclusion criteria included all study types. Risk of bias was assessed using the Cochrane risk of bias tool for randomized controlled trials and the National Heart, Lung, and Blood tool for assessing risk bias for observational cohort studies. Pooled analysis of the risk difference (RD) of incorrect needle placement was calculated. Pooled analysis of 7 studies demonstrated an 11% RD (P < 0.0009) of incorrect needle placement for US-guided MBB confirmed using fluoroscopy with and without contrast. Pooled analysis of 3 studies demonstrated a 13% RD (P < 0.0001) of incorrect needle placement for US-guided FJI confirmed using CT. The time to complete a single-level MBB ranged from 2.6 to 5.0 minutes. The certainty of evidence was low to very low. Ultrasound-guided lumbar MBB and FJI are associated with a significant risk of incorrect needle placement when confirmed by fluoroscopy or CT. The technical limitations of US and individual patient factors could contribute to the risk of incorrect needle placement.

Effects of Slow Deep Breathing on Acute Clinical Pain in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Slow deep breathing (SDB) may help patients with acute pain. The primary aim of this systematic review and meta-analysis is to investigate the effects of SDB on acute pain. Secondary aims include investigating the effects of SDB on acute pain-related physical and emotional functioning. An a priori protocol was registered and a database search was conducted by a reference librarian. Randomized controlled trials (RCT) were eligible for inclusion and exclusion criteria included studies of SDB for non-pain indications and studies that applied SDB as a component of an encompassing intervention. The risk or bias was assessed using the Cochrane Collaboration's revised tool for assessing risk of bias in randomized trials. Meta-analysis was conducted using the random effects model. A total of 11 968 studies were screened and seven RCTs met inclusion criteria; five were judged to have low risk of bias. Meta-analysis of post-intervention pain scores demonstrated that SDB was associated with significantly lower pain scores compared with a control group, but with high levels of heterogeneity. Subgroup analyzes demonstrated that trials of burn pain were associated with a larger reduction in pain which partially explains the heterogeneity. Very low certainty evidence suggests that SDB may reduce acute pain intensity. Further research is needed to identify patients who are candidates for SDB and determine the best approach to deliver this therapy.

Prevalence of postamputation pain and its subtypes: a meta-analysis with meta-regression.

INTRODUCTION: The inconsistent use of standardized approaches for classifying postamputation pain (PAP) has been a barrier to establishing its prevalence. OBJECTIVES: The primary objective of this systematic review and meta-analysis is to determine the prevalence of nontraumatic lower-extremity PAP using an established taxonomy. The secondary objective is to determine the prevalence of PAP subtypes, including phantom limb pain and residual limb pain (RLP). METHODS: An a priori protocol was registered, and a database search was conducted by a reference librarian. Randomized trials and uncontrolled studies were eligible for inclusion. The risk of bias was assessed using a tool developed for uncontrolled studies. A total of 2679 studies were screened, and 13 studies met inclusion criteria (n = 1063). RESULTS: The sources of risk of bias included selection bias and, to a lesser extent, whether the outcome was adequately ascertained. Two studies reported the prevalence of PAP and the pooled prevalence was 61% (95% confidence interval [CI], 33%-86%) with high heterogeneity (I2 = 93%). Thirteen studies reported the prevalence of phantom limb pain and the pooled prevalence was 53% (95% CI, 40%-66%) with high heterogeneity (I2 = 93%). Eight studies reported the prevalence of RLP and the pooled prevalence was 32% (95% CI 24%-41%) with high heterogeneity (I2 = 76%). Clinical subtypes of RLP were not reported. CONCLUSIONS: The prevalence of PAP is high in patients with nontraumatic lower-extremity amputations. Ongoing research that uses a taxonomy for PAP is needed to fully delineate the prevalence of PAP subtypes.

Lidocaine for postoperative pain after cardiac surgery: a systematic review.

OBJECTIVE: Lidocaine is one of the most widely used local anesthetics with well-known pharmacological properties. The purpose of this systematic review is to investigate the effects of lidocaine on postoperative pain scores and recovery after cardiac surgery. METHODS: A comprehensive database search was conducted by a reference librarian for randomized clinical trials (RCT) from January 1, 1980 to September 1, 2019. Eligible study designs included randomized controlled trials of lidocaine for postoperative pain management in adults undergoing cardiac surgery. After removal of duplicates, 947 records were screened for eligibility and 3 RCTs met inclusion criteria. RESULTS: Sources of bias were identified in 2 of 3 RCTs. Lidocaine was administered intravenously, topically, and intrapleurally. Key findings included [1] 2% lidocaine placed topically on chest tube prior to intraoperative insertion was associated with significantly lower pain scores and lower cumulative doses of fentanyl; and [2] 2% lidocaine administered intrapleurally was associated with significantly lower pain scores and significant improvements in pulmonary mechanics. Lidocaine infusions were not associated with significant changes in pain scores or measures of recovery. No significant associations were observed between lidocaine and overall mortality, hospital length of stay or ICU length of stay. No data were reported for postoperative nausea and vomiting or arrhythmias. CONCLUSIONS: Due to the favorable risk profile of topical lidocaine and the need for further advancements in the postoperative care of adults after cardiac surgery, topically administered lidocaine could be considered for incorporation into established postoperative recovery protocols.

Workplace Violence in the Setting of Pain Management.

In the context of the opioid crisis, increased attention has been placed on the risk of violence in outpatient pain medicine clinics. The primary objective of this study was to determine the prevalence and characteristics of workplace violence in a mixed group of clinicians (ie, practicing physicians, resident and fellow physicians in training, nurse practitioners, physician assistants, psychologists) participating in a workplace violence education session at a national pain conference held March 6 through March 10, 2019. A published survey instrument developed to assess workplace violence among pain management clinicians was offered to all 70 attendees, and 58 (82.9%) completed the survey. The mean age of respondents was 47.5 years, and 23 of 56 (41.1%) were female. Of the 58 respondents, 48 (82.8%) reported calling security at least once in the past year, and 39 of 57 (68.4%) reported being threatened with bodily harm. Among those threatened (multiple responses possible per respondent), 41 of 78 responses (52.6%) reported verbal threats, 11 of 78 (14.1%) reported being threatened with an object, and 11 of 78 (14.1%) reported threats of physical violence. Of 59 reponses, 15 (25.6%) endorsed carrying a weapon or using protective equipment. When asked about the clinical context of threats, 37 of 77 responses (48.1%) cited opioid management, 9 (11.7%) cited Workers' Compensation, 6 (7.8%) cited disability request, and 4 (5.2%) cited litigation related to an automobile accident. The observations from this survey suggest that clinicians practicing pain medicine experience workplace violence and threats of violence on a frequent basis. It is imperative for clinicians to acknowledge the risk of workplace violence and to recognize high-risk clinical scenarios. Future research should be directed toward developing and implementing data-driven risk mitigation strategies aimed at reducing the rate of workplace violence in outpatient pain clinics.

Prevalence of smoking in adults with spinal cord stimulators: a systematic review and meta-analysis.

BACKGROUND: Smoking adversely impacts pain-related outcomes of spinal cord stimulation (SCS). However, the proportion of SCS patients at risk of worse outcomes is limited by an incomplete knowledge of smoking prevalence in this population. Thus, the primary aim of this systematic review is to determine the prevalence of smoking in adults with chronic pain treated with SCS. METHODS: A comprehensive search of databases from 1 January 1980 to 3 January 2019 was conducted. Eligible study designs included (1) randomized trials; (2) prospective and retrospective cohort studies; and (3) cross-sectional studies. The risk of bias was assessed using a tool specifically developed for prevalence studies. A total of 1619 records were screened, 19 studies met inclusion criteria, and the total number of participants was 10 838. RESULTS: Thirteen studies had low or moderate risk of bias, and six had a high risk of bias. All 19 studies reported smoking status and the pooled prevalence was 38% (95% CI 30% to 47%). The pooled prevalence in 6 studies of peripheral vascular diseases was 56% (95% CI 42% to 69%), the pooled prevalence of smoking in 11 studies of lumbar spine diagnoses was 28% (95% CI 20% to 36%) and the pooled prevalence in 2 studies of refractory angina was 44% (95% CI 31% to 58%). CONCLUSIONS: The estimated prevalence of smoking in SCS patients is 2.5 times greater than the general population. Future research should focus on development, testing and deployment of tailored smoking cessation treatments for SCS patients.

High Cervical Intrathecal Targeted Drug Delivery: A Case Report of Refractory Oropharyngeal Cancer Pain.

INTRODUCTION: Some patients with head and neck cancers have pain refractory to aggressive multimodal therapies. Herein, we report the use of an intrathecal targeted drug delivery (TDD) system catheter tip placed at C1 for the treatment of recalcitrant oropharyngeal cancer pain. CASE REPORT: A patient with recurrent metastatic squamous cell tongue cancer reported severe pain not controlled despite high-dose opioids and nonopioid adjuvants. It was elected to proceed with an intrathecal TDD system with the catheter tip placed at the C1 level. After pump placement, we were able to decrease her daily oral morphine equivalents (OME) from nearly 1000 mg to 300 mg over the course of two months while titrating her TDD from 0.3 mg/day to 0.7 mg/day of intrathecal hydromorphone. Unfortunately, her improvement was limited secondary to aggressive cancer-directed treatments likely contributing to device infection and explant. CONCLUSIONS: In this patient, high cervical placement of an intrathecal TDD catheter was associated with a decrease in OME. While used in clinical practice on occasion, the use of high cervical TDD placement such as this implantable C1 intrathecal TDD system for cancer-associated pain is underreported in the literature. Further studies on this intervention within this challenging population are warranted.

Red blood cell transfusion in acute brain injury subtypes: An observational cohort study.

PURPOSE: Optimal red blood cell (RBC) transfusion thresholds in acute brain injury (ABI) are poorly defined. MATERIALS AND METHODS: We conducted a retrospective cohort study of adult patients with ABI and moderate anemia (Hb 7-10 g/dL) in a neurological intensive care unit (ICU) at an academic medical center between 2008 and 2015. Transfused and non-transfused patients were matched based on age, ABI subtype, pre-transfusion hemoglobin, and ICU length of stay (LOS) at the time of RBC transfusion. Multivariable regression analyses were performed to assess the relationship between RBC transfusion and hospital LOS, hospital mortality, ICU LOS, ICU mortality, and 24 h change in sequential organ failure assessment (SOFA) scores. RESULTS: 2638 patients met inclusion criteria, with 225 (8.5%) receiving RBC transfusion. Acute ischemic stroke was the most prevalent ABI diagnosis (43.3%) then intracranial hemorrhage (25.6%), subarachnoid hemorrhage (16.5%), and traumatic brain injury (TBI) (14.6%). In multivariable analyses, RBC transfusion was associated with longer hospital and ICU LOS, and higher SOFA scores. Each ABI subtype had similar results, except for TBI which showed no difference in hospital LOS. Mortality was not significantly different. CONCLUSIONS: In moderately anemic patients with ABI, RBC transfusion was associated with longer hospital and ICU LOS. Prospective investigations are necessary to further assess these relationships.

Impact of individualized target mean arterial pressure for septic shock resuscitation on the incidence of acute kidney injury: a retrospective cohort study.

BACKGROUND: To examine the relationship between delta mean arterial pressure (ΔMAP; MAP change between pre-admission minus post-resuscitation) and acute kidney injury (AKI) among patients with septic shock. In this retrospective, single-center cohort study of adult patients pre-admission MAP is defined as the median MAP recorded from 365 to 7 days before admission. Post-resuscitation MAP was median MAP during the 7th hour after initiating resuscitation. RESULTS: In our cohort (N = 233; 55% male), the median (interquartile range [IQR]) age was 71 (58-81) years and the median (IQR) acute physiology, age, chronic health evaluation (APACHE) III score was 81 (66-97). Although those in the lowest ΔMAP quartile (-24.5 to 3.9 mmHg) had no demographic differences compared with the rest of the cohort, the odds ratio for AKI was 0.26 (95% CI 0.11-0.57) after adjustment for other known AKI risk factors. Among patients with a history of hypertension, the lowest quartile had an odds ratio for AKI of 0.12 (95% CI 0.04-0.37) after adjusting for risk factors for AKI in this cohort. CONCLUSIONS: The incidence of AKI was lowest among those whose post-resuscitation MAP was closest to or higher than their pre-admission MAP. Further study regarding the effect of targeting the pre-admission MAP for post-resuscitation on the incidence of AKI is warranted.