Mechanisms of Orthopnea in Stable Obese Subjects.
BACKGROUND: The present study explored the role of closing volume as a determinant of orthopnea in stable obese subjects. We hypothesized that: (1) increase in closing volume in supine position would be greater in orthopneic than in non-orthopneic subjects, and (2) the relationship of change in clos...
| Publicado en: | Respiratory Care Vol. 61; no. 8; pp. 1015 - 1023 |
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| Autores principales: | , , , |
| Formato: | CEU research tables/charts Journal Article |
| Publicado: |
Mary Ann Liebert, Inc.
Aug2016
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=117140851&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 117140851 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 00201324 4GG jtl: Respiratory Care issn: 00201324 maglogo: N pubinfo: dt: Aug2016 vid: 61 iid: 8 pid: 1365 pub: Mary Ann Liebert, Inc. place: New Rochelle, New York artinfo: ui: 117140851 117140851 117140851 10.4187/respcare.04146 117140851 ppf: 1015 ppct: 8 formats: fmt: @attributes: type: P tig: atl: Mechanisms of Orthopnea in Stable Obese Subjects. aug: au: Perino, Emilie Nesme, Pascale Germain, Michèle Guérin, Claude affil: Réanimation médicale, Hôpital de la Croix Rousse, Hospices Civils, Lyon, France sug: subj: Obesity Patient Positioning Dyspnea Human Education, Continuing (Credit) Supine Position Sitting Scales Expiration Evaluation Nitrogen Analysis Male Female Middle Age Body Mass Index Respiratory Function Tests France Outpatients Convenience Sample Prospective Studies Mann-Whitney U Test Wilcoxon Signed Rank Test Experimental Studies Fisher's Exact Test Spearman's Rank Correlation Coefficient Confidence Intervals Intraclass Correlation Coefficient Adult Middle Aged: 45-64 years Adult: 19-44 years Male Female ab: BACKGROUND: The present study explored the role of closing volume as a determinant of orthopnea in stable obese subjects. We hypothesized that: (1) increase in closing volume in supine position would be greater in orthopneic than in non-orthopneic subjects, and (2) the relationship of change in closing volume to change in dyspnea with position would be dependent on expiratory flow limitation in the sitting position. METHODS: In stable obese subjects, in sitting and supine positions, we measured the Borg dyspnea score, static lung volumes, expiratory flow limitation during tidal breathing, and single-breath nitrogen expiration test. From the latter, we determined closing volume and closing capacity, slope of phase III, and opening capacity. Orthopnea was defined as any increase in the Borg score in the supine position from its value in the sitting position. RESULTS: Twenty-one subjects (13 women), median age (interquartile range) 55 (49-57) y and with body mass index of 39 (38-42) kg/m² were included, of whom 12 were orthopneic and 11 had expiratory flow limitation while seated. In the sitting position, orthopneic and non-orthopneic subjects were similar for age, body mass index, and pulmonary function tests, including single-breath nitrogen expiration test-derived variables. In the orthopneic subjects, there were no changes in any respiratory variable between positions. In the non-orthopneic subjects, there was a significant decrease in slope of phase III in the supine position from 1.67 (1.33-3.60) to 1.40 (1.25-1.66)%/L (P = .008). Overall, the subjects' Borg score significantly correlated with the slope of phase III (r = 0.63, P = .002) and opening capacity (r = -0.47, P = .03). In 10 subjects without expiratory flow limitation, it correlated with slope of phase III (r = 0.68, P = .03). CONCLUSIONS: In stable obese subjects, magnitude of orthopnea correlated with an increase in the slope of phase III in subjects without expiratory flow limitation. Expiratory flow limitation should be taken into account in obese patients. pubtype: Academic Journal doctype: CEU research tables/charts Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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