[Rebound pain-From definition to treatment]. / "Rebound pain" ­ von der Definition bis zur Therapie.

BACKGROUND: Rebound pain as a side effect of regional anaesthesia is an excessive sensation of pain after the effect of local anaesthesia has subsided. This sensation goes well beyond the normal wound pain following a surgical intervention. This phenomenon has entered focus of research in the past 10 years now, but the specific causes are so far unclear and there are still no targeted treatment recommendations. OBJECTIVE: This review article is intended to give the readership an overview of the current state of research about rebound pain. The theories of pathophysiology are presented and prophylaxis as well as treatment strategies are explained. MATERIAL AND METHODS: For this review article, the publications about rebound pain that appeared from 2005 up to May 2021 in PubMed were reviewed and the authors' definitions of rebound pain as well as the assumptions on pathophysiology and treatment recommendations were summarized. RESULTS AND DISCUSSION: A total of 22 original papers from the years 2005-2021 were evaluated regarding the differences between the definitions of rebound pain, the assumption of its occurrence as well as possible treatment options. It turns out that there is no uniform definition by the professional societies, the pathophysiology has not yet been clearly identified and no clear recommendations for prophylaxis or treatment can be given to date; however, early administration of pain medication (e.g. NSAIDs) before the end of the nerve block has proven to be helpful. Likewise, dexamethasone as an adjuvant to regional anaesthesia shows positive effects regarding the occurrence of rebound pain. In any case, it makes sense to provide patients with comprehensive information about this special side effect of regional anaesthesia so that those affected can correctly classify the excessive pain reaction. Targeted studies to avoid severe pain after regional anaesthesia, e.g. through the addition of adjuvants, are necessary in order to keep side effects as low as possible and thereby improve patient comfort and the acceptance of regional anaesthesia.

Cognitive Change and Relaxation as Key Mechanisms of Treatment Outcome in Chronic Pain: Evidence From Routine Care.

Despite effective treatment approaches within the cognitive behavioral framework general treatment effects for chronic pain are rather small to very small. Translation from efficacy trials to naturalistic settings is questionable. There is an urgent need to improve the effectiveness of well-established treatments, such as cognitive-behavior therapy (CBT) and the investigation of mechanisms of change is a promising opportunity. We performed secondary data analysis from routine data of 1,440 chronic pain patients. Patients received CBT in a multidisciplinary setting in two inpatient clinics. Effect sizes and reliable change indices were computed for pain-related disability and depression. The associations between changes in the use of different pain coping skills (cognitive restructuring, activity despite pain, relaxation techniques and mental distraction) and changes in clinical outcomes were analyzed in structural equation models. Pre-post effect sizes range from g = 0.47 (disability) to g = 0.89 (depression). Changes in the use of cognitive restructuring, relaxation and to a lesser degree mental distraction were associated with changes in disability and depression. Effects from randomized trials can be translated to naturalistic settings. The results complement experimental research on mechanisms of change in the treatment of chronic pain and indicate an important role of cognitive change and relaxation as mechanisms of change. Our findings cautiously suggest that clinicians should optimize these processes in chronic pain patients to reduce their physical and emotional disability.