From One-Size-Fits-All to Precision Care: Biomarker-Guided Lung Recruitment in Acute Respiratory Distress Syndrome.

Acute respiratory distress syndrome (ARDS) poses the problem of ventilating a heterogeneous lung with both well-aerated and collapsed lung units with different elastances. The interfaces between open and closed alveoli are exposed to amplified stress, thereby increasing the probability of ventilator-induced lung injury (VILI). An "open lung approach" of opening closed alveoli with recruitment maneuvers (RM) and keeping them open with high positive end-expiratory pressure (PEEP) was proposed as a promising method of homogenizing gas distribution and reducing the risk of VILI. This approach has been shown to improve oxygenation consistently. However, studies have found conflicting results on the effect of RM on patient outcomes, with the latest randomized controlled trial (RCT) showing increased mortality with the use of RMs. The failure of randomized trials testing RMs may be due to the inclusion of a heterogeneous group of ARDS patients without focusing on the ARDS phenotypes most likely to benefit from RM. Recent exploration of ARDS inflammatory phenotypes and the differential effect of therapeutics, especially high PEEP, based on phenotypes, raises the possibility of personalizing RMs to identify patient subgroups likely to benefit from the procedure. Findings of the research measuring inflammatory cytokines in bronchoalveolar lavage (BAL) fluid before and 24 hours after RMs in ARDS patients indicate the need for further research to define the role of inflammatory biomarkers in individualizing ventilation strategies in ARDS patients.