New insights in mechanical ventilation and adjunctive therapies in ARDS

The definition of acute respiratory distress syndrome (ARDS) dates back to 1967. Despite 55 years of research and clinical experience, ARDS management remains challenging, and the syndrome is associated with a high mortality rate, requiring intensive care unit (ICU) admission and mechanical ventilation (MV).

In recent decades, a huge effort has been made to investigate the impact of lung-protective ventilation on ARDS outcome and to modify ventilatory management strategies to reduce the risk of ventilator induced lung injury (VILI). Although several ventilatory strategies are now recognized as the standard of care in the management of ARDS patients, an individualized approach, which takes into account the limits of physiological gain and the uncertainty concerning ventilatory manipulation on outcome, is now under consideration.

Researchers from Anesthesia and Intensive Care, San Martino Policlinico Hospital of Italy, and Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro of Brazil, Dr. Denise Battaglini, Dr. Patricia Rieken Macedo Rocco and Dr. Paolo Pelosi recently published a review article in Signa Vitae journal, which aims to discuss the cornerstones of MV and new insights in ARDS ventilatory management, as well as their rationales, to guide the physician in an individually tailored rather than a fixed, sub-physiological approach.

Current recommended MV strategies include the use of low tidal volume (V_T) at 4–6 mL/kg of predicted body weight (PBW) and plateau pressure (P_PLAT) below 27 cmH₂O. Some patients achieve better outcomes with low V_T than others, and several strategies have been proposed to individualize V_T, including standardization for end-expiratory lung volume or inspiratory capacity. To date, no strategy for individualizing positive-end expiratory pressure (PEEP) based on oxygenation, recruitment, respiratory mechanics, or hemodynamics has proven superior for improving survival. Driving pressure, transpulmonary pressure, and mechanical power have been proposed as markers to quantify risk of VILI and optimize ventilator settings. Several rescue therapies, including neuromuscular blockade, prone positioning, recruitment maneuvers (RMs), vasodilators, and extracorporeal membrane oxygenation (ECMO), may be considered in severe ARDS. New ventilator strategies such as airway pressure release ventilation (APRV) and time-controlled adaptive ventilation (TCAV) have demonstrated potential benefits to reduce VILI, but further studies are required to evaluate their clinical relevance.

They recommend that MV be individualized based on physiological targets, which might be the cornerstone of future enhancement of MV in ARDS and may represent a promising approach for respiratory diseases with presentations like ARDS, such as COVID-19.
Contact the author(s):
Denise Battaglini, battaglini.denise@gmail.com
Paolo Pelosi, ppelosi@hotmail.com

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