Background: Dyspnea is a common, distressing symptom of cardiopulmonary and neuromuscular diseases. Since the ATS published a consensus statement on dyspnea in 1999, there has been enormous growth in knowledge about the neurophysiology of dyspnea and increasing interest in dyspnea as a patient-reported outcome.Purpose: The purpose of this document is to update the 1999 ATS Consensus Statement on dyspnea.Methods: An interdisciplinary committee of experts representing ATS assemblies on Nursing, Clinical Problems, Sleep and Respiratory Neurobiology, Pulmonary Rehabilitation, and Behavioral Science determined the overall scope of this update through group consensus. Focused literature reviews in key topic areas were conducted by committee members with relevant expertise. The final content of this statement was agreed upon by all members.Results: Progress has been made in clarifying mechanisms underlying several qualitatively and mechanistically distinct breathing sensations. Brain imaging studies have consist...

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An Official American Thoracic Society Statement: Update on the Mechanisms, Assessment, and Management of Dyspnea

Pain catastrophizing, or characterizations of pain as awful, horrible and unbearable, is increasingly being recognized as an important factor in the experience of pain. The purpose of this investigation was to examine the association between catastrophizing, as measured by the Coping Strategies Questionnaire Catastrophizing Subscale, and brain responses to blunt pressure assessed by functional MRI among 29 subjects with fibromyalgia. Since catastrophizing has been suggested to augment pain perception through enhanced attention to painful stimuli, and heightened emotional responses to pain, we hypothesized that catastrophizing would be positively associated with activation in structures believed to be involved in these aspects of pain processing. As catastrophizing is also strongly associated with depression, the influence of depressive symptomatology was statistically removed. Residual scores of catastrophizing controlling for depressive symptomatology were significantly associated with increased activity in the ipsilateral claustrum (r = 0.51, P < 0.05), cerebellum (r = 0.43, P < 0.05), dorsolateral prefrontal cortex (r = 0.47, P < 0.05), and parietal cortex (r = 0.41, P < 0.05), and in the contralateral dorsal anterior cingulate gyrus (ACC; r = 0.43, P < 0.05), dorsolateral prefrontal cortex (r = 0.41, P < 0.05), medial frontal cortex (r = 0.40, P < 0.05) and lentiform nuclei (r = 0.40, P < 0.05). Analysis of subjects classified as high or low catastrophizers, based on a median split of residual catastrophizing scores, showed that both groups displayed significant increases in ipsilateral secondary somatosensory cortex (SII), although the magnitude of activation was twice as large among high catastrophizers. Both groups also had significant activations in contralateral insula, SII, primary somatosensory cortex (SI), inferior parietal lobule and thalamus. High catastrophizers displayed unique activation in the contralateral anterior ACC, and the contralateral and ipsilateral lentiform. Both groups also displayed significant ipsilateral activation in SI, anterior and posterior cerebellum, posterior cingulate gyrus, and superior and inferior frontal gyrus. These findings suggest that pain catastrophizing, independent of the influence of depression, is significantly associated with increased activity in brain areas related to anticipation of pain (medial frontal cortex, cerebellum), attention to pain (dorsal ACC, dorsolateral prefrontal cortex), emotional aspects of pain (claustrum, closely connected to amygdala) and motor control. These results support the hypothesis that catastrophizing influences pain perception through altering attention and anticipation, and heightening emotional responses to pain. Activation associated with catastrophizing in motor areas of the brain may reflect expressive responses to pain that are associated with greater pain catastrophizing.

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Pain catastrophizing and neural responses to pain among persons with fibromyalgia

Everybody is an expert on pain, by virtue of biological preparedness and personal experience. Unfortunately, this expertise fails large numbers of people, and we must improve our understanding through theoretical and research advances. A vast research-based literature on the nature and management of pain is now available, and there have been dramatic advances in our understanding and management of pain. Nevertheless, there continue to be major problems in the management of severe acute pain and chronic pain. It is argued that a formulation of pain that explicitly focuses upon social factors would more readily address human needs than models that focus upon biophysical and/or psychological factors alone (intrapersonal processes). Although ancient protective biological systems provide for escape and avoidance of pain, evolution of human capacities for cognitive processing and social adaptation necessitate a model of pain incorporating these capabilities (interpersonal processes). The more inclusive and comprehensive social communication model of pain is described and illustrated.

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The social communication model of pain.

The multiple dimensions of dyspnea: review and hypotheses

Recent studies have identified brain correlates of placebo analgesia, but none have assessed how accurately patterns of brain activity can predict individual differences in placebo responses. We reanalyzed data from two fMRI studies of placebo analgesia (N = 47), using patterns of fMRI activity during the anticipation and experience of pain to predict new subjects' scores on placebo analgesia and placebo-induced changes in pain processing. We used a cross-validated regression procedure, LASSO-PCR, which provided both unbiased estimates of predictive accuracy and interpretable maps of which regions are most important for prediction. Increased anticipatory activity in a frontoparietal network and decreases in a posterior insular/temporal network predicted placebo analgesia. Patterns of anticipatory activity across the cortex predicted a moderate amount of variance in the placebo response (∼12% overall, ∼40% for study 2 alone), which is substantial considering the multiple likely contributing factors. The most predictive regions were those associated with emotional appraisal, rather than cognitive control or pain processing. During pain, decreases in limbic and paralimbic regions most strongly predicted placebo analgesia. Responses within canonical pain-processing regions explained significant variance in placebo analgesia, but the pattern of effects was inconsistent with widespread decreases in nociceptive processing. Together, the findings suggest that engagement of emotional appraisal circuits drives individual variation in placebo analgesia, rather than early suppression of nociceptive processing. This approach provides a framework that will allow prediction accuracy to increase as new studies provide more precise information for future predictive models.

https://www.jneurosci.org/content/jneuro/31/2/439.full.pdf

Predicting individual differences in placebo analgesia: contributions of brain activity during anticipation and pain experience.

Pain is now regarded as 'the fifth vital sign' and patients are frequently asked to score the intensity of their pain on a numerical pain rating scale (NPRS). However, the use of a unidimensional scale is questionable in view of the belief, overwhelmingly supported by clinical experience as well as by empirical evidence from multidimensional scaling and other sources, that pain has at least two dimensions: somatosensory qualities and affect. We used a Chinese translation of the 101 descriptor multidimensional affect and pain survey (MAPS) questionnaire to determine the relative contributions of various dimensions of postoperative pain to a patient's score on a unidimensional NPRS. MAPS and NPRS were administered postoperatively to 69 patients with descending colon carcinoma who were recovering from left hemi-colectomy. Multiple linear regression revealed that the emotional pain qualities supercluster (P=0.0005) and four of its eight subclusters, anxiety, depressed mood, fear and anger, significantly (P=0.001-0.007) predicted a patient's score on the unidimensional NPRS. Notably, none of the 17 subclusters in the somatosensory pain qualities supercluster predicted NPRS scores. It may be concluded that patient scores on unidimensional pain intensity scales reflect the emotional qualities of pain much more than its sensory intensity or other qualities. Accordingly such scales are poor indicators of analgesic requirement. The results also suggest that patients' postoperative anxiety and depression are inadequately treated. Based on our findings we present six unidimensional scales that should yield a more accurate assessment of the sources of a patient's pain.

Unidimensional pain rating scales: a multidimensional affect and pain survey (MAPS) analysis of what they really measure

Fat absorption in essential fatty acid deficiency: a model experimental approach to studies of the mechanism of fat malabsorption of unknown etiology

Chapter 6 – Pain Measurement

Goals: The purpose of this study is to determine the weight given to each of 3 pain dimensions by physicians who assess patients' pain experiences. Background: Pain is a subjective experience that has profound impact on the quality of life. The 101-Multidimensional Affect and Pain Survey (101—MAPS) is currently the only available instrument that takes into account all 3 validated dimensions of pain by classifying 101 items into "superclusters" of sensory pain, suffering, and well-being. Study: Fourteen gastroenterologists, 11 internists, and 11 medicine residents from 2 teaching hospitals rated the items on the 101— MAPS based on their perception of the items' relevance to pain in gastrointestinal diseases, on a scale of 0 (least relevant) to 5 (most relevant). Results: Of the 101 items in the MAPS rated by gastroenterologists, 25 items received a median rating of 4 or above. Of these, 23 were selected from the 57 items in the sensory pain supercluster (40%) and only 1 item each from the 26 in the suffering (3.8%), and the 18 in the well-being (5.5%) dimensions. These proportions were significantly lower for the suffering (P < 0.01) and well-being (P < 0.05) superclusters than for the sensory pain dimension. Conclusions: These findings suggest a bias among physicians toward sensory and against affective qualities when eliciting patients' pain experiences. The results also suggest that this bias is found as early as residency training and persists among specialists.

Susanne Bennett Clark

Papers

Unidimensional pain rating scales: a multidimensional affect and pain survey (MAPS) analysis of what they really measure

Fat absorption in essential fatty acid deficiency: a model experimental approach to studies of the mechanism of fat malabsorption of unknown etiology

Chapter 6 – Pain Measurement

Is There Physician Bias Against Eliciting Affective Qualities of Pain