Search results for "Lung mechanics"
showing 5 items of 5 documents
The AVL-mode: a safe closed loop algorithm for ventilation during total intravenous anesthesia.
1994
The Adaptive Lung Ventilation Controller (ALV-Controller) represents a new approach to closed loop control of ventilation. It is based on a pressure controlled ventilation mode. Adaptive lung ventilation signifies automatic breath by breath adaptation of breathing patterns to the lung mechanics of an individual patient. The specific goals are to minimize work of breathing, to maintain a preset alveolar ventilation and to prevent the occurrence of intrinsic PEEP. We ventilated 5 patients undergoing major abdominal procedures using ALV. ALV was tolerated well in all patients. Alveolar ventilation was preset between 5500 and 6500 ml/min. Serial dead space (Vds) and respiratory time constant (r…
Effect of lung mechanics on mechanically assisted flows and volumes.
2004
To correlate the air flows generated by mechanical insufflation-exsufflation as a function of pressure delivery in a lung model at two pulmonary compliance and three airway resistance settings.With each combination of pulmonary compliances of 25 and 50 ml/cm H2O and airway resistances of 6, 11, and 17 cm H2O/liter/sec, ten cycles of mechanical insufflation-exsufflation were applied using pressure deliveries of 40 to -40, 50 to -50, 60 to -60, and 70 to -70 cm H2O. The resulting peak exsufflation flows and volumes were recorded.In a multivariate analysis, the pulmonary compliance, airway resistance, and pressure delivery were all found to significantly affect exsufflation flows and volumes s…
Structural and functional evidence for the scaffolding effect of alveolar blood vessels
2017
A contribution of pulmonary blood distension to alveolar opening was first proposed more than 100 years ago. To investigate the contribution of blood distension to lung mechanics, we studied control mice (normal perfusion), mice after exsanguination (absent perfusion) and mice after varying degrees of parenchymal resection (supra-normal perfusion). On inflation, mean tracheal pressures were higher in the bloodless mouse (4.0α2.5 cmH2O); however, there was minimal difference between conditions on deflation (0.7α0.9 cmH2O). To separate the peripheral and central mechanical effects of blood volume, multi-frequency lung impedance data was fitted to the constant-phase model. The presence or abse…