Activation of nociceptors causes them to secrete neuropeptides, such as substance P (SP) and calcitonin-gene related peptide (CGRP). By reacting with receptors on blood vessels these peptides contribute to inflammation by evoking vasodilation and increasing vascular permeability that allows proteins and fluid to leave the blood vessels (plasma extravasation, PE). These substances can also lead to the sensitization of nociceptors and the resulting positive feedback thereby prolongs inflammation and pain. Thus, blocking the release of neuropeptides may have important therapeutic value in pain conditions where neuropeptides have been implicated. Therefore, the aim of this study was to define the time course of changes in vascular permeability and to test the ability of novel agents to modulate this response. PE and vasodilation was evoked by stimulating the saphenous nerve or by injecting the chemical irritant capsaicin into the rat hindpaw. Changes in blood flow were evaluated with a laser Doppler and digitized image analysis was used to measure changes in reflectance of the skin due to accumulation of extravasated (EB) dye. Analysis of the change in pixel intensity in the digitized images revealed that the magnitude of PE was dependent on the stimulus pulse number. Moreover, the time course of enhanced vascular permeability produced by electrical stimulation was a transient event compared to a much longer response with capsaicin. It was also demonstrated that sumatriptan, (a 5-HT1B/D receptor agonist) and botulinum neurotoxin type-A were effective treatments for capsaicin and saphenous nerve induced vasodilation and PE. Neither drug interfered with activation of the SP or CGRP receptor, which may suggest that both drugs work by inhibiting neuropeptide release. Therefore, this study has described the time course of vascular permeability evoked by two different stimuli and has demonstrated the ability of two novel agents to attenuate these responses.

No description available.

Thesis (Ph. D.)--University of Hawaii at Manoa, 1990. / Includes bibliographical references (leaves 145-158) / Microfiche. / viii, 158 leaves, bound 29 cm

This thesis was concerned with determining the scope, nature and impact of pain on quality of life (QOL) among a community-based sample of people with multiple sclerosis (MS). An analysis of the research literature on pain in MS reveals that pain is a significant problem which has historically been underinvestigated and is currently poorly understood. The vast majority of the published literature consists of prevalence studies, descriptive research and clinical reports. Where available, empirical data are often limited by methodological and analytical problems such that substantive conclusions about the scope and nature of MS-related pain remain unclear. Among the most fundamental issues is the extent to which pain is problematic in a population which is already impaired by other physical disabilities. Little is known about how pain contributes to MS-related disability, distress and QOL. Moreover, research examining the psychosocial aspects of MS-related pain is noticeably absent. It is clear that there are substantial gaps in the literature and that many basic questions about the scope, nature and impact of pain problems among individuals with MS remain unanswered. Thus the primary aim of this study was to begin to fill some of these gaps by systematically investigating the following research questions: (1) What is the prevalence and nature of pain experienced by people with MS? (2) What is the impact of pain on the QOL of people with MS, over and above the impact of disability itself? (3) To what extent do physical and psychosocial factors influence adjustment to chronic pain in people with MS? (4) What meaning is given to the pain experience by people with MS? The present study utilised a multimethod research design involving cross-sectional postal survey, structured in-person pain interviews and focus groups. Survey respondents were a 219-person sample recruited from the Queensland MS Society membership database via systematic random sampling. All participants completed a piloted questionnaire containing questions about their demographic and clinical characteristics, validated measures of QOL and MS-related disability, and a question on whether or not they had experienced clinically significant pain in the previous two weeks. Respondents who reported pain then completed face-to-face structured pain interviews assessing pain characteristics (viz. intensity, quality, location, extent and duration), pain-related beliefs and coping strategies, and pain management techniques used. Four focus groups were also conducted that included 32 people with MS living in the community. Study participants were a purposive sample drawn from four MS support groups located in the South-East Queensland region. Pain was found to be common with some 67.1% of the sample reporting pain during the two weeks preceding the study. Comprehensive pain assessment revealed that a substantial subset of these individuals experience chronic pain conditions characterised by moderate-to-severe pain intensity. Pain prevalence and intensity were found to be strongly correlated with QOL: physical health, psychological health, level of independence and global QOL were more likely to be impaired among people with MS when pain was present, and the extent of impairment was associated with the intensity of pain. Moreover, these relationships remained significant even after statistically controlling for multiple demographic and clinical covariates associated with self-reported QOL. Pain-related beliefs and coping strategies were also associated with and explained a significant proportion of the variance in adjustment to pain among people with MS, over and above that accomplished by demographic and MS-related variables and pain intensity. Finally, qualitative data analysis revealed four broad conceptualisations of the experience of chronic MS-related pain including: pain is pervasive, nobody understands, I'm fine, and always a factor in the equation. These findings suggest that for people with MS, pain is an important source of distress and disability over and above that caused by neurological impairments. These data also lead to the hypothesis that recognition and effective treatment of pain would improve the QOL of people with MS, irrespective of their level of neurologic disability. Although correlational, the findings provide support for a biopsychosocial model of pain and adjustment to pain in people with MS.

This study focuses specifically on nurses' actions related to pain. / Thesis (PhD)--University of South Australia, 2000

Thesis (MAppSc in Physiotherapy)--University of South Australia, 1997

Thesis (M.App.Sc. in Physiotherapy)--University of South Australia, 1996.

Doctor of Philosophy / Despite the demonstrated efficacy of cognitive-behavioural therapy for chronic pain, recent research has attempted to identify predictors of treatment outcome in order to improve the effectiveness of such treatments. This research has indicated that variables such as the nature of the onset of the pain and psychopathology are associated with poor adjustment to chronic pain. Accordingly, these variables might also be predictive of poor response to treatment. Individuals who experience a sudden onset of pain following an injury or accident, particularly when the instigating event is experienced as psychologically traumatic, may present for treatment with high levels of distress, including symptoms consistent with a posttraumatic stress response. The impact of this type of onset of pain and posttraumatic stress symptoms on adjustment to chronic pain and treatment outcome is the focus of this thesis. Three studies were conducted to clarify and extend earlier research findings in this area. Using 536 patients referred for treatment in a tertiary referral pain management centre, the first study examined the psychometric properties of a widely used self-report measure of posttraumatic stress symptoms (the PTSD Checklist, or PCL), modified for use in a chronic pain sample. This study provided preliminary support for the suitability of the PCL as a self-report measure of Posttraumatic Stress Disorder (PTSD) symptoms in chronic pain patients. However, the study also highlighted a number of issues with the use of self-report measures of posttraumatic stress symptoms in chronic pain patient samples. In particular, PCL items enquiring about symptoms which are a common aspect of the chronic pain experience (e.g. irritability, sleep problems) appeared to contribute to high mean scores on the PCL Avoidance and Arousal subscales. Furthermore, application of diagnostic cut-off scores and an algorithm recommended for the PCL in other trauma groups suggested that a much larger proportion of the sample was identified as potentially meeting diagnostic criteria for PTSD than would have been expected from previous research. The second study utilised the modified PCL to investigate the impact of different types of onset of pain (e.g. traumatic onset) and posttraumatic stress symptoms on adjustment to chronic pain in a sample of 196 chronic pain patients referred to the same centre. For patients who experienced the onset of pain related to a specific event, two independent experts in the field of PTSD determined whether these events satisfied the definition of a traumatic event according to DSM-IV diagnostic criteria. Adjustment was assessed through a number of validated measures of mood, disability, pain experience, and pain-related cognitions. Contrary to expectations, comparisons between patients who had experienced different types of onset of pain revealed few significant differences between them. That is, analyses comparing patients presenting with accident-related pain, or pain related to other specific events, to patients who had experienced spontaneous or insidious onset of pain revealed no significant differences between the groups on measures of pain severity, pain-related disability, and symptoms of affective distress after adjustment for age, pain duration, and compensation status. Similarly, comparisons between patients who had experienced a potentially traumatic onset of pain with those who had experienced a non-traumatic or spontaneous or insidious onset of pain also revealed no significant differences on the aforementioned variables. In contrast, compensation status, age, and a number of cognitive variables were significant predictors of pain severity, pain-related disability, and depression. The final study investigated the impact of type of pain onset and posttraumatic stress symptoms on response to a multidisciplinary cognitive-behavioural pain management program. Unlike the previous study, this treatment outcome study revealed a number of differences between onset groups. Most notably, patients who had experienced an insidious or spontaneous onset of pain reported greater improvements in pain severity and maintained these improvements more effectively over a one month period than patients who had experienced pain in the context of an accident or other specific incident. There was also limited evidence that improvements in depression favoured patients who had experienced an insidious or spontaneous and non-traumatic onset of pain. Consistent with this, posttraumatic stress symptoms were a significant predictor of treatment outcome, with higher levels of symptoms being associated with smaller improvements in pain-related disability and distress. Notably, this study also revealed that certain cognitive variables (i.e. catastrophising, self-efficacy, and fear-avoidance beliefs) were also significant predictors of treatment outcome, consistent with previous findings in the pain literature. This provided some perspective on the relative roles of both PTSD symptoms and cognitive variables in adjustment to persisting pain and treatment response. These findings were all consistent with expectations and with previous research. Implications for future research and for the assessment and treatment of chronic pain patients who present with posttraumatic stress symptoms are discussed.

Purpose: The purpose of this study was three-fold; to investigate the use of pain assessment tools and pain reduction strategies during minor painful procedures in neonatal units in Australia; to map the history of an infant’s prolonged hospitalisation in a tertiary neonatal intensive care unit with respect to painful procedures and pain management practices, and to describe the effectiveness of oral sucrose in reducing procedural pain during the course of an infant’s prolonged hospitalisation (greater than/equal to 28 days). (For complete abstract open document)

Doctor of Philosophy / Despite the demonstrated efficacy of cognitive-behavioural therapy for chronic pain, recent research has attempted to identify predictors of treatment outcome in order to improve the effectiveness of such treatments. This research has indicated that variables such as the nature of the onset of the pain and psychopathology are associated with poor adjustment to chronic pain. Accordingly, these variables might also be predictive of poor response to treatment. Individuals who experience a sudden onset of pain following an injury or accident, particularly when the instigating event is experienced as psychologically traumatic, may present for treatment with high levels of distress, including symptoms consistent with a posttraumatic stress response. The impact of this type of onset of pain and posttraumatic stress symptoms on adjustment to chronic pain and treatment outcome is the focus of this thesis. Three studies were conducted to clarify and extend earlier research findings in this area. Using 536 patients referred for treatment in a tertiary referral pain management centre, the first study examined the psychometric properties of a widely used self-report measure of posttraumatic stress symptoms (the PTSD Checklist, or PCL), modified for use in a chronic pain sample. This study provided preliminary support for the suitability of the PCL as a self-report measure of Posttraumatic Stress Disorder (PTSD) symptoms in chronic pain patients. However, the study also highlighted a number of issues with the use of self-report measures of posttraumatic stress symptoms in chronic pain patient samples. In particular, PCL items enquiring about symptoms which are a common aspect of the chronic pain experience (e.g. irritability, sleep problems) appeared to contribute to high mean scores on the PCL Avoidance and Arousal subscales. Furthermore, application of diagnostic cut-off scores and an algorithm recommended for the PCL in other trauma groups suggested that a much larger proportion of the sample was identified as potentially meeting diagnostic criteria for PTSD than would have been expected from previous research. The second study utilised the modified PCL to investigate the impact of different types of onset of pain (e.g. traumatic onset) and posttraumatic stress symptoms on adjustment to chronic pain in a sample of 196 chronic pain patients referred to the same centre. For patients who experienced the onset of pain related to a specific event, two independent experts in the field of PTSD determined whether these events satisfied the definition of a traumatic event according to DSM-IV diagnostic criteria. Adjustment was assessed through a number of validated measures of mood, disability, pain experience, and pain-related cognitions. Contrary to expectations, comparisons between patients who had experienced different types of onset of pain revealed few significant differences between them. That is, analyses comparing patients presenting with accident-related pain, or pain related to other specific events, to patients who had experienced spontaneous or insidious onset of pain revealed no significant differences between the groups on measures of pain severity, pain-related disability, and symptoms of affective distress after adjustment for age, pain duration, and compensation status. Similarly, comparisons between patients who had experienced a potentially traumatic onset of pain with those who had experienced a non-traumatic or spontaneous or insidious onset of pain also revealed no significant differences on the aforementioned variables. In contrast, compensation status, age, and a number of cognitive variables were significant predictors of pain severity, pain-related disability, and depression. The final study investigated the impact of type of pain onset and posttraumatic stress symptoms on response to a multidisciplinary cognitive-behavioural pain management program. Unlike the previous study, this treatment outcome study revealed a number of differences between onset groups. Most notably, patients who had experienced an insidious or spontaneous onset of pain reported greater improvements in pain severity and maintained these improvements more effectively over a one month period than patients who had experienced pain in the context of an accident or other specific incident. There was also limited evidence that improvements in depression favoured patients who had experienced an insidious or spontaneous and non-traumatic onset of pain. Consistent with this, posttraumatic stress symptoms were a significant predictor of treatment outcome, with higher levels of symptoms being associated with smaller improvements in pain-related disability and distress. Notably, this study also revealed that certain cognitive variables (i.e. catastrophising, self-efficacy, and fear-avoidance beliefs) were also significant predictors of treatment outcome, consistent with previous findings in the pain literature. This provided some perspective on the relative roles of both PTSD symptoms and cognitive variables in adjustment to persisting pain and treatment response. These findings were all consistent with expectations and with previous research. Implications for future research and for the assessment and treatment of chronic pain patients who present with posttraumatic stress symptoms are discussed.