Puget Sound Veterans Affairs Health Care System

Seattle, WA, United States

Puget Sound Veterans Affairs Health Care System

Seattle, WA, United States
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Bailey D.M.,University of South Wales | Dehnert C.,University of Heidelberg | Luks A.M.,University of Washington | Menold E.,University of Heidelberg | And 14 more authors.
Journal of Physiology | Year: 2010

High altitude (HA)-induced pulmonary hypertension may be due to a free radical-mediated reduction in pulmonary nitric oxide (NO) bioavailability. We hypothesised that the increase in pulmonary artery systolic pressure (PASP) at HA would be associated with a net transpulmonary output of free radicals and corresponding loss of bioactive NO metabolites. Twenty-six mountaineers provided central venous and radial arterial samples at low altitude (LA) and following active ascent to 4559 m (HA). PASP was determined by Doppler echocardiography, pulmonary blood flow by inert gas re-breathing, and vasoactive exchange via the Fick principle. Acute mountain sickness (AMS) and high-altitude pulmonary oedema (HAPE) were diagnosed using clinical questionnaires and chest radiography. Electron paramagnetic resonance spectroscopy, ozone-based chemiluminescence and ELISA were employed for plasma detection of the ascorbate free radical (A·-), NO metabolites and 3-nitrotyrosine (3-NT). Fourteen subjects were diagnosed with AMS and three of four HAPE-susceptible subjects developed HAPE. Ascent decreased the arterio-central venous concentration difference (a-cvD) resulting in a net transpulmonary loss of ascorbate, α -tocopherol and bioactive NO metabolites (P < 0.05 vs. LA). This was accompanied by an increased a-cvD and net output of A·- and lipid hydroperoxides (P < 0.05 vs. sea level, SL) that correlated against the rise in PASP (r= 0.56-0.62, P < 0.05) and arterial 3-NT (r= 0.48-0.63, P < 0.05) that was more pronounced in HAPE. These findings suggest that increased PASP and vascular resistance observed at HA are associated with a free radical-mediated reduction in pulmonary NO bioavailability. What causes pulmonary hypertension at high altitude remains unknown. By measuring the transpulmonary exchange kinetics of redox-reactive biomarkers, this study suggests that hypertension may be related to a free radical-mediated reduction in pulmonary vascular nitric oxide bioavailability due in part to inadequate antioxidant defence. These findings have broader implications for other clinical models of human disease characterised by global hypoxaemia and identify the hypoxic human lungs as a contributory source of oxidative-nitrosative-inflammatory stress. © 2010 The Authors. Journal compilation © 2010 The Physiological Society.


Hafner B.J.,University of Washington | Morgan S.J.,University of Washington | Abrahamson D.C.,Puget Sound Veterans Affairs Health Care System | Amtmann D.,University of Washington
Prosthetics and Orthotics International | Year: 2016

Background: Input from target respondents in the development of patient-reported outcome measures is necessary to ensure that the instrument is meaningful. Objectives: To solicit perspectives of prosthetic limb users about their mobility experiences and to inform development of the Prosthetic Limb Users Survey of Mobility. Study design: Qualitative study. Methods: Four focus groups of lower limb prosthesis users were held in different regions of the United States. Focus group transcripts were coded, and themes were identified. Feedback from participants was used to develop a framework for measuring mobility with a lower limb prosthesis. Results: Focus group participants (N = 37) described mobility as a confluence of factors that included characteristics of the individual, activity, and environment. Identified themes were defined as individual characteristics, forms of movement, and environmental situations. Prosthetic mobility was conceptualized as movement activities performed in an environmental or situational context. Conclusion: Respondent feedback used to guide development of Prosthetic Limb Users Survey of Mobility established a foundation for a new person-centered measure of mobility with a prosthetic limb. Clinical relevance Perspectives of target respondents are needed to guide development of instruments intended to measure health outcomes. Focus groups of prosthetic limb users were conducted to solicit experiences related to mobility with a lower limb prosthesis. Results were used to inform development of a clinically meaningful, person-centered instrument. © International Society for Prosthetics and Orthotics International.


PubMed | Puget Sound Veterans Affairs Health Care System and University of Washington
Type: Journal Article | Journal: Prosthetics and orthotics international | Year: 2016

Input from target respondents in the development of patient-reported outcome measures is necessary to ensure that the instrument is meaningful.To solicit perspectives of prosthetic limb users about their mobility experiences and to inform development of the Prosthetic Limb Users Survey of Mobility.Qualitative study.Four focus groups of lower limb prosthesis users were held in different regions of the United States. Focus group transcripts were coded, and themes were identified. Feedback from participants was used to develop a framework for measuring mobility with a lower limb prosthesis.Focus group participants (N=37) described mobility as a confluence of factors that included characteristics of the individual, activity, and environment. Identified themes were defined as individual characteristics, forms of movement, and environmental situations. Prosthetic mobility was conceptualized as movement activities performed in an environmental or situational context.Respondent feedback used to guide development of Prosthetic Limb Users Survey of Mobility established a foundation for a new person-centered measure of mobility with a prosthetic limb.Perspectives of target respondents are needed to guide development of instruments intended to measure health outcomes. Focus groups of prosthetic limb users were conducted to solicit experiences related to mobility with a lower limb prosthesis. Results were used to inform development of a clinically meaningful, person-centered instrument.

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