Single-breath washouts in a rotating stretcher
| Autor: | N. Gonzalez Mangado, Germán Peces-Barba, Sylvia Verbanck, Manuel Paiva, María Jesús Rodríguez-Nieto |
|---|---|
| Přispěvatelé: | Internal Medicine Specializations |
| Rok vydání: | 2001 |
| Předmět: |
phase III slope
Adult Male Supine position Rotation Nitrogen Physiology Posture Vital Capacity ventilation inhomogeneity phase TV height Sitting Cardiogenic oscillations Physiology (medical) Prone Position Supine Position Humans Medicine Pulmonary Gas Exchange business.industry Hemodynamics cardiogenic oscillations Single breath Middle Aged Respiratory Function Tests Anesthesia Respiratory Mechanics Female business Inspiratory Capacity |
| Zdroj: | Vrije Universiteit Brussel |
| ISSN: | 1522-1601 8750-7587 |
| DOI: | 10.1152/jappl.2001.90.4.1415 |
| Popis: | Vital capacity single-breath washouts using 90% O2-5% He-5% SF6 as a test gas mixture were performed with subjects sitting on a stool (upright) or recumbent on a stretcher (prone, supine, lateral left, lateral right, with or without rotation at end of inhalation). On the basis of the combinations of supine and prone maneuvers, gravity-dependent contributions to N2 phase III slope and N2 phase IV height in the supine posture were estimated at 18% and 68%, respectively. Whereas both He and SF6 slope decreased from supine to prone, the SF6-He slope difference actually increased ( P = 0.015). N2 phase III slopes, phase IV heights, and cardiogenic oscillations were smallest in the prone posture, and we observed similarities between the modifications of He and SF6 slopes from upright to prone and from upright to short-term microgravity. These results suggest that phase III slope is partially due to emptying patterns of small units with different ventilation-to-volume ratios, corresponding to acini or groups of acini. Of all body postures under study, the prone position most reduces the inhomogeneities of ventilation during a vital capacity maneuver at both inter- and intraregional levels. |
| Databáze: | OpenAIRE |
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