Ventilator-induced lung injury and lung mechanics

Abstract

Mechanical ventilation applies physical stresses to the tissues of the lung and thus may give rise to ventilator-induced lung injury (VILI), particular in patients with acute respiratory distress syndrome (ARDS). The most dire consequences of VILI result from injury to the blood-gas barrier. This allows plasma-derived fluid and proteins to leak into the airspaces where they flood some alveolar regions, while interfering with the functioning of pulmonary surfactant in those regions that remain open. These effects are reflected in commensurately increased values of dynamic lung elastance (E L), a quantity that in principle is readily measured at the bedside. Recent mathematical/computational modeling studies have shown that the way in which E L varies as a function of both time and positive end-expiratory pressure (PEEP) reflects the nature and degree of lung injury, and can even be used to infer the separate contributions of volutrauma and atelectrauma to VILI. Interrogating such models for minimally injurious regimens of mechanical ventilation that apply to a particular lung may thus lead to personalized approaches to the ventilatory management of ARDS.

Prevention and treatment of acute lung injury with time-controlled adaptive ventilation: physiologically informed modification of airway pressure release ventilation

“…"Compliant collapse" suggests that fluid movement in the microenvironment would play a role in airway collapse and reopening. Thus, the function of time during inspiration and expiration, and the opening and closing pressures, would be key components in keeping the lung open and stable [57].…”

“…Fluid movement in the microenvironment during airway collapse and reopening suggests that the pressures necessary for opening and collapse are also a function of the time at which they are applied [56]. Thus, a long inspiratory time with a short expiratory time would open more alveoli and prevent more alveolar collapse, as compared to the same airway pressures applied for shorter or longer amounts of time [57].…”

COVID-19 pathology and therapeutics

“…Humidified high flow oxygen therapy could be considered and is superior to mechanical ventilation (Shike Geng, Qing Mei et al 2020). Mechanical ventilation should be a last resort as its use has been associated with worsening lymphopenia, ventilator-associated lung injury (VLI) and ventilator-associated pneumonia (Plötz, Vreugdenhil et al 2002, Vreugdenhil, Heijnen et al 2004, Bates and Smith 2018. In case of mechanical ventilation, a lung protective protocol should be adopted with low tidal volumes (6ml/kg of measured body weight) and the application of positive end expiratory pressure (PEEP) less than or equal to (30cm H2O) based on the fraction of inspired oxygen (FIO2) (Gurka and Balk 2008).…”

Detection of Lung Affections of Stray Cats in Mosul City, Iraq.

“…These cats are susceptible to infection with biological agents such as bacteria, viruses, parasites, and fungi. Also trauma caused by being hit by a car or beating may lead to lung disorders (Bates and Smith, 2018).…”