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.

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.

Sensor-driven position-adaptive spinal cord stimulation for chronic pain.

BACKGROUND: Variation in the intensity of neurostimulation due to body position is a practical problem for many patients implanted with spinal cord stimulation (SCS) systems because positional changes may result in overstimulation or understimulation that leads to frequent need for compensatory manual programming adjustments. OBJECTIVES: The purpose of this study was to assess the safety and effectiveness of a novel type of SCS therapy designed to automatically adapt stimulation amplitude in response to changes in a patient's position or activity.The primary objective of the study was to demonstrate that automatic position adaptive SCS benefited patients in terms of pain relief and/or convenience compared with neurostimulation adjusted with conventional manual programming. Secondary objectives included assessment of worsened pain relief with automatic adjustment; change in pain score; and the number of manual programming adjustments with position-adaptive neurostimulation compared with manual programming. STUDY DESIGN: Prospective, multicenter, open-label, randomized crossover study. SETTING: Ten interventional pain management centers in the US. METHODS: Patients were enrolled a minimum of one week after a successful SCS screening trial. They were then implanted with the RestoreSensor neurostimulation device (Medtronic, Inc., Minneapolis, MN) that could be programmed to either automatic position-adaptive stimulation (AdaptiveStim) or manual adjustment of stimulation parameters. After implant, all devices were programmed to conventional manual adjustment for a 4-week postoperative period. The patients were then randomized to either conventional manual programming adjustment or position-adaptive stimulation with crossover to the opposite treatment arm occurring at 6 weeks after randomization. The patients were followed for another 6 weeks after crossover. This study was conducted under an FDA-approved Investigational Device Exemption (IDE) and approval of the responsible Institutional Review Boards (IRBs) of the study centers. RESULTS: Seventy-nine patients were enrolled in the study. In an intent-to-treat analysis, 86.5% of patients achieved the primary objective of improved pain relief with no loss of convenience or improved convenience with no loss of pain relief using automatic position-adaptive stimulation compared with using conventional manual programming adjustment alone. This was statistically significantly greater than the predefined minimum success rate of 25%, p < 0.001 (exact one-sided 97.5% lower confidence limit was 76.5%). Only 2.8% of patients reported worsened pain relief during position-adaptive stimulation compared with manual programming. There was a statistically significant reduction in the mean numeric pain rating scale score compared with baseline scores in both treatment arms. Additionally, position-adaptive stimulation demonstrated a statistically significant 41% reduction in the daily average number of programming button presses for amplitude adjustment compared with manual programming (18.2 per day versus 30.7 per day, P = 0.002). Functional improvements reported with position-adaptive stimulation included: improved comfort during position changes (80.3%); improved activity (69%); and improved sleep (47.9%). Adverse events associated with uncomfortable sensations from stimulation did not differ significantly between treatment arms. The incidence of device-related serious adverse events was 3.9%. LIMITATIONS: Patients and physicians were not blinded to whether devices were programmed to automatic position-adaptive stimulation or manual adjustment. Responses to assessment questionnaires were based on patient recall. CONCLUSIONS: The study demonstrated that automatic position-adaptive stimulation is safe and effective in providing benefits in terms of patient-reported improved pain relief and convenience compared with using manual programming adjustment alone. CLINICAL TRIAL: NCT01106404.

Automatic adaptation of neurostimulation therapy in response to changes in patient position: results of the Posture Responsive Spinal Cord Stimulation (PRS) Research Study.

BACKGROUND: Variation in the intensity of neurostimulation with body position is a practical problem for many patients implanted with a spinal cord stimulation system because positional changes may result in overstimulation or understimulation. These posture-related changes in patients' perception of paresthesia can affect therapeutic outcomes of spinal cord stimulation therapy. An accelerometer-based algorithm that automatically adjusts spinal cord stimulation based on sensed body position or activity represents a potential solution to the problem of position-mediated variations in paresthesia perception. OBJECTIVE: The objective of this study was to compare patient satisfaction ratings for manual versus automatic adjustment of spinal cord stimulation amplitude in response to positional changes. STUDY DESIGN: Prospective, multicenter, open-label, randomized trial SETTING: 2 pain centers in the US. METHOD: Twenty patients at 2 centers in the U.S. who had been implanted with a spinal cord stimulation system for low back and/or leg pain were enrolled in the study. During a 3-day run-in phase, patient position and activity changes were monitored with an ambulatory data recorder and with a research patient programmer which recorded all stimulation parameter changes. Patients who made >/= 2 amplitude adjustments per 24-hour period were invited to participate in an in-clinic phase. During the in-clinic phase, patients' preferred stimulation amplitude and therapy impedance measured at the preferred stimulation amplitude were determined as they performed a series of 8 physical tasks. Satisfaction ratings were determined during position transitions between the physical tasks using both manual and automatic adjustments. RESULTS: Among the 15 patients who completed the in-clinic test protocol, overall satisfaction ratings were significantly higher for automatic adjustment of stimulation amplitudes versus manual adjustments. Patients reported statistically significant improvements with automatic versus manual adjustment for the standing to supine transition and for supine to standing transition. Approximately 74% of participants rated the paresthesia intensity of the automatic adjustment algorithm as "just right" for the physical tasks that were completed. LIMITATIONS: Small study size. CONCLUSION: Patients preferred automatic versus manual adjustment of stimulation amplitude in response to changes in paresthesia consequent to positional changes during in-clinic testing.

Cardiovascular effects of spinal cord stimulation in hypertensive patients.

BACKGROUND: Several animal and clinical studies have shown that thoracic spinal cord stimulation (SCS) may decrease mean arterial pressure (MAP). A previous study in normotensive participants demonstrated a small reduction in MAP during SCS at the T5-T6 spinal level. It has also been demonstrated that chronic SCS at the subthreshold stimulation level significantly improved angina attacks and 6-minute hall walk distance in drug refractory angina patients. OBJECTIVES: To determine if thoracic SCS at 2 different stimulation strengths would decrease blood pressure (BP) and heart rate (HR) during baseline conditions and during activation of the sympathetic system by the cold pressor test (CPT). METHODS: Six hypertensive participants and 9 normotensive participants were evaluated. The SCS leads were implanted under sedation (midazolam and fentanyl) 3 days prior to the study. The SCS device was not implanted at the time of lead implantation; the exteriorized leads were connected to an external programmer at the time of the study. MAP was measured at the finger using beat-to-beat photoplethysmographic recordings at rest and during CPT with a Finometer (Model 1, Finapress Medical Systems, Amsterdam, The Netherlands). SCS at threshold (100%, SCS100) and subthreshold (80%, SCS80) intensities were randomly performed in the T5-T6 region of the spinal cord during normal conditions as well as during CPT. Each participant had 3 CPTs with the placebo (control, no SCS) CPT always performed first. CPT was performed by immersing the right hand into ice water for 90 seconds. Thirty seconds of beat-to-beat data prior to starting each CPT (baseline) was analyzed. During the 90 second CPT, the median values of the last 30 seconds of data were used for analysis. Heart rate variability (HRV) during baseline and SCS was computed using Kubios HRV Version 2.0 software (University of Kuopio, Kuopio, Finland). Since the median values of HR, MAP and their changes did not follow a normal distribution, groups were compared with a non-parametric Friedman's or Wilcoxon's signed rank test. The HRV data were normally distributed and a repeated measures analysis of variance (ANOVA) was used. RESULTS: SCS did not significantly alter MAP or HR at baseline nor did it appear to blunt changes in MAP or HR in response to CPT. In the normotensive group, MAP was significantly elevated by a median value of 16 mmHg (P<0.001) during the placebo phase, and by 18 and 10.5 mmHg during the SCS80 and SCS100 phases, respectively. In the hypertensive group, an enhanced response to the CPT was observed. In these participants, the MAP was significantly elevated by a median value of 26.8 mmHg (P<0.001) during the placebo phase, and by 20 and 17 mmHg during the SCS80 and SCS100 phases, respectively. There was a non-significant trend for the CPT-induced increase in BP to be attenuated during SCS80. HRV tended to decrease in both the time and frequency domain in hypertensive participants, although this decrease was not statistically significant. LIMITATIONS: This was a pilot study including a limited number of participants CONCLUSIONS: Acute SCS at the T5-T6 region did not significantly alter MAP or HR compared to baseline (no SCS) in participants without sedation, supporting our previous findings in sedated patients. Hypertensive participants had a heightened response to transient cold stress, consistent with the literature. The observation of the tendency for a reduction in HRV in both the time and frequency domain in hypertensive participants is also consistent with the literature. In contrast to acute SCS, the hemodynamic effects of chronic SCS should be explored in the future.

Mortality associated with implantation and management of intrathecal opioid drug infusion systems to treat noncancer pain.

BACKGROUND: In 2006, the authors observed a cluster of three deaths, which circumstances suggested were opioid-related, within 1 day after placement of intrathecal opioid pumps for noncancer pain. Further investigation suggested that mortality among such patients was higher than previously appreciated. The authors performed investigations to quantify that mortality and compare the results to control populations, including spinal cord stimulation and low back surgery. METHODS: After analyzing nine index cases--three sentinel cases and six identified by a prospective strategy--the authors used epidemiological methods to investigate whether mortality rates reflected patient- or therapy-related differences. Mortality rates after intrathecal opioid therapy and spinal cord stimulation were derived by correlating Medtronic device registration data with de-identified data from the Social Security Death Master File. Aggregate demographic and comorbidity data were obtained from Medicare and United Healthcare population databases to examine the influence of demographics and comorbidities on mortality. RESULTS: Device registration and Social Security analyses revealed an intrathecal opioid therapy mortality rate of 0.088% at 3 days after implantation, 0.39% at 1 month, and 3.89% at 1 yr-a higher mortality than after spinal cord stimulation implants or after lumbar diskectomy in community hospitals. Demographic, illness profile, and mortality analyses of large databases suggest, despite limitations, that excess mortality was related to intrathecal opioid therapy, and could not be fully explained by other factors. These findings were consistent with the nine index cases that revealed that respiratory arrest caused or contributed to death in all patients. No device malfunctions associated with overinfusion were identified among cases where data were available. CONCLUSIONS: Patients with noncancer pain treated with intrathecal opioid therapy experience increased mortality compared to similar patients treated by using other therapies. Respiratory depression as a consequence of intrathecal drug overdosage or mixed intrathecal and systemic drug interactions is one plausible, but hypothetical mechanism. The exact causes for patient deaths and the proportion of those deaths attributable to intrathecal opioid therapy remain to be determined. These findings, although based on incomplete information, suggest that it may be possible to reduce mortality in noncancer intrathecal opioid therapy patients.

Comprehensive evidence-based guidelines for interventional techniques in the management of chronic spinal pain.

BACKGROUND: Comprehensive, evidence-based guidelines for interventional techniques in the management of chronic spinal pain are described here to provide recommendations for clinicians. OBJECTIVE: To develop evidence-based clinical practice guidelines for interventional techniques in the diagnosis and treatment of chronic spinal pain. DESIGN: Systematic assessment of the literature. METHODS: Strength of evidence was assessed by the U.S. Preventive Services Task Force (USPSTF) criteria utilizing 5 levels of evidence ranging from Level I to III with 3 subcategories in Level II. OUTCOMES: Short-term pain relief was defined as relief lasting at least 6 months and long-term relief was defined as longer than 6 months, except for intradiscal therapies, mechanical disc decompression, spinal cord stimulation and intrathecal infusion systems, wherein up to one year relief was considered as short-term. RESULTS: The indicated evidence for accuracy of diagnostic facet joint nerve blocks is Level I or II-1 in the diagnosis of lumbar, thoracic, and cervical facet joint pain. The evidence for lumbar and cervical provocation discography and sacroiliac joint injections is Level II-2, whereas it is Level II-3 for thoracic provocation discography. The indicated evidence for therapeutic interventions is Level I for caudal epidural steroid injections in managing disc herniation or radiculitis, and discogenic pain without disc herniation or radiculitis. The evidence is Level I or II-1 for percutaneous adhesiolysis in management of pain secondary to post-lumbar surgery syndrome. The evidence is Level II-1 or II-2 for therapeutic cervical, thoracic, and lumbar facet joint nerve blocks; for caudal epidural injections in managing pain of post-lumbar surgery syndrome, and lumbar spinal stenosis, for cervical interlaminar epidural injections in managing cervical pain (Level II-1); for lumbar transforaminal epidural injections; and spinal cord stimulation for post-lumbar surgery syndrome. The indicated evidence for intradiscal electrothermal therapy (IDET), mechanical disc decompression with automated percutaneous lumbar discectomy (APLD), and percutaneous lumbar laser discectomy (PLDD) is Level II-2. LIMITATIONS: The limitations of these guidelines include a continued paucity of the literature, lack of updates, and conflicts in preparation of systematic reviews and guidelines by various organizations. CONCLUSION: The indicated evidence for diagnostic and therapeutic interventions is variable from Level I to III. These guidelines include the evaluation of evidence for diagnostic and therapeutic procedures in managing chronic spinal pain and recommendations for managing spinal pain. However, these guidelines do not constitute inflexible treatment recommendations. Further, these guidelines also do not represent "standard of care."

Spinal cord stimulation for patients with failed back surgery syndrome: a systematic review.

BACKGROUND: Failed back surgery syndrome is common in the United States. Management of post lumbar surgery syndrome with multiple modalities includes interventional techniques, resulting in moderate improvement, leaving a proportion of patients in intractable pain. The systematic reviews of long-term benefits and risks of spinal cord stimulation (SCS) for patients with failed back surgery syndrome showed limited to moderate evidence and cost effectiveness. However, with the exponential increase in surgery in the United States, spinal cord implants are also increasing. Thus, the discussion continues with claims of lack of evidence on one hand and escalating increases in utilization on the other hand. STUDY DESIGN: A systematic review of SCS in patients with failed back surgery syndrome. OBJECTIVES: This systematic review is undertaken to examine the evidence from randomized controlled trials (RCTs) and observational studies to evaluate the effectiveness of SCS in post lumbar surgery syndrome and to demonstrate clinical and cost effectiveness. METHODS: Review of the literature was performed according to the Cochrane Musculoskeletal Review Group Criteria as utilized for interventional techniques for randomized trials and the Agency for Healthcare Research and Quality (AHRQ) criteria for observational studies. The 5 levels of evidence were classified as Level I, II, or III with 3 subcategories in Level II based on the quality of evidence developed by the U.S. Preventive Services Task Force (USPSTF). Data sources included relevant literature of the English language identified through searches of PubMed and EMBASE from 1966 to December 2008, and manual searches of bibliographies of known primary and review articles. OUTCOME MEASURES: The primary outcome measure was pain relief (short-term relief < or = one-year and long-term > one-year). Secondary outcome measures of improvement in functional status, psychological status, return to work, and reduction in opioid intake were utilized. RESULTS: The indicated evidence is Level II-1 or II-2 for long-term relief in managing patients with failed back surgery syndrome. LIMITATIONS: The limitations of this review included the paucity and heterogeneity of the literature. CONCLUSION: This systematic review evaluating the effectiveness of SCS in relieving chronic intractable pain of failed back surgery syndrome indicated the evidence to be Level II-1 or II-2 for clinical use on a long-term basis.

Reassessment of evidence synthesis of occupational medicine practice guidelines for interventional pain management.

BACKGROUND: Appropriately developed practice guidelines present statements of best practice based on a thorough evaluation of the evidence from published studies on the outcomes of treatments, which include the application of multiple methods for collecting and evaluating evidence for a wide range of clinical interventions and disciplines. However, the guidelines are neither infallible, nor a substitute for clinical judgment. While the guideline development process is a complex phenomenon, conflict of interest in guideline development and inappropriate methodologies must be avoided. It has been alleged that the guidelines by the American College of Occupational and Environmental Medicine (ACOEM) prevent injured workers from receiving the majority of medically necessary and appropriate interventional pain management services. An independent critical appraisal of both chapters of the ACOEM guidelines showed startling findings with a conclusion that these guidelines may not be applied in patient care as they scored below 30% in the majority of evaluations utilizing multiple standardized criteria. OBJECTIVE: To reassess the evidence synthesis for the ACOEM guidelines for the low back pain and chronic pain chapters utilizing an expanded methodology, which includes the criteria included in the ACOEM guidelines with the addition of omitted literature and application of appropriate criteria. METHODS: For reassessment, randomized trials were utilized as it was in the preparation of the guidelines. In this process, quality of evidence was assessed and recommendations were made based on grading recommendations of Guyatt et al. The level of evidence was determined utilizing the quality of evidence criteria developed by the U.S. Preventive Services Task Force (USPSTF), as well as the outdated quality of evidence criteria utilized by ACOEM in the guideline preparation. Methodologic quality of each individual article was assessed utilizing the Agency for Healthcare Research and Quality (AHRQ) methodologic assessment criteria for diagnostic interventions and Cochrane methodologic quality assessment criteria for therapeutic interventions. RESULTS: The results of reassessment are vastly different from the conclusions derived by the ACOEM guidelines. The differences in strength of rating for the diagnosis of discogenic pain by provocation discography and facet joint pain by diagnostic facet joint nerve blocks is established with strong evidence. Therapeutic cervical and lumbar medial branch blocks and radiofrequency neurolysis, therapeutic thoracic medial branch blocks, cervical interlaminar epidural steroid injections, caudal epidural steroid injections, lumbar transforaminal epidural injections, percutaneous and endoscopic adhesiolysis, and spinal cord stimulation qualified for moderate to strong evidence. Additional insight is also provided for evidence rating for intradiscal electrothermal therapy (IDET), automated percutaneous disc decompression, and intrathecal implantables. CONCLUSION: The reassessment and reevaluation of the low back and chronic pain chapters of the ACOEM guidelines present results that are vastly different from the published and proposed guidelines. Contrary to ACOEM's conclusions of insufficient evidence for most interventional techniques, the results illustrate moderate to strong evidence for most diagnostic and therapeutic interventional techniques.

Acute cardiovascular effects of epidural spinal cord stimulation.

BACKGROUND: Several animal studies support the contention that thoracic spinal cord stimulation (SCS) might decrease arterial blood pressure. OBJECTIVE: To determine if electrical stimulation of the dorsal spinal cord in humans will lower mean arterial pressure (MAP) and heart rate (HR). DESIGN: Case Series METHODS: Ten normotensive subjects that were clinically indicated for SCS testing were studied. Two of the 10 patients who underwent testing were excluded from the analysis because they did not respond to the Cold Pressor Test (CPT). Systolic blood pressure, diastolic blood pressure, and heart rate were measured continuously at the wrist (using the Vasotrac device). SCS was administered with quadripolar leads implanted into the epidural space under fluoroscopic guidance. SCS was randomly performed either in the T1-T2 or T5-T6 region of the spinal cord during normal conditions as well as during transient stress induced by CPT. The CPT was conducted by immersing the non-dominant hand in ice-cold water for 2 minutes. RESULTS: There were moderate decreases in MAP and HR during SCS at the T5-T6 region compared to baseline that did not reach statistical significance. However, SCS at the T1-T2 region tended to increase MAP and HR compared to baseline but the change did not reach statistical significance. Arterial blood pressure was transiently elevated by 9.4 +/- 3.8 mmHg using CPT during the control period with SCS turned off and also during SCS at either the T1-T2 region or T5-T6 region of the spinal cord (by 9.2 +/- 5 mmHg and 10.7 +/- 8.4 mmHg, respectively). During SCS at T5-T6, the CPT significantly increased MAP by 5.9+/-7.1 mmHg compared to control CPT (SCS off). CONCLUSION: This study demonstrated that SCS at either the T1-T2 or T5-T6 region did not significantly alter MAP or HR compared to baseline (no SCS). However, during transcient stress (elevated sympathetic tone) induced by CPT, there was a significant increase in MAP and moderate decrease in HR during SCS at T5-T6 region, which is not consistent with previous data in the literature. Acute SCS did not result in adverse cardiovascular responses and proved to be safe.