Lung function during and after prolonged head-down bed rest
| Autor: | D. Linnarsson, Stéphanie Montmerle, Jonas Spaak |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Adult
Male Spirometry medicine.medical_specialty Supine position Physiology Rest medicine.medical_treatment Bed rest Head-Down Tilt Hypokinesia Physiology (medical) Diffusing capacity Respiratory muscle Humans Medicine Lung Weightlessness Simulation Lung function Carbon Monoxide Blood Volume medicine.diagnostic_test Pulmonary Gas Exchange business.industry Respiratory Function Tests Surgery Anesthesia Pulmonary Diffusing Capacity medicine.symptom Lung Volume Measurements business Gravitation |
| Zdroj: | Journal of Applied Physiology. 92:75-83 |
| ISSN: | 1522-1601 8750-7587 |
| DOI: | 10.1152/jappl.2002.92.1.75 |
| Popis: | We determined the effects of prolonged head-down tilt bed rest (HDT) on lung mechanics and gas exchange. Six subjects were studied in supine and upright postures before (control), during [ day 113(D113)], and after (R + number of days of recovery) 120 days of HDT. Peak expiratory flow (PF) never differed between positions at any time and never differed from controls. Maximal midexpiratory flow (FEF25–75%) was lower in the supine than in the upright posture before HDT and was reduced in the supine posture by about 20% between baseline and D113, R + 0, and R + 3. The diffusing capacity for carbon monoxide corrected to a standardized alveolar volume (volume-corrected Dl CO) was lower in the upright than in the supine posture and decreased in both postures by 20% between baseline and R + 0 and by 15% between baseline and R + 15. Pulmonary blood flow (Q˙C) increased from R + 0 to R + 3 by 20 (supine) and 35% (upright). As PF is mostly effort dependent, our data speak against major respiratory muscle deconditioning after 120 days of HDT. The decrease in FEF25–75% suggests a reduction in elastic recoil. Time courses of volume-corrected Dl CO andQ˙C could be explained by a decrease in central blood volume during and immediately after HDT. |
| Databáze: | OpenAIRE |
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