Co-occurrence of pain syndromes.

Many pain conditions in patients tend to co-occur, influencing the clinical expressions of each other in various ways. This paper summarizes the main concurrent pain conditions by analyzing the major interactions observed. In particular, co-occurrence will be examined in: visceral pain (especially ischemic heart disease, irritable bowel syndrome, dysmenorrhea/endometriosis and urinary pain), fibromyalgia, musculoskeletal pain and headache. Two concurrent visceral pains from internal organs sharing at least part of their central sensory projection can give rise to viscero-visceral hyperalgesia, i.e., enhancement of typical pain symptoms from both districts. Visceral pain, headache and musculoskeletal pains (myofascial pain from trigger points, joint pain) can enhance pain and hyperalgesia from fibromyalgia. Myofascial pain from trigger points can perpetuate pain symptoms from visceral pain conditions and trigger migraine attacks when located in the referred pain area from an internal organ or in cervico-facial areas, respectively. The pathophysiology of these pain associations is complex and probably multifactorial; among the possible processes underlying the mutual influence of symptoms recorded in the associations is modulation of central sensitization phenomena by nociceptive inputs from one or the other condition. A strong message in these pain syndrome co-occurrence is that effective treatment of one of the conditions can also improve symptoms from the other, thus suggesting a systematic and thorough evaluation of the pain patient for a global effective management of his/her suffering.

The Effects of Ultrasound-Guided Transversus Abdominis Plane Block on Acute and Chronic Postsurgical Pain After Robotic Partial Nephrectomy: A Prospective Randomized Clinical Trial.

BACKGROUND: Use of a locoregional analgesia technique, such as the ultrasound-guided transversus abdominis plane block (TAPb), can improve postoperative pain management. We investigated the role of TAPb in robotic partial nephrectomy, a surgery burdened by severe postoperative pain. METHODS: In this prospective trial, patients with American Society of Anesthesiologists class I-III physical status undergoing robotic partial nephrectomy were randomly assigned to standard general anesthetic plus ultrasound-guided TAPb (TAP group) or sole standard general anesthetic (NO-TAP group). The primary end point was morphine consumption 24 hours after surgery. Secondary outcomes were postoperative nausea and vomiting in the first 24 hours, sensitivity, and acute and chronic pain, as measured by multiple indicators. RESULTS: A total of 96 patients were evaluated: 48 patients in the TAP group and 48 in the NO-TAP group. Median morphine consumption after 24 hours was higher in the NO-TAP group compared with the TAP group (14.1 ± 4.5 mg vs 10.6 ± 4.6, P < 0.008). The intensity of acute somatic pain and the presence of chronic pain at three and six months were higher in the NO-TAP group. CONCLUSIONS: Our results show that TAPb can significantly reduce morphine consumption and somatic pain, but not visceral pain. TAPb reduced the incidence of chronic pain.

Rates and Correlates of Unemployment Across Four Common Chronic Pain Diagnostic Categories.

PURPOSE: To examine rates and correlates of unemployment across distinct common chronic pain diagnoses. METHODS: Data were analyzed from a sample of 2,382 patients with chronic pain in the Quebec Pain Registry (QPR). Patients were grouped into the following diagnostic categories based on their primary pain diagnosis recorded in the QPR: musculoskeletal pain; myofascial pain; neuropathic pain, and visceral pain. Analyses were performed to examine the associations between pain diagnosis, patient demographics, pain intensity, depressive symptoms, and unemployment status. RESULTS: Pain diagnosis, age, marital status, education, pain intensity, and depressive symptoms were each significant unique predictors of unemployment status in a hierarchical logistic regression analysis; the addition of depressive symptoms in this model contributed to the greatest increment of model fit. CONCLUSIONS: Depressive symptoms are associated with unemployment across a number of common chronic pain conditions, even when controlling for other factors that are associated with unemployment in these patients. Depressive symptoms, as a modifiable factor, may thus be an important target of intervention for unemployed patients with chronic pain.

[Visceral pain]. / Viszeraler Schmerz.

Chronic visceral pain is an unresolved neurobiological, medical and socioeconomic challenge. Up to 20% of the adult population suffer from chronic visceral pain and abdominal complaints constitute a prevalent symptom also in children and adolescents. Existing treatment approaches are often unsuccessful and patients typically suffer from multiple somatic and psychological symptoms. This complex situation requires integrative treatment approaches. This review summarizes current basic and clinical research on acute and chronic visceral pain with a focus on research groups in Germany. Despite significant clinical and scientific advances, a number of questions remain open calling for more funding to support research to elucidate the complex pathophysiology of chronic visceral pain and to develop and test new treatment approaches. Research support should focus on interdisciplinary concepts and methodology using expertise from multiple disciplines. The field would also benefit from a broader integration of visceral pain into teaching curricula in medicine and psychology and should aim to motivate young clinicians and scientists to strive for a career within this important and highly fascinating area.

Early pain after laparoscopic inguinal hernia repair. A qualitative systematic review.

BACKGROUND: Early post-operative pain after laparoscopic groin hernia repair may, as in other laparoscopic operations, have its own individual pain pattern and patient-related predictors of early pain. The purpose of this review was to characterise pain within the first post-operative week after transabdominal pre-peritoneal repair (TAPP) and total extraperitoneal repair (TEP), and to identify patient-related predictors of early pain. METHODS: A qualitative systematic review was conducted. Pubmed, Embase, CINAHL, and the Cochrane database were searched for studies on early pain (first week) after TAPP or TEP. RESULTS: We included 71 eligible studies with 14,023 patients. Post-operative pain is most severe on day 0 and mainly on a level of 13-58 mm on a visual analogue scale and decreases to low levels on day 3. There seems to be no difference in pain intensity and duration when TEP and TAPP are compared. Deep abdominal pain (i.e. groin pain/visceral pain) dominates over superficial pain (i.e. somatic pain) and shoulder pain (i.e. referred pain) after TAPP. Predictors of early pain are young age and pre-operative high pain response to experimental heat stimulation. Furthermore, evidence supported early pain intensity as a predictive risk factor of chronic pain after laparoscopic groin hernia repair. CONCLUSION: Early pain within the first week after TAPP and TEP is most severe on the first post-operative day, and the pain pattern is dominated by deep abdominal pain. Early post-operative pain is most intense in younger patients and can be predicted by pre-operative high pain response to experimental heat stimulation.

[Psychosocial aspects and body pain: results from an employee survey in the frame of the MAF-project "integrated health management in companies: employee survey about working conditions as management tool"]. / Psychosoziale Aspekte und körperliche Beschwerden - Ergebnisse einer Mitarbeiterbefragung im Rahmen des MAF-Projekts "Ganzheitliches betriebliches Gesundheitsmanagement: Mitarbeiterbefragung über Arbeitsbedingungen als Führungselement"

INTRODUCTION: The aim of the study is to present a compact employee attitude survey for companies within a health care management tool. Beside body pains work-related psychosocial risk factors as well as further influencing factors, are taken into consideration. The questionnaire was evaluated by 6 Bavarian companies. METHOD: Potential influencing factors on physical problems like back pain, neck- and shoulder tension, gastro-intestinal diseases and headache were examined by multiple analysis. Dissatisfaction with working conditions was also examined in the same way. All analyses were carried out age and sex adjusted. RESULTS: Statistical analyses are based on 3,720 employees of 3 companies out of a total of 6 companies who answered the questionnaires. Response rates of the different companies ranged from 34 to 60%. Psychomental demands and psychosocial strains were found to be the strongest predictors for body pains as well as for dissatisfaction with working conditions. CONCLUSIONS: The introduced questionnaire is easy to implement within the framework of a company health care management. It has an holistic approach. We could demonstrate that this instrument is able to reveal multiple aspects of work-related body pain as well as multiple aspects of dissatisfaction with working conditions. Thus it is a starting point for the development of necessary measures for health promotion.

Visceral pain as a triggering factor for fibromyalgia symptoms in comorbid patients.

Fibromyalgia syndrome (FMS) is a central sensitization syndrome; however, peripheral pain sources potentially exacerbate its symptoms of chronic diffuse musculoskeletal pain and hyperalgesia. This prospective study evaluated visceral pain as a possible triggering factor for FMS pain and hyperalgesia in comorbid patients. Women with (1) FMS + irritable bowel syndrome (IBS); (2) FMS + primary dysmenorrhea (Dys); (3) FMS + Dys secondary to endometriosis (Endo); (4) FMS + colon diverticulosis (Div) were compared with FMS-only women, for fibromyalgia pain (number and intensity of episodes and analgesic consumption) over comparable periods and for somatic hyperalgesia (electrical and pressure pain thresholds) in painful (tender points) and control areas (trapezius, deltoid, quadriceps muscles, and overlying subcutis and skin). In comorbid subgroups, FMS symptoms were also reassessed after treatment of the visceral condition or no treatment. All comorbid groups vs FMS-only had significantly higher FMS pain (number/intensity of episodes and analgesic consumption) and hyperalgesia in deep somatic tissues (subcutis and muscle) at all sites (0.05 < P < 0.0001). Visceral pain (number of IBS days, painful menstrual cycles, and abdominal pain episodes from diverticulitis) correlated directly with all parameters of FMS pain and inversely with muscle pain thresholds at all sites (0.03 < P < 0.0001). Fibromyalgia syndrome pain and hyperalgesia in all tissues and all sites significantly decreased in patients after visceral comorbidity treatment (dietary for 6 months [IBS], hormonal for 6 months [dysmenorrhea], laser [endometriosis], and surgery [diverticulosis]) (0.05 < P < 0.0001) vs no change in untreated patients. Visceral pain enhances FMS symptoms, probably augmenting the level of central sensitization typical of the syndrome. Systematic assessment and treatment of visceral pain comorbidities should be a part of FMS management strategy.

Effects of Intrathecal Dexmedetomidine as an Adjuvant to Hyperbaric Bupivacaine for Spinal Anaesthesia in Adults Undergoing Elective Infra-umbilical Surgery.

INTRODUCTION: Various adjuvants to local anaesthetic are used to improve quality and duration of spinal anaesthesia. Dexmedetomidine, a novel alpha-2 adrenergic agonist, has been proposed to augment local anaesthetic effects. This study aims to investigate effects of intrathecal Dexmedetomidine on duration of analgesia and duration of sensory block during spinal anaesthesia. METHODS: In this randomized double-blind study 38 patients were allocated into each of two groups. Otherwise healthy patients (18 to 75 years) scheduled for inguinal hernia repair or vaginal hysterectomy were included. For spinal anaesthesia, Group A received 2.5 ml hyperbaric Bupivacaine 0.5%, whereas Group B received five micrograms intrathecal Dexmedetomidine in addition. Characteristics of sensory and motor blocks, duration of analgesia, analgesic requirements, and side effects were studied for 24 hours. Student's t-test for quantitative variables and Chi- squared test for qualitative variables were used for statistical analysis. RESULTS: Duration of analgesia was prolonged in Group B (326 min ±91) as compared to 217 min ±98 in Group A (P value <0.05). Sensory and motor block durations were significantly prolonged in Group B. Time taken to reach significant peak sensory block level was earlier in Group B. Significant reductions in incidence of visceral pain, shivering and analgesic requirements were observed in Dexmedetomidine group, without increased need of medications for altered hemodynamic parameters. CONCLUSIONS: Dexmedetomidine as an intrathecal adjuvant to hyperbaric Bupivacaine in spinal anaesthesia prolongs duration of analgesia and sensory block with minimal adverse effects.

Irritable Bowel Syndrome: A Clinical Review.

Symptoms of irritable bowel syndrome (IBS) are common in population studies including chronic abdominal pain associated with altered bowel habits. Patients often have associated gastrointestinal and somatic symptoms suggesting a possible common contributing mechanism, but the heterogeneous symptom patterns of individual patients make generalizations difficult. The pathophysiology of IBS is incompletely understood but includes disturbances of the brain-gut axis. Central mechanisms are: the psychosocial history and environment, dysfunctional brain processing of peripheral signals attributed to the intestine including the enteric nervous system, the microbiome and the innate and adaptive immune system. As a result there is visceral hypersensitivity and disturbed intestinal secretory and motor activity. Some mechanisms of visceral pain hypersensitivity may overlap with other pain syndromes including fibromyalgia (FMS). Central Sensitization (CS) would offer a way to conceptualize an integration of life experience and psychologic response into a biopsychosocial framework of pathophysiology, diagnosis and treatment of IBS. Corticotropin-releasing factor, a principle regulator in the stress and pain response may contribute to a neuroendocrine mechanism for the brain-gut interaction. The positive diagnostic approach to IBS symptoms to avoid excess testing and enhance the patient-provider therapeutic relationship requires the recognition of the "cluster" of IBS symptoms while identifying "alarm" symptoms requiring specific attention. The severity of the symptoms and other individual psychosocial factors characterize patients who seek medical care. The presence of significant psychosocial comorbidities adds to the complexity of management which often requires a multidisciplinary approach. Several treatment options exist but no single method is effective for all the symptoms of IBS. The therapeutic benefit of the well-executed physician-patient relationship is considered essential to success in managing IBS symptoms over the long term.

The effects of gabapentin in two animal models of co-morbid anxiety and visceral hypersensitivity.

Visceral hypersensitivity and an increased response to stress are two of the main symptoms of irritable bowel syndrome. Thus efforts to develop animal models of irritable bowel syndrome have centred on both of these parameters. The anticonvulsant gabapentin, which is widely used as an analgesic agent, also reduces anxiety. No data exists to our knowledge of the effects of gabapentin in animal models of co-morbid exaggerated stress response and visceral pain. Our aim was to assess the effect of gabapentin on stress and visceral hypersensitivity in two different animal models of irritable bowel syndrome. The animal models employed were the genetically susceptible Wistar Kyoto rat and the neonatally stressed maternal separation model. These animals were subjected to the open field paradigm to assess stress-induced defecation rates and colorectal distension to assess the level of visceral sensitivity. Gabapentin (30 mg/kg) prevented the stress-induced increase in faecal pellet output in the maternally separated rat, but not the Wistar Kyoto animals. On the other hand gabapentin (30 mg/kg) reduced the number of pain behaviours in response to colorectal distension in both models. These results show that whilst both models have similar responses to gabapentin in terms of visceral pain they differ in terms of their physiological response to stress. This indicates that the origin of anxiety and perhaps then visceral hypersensitivity differs in these models. Overall, these data suggest that gabapentin may be a useful treatment in disorders of co-morbid pain and an overactive stress system such as irritable bowel syndrome.