Showing papers by "Marcelo B. P. Amato published in 2000"
Patent•
08 Aug 2000
TL;DR: In this article, a system and method of controlling the termination of the inhalation phase in a pressure support ventilation system is disclosed, in which an expiratory trigger sensitivity, or ratio of inspiratory flow rate to peak inspiration flow rate at which the inspiration phase is terminated, is varied in proportion to variations in a calculated respiratory time constant.
Abstract: A system and method of controlling the termination of the inhalation phase in a pressure support ventilation system is disclosed, in which an expiratory trigger sensitivity, or ratio of inspiratory flow rate to peak inspiratory flow rate at which the inspiration phase is terminated, is varied in proportion to variations in a calculated respiratory time constant. The system includes sensors for monitoring pressure and flow of gas during each breath, and, based on the sensor outputs, calculates the respiratory time constant for one breath or a series of breaths. The expiratory trigger sensitivity is automatically increased with increasing patient respiratory time constant, providing a closed loop control of expiratory trigger sensitivity. The expiratory trigger sensitivity may also be varied in response to changes in supra-plateau pressure.
164 citations
TL;DR: Accumulating data suggest that the maximization and maintenance of lung recruitment may reduce lung parenchymal injury from positive pressure ventilation in ARDS and that a high‐pressure recruitment maneuver was required.
Abstract: Objective:To present the use of a novel high-pressure recruitment maneuver followed by high levels of positive end-expiratory pressure in a patient with the acute respiratory distress syndrome (ARDS).Design:Observations in one patient.Setting:The medical intensive care unit at a tertiary care univer
125 citations
TL;DR: Using EIT, determination of LIP and UDP from the regional PI curves is possible and the obtained information may help in understanding alveolar recruitment.
Abstract: Objective: A new noninvasive method, electrical impedance tomography (EIT), was used to make pressure-impedance (PI) curves in a lung lavage model of acute lung injury in pigs. The lower inflection point (LIP) and the upper deflection point (UDP) were determined from these curves and from the traditional pressure-volume (PV) curves to determine whether the PI curves resemble the traditional PV curves. Furthermore, regional differences in the mentioned determinants were investigated. Design: Prospective, experimental study. Setting: Animal research laboratory. Interventions: In nine anesthetized pigs, repeated lung lavage was performed until a PaO 2 <80 torr was reached. Thereafter, an inspiratory PV curve was made using a constant flow of oxygen. During the intervention, EIT measurements were performed. Measurements and Main Results: In this study, the LIP EIT was within 2 cm H 2 O of the LIP PV . Furthermore, it was possible to visualize regional PI curves by EIT. No significant difference was found between the LIP PV (21.3 ± 3.0 cm H 2 O) and the LIP EIT of the total lung (21.5 ± 3.0 cm H 2 O) or the anterior parts of the lung (21.5 ± 2.9 cm H 2 O). A significantly higher LIP (29.5 ± 4.9 cm H 2 O) was found in the posterior parts of the lung. A UDP PV could be found in three animals only, whereas in all animals a UDP EIT could be determined from the anterior part of the lung. Conclusions: Using EIT, determination of LIP and UDP from the regional PI curves is possible. The obtained information from the regional PI curves may help in understanding alveolar recruitment. The use of this new bedside technique for clinical decision making remains to be examined.
109 citations