Bradford J. Smith

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IMPORTANCE Ventilator-induced lung injury may arise from heterogeneous lung microanatomy, whereby some alveoli remain collapsed throughout the breath cycle while their more compliant or surfactant-replete neighbors become overdistended, and this is called dynamic alveolar heterogeneity. OBJECTIVE To determine how dynamic alveolar heterogeneity is(More)
Acute respiratory distress syndrome is a pulmonary disease with a mortality rate of ∼40% and 75,000 deaths annually in the United States. Mechanical ventilation restores airway patency and gas transport but leads to ventilator-induced lung injury. Furthermore, surfactant replacement therapy is ineffective due to surfactant delivery difficulties and(More)
IMPORTANCE Improper mechanical ventilation settings can exacerbate acute lung injury by causing a secondary ventilator-induced lung injury. It is therefore important to establish the mechanism by which the ventilator induces lung injury to develop protective ventilation strategies. It has been postulated that the mechanism of ventilator-induced lung injury(More)
Idiopathic pulmonary fibrosis (IPF) and bleomycin-induced pulmonary fibrosis are associated with surfactant system dysfunction, alveolar collapse (derecruitment), and collapse induration (irreversible collapse). These events play undefined roles in the loss of lung function. The purpose of this study was to quantify how surfactant inactivation, alveolar(More)
Management of ALI/ARDS involves supportive ventilation at low tidal volumes (V t) to minimize the rate at which ventilator induced lung injury (VILI) develops while the lungs heal. However, we currently have few details to guide the minimization of VILI in the ALI/ARDS patient. The goal of the present study was to determine how VILI progresses with time as(More)
Mechanical ventilation is a crucial component of the supportive care provided to patients with acute respiratory distress syndrome. Current practice stipulates the use of a low tidal volume (VT) of 6 ml/kg ideal body weight, the presumptive notion being that this limits overdistension of the tissues and thus reduces volutrauma. We have recently found,(More)
We computationally investigate the unsteady pulsatile propagation of a finger of air through a liquid-filled cylindrical rigid tube using a combined boundary element method and lubrication theory approach. The flow-field is governed by the dimensionless parameters Ca(Q)(t) = Ca(M) + Ca(Omega) sin(Omegat) = muQ*(t*)/piR(2)gamma, Omega = muomegaR/gamma and A(More)
Patients with acute respiratory distress syndrome receiving mechanical ventilation typically experience repetitive closure (derecruitment) and subsequent reopening (recruitment) of airways and alveoli. This can lead, over time, to further ventilator-induced lung injury (VILI). Recruitment and derecruitment (R/D) thus reflect both the current level of lung(More)
BACKGROUND Improper mechanical ventilation can exacerbate acute lung damage, causing a secondary ventilator-induced lung injury (VILI). We hypothesized that VILI can be reduced by modifying specific components of the ventilation waveform (mechanical breath), and we studied the impact of airway pressure release ventilation (APRV) and controlled mandatory(More)
Managing acute respiratory distress syndrome (ARDS) invariably involves the administration of mechanical ventilation, the challenge being to avoid the iatrogenic sequellum known as ventilator-induced lung injury (VILI). Devising individualized ventilation strategies in ARDS requires that patient-specific lung physiology be taken into account, and this is(More)