Biomedical subjects

C Richard Chapman

Publications and source records attributed to C Richard Chapman.

7 recordsLinked to original sources

PubMed2005

Correlation of change in visual analog scale with pain relief in the ED.

OBJECTIVES: To evaluate the validity of change in visual analog Scale (VAS) as a measure of pain relief using a verbal descriptor Scale (VDS) of change in pain. METHODS: A prospective observational study of emergency department patients measured pain with VAS and recorded verbal report of change in pain. RESULTS: One thousand four hundred ninety patients yielded 1999 comparisons between change in VAS and VDS. Correlation of change in VAS and VDS of change in pain was rho = 0.667 ( P < .001). A wide range of change in VAS, large standard deviations for the mean change in VAS, and discordance in the direction of change in VAS were present within each verbal descriptor category. CONCLUSIONS: Change in VAS is moderately correlated with a VDS of change in pain. Wide variability in change in VAS and discordance with a VDS demonstrate that change in VAS is not a valid indicator of pain relief for individual patients.

Adolescent↗

PubMed2005

National Institutes of Health grant awards for pain, nausea, and dyspnea research: an assessment of funding patterns in 2003.

UNLABELLED: We introduce an interactive database that permits description and exploration of National Institutes of Health (NIH) funding patterns for research on pain, nausea, and dyspnea. The database encompasses both basic science and clinical research. This article describes how we created the database, including the procedures we developed for reviewing and classifying research grants. In addition, it reports NIH grants and funding activity for the year 2003, with a breakdown of funding activity by Institute and funding comparisons across Institutes. It also describes a first attempt to identify clinically significant but underfunded research domains. In 2003, the NIH funded 1148 grants having relevance to the domain of pain, representing 2.5% of the total NIH research budget. Of those, 581 grants, or about 1% of the NIH budget, had a primary focus on pain. Of the diseases and conditions addressed by the current implementation, musculoskeletal conditions were the best represented with 105 grants, whereas cardiac conditions had the fewest number of grants with 7. The NIH funded 43 grants for dyspnea research and a scant 29 grants for nausea studies. We discuss the current limitations of the database and our plans for further development. PERSPECTIVE: The interactive database and classification system for pain, nausea, and dyspnea research funded by the NIH reported on in this article represents an objective and verifiable resource for health policy makers and others interested in NIH funding decisions. The high inter-rater reliability achieved attests to the objectivity of the classification method. Initial analyses demonstrate that these data can usefully track funding patterns by NIH institutes and reveal underfunded areas of research.

Budgets↗

PubMed2003

Pain and the defense response: structural equation modeling reveals a coordinated psychophysiological response to increasing painful stimulation.

The defense response theory implies that individuals should respond to increasing levels of painful stimulation with correlated increases in affectively mediated psychophysiological responses. This paper employs structural equation modeling to infer the latent processes responsible for correlated growth in the pain report, evoked potential amplitudes, pupil dilation, and skin conductance of 92 normal volunteers who experienced 144 trials of three levels of increasingly painful electrical stimulation. The analysis assumed a two-level model of latent growth as a function of stimulus level. The first level of analysis formulated a nonlinear growth model for each response measure, and allowed intercorrelations among the parameters of these models across individuals. The second level of analysis posited latent process factors to account for these intercorrelations. The best-fitting parsimonious model suggests that two latent processes account for the correlations. One of these latent factors, the activation threshold, determines the initial threshold response, while the other, the response gradient, indicates the magnitude of the coherent increase in response with stimulus level. Collectively, these two second-order factors define the defense response, a broad construct comprising both subjective pain evaluation and physiological mechanisms.

Adolescent↗

PubMed2003

Pain medication use before ED arrival.

The objective of this study was to determine the frequency and types of pain medications taken before ED arrival based on pain intensity, duration of pain, chief complaint, gender, age, and race. A convenience sample of patients in pain was enrolled in this university hospital-based prospective, observational study. A total of 1233 patients were enrolled. Five hundred thirty-nine of 1233 (44%) patients took pain medication before arrival. Two hundred three (38%) took ibuprofen, 147 of 539 (27%) took oral opioids, and 135 of 539 (25%) took acetaminophen, which were the most frequently used medications. Severity of pain, age, duration of pain, and chief complaint were associated (chi-squared P <.05) with variations in prior medication use. Race and gender were not associated (chi-squared P >.05) with differences in medication use before arrival. Many patients (44%) take medication before arrival in the ED. Age, severity and duration of pain, as well as chief complaint are associated with differences in frequency of self-administered medication.

Age Factors↗

PubMed2003

Pain trajectory of Taiwanese with nasopharyngeal carcinoma over the course of radiation therapy.

The purpose of this study was to describe the characteristics and management of pain among patients with nasopharyngeal carcinoma (NPC) prior to and during the 7-week course of radiation therapy (RT) in Taiwan. Twenty-nine men and 11 women with NPC participated in this prospective, longitudinal study. A modified Brief Pain Inventory was used to assess pain and its interference with daily activities weekly. Medical records were reviewed to abstract pain management and disease data. Findings showed that the pain intensity and pain interference scores escalated prominently at Week 3 and peaked at Week 5, representing the time course of RT complications. Pain prior to RT exacerbated the RT-induced mucositis pain. The pain related to RT for NPC was often severe and undertreated, and affected swallowing and talking more than sleeping or other general activities. We recommend interventions to control pain be instituted prior to Week 3 to minimize the potentiation of subsequent pain.

Adult↗

PubMed2002

Measuring pain: an introspective look at introspection.

The measurement of pain depends upon subjective reports, but we know very little about how research subjects or pain patients produce self-reported judgments. Representationalist assumptions dominate the field of pain research and lead to the critical conjecture that the person in pain examines the contents of consciousness before making a report about the sensory or affective magnitude of pain experience as well as about its nature. Most studies to date have investigated what Fechner termed "outer psychophysics": the relationship between characteristics of an external stimulus and the magnitude and nature of pain experience. In contrast, Fechner originally envisioned that "inner psychophysics" should investigate the relationship between physiological states and subjective experience. Despite the lack of established research tradition, inner psychophysics has a potential utility in elucidating underlying mechanisms for the production of phenomenal self-report. We illustrate this, using causal modeling analyses of the accuracy of self-reported pain ratings from our laboratory. We submit that the results are inconsistent with representationalist assumptions. Converging trends from several domains of consciousness studies seem to suggest that we need to abandon the unquestioned doctrine of representationalism and search for a more viable framework for understanding the generation of subjective self-report.

Adult↗

PubMed2002

A psychophysiological causal model of pain report validity.

The validity of the pain report is vitally important but difficult to assess because pain is a personal experience. Human laboratory research affords an opportunity to investigate validity because one can measure the consistency and sensitivity of pain ratings produced in response to known stimuli. This article presents 2 levels of evidence characterizing the validity of the pain report measure. The within-subject agreement of pain report with known stimulus variation quantifies the criterion validity, or accuracy, of the measure. Causal modeling defines a second, between-subject, level of construct validity by suggesting a psychophysiological mechanism determining the observed individual variation in accuracy. We analyzed pain rating data obtained in a laboratory study where 100 subjects (56 men and 44 women) experienced varied levels of painful fingertip electrical stimulation, delivered in random order across 144 trials. Unknown to the subjects, there were only 3 stimulus intensities. Accuracy, defined operationally as the proportion of variance in pain report explained by stimulus level, ranged from 0.07 to 0.91 with a median of 0.64. Hypothesized determinants of accuracy comprised current intensity, event-related late near field evoked potentials, skin conductance response, heart rate, and pupil diameter change. We limited the evoked potential measures to the amplitude of the negative peak at 150 msec (N150amp) and combined the latter 3 measures to form a single index of overall sympathetic nervous system arousal (Arousal). Although men chose higher stimulus levels for the experiment and had higher Arousal than did women, their mean pain reports and their Accuracy did not differ from those of female subjects. We constructed a sequence of path analysis models designed to clarify the causal contributions of current intensity, N150amp, and Arousal, and to determine whether these relationships differ in men and women. The final model revealed a direct causal chain. Stimulus current determined the amplitude of N150amp (possibly an indicator of attention). N150amp in turn determined Arousal, and Arousal emerged as the sole determinant of the Accuracy of the pain report. In addition, this latter effect differed across the sexes. Men who experienced higher levels of Arousal gave more accurate pain reports than those who had lower levels, but women who had higher levels of Arousal gave less accurate pain reports than those with lower levels. Thus construct validation emerged, not from direct stimulus-response correlation, but from the elucidation of a causal chain that related stimulus to response.

Journal Article↗