Lung protection in acute respiratory distress syndrome: what should we target?

Abstract

Purpose of Review: Most clinical trials of lung-protective ventilation have tested one-size-fitsall strategies with mixed results. Data are lacking on how best to tailor mechanical ventilation to patient-specific risk of lung injury.Recent Findings: Risk of ventilation-induced lung injury is determined by biological predisposition to biophysical lung injury and physical mechanical perturbations that concentrate stress and strain regionally within the lung. Recent investigations have identified molecular subphenotypes classified as hyper-and hypo-inflammatory ARDS, which may have dissimilar risk for ventilation-induced lung injury. Mechanically, gravity-dependent atelectasis has long been recognized to decrease total aerated lung volume available for tidal ventilation, a concept termed the "ARDS baby lung." Recent studies have demonstrated that the aerated baby lung also has nonuniform stress/strain distribution, with potentially injurious forces concentrated in zones of heterogeneity where aerated alveoli are adjacent to flooded or atelectatic alveoli. The preponderance of evidence also indicates that current standard-of-care tidal volume management is not universally protective in ARDS. When considering escalation of lung-protective interventions, potential benefits of the intervention should be weighed against tradeoffs of accompanying cointerventions required, for example deeper sedation or neuromuscular blockade. A precision medicine approach to lung-protection would weigh Summary: A precision medicine approach to lung-protective ventilation requires weighing four key factors in each patient: biological predisposition to biophysical lung injury, mechanical predisposition to biophysical injury accounting for spatial mechanical heterogeneity within the lung, anticipated benefits of escalating lung-protective interventions, and potential unintended adverse effects of mandatory cointerventions.

Venovenous extracorporeal CO2 removal to support ultraprotective ventilation in moderate-severe acute respiratory distress syndrome: A systematic review and meta-analysis of the literature

“…A recent large RCT comparing conventional low tidal volumes with ECCO 2 R-enabled ultraprotective ventilation found no difference in 28-day mortality, a longer duration of mechanical ventilation and ICU length of stay (LOS) and a 31% rate of serious adverse events in the intervention group, 48 furthermore this study was halted prior to full recruitment due to futility. Patients with moderate-to-severe ARDS are a heterogenous cohort with emerging clinical sub-phenotypes, 60,61 thus the absence of mortality benefit unsurprising. 48,62 Our analysis showed a pooled 28-day mortality was 41.6% (95%CI: 30.0%–53.5%), which is similar to that reported in a large meta-analysis of mechanically ventilated ARDS patients of comparable severity.…”

Mecánica respiratoria en anestesia general: Revisión de conceptos

“…Las diferencias entre la presión meseta y la presión transpulmonar meseta son más pronunciadas en obesos y en aquellos con trastornos restrictivos del tórax (causas de elastancia torácica aumentada). Limitar la presión transpulmonar meseta (al final de la inspiración o teleinspiratoria) a menos de 20 cmH 2 0 parece minimizar el riesgo de distensión alveolar [22], [24] (Figura 4).…”

Development of an Intelligent Reactive Oxygen Species-Responsive Dual-Drug Delivery Nanoplatform for Enhanced Precise Therapy of Acute Lung Injury

“… 19 Moreover, the use of ECMO or ventilators may cause a secondary hit that exacerbates lung injury. 10 , 20 In addition, there is a serious shortage of ECMO and ventilator equipment as well as medical staff during fatal epidemic bursts. A large number of drug candidates for ARDS has been reported in recent years; unfortunately, none of them have been proven to be effective in reducing mortality in clinical trials.…”