Sensory-mechanical relationships during high-intensity, constant-workrate exercise in COPD

Sensory-mechanical relationships during high-intensity, constant-workrate exercise in COPD

ARTICLE IN PRESS Literature review 107 proxies over-reported the degree of the patient’s overall health status impairment, especially at mild-modera...

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ARTICLE IN PRESS Literature review

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proxies over-reported the degree of the patient’s overall health status impairment, especially at mild-moderate scores. Proxies showed weaker correlations at the more severe scores. Conclusions: The SGRQ was reliable and valid when administered to relatives of male COPD patients; however due to the systematic overreporting of the level of the patient’s health status impairment, caution should be applied whilst trying to use proxies as surrogates for male COPD patients.

in univariate analysis. LVRS did not affect the prognosis. The multivariate analysis showed short distance and increase of DeltaSpO2 as significant independent predictors of the risk of death. Six minutes walk test was very useful for predicting the prognosis of the COPD patients.

& 2006 Published by Elsevier Ltd.

Sensory-mechanical relationships during high-intensity, constant-work-rate exercise in COPD J Appl Physiol 2006;101:1025–35

doi:10.1016/j.rmedu.2006.09.016

& 2006 Published by Elsevier Ltd. doi:10.1016/j.rmedu.2006.09.017

D.E. O’donnell, A.L. Hamilton, K.A. Webb Distance and oxygen desaturation in 6-min walk test predict prognosis in COPD patients Respir Med 2006; published online ahead of print on 7 August 2006 as doi:10.1016/j.rmed.2006. 06.017

N. Takigawa, A. Tada, R. Soda, H. Date, H.M. Yamashita, S. Endo, S. Takahashi, N. Kawata, T. Shibayama, N. Hamada, M. Sakaguchi, A. Hirano, G. Kimura, C. Okada, K. Takahashi Department of Internal Medicine, National Hospital Organization, Minami-Okayama Medical Center, 4066 Hayashima, Okayama 701 0304, Japan E-mail address: [email protected] (N. Takigawa) The aim of the present study was to predict the prognosis of chronic obstructive pulmonary disease (COPD) patients who underwent comprehensive pulmonary rehabilitation (PR). A total of 144 patients who performed PR between 1992 and 1999 was assessed. After PR, 67 patients underwent lung volume reduction surgery (LVRS). Baseline data before PR consisted of body mass index, serum albumin levels, use of supplement oxygen at home, pulmonary function, arterial blood gas analysis, and distance and fall of hemoglobin oxygen saturation (DeltaSpO2) in 6-min walk test. In addition to prePR factors, treatment with LVRS was taken into the analysis. The prognostic significance of variables influencing survival was determined by univariate analysis with Log rank test or multivariate analysis using Cox’s proportional hazard model. By a median follow-up time of 8.4 years, the median survival time was 8.1 years (95% confidence interval: 6.9–9.4 years). Albumin level, PaCO2, distance and DeltaSpO2 were significant prognostic factors

102 Stuart St., Kingston, Ontario, Canada K7L 2V6 E-mail address: [email protected] (D.E. O’donnell) During constant-work-rate exercise in chronic obstructive pulmonary disease, dyspnea increases steeply once inspiratory reserve volume (IRV) falls to a critical level that prevents further expansion of tidal volume (Vt). We studied the effects of this mechanical restriction on the quality and intensity of exertional dyspnea and examined the impact of an anticholinergic bronchodilator. In a randomized, double-blind, crossover study, 18 patients with chronic obstructive pulmonary disease (forced expiratory volume in 1 s ¼ 4073% predicted; mean 7SE) inhaled tiotropium 18 mug or placebo once daily for 7–10 days each. Pulmonary function tests and symptom-limited cycle exercise at 75% of each patient’s maximal work capacity were performed 2 h after dosing. Dyspnea intensity (Borg scale), operating lung volumes, breathing pattern, and esophageal pressure (n ¼ 11) were measured during exercise. Dynamic hyperinflation reached its maximal value early in exercise and was associated with only mild increases in dyspnea intensity and the effort-displacement ratio, which is defined as the ratio between tidal swings of esophageal pressure (expressed relative to maximum inspiratory pressure) and Vt (expressed relative to predicted vital capacity). After a minimal IRV of 0.570.1 liter was reached, both dyspnea and the effort-displacement ratio rose steeply until an intolerable level was reached. Tiotropium did not alter dyspnea-IRV relationships, but the increase in resting and exercise inspiratory capacity was associated with an improved effort-displacement ratio throughout exercise. Once a critically low IRV was reached during exercise, dyspnea rose with the

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Literature review

disparity between respiratory effort and the Vt response. Changes in dyspnea intensity after tiotropium were positively correlated with changes in this index of neuromechanical coupling.

that symptom reporting is similar by sex. The clinical course of chronic obstructive pulmonary disease can differ by sex, as males show greater response to cigarette exposure and treatment.

Reproduced with permission from the American Physiological Society.

Reproduced with permission from European Respiratory Society Journals Ltd.

doi:10.1016/j.rmedu.2006.09.018

doi:10.1016/j.rmedu.2006.09.019

Predictors of COPD symptoms: Does the sex of the patient matter? Eur Respir J 2006;28:311–8

Early emphysematous changes in asymptomatic smokers: Detection with 3He MR imaging Radiology 2006;239:875–83

L. Watson, J.P. Schouten, C.G. Lofdahl, N.B. Pride, L.A. Laitinen, D.S. Postma, European Respiratory Society Study on Chronic Obstructive Pulmonary Disease

S.B. Fain, S.R. Panth, M.D. Evans, A.L. Wentland, J.H. Holmes, F.R. Korosec, M.J. O’Brien, H. Fountaine, T.M. Grist

Department of Pulmonology, University Medical Centre Groningen, University of Groningen, Hanzeplein 1, 9731 GZ Groningen, The Netherlands E-mail address: [email protected] (D.S. Postma) Although chronic obstructive pulmonary disease (COPD) patients frequently report symptoms, it is not known which factors determine the course of symptoms over time and if these differ according to the sex of the patient. The current study investigated predictors for presence, development and remission of COPD symptoms in 816 males and 312 females completing 3-yr-follow-up in the European Respiratory Society Study on Chronic Obstructive Pulmonary Disease (EUROSCOP). The following were included in generalised estimating equations logistic regression analyses: explanatory variables of treatment; pack-years smoking; age, forced expiratory volume in 1 second % predicted (FEV1% pred); annual increase in FEV1 and number of cigarettes smoked; body mass index; and phadiatop. Interaction terms of sex multiplied by explanatory variables were tested. Over 3 yrs, similar proportions of males and females reported symptoms. In males only, higher FEV1% pred was associated with reduction in new symptoms of wheeze and dyspnoea, and symptom prevalence was reduced with annual FEV1 improvement and phlegm prevalence reduced with budesonide treatment (odds ratio 0.66; 95% confidence interval 0.52–0.83). Additionally an increase in the number of cigarettes smoked between visits increased the risk of developing phlegm (1.40 (1.14–1.70)) and wheeze (1.24 (1.03–1.51)) in males but not females. The current study shows longitudinally

Department of Radiology, University of Wisconsin, J3/110 CSC Medical Physics, 600 Highland Ave, Madison, WI 53792, USA E-mail address: [email protected] (S.B. Fain) Purpose: To prospectively compare apparent diffusion coefficient (ADC) measurements derived from diffusion-weighted hyperpolarized helium 3 (3He) magnetic resonance (MR) imaging with functional and structural findings using spirometric tests and thin-section computed tomography (CT) of the lungs in asymptomatic smokers and healthy nonsmokers of similar age. Materials and methods: All studies were HIPAA compliant and were approved by the institutional review board. Informed consent was obtained. Ventilation and diffusion-weighted 3He MR images were obtained in healthy subjects: 11 smokers (five women, six men; mean age, 47 years 718 [standard deviation]; range, 23–73 years) and eight nonsmokers (o100 cigarettes in lifetime) (four women, four men; mean age, 46 years 716; range, 23–69 years). Mean ADC values for smokers and nonsmokers were compared with spirometric values, diffusing capacity of the lung for carbon monoxide (Dlco), age, and pack-years with Spearman rank correlation coefficient (rs) and multiple linear regression analysis. Mean ADC value and thin-section CT emphysema index of relative area less than 950 HU (RA950) were compared on a regional basis by using linear mixed-effect models. Results: Mean ADC values and number of pack-years were significantly correlated (rs ¼ 0.60; 95% confidence interval (CI): 0.21, 1.00; P ¼ 0.007); relationship remained significant after adjustment for age (P ¼ 0.003). Dlco was strongly correlated