What do people living with chronic pain want from a pain forecast? A research prioritization study.

Because people with chronic pain feel uncertain about their future pain, a pain-forecasting model could support individuals to manage their daily pain and improve their quality of life. We conducted two patient and public involvement activities to design the content of a pain-forecasting model by learning participants' priorities in the features provided by a pain forecast and understanding the perceived benefits that such forecasts would provide. The first was a focus group of 12 people living with chronic pain to inform the second activity, a survey of 148 people living with chronic pain. Respondents prioritized forecasting of pain flares (100, or 68%) and fluctuations in pain severity (94, or 64%), particularly the timing of the onset and the severity. Of those surveyed, 75% (or 111) would use a future pain forecast and 80% (or 118) perceived making plans (e.g., shopping, social) as a benefit. For people with chronic pain, the timing of the onset of pain flares, the severity of pain flares and fluctuations in pain severity were prioritized as being key features of a pain forecast, and making plans was prioritized as being a key benefit.

Questions about Tosepu et al. (2020) "Correlation between weather and Covid-19 pandemic in Jakarta, Indonesia".

A critical review of Tosepu et al. (2020a) "Correlation between weather and Covid-19 pandemic in Jakarta, Indonesia" identifies five questions about the data, analysis, and interpretation of their results. These questions are the number of days and dates of data that go into the analysis, interpretation of the "rapid increase" in COVID-19, 0 °C values of temperature suspected to be missing data, no time lag between the weather on the day of infection and the date the case was recorded in the database, and the significance of their results. The scientific community would benefit from reading answers to the five questions from Tosepu et al.

Heterogeneity in the association between weather and pain severity among patients with chronic pain: a Bayesian multilevel regression analysis.

INTRODUCTION: Previous studies on the association between weather and pain severity among patients with chronic pain have produced mixed results. In part, this inconsistency may be due to differences in individual pain responses to the weather. METHODS: To test the hypothesis that there might be subgroups of participants with different pain responses to different weather conditions, we examined data from a longitudinal smartphone-based study, Cloudy with a Chance of Pain, conducted between January 2016 and April 2017. The study recruited more than 13,000 participants and recorded daily pain severity on a 5-point scale (range: no pain to very severe pain) along with hourly local weather data for up to 15 months. We used a Bayesian multilevel model to examine the weather-pain association. RESULTS: We found 1 in 10 patients with chronic pain were sensitive to the temperature, 1 in 25 to relative humidity, 1 in 50 to pressure, and 3 in 100 to wind speed, after adjusting for age, sex, belief in the weather-pain association, mood, and activity level. The direction of the weather-pain association differed between people. Although participants seem to be differentially sensitive to weather conditions, there is no definite indication that participants' underlying pain conditions play a role in weather sensitivity. CONCLUSION: This study demonstrated that weather sensitivity among patients with chronic pain is more apparent in some subgroups of participants. In addition, among those sensitive to the weather, the direction of the weather-pain association can differ.

Safety of Interlaminar Cervical Epidural Injections: Experience With 12,168 Procedures in a Single Pain Clinic.

BACKGROUND: Cervical epidural steroid injections have long been utilized to treat intraspinal inflammation causing cervicalgia and/or cervical radiculopathy, and much has been written about safety and efficacy. There are published opinions, without evidence basis, that these injections should not be performed above C7-T1 for fear of dural puncture, spinal cord injury, and other complications that might occur more frequently at higher spinal levels. However, many experienced interventional pain physicians believe that epidural injections targeted to the level of spinal inflammation may be more effective. Although medication injected at the lowest cervical level C7-T1 may ascend to higher spinal levels, it often does not since inflammation and swelling at the cervical level of pathology may increase epidural pressure causing the injectate to move caudally down the path of least resistance. OBJECTIVES: We sought to provide evidence for safety of posterior interlaminar epidural steroid injections at spinal levels at and above C7-T1 and to outline a 'best practices' approach to posterior cervical epidural injection based on experience with over 12,000 injections over 2 decades. We provide a discussion of cervical spinal anatomy, preferred technique for injection, and briefly review published literature to date regarding safety and efficacy of this procedure. STUDY DESIGN: Retrospective case series. SETTING: Single center, private practice institution. METHODS: To document safety of interlaminar cervical epidural injections at levels above C7-T1, we conducted a retrospective study where we queried our electronic medical record database for information regarding 12,168 interlaminar cervical epidural steroid injections performed on 6,158 unique patients during a 14-year period by 5 different board-certified interventional pain physicians using similar technique within a single medical practice. Each injection was performed using fluoroscopic guidance with cervical epidurography routinely performed prior to injection of a therapeutic steroid and local anesthetic mixture. We found 129 minor complications (complications that did not require medical care beyond the post-anesthesia care unit [PACU] and 7 complications which we considered serious (required care beyond PACU stay), although no patients suffered paralysis or death. There was no correlation between spinal level of injection and complication rates. RESULTS: Our most common spinal level for injection was C5-6, followed closely by C6-7. Hundreds of injections were performed at spinal levels above C5-6 with the most cephalad level C2-3. LIMITATIONS: Retrospective design. CONCLUSION: Our article supports the contention that interlaminar cervical epidural injections above C7-T1 are safe. Complication rates were not increased with cervical injections cephalad to C7-T1.

Understanding the Predictors of Missing Location Data to Inform Smartphone Study Design: Observational Study.

BACKGROUND: Smartphone location data can be used for observational health studies (to determine participant exposure or behavior) or to deliver a location-based health intervention. However, missing location data are more common when using smartphones compared to when using research-grade location trackers. Missing location data can affect study validity and intervention safety. OBJECTIVE: The objective of this study was to investigate the distribution of missing location data and its predictors to inform design, analysis, and interpretation of future smartphone (observational and interventional) studies. METHODS: We analyzed hourly smartphone location data collected from 9665 research participants on 488,400 participant days in a national smartphone study investigating the association between weather conditions and chronic pain in the United Kingdom. We used a generalized mixed-effects linear model with logistic regression to identify whether a successfully recorded geolocation was associated with the time of day, participants' time in study, operating system, time since previous survey completion, participant age, sex, and weather sensitivity. RESULTS: For most participants, the app collected a median of 2 out of a maximum of 24 locations (1760/9665, 18.2% of participants), no location data (1664/9665, 17.2%), or complete location data (1575/9665, 16.3%). The median locations per day differed by the operating system: participants with an Android phone most often had complete data (a median of 24/24 locations) whereas iPhone users most often had a median of 2 out of 24 locations. The odds of a successfully recorded location for Android phones were 22.91 times higher than those for iPhones (95% CI 19.53-26.87). The odds of a successfully recorded location were lower during weekends (odds ratio [OR] 0.94, 95% CI 0.94-0.95) and nights (OR 0.37, 95% CI 0.37-0.38), if time in study was longer (OR 0.99 per additional day in study, 95% CI 0.99-1.00), and if a participant had not used the app recently (OR 0.96 per additional day since last survey entry, 95% CI 0.96-0.96). Participant age and sex did not predict missing location data. CONCLUSIONS: The predictors of missing location data reported in our study could inform app settings and user instructions for future smartphone (observational and interventional) studies. These predictors have implications for analysis methods to deal with missing location data, such as imputation of missing values or case-only analysis. Health studies using smartphones for data collection should assess context-specific consequences of high missing data, especially among iPhone users, during the night and for disengaged participants.

Targeted Drug Delivery for Chronic Nonmalignant Pain: Longitudinal Data From the Product Surveillance Registry.

OBJECTIVES: To assist in assessment of therapy risks and benefits of targeted drug delivery (TDD) for chronic nonmalignant pain using registry data on product performance, adverse events, and elective device replacement. MATERIALS AND METHODS: The Product Surveillance Registry (PSR) (NCT01524276) is an ongoing prospective, long-term, multicenter registry enrolling consented patients implanted with an intrathecal drug delivery system. Patients are followed prospectively with participating investigators providing pump and catheter performance data for events related to the device, procedure, and therapy. Event descriptions include patient symptoms and outcomes. RESULTS: Registry data from the 4646 patients (59.7% female) treated with TDD for chronic, nonmalignant pain at 59 registry sites between August 2003 and October 2019, with over 17,000 patient-years (4646 patients with 44 months average follow-up), were analyzed. Registry discontinuation was largely (46.2% of discontinued patients) due to study site closure and patient death; exit due to an adverse or device event was limited to 10.2%. CONCLUSIONS: Treating chronic pain with escalating doses of strong systemic opioids often leads to inconsistent pain control, impaired function, untenable side effects, and reduced quality of life and this practice has contributed to the current opioid crisis in the United States. TDD has been an available therapy for these patients for greater than 30 years, and data from this real-world registry offer supporting evidence to the long-term safety of this therapy as an alternative to systemic opioids, as well as insights into patient acceptance and satisfaction.

Patient Satisfaction Following Intrathecal Targeted Drug Delivery for Benign Chronic Pain: Results of a Single-Center Survey Study.

OBJECTIVES: Targeted Drug Delivery (TDD) is commonly used for the management of patients with intractable pain. Past studies have proven efficacy in pain relief and reduction in opioid use and cost-effectiveness in long-term pain management. There are few studies investigating satisfaction among patients with implanted pain pumps that are managed with targeted intrathecal medications. MATERIAL AND METHODS: Patients in a single medical practice implanted with pain pumps for relief of intractable pain were identified and extracted from the electronic health record (EHR). Six hundred and ten active TDD patients were identified and an anonymous 18-question survey was administered to determine satisfaction with TDD therapy. During an 18-month period from May 2018 to August 2019, patients were invited to take a satisfaction survey. Both primary and secondary outcomes were reported as proportions; P < 0.05 was considered significant. RESULTS: Four hundred and forty-three patients (74% of the active pump population) completed the survey. The majority of patients reported improvement in pain, improvement of physical function, improvement in quality of life and reduction in opioid use. Complete discontinuation of oral opioid intake was reported in 38.9% of patients. The majority of patients had a 40 cc reservoir implanted in an upper buttock pocket site and overall, 91% of patients were happy with pump pocket location. CONCLUSION: Intrathecal TDD therapy can relieve pain and improve quality of life in patients with intractable pain and offers a reasonable alternative to long-term oral or skin patch opioid management. Patients utilizing TDD therapy reported high degrees of satisfaction.

Are weather conditions associated with chronic musculoskeletal pain? Review of results and methodologies.

Many people believe that weather influences chronic musculoskeletal pain. Previous studies on this association are narratively reviewed, with particular focus on comparing methodologies and summarising study findings in light of study quality. We searched 5 databases (Medline, Embase, Web of Science, PsycINFO, and Scopus) for observational studies on the association between weather variables and self-reported musculoskeletal pain severity. Of 4707 located articles, 43 were eligible for inclusion. The majority (67%) found some association between pain and a weather variable. Temperature, atmospheric pressure, relative humidity, and precipitation were most often investigated. For each weather variable, some studies found an association with pain (in either direction), and others did not. Most studies (86%) had a longitudinal study design, usually collecting outcome data for less than a month, from fewer than 100 participants. Most studies blinded participants to study aims but were at a high risk of misclassification of exposure and did not meet reporting requirements. Pain severity was most often self-reported (84%) on a numeric rating scale or visual analog scale. Weather data were collected from local weather stations, usually on the assumption that participants stayed in their home city. Analysis methods, preparation of weather data, and adjustment for covariates varied widely between studies. The association between weather and pain has been difficult to characterise. To obtain more clarity, future studies should address 3 main limitations of the previous literature: small sample sizes and short study durations, misclassification of exposure, and approach to statistical analysis (specifically, multiple comparisons and adjusting for covariates).

How the weather affects the pain of citizen scientists using a smartphone app.

Patients with chronic pain commonly believe their pain is related to the weather. Scientific evidence to support their beliefs is inconclusive, in part due to difficulties in getting a large dataset of patients frequently recording their pain symptoms during a variety of weather conditions. Smartphones allow the opportunity to collect data to overcome these difficulties. Our study Cloudy with a Chance of Pain analysed daily data from 2658 patients collected over a 15-month period. The analysis demonstrated significant yet modest relationships between pain and relative humidity, pressure and wind speed, with correlations remaining even when accounting for mood and physical activity. This research highlights how citizen-science experiments can collect large datasets on real-world populations to address long-standing health questions. These results will act as a starting point for a future system for patients to better manage their health through pain forecasts.

Indented intrathecal drug delivery system with loss of reservoir volume.

OBJECTIVES: We report two patients who underwent elective revision surgery were found to have reduced reservoir volumes and indented bottom shield of intrathecal drug delivery system (IDDS). CASE REPORTS: Case #1: A 59-year-old man stable on IDDS medications for chronic neck and upper back pain was found to have an irreversible reduction in reservoir volume from 40 to 28 cc on routine refill appointment. Despite having stable pain control, the reservoir volume decreased from 40 to 22 cc and subsequently to 17 cc when the patient had inadequate pain control. During replacement surgery, the posterior shield of the IDDS was found to be collapsed. The patient had exposure to hyperbaric oxygen treatments for chronic non-healing wounds of the lower extremities. Case #2: A 68-year-old woman had an IDDS implanted for chronic low back pain secondary to failed back surgery syndrome. The reservoir volume was found to be reduced to 15 cc of medication from 20 cc during the seventh year of therapy. There was a report of a fall. Routine reservoir exchange at the end of battery life revealed that the bottom shield of the reservoir was indented. CONCLUSIONS: Inability to refill the medication to full capacity should be an indication to investigate device deformation. Information about exposure to hyperbaric therapy or local trauma should be obtained.

Complications associated with stellate ganglion nerve block: a systematic review.

Stellate ganglion nerve blockade (SGNB) is a vital tool in our armamentarium for the treatment of various chronic pain syndromes. SGNB can be performed using the traditional landmark-based approach, or with image guidance using either fluoroscopy or ultrasound. In this review, we systematically analyzed reported SGNB-related complications between 1990 and 2018. Seven databases were queried for SGNB between January 1, 1990 and November 27, 2018. Search results of the complications associated with SGNB were reported as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations. Out of a total of 1909 articles, 67 articles met our inclusion criteria, yielding 260 cases with adverse events. In 134 of the 260 (51.5%) cases, SGNB was performed with image guidance. Sixty-four (24.6%) and 70 (26.9%) of the complication cases reported the use of ultrasound and fluoroscopy guidance, respectively. One hundred and seventy-eight (68.4%) patients had medication-related or systemic side effects, and 82 (31.5%) had procedure-related or local side effects. There was one report of death due to massive hematoma leading to airway obstruction. There was one case report of quadriplegia secondary to pyogenic cervical epidural abscess and discitis following an SGNB. Complications following SGNB have been reported with both landmark-based techniques and with imaging guidance using fluoroscopy or ultrasound. In our systematic review, most adverse events that were reported occurred during or shortly after SGNB. Vigilance, American Society of Anesthesiologists standard monitors for conscious sedation, and accessibility to resuscitation equipment are vital to the safe performance of SGNB.

Extreme sensitivity in Snowball Earth formation to mountains on PaleoProterozoic supercontinents.

During the PaleoProterozoic 2.45 to 2.2 billion years ago, several glaciations may have produced Snowball Earths. These glacial cycles occurred during large environmental change when atmospheric oxygen was increasing, a supercontinent was assembled from numerous landmasses, and collisions between these landmasses formed mountain ranges. Despite uncertainties in the composition of the atmosphere and reconstruction of the landmasses, paleoclimate model simulations can test the sensitivity of the climate to producing a Snowball Earth. Here we present a series of simulations that vary the atmospheric methane concentration and latitudes of west-east-oriented mountain ranges on an idealised supercontinent. For a given methane concentration, the latitudes of mountains control whether a Snowball Earth forms or not. Significantly, mountains in middle latitudes inhibited Snowball Earth formation, and mountains in low latitudes promoted Snowball Earth formation, with the supercontinent with mountains at ±30° being most conducive to forming a Snowball Earth because of reduced albedo at low latitudes. We propose that the extreme sensitivity of a Snowball Earth to reconstructions of the paleogeography and paleoatmospheric composition may explain the observed glaciations, demonstrating the importance of high-quality reconstructions to improved understanding of this early period in Earth's history.

Effects of a Brief Mindfulness Induction on Death-Related Anxiety.

This study examined effects of a mindfulness induction on proximal and distal defense responses to mortality salience and negative affect. Three experimental conditions were included: mindfulness, mind-wandering, and worrying. Participants in the mindfulness condition underwent a mindfulness induction at the experiment's outset, while participants in the other two conditions underwent a mind-wandering or worry induction. Inductions involved following guided audio instructions presented via headphones. All conditions (N = 77) underwent a mortality salience induction after experimental manipulation, involving a written exercise pertaining to one's death. Results indicated fewer proximal responses in the mindfulness and mind-wandering groups, compared with the worrying group, but no differences in distal responses. Negative affect was lower in the mindfulness group than in the worrying group following mortality salience. Results suggest that mindfulness exercises effectively buffer against negative affect and some responses to mortality salience, although these effects are not different from those of mind-wandering.

Recruitment and Ongoing Engagement in a UK Smartphone Study Examining the Association Between Weather and Pain: Cohort Study.

BACKGROUND: The huge increase in smartphone use heralds an enormous opportunity for epidemiology research, but there is limited evidence regarding long-term engagement and attrition in mobile health (mHealth) studies. OBJECTIVE: The objective of this study was to examine how representative the Cloudy with a Chance of Pain study population is of wider chronic-pain populations and to explore patterns of engagement among participants during the first 6 months of the study. METHODS: Participants in the United Kingdom who had chronic pain (≥3 months) and enrolled between January 20, 2016 and January 29, 2016 were eligible if they were aged ≥17 years and used the study app to report any of 10 pain-related symptoms during the study period. Participant characteristics were compared with data from the Health Survey for England (HSE) 2011. Distinct clusters of engagement over time were determined using first-order hidden Markov models, and participant characteristics were compared between the clusters. RESULTS: Compared with the data from the HSE, our sample comprised a higher proportion of women (80.51%, 5129/6370 vs 55.61%, 4782/8599) and fewer persons at the extremes of age (16-34 and 75+). Four clusters of engagement were identified: high (13.60%, 865/6370), moderate (21.76%, 1384/6370), low (39.35%, 2503/6370), and tourists (25.44%, 1618/6370), between which median days of data entry ranged from 1 (interquartile range; IQR: 1-1; tourist) to 149 (124-163; high). Those in the high-engagement cluster were typically older, whereas those in the tourist cluster were mostly male. Few other differences distinguished the clusters. CONCLUSIONS: Cloudy with a Chance of Pain demonstrates a rapid and successful recruitment of a large, representative, and engaged sample of people with chronic pain and provides strong evidence to suggest that smartphones could provide a viable alternative to traditional data collection methods.

Cloudy with a Chance of Pain: Engagement and Subsequent Attrition of Daily Data Entry in a Smartphone Pilot Study Tracking Weather, Disease Severity, and Physical Activity in Patients With Rheumatoid Arthritis.

BACKGROUND: The increasing ownership of smartphones provides major opportunities for epidemiological research through self-reported and passively collected data. OBJECTIVE: This pilot study aimed to codesign a smartphone app to assess associations between weather and joint pain in patients with rheumatoid arthritis (RA) and to study the success of daily self-reported data entry over a 60-day period and the enablers of and barriers to data collection. METHODS: A patient and public involvement group (n=5) and 2 focus groups of patients with RA (n=9) supported the codesign of the app collecting self-reported symptoms. A separate "capture app" was designed to collect global positioning system (GPS) and continuous raw accelerometer data, with the GPS-linking providing local weather data. A total of 20 patients with RA were then recruited to collect daily data for 60 days, with entry and exit interviews. Of these, 17 were loaned an Android smartphone, whereas 3 used their own Android smartphones. RESULTS: Of the 20 patients, 6 (30%) withdrew from the study: 4 because of technical challenges and 2 for health reasons. The mean completion of daily entries was 68% over 2 months. Patients entered data at least five times per week 65% of the time. Reasons for successful engagement included a simple graphical user interface, automated reminders, visualization of data, and eagerness to contribute to this easily understood research question. The main barrier to continuing engagement was impaired battery life due to the accelerometer data capture app. For some, successful engagement required ongoing support in using the smartphones. CONCLUSIONS: This successful pilot study has demonstrated that daily data collection using smartphones for health research is feasible and achievable with high levels of ongoing engagement over 2 months. This result opens important opportunities for large-scale longitudinal epidemiological research.

Spinal Cord Stimulation (SCS)-The Implantable Systems Performance Registry (ISPR).

OBJECTIVES: The Implantable Systems Performance Registry (ISPR) was created to monitor the product performance of Medtronic Spinal Cord Stimulation (SCS) and implanted intrathecal drug infusion systems available in the United States. MATERIALS AND METHODS: Data were collected on 2605 patients from 44 centers from various geographic regions across the United States implanting and following patients with SCS systems between June 25, 2004 and January 31, 2014. Actuarial life table methods are used to estimate device performance over time. Of the 2605 patients, 1490 (57.2%) were female, 1098 (42.1%) were male and 17 (0.7%) did not provide gender data. The average age at enrollment was 56.3 years (range: 4-97, SD = 14.3) and average follow-up time was 20.1 months (SD = 22.5). RESULTS: Currently the estimates of device survival from neurostimulator-related events exceed 97% for all neurostimulator models across the applicable follow-up time points and all applicable extension models had greater than 95% survival from extension events. The majority of product performance events were lead-related. At 5 years of follow-up, all applicable lead families, with the exception of the Pisces-Quad LZ family, had greater than 75% survival from lead events. CONCLUSIONS: The ISPR is designed to serve as an ongoing source of system and device-related information with a focus on "real-world" safety and product performance. ISPR data continue to be used to guide future product development efforts aimed at improving product reliability and quality.

Increased pain catastrophizing associated with lower pain relief during spinal cord stimulation: results from a large post-market study.

BACKGROUND: Pain catastrophizing is a negative cognitive distortion to actual or anticipated pain. Our aim was to determine if greater catastrophizing has a deleterious relationship with pain intensity and efficacy outcomes in patients receiving SCS. METHODS: As part of an ongoing Institutional Review Board-approved, multi-site, single arm post-market study, 386 patients were implanted with an Eon Mini™ SCS system and had follow-up visits at 3, 6, and 12 months post-implant. Outcomes collected during the study included, but were not limited to pain intensity using the numeric rating scale (NRS), patient reported pain relief (PRP), satisfaction with their SCS system, quality of life (QOL), pain catastrophizing scale (PCS) and state-trait anxiety index (STAI). RESULTS: NRS scores were associated with higher PCS scores at six months (r = 0.50, p < 0.001). The PCS was a strong predictor of the NRS when controlled for known confounders. Patients with PCS ≥30 at 6-months post-implant had a lower six-month PRP (p < 0.001) and were five times more likely to report dissatisfaction with their SCS device (p < 0.001, OR = 5.46, 95% CI: 2.51-6.35). Additionally, at six months, those who were clinically catastrophizing were three times more likely to report deterioration in QOL (p < 0.002, OR = 3.12, 95% CI: 1.62-5.51). These findings were similar at the 12 months follow visit. CONCLUSIONS: Our results indicate that patients with greater catastrophizing, post-implant, were more likely to report higher pain intensity and lower pain relief, quality of life and satisfaction with SCS. These results indicate that associations between pain intensity and pain-related mental health may contribute to influence the overall efficacy of SCS.

Intrathecal gabapentin to treat chronic intractable noncancer pain.

BACKGROUND: Oral gabapentin is approved as an anticonvulsant medication and to treat postherpetic neuralgia. Its nonopioid properties and presumed spinal site of analgesic action made the study on intrathecal gabapentin attractive to establish the minimum effective dose for a later, pivotal trial. METHODS: The authors examined the safety and efficacy of intrathecal gabapentin in a randomized, blinded, placebo-controlled, multicenter trial in a heterogeneous cohort of candidates with chronic pain for intrathecal drug therapy. RESULTS: Patients (N = 170) were randomized to receive continuous intrathecal gabapentin (0 [placebo], 1, 6, or 30 mg/day) during 22 days of blinded treatment after implantation of a permanent drug delivery system. The highest dose, 30 mg/day, was selected to maintain a safety margin below the 100-mg/day dose that was explored in a phase 1 study. The authors found no statistically significant difference in the primary outcome measure, which was the numerical pain rating scale and response rate after 3 weeks, for any dose versus placebo. Physical functioning, quality of life, and emotional functioning also revealed no differences. Small, nonsignificant changes occurred in opioid medication use. The most frequent device-related adverse events were transient postimplant (lumbar puncture) headache, pain, and nausea. The most frequent gabapentin-related adverse events were nausea, somnolence, headache, dizziness, fatigue, and peripheral edema. CONCLUSION: Twenty-two days of intrathecal gabapentin did not demonstrate statistically significant or clinically meaningful analgesic effects. The study sponsor has no current plans for further studies. Drug-related adverse events were similar to those for oral gabapentin. Most device-related adverse events resulted from the implant surgery or anesthesia.

Assessment of bleeding risk of interventional techniques: a best evidence synthesis of practice patterns and perioperative management of anticoagulant and antithrombotic therapy.

BACKGROUND: Interventional pain management is a specialty that utilizes invasive procedures to diagnose and treat chronic pain. Patients undergoing these treatments may be receiving exogenous anticoagulants and antithrombotics. Even though the risk of major bleeding is very small, the consequences can be catastrophic. However, the role of antithrombotic therapy for primary and secondary prevention of cardiovascular disease to decrease the incidence of acute cerebral and cardiovascular events is also crucial. Overall, there is a paucity of literature on the subject of bleeding risk in interventional pain management along with practice patterns and perioperative management of anticoagulant and anti-thrombotic therapy. STUDY DESIGN: Best evidence synthesis. OBJECTIVE: To critically appraise and synthesize the literature with assessment of the bleeding risk of interventional techniques including practice patterns and perioperative management of anticoagulant and antithrombotic therapy. METHODS: The available literature on the bleeding risk of interventional techniques and practice patterns and perioperative management of anticoagulant and antithrombotic therapy was reviewed. Data sources included relevant literature identified through searches of PubMed and EMBASE from 1966 through December 2012 and manual searches of the bibliographies of known primary and review articles. RESULTS: There is good evidence for the risk of thromboembolic phenomenon in patients who discontinue antithrombotic therapy, spontaneous epidural hematomas occur with or without traumatic injury in patients with or without anticoagulant therapy associated with stressors such as chiropractic manipulation, diving, and anatomic abnormalities such as ankylosing spondylitis, and the lack of necessity of discontinuation of nonsteroidal anti-inflammatory drugs (NSAIDs), including low dose aspirin prior to performing interventional techniques. There is fair evidence that excessive bleeding, including epidural hematoma formation may occur with interventional techniques when antithrombotic therapy is continued, the risk of thromboembolic phenomenon is higher than the risk of epidural hematomas with discontinuation of antiplatelet therapy prior to interventional techniques, to continue phosphodiesterase inhibitors (dipyridamole [Persantine], cilostazol [Pletal], and Aggrenox [aspirin and dipyridamole]), and that anatomic conditions such as spondylosis, ankylosing spondylitis and spinal stenosis, and procedures involving the cervical spine; multiple attempts; and large bore needles increase the risk of epidural hematoma; and rapid assessment and surgical or nonsurgical intervention to manage patients with epidural hematoma can avoid permanent neurological complications. There is limited evidence to discontinue antiplatelet therapy with platelet aggregation inhibitors to avoid bleeding and epidural hematomas and/or to continue antiplatelet therapy clopidogrel (Plavix), ticlopidine (Ticlid), or prasugrel (Effient) during interventional techniques to avoid cerebrovascular and cardiovascular thromboembolic fatalities. There is limited evidence in reference to newer antithrombotic agents dabigatran (Pradaxa) and rivaroxaban (Xarelto) to discontinue to avoid bleeding and epidural hematomas during interventional techniques and to continue to avoid cerebrovascular and cardiovascular thromboembolic events. RECOMMENDATIONS: The recommendations derived from the comprehensive assessment of the literature and guidelines are to continue NSAIDs and low dose aspirin, and phosphodiesterase inhibitors (dipyridamole, cilostazol, Aggrenox) during interventional techniques. However, the recommendations for discontinuation of antiplatelet therapy with platelet aggregation inhibitors (clopidogrel, ticlopidine, prasugrel) is variable with clinical judgment to continue or discontinue based on the patient's condition, the planned procedure, risk factors, and desires, and the cardiologist's opinion. Low molecular weight heparin (LMWH) or unfractionated heparin may be discontinued 12 hours prior to performing interventional techniques. Warfarin should be discontinued or international normalized ratio (INR) be normalized to 1.4 or less for high risk procedures and 2 or less for low risk procedures based on risk factors. It is also recommended to discontinue Pradaxa for 24 hours for paravertebral interventional techniques in 2 to 4 days for epidural interventions in patients with normal renal function and for longer periods of time in patients with renal impairment, and to discontinue rivaroxaban for 24 hours prior to performing interventional techniques. LIMITATIONS:   The paucity of the literature. CONCLUSION: Based on the available literature including guidelines, the recommendations in patients with antithrombotic therapy for therapy prior to interventional techniques are provided.