Regional coupling between chest wall and lung expansion during HFV: a positron imaging study.

作者: J. G. Venegas , K. Tsuzaki , B. J. Fox , B. A. Simon , C. A. Hales

DOI: 10.1152/JAPPL.1993.74.5.2242

关键词: High-frequency ventilationSupine positionLungNuclear medicineRib cageBreathingLung volumesMaterials scienceRespiratory systemDiaphragm (structural system)

摘要: Apparently conflicting differences between the regional chest wall motion and gas transport have been observed during high-frequency ventilation (HFV). To elucidate mechanism responsible for such differences, a positron imaging technique capable of assessing dynamic volumetric expansion, lung volume, was developed. Anesthetized supine dogs were studied at ventilatory frequencies (f) ranging from 1 to 15 Hz eucapnic tidal volumes. The distribution mean volume found be independent f, but apex-to-base ratio expansion favored bases low f became more homogeneous higher f. Regional per unit assessed washout maneuvers, Hz, progressively as increased 9 returned homogeneity Hz. Interregional asynchrony (pendelluft) right-to-left small this large scale. Analysis data spatial resolution showed that diaphragm relative excursions rib cage decreased increased. These apex base in consistent with simple model including lung, cage, impedances viscous coupling lungs caused by sliding pleural surfaces. further test model, we five additional animals under open conditions. studies resulted f-independent transport. We conclude HFV is not intrinsic heterogeneity rather result dynamics its lung.

参考文章(0)