Optimal Ventilator Strategies in Acute Respiratory Distress Syndrome

Abstract

Mechanical ventilation practices in patients with acute respiratory distress syndrome (ARDS) have progressed with a growing understanding of the disease pathophysiology. Paramount to the care of affected patients is the delivery of lung-protective mechanical ventilation which prioritizes tidal volume and plateau pressure limitation. Lung protection can probably be further enhanced by scaling target tidal volumes to the specific respiratory mechanics of individual patients. The best procedure for selecting optimal positive end-expiratory pressure (PEEP) in ARDS remains uncertain; several relevant issues must be considered when selecting PEEP, particularly lung recruitability. Noninvasive ventilation must be used with caution in ARDS as excessively high respiratory drive can further exacerbate lung injury; newer modes of delivery offer promising approaches in hypoxemic respiratory failure. Airway pressure release ventilation offers an alternative approach to maximize lung recruitment and oxygenation, but clinical trials have not demonstrated a survival benefit of this mode over conventional ventilation strategies. Rescue therapy with high-frequency oscillatory ventilation is an important option in refractory hypoxemia. Despite a disappointing lack of benefit (and possible harm) in patients with moderate or severe ARDS, possibly due to lung hyperdistention and right ventricular dysfunction, high-frequency oscillation may improve outcome in patients with very severe hypoxemia.

Thrombosis in Coronavirus disease 2019 (COVID-19) through the prism of Virchow’s triad

“…The microthrombi may cause altered lung perfusion and hypoxic vasoconstriction, worsening the hypoxemia [16]. Prone positioning may help by improving ventilation-perfusion ratio by changing vascular flow distribution in the pulmonary vessels, and not by recruitment as in the case of ARDS [17].…”

HFOV vs CMV for neonates with moderate-to-severe perinatal onset acute respiratory distress syndrome (NARDS): a propensity score analysis

“…The disease severity, clinical management, ventilator properties, and clinical interventions warrant further exploration of outcomes with a multivariate modeling approach. Considering the patient’s clinical features, physiological status, and response to ventilatory support to determine how to optimally ventilate the patient is of great importance [ 31 ]. A study showed that the use of a reduced tidal volume and avoidance of high airway pressures were associated with improved mortality when compared with a conventional ventilatory approach [ 32 ].…”

Proxies for COVID-19 Diagnosis for Adults in Resource Limited Settings: A Case Series Study in Zambia. 

“…Microthrombi occurring in the pulmonary vasculature in COVID-19 has been postulated to be responsible for hypoxia as it alters lung perfusion, impairs gas exchange and results in loss of oxygen transfer capacity of haemoglobin. It is further proposed that if these processes are not identi ed and managed early through anti-in ammatory medication, lung recruitment strategies such as awake prone ventilation and anticoagulation (9,12), they may lead to rapid clinical deterioration requiring more expensive interventions such as invasive ventilation and often lead to poor clinical outcomes as was noted in our rst patient.…”