Although being more challenging to patients, Exposure is an effective treatment, which can be delivered in a psychological treatment setting and should be offered as a short-term treatment. (PsycINFO Database Record

The relevance of a phobia-based conceptualization of fear for individuals with chronic pain has been much debated in the literature. This study investigated whether patients with highly fearful chronic low back pain show distinct physiological reaction patterns compared with less fearful patients when anticipating aversive back pain-related movements. We used an idiosyncratic fear induction paradigm and collected 2 different measures of autonomic nervous system activation and muscle tension in the lower back. We identified 2 distinct psychophysiological response patterns. One pattern was characterized by a moderate increase in skin conductance, interbeat interval (IBI) increase, and muscle tension increase in the lower back. This response was interpreted as an attention reaction to a moderately stressful event. The other pattern, found in 58% of the participants, was characterized by a higher skin conductance response, IBI decrease, and muscle tension increase in the lower back. According to Bradley and Lang defense cascade model, this response is typical of a fear reaction. Participants showing the psychophysiological pattern typical of fear also had elevated scores on some self-report measures of components of the fear-avoidance model, relative to participants showing the reaction pattern characteristic of attention. This study is the first to provide psychophysiological evidence for the fear-avoidance model of chronic pain.

Results indicate that the BAT-Back is a reliable and valid measure of pain-related avoidance behavior. It may be useful for clinicians in tailoring treatments for chronic pain as well as an outcome measure for exposure treatments.

BackgroundThe purpose of the present study is to introduce an adapted protocol of in vivo exposure for fear avoidant back pain patients and its implementation in the German health care system without multidisciplinary teams. Case studies demonstrated promising effects but three preceding randomized controlled trials (RCTs) could not support the former results. More empirical support is necessary to further substantiate the effectiveness of in vivo exposure.MethodsA total of 108 chronic low back pain patients are randomly assigned to one out of three conditions (A: exposure_long (15 sessions), B: exposure_short (10 sessions) or C: control condition cognitive behavioral therapy (15 sessions)). The inclusion criteria are: back pain ≥3 months and a sufficient level of fear-avoidance. An effect evaluation, a process evaluation and an economic evaluation are conducted. Primary outcomes are pain-related disability and pain intensity. Secondary outcomes are: emotional distress, fear avoidance, catastrophizing and costs. Data are collected at baseline, upon completion of the intervention, after 10 sessions, and at six months following completion of treatment. Besides the comparison of exposure in vivo and cognitive behavioral therapy (CBT), we additionally compare a short and a long version of exposure to analyze dose response effects.DiscussionThis is, to our knowledge, the first RCT comparing in vivo exposure to psychological treatment as usual in terms of cognitive behavioral therapy. Results will help to find out whether a tailored treatment for fear avoidant back pain patients is more effective than a general pain management treatment.Trial registrationThe trial has been registered to ClinicalTrial.gov. The trial registration number is NCT01484418

Globally occurring nitrate pollution in groundwater is harming the environment and human health. In situ hydrogen addition to stimulate denitrification has been proposed as a remediation strategy. However, observed nitrite accumulation and incomplete denitrification are severe drawbacks that possibly stem from the specific microbial community composition. We set up a microcosm experiment comprising sediment and groundwater from a nitrate polluted oxic oligotrophic aquifer. After the microcosms were sparged with hydrogen gas, samples were taken regularly within 122 h for nitrate and nitrite measurements, community composition analysis via 16S rRNA gene amplicon sequencing and gene and transcript quantification via qPCR of reductase genes essential for complete denitrification. The highest nitrate reduction rates and greatest increase in bacterial abundance coincided with a 15.3-fold increase in relative abundance of Rhodocyclaceae, specifically six ASVs that are closely related to the genus Dechloromonas. The denitrification reductase genes napA, nirS and clade I nosZ also increased significantly over the observation period. We conclude that taxa of the genus Dechloromonas are the prevailing hydrogenotrophic denitrifiers in this nitrate polluted aquifer and the ability of hydrogenotrophic denitrification under the given conditions is species-specific.