Current and evolving standards of care for patients with ARDS

Abstract

Care for patients with acute respiratory distress syndrome (ARDS) has changed considerably over the 50 years since its original description. Indeed, standards of care continue to evolve as does how this clinical entity is defined and how patients are grouped and treated in clinical practice. In this narrative review we discuss current standards-treatments that have a solid evidence base and are well established as targets for usual care-and also evolving standards-treatments that have promise and may become widely adopted in the future. We focus on three broad domains of ventilatory management, ventilation adjuncts, and pharmacotherapy. Current standards for ventilatory management include limitation of tidal volume and airway pressure and standard approaches to setting PEEP, while evolving standards might focus on limitation of driving pressure or mechanical power, individual titration of PEEP, and monitoring efforts during spontaneous breathing. Current standards in ventilation adjuncts include prone positioning in moderate-severe ARDS and veno-venous extracorporeal life support after prone positioning in patients with severe hypoxemia or who are difficult to ventilate. Pharmacotherapy current standards include corticosteroids for patients with ARDS due to COVID-19 and employing a conservative fluid strategy for patients not in shock; evolving standards may include steroids for ARDS not related to COVID-19, or specific biological agents being tested in appropriate subphenotypes of ARDS. While much progress has been made, certainly significant work remains to be done and we look forward to these future developments.

COVID-19-associated acute respiratory distress syndrome (CARDS): Current knowledge on pathophysiology and ICU treatment – A narrative review

“…With emerging evidence on CARDS, it appears that many features of CARDS and non-COVID ARDS are rather comparable [ 18 , 87 ] and thus the principles of ventilatory support do not largely differ between ARDS and CARDS patients [ 88 , 89 ]. Strategies typically used are limiting tidal volumes to 6 ml/kg ideal body weight and keeping plateau pressures below 30 cm H 2 0 [ 88 , 90 , 91 ]. However, more recent evidence stresses the importance of transpulmonary driving pressures (i.e., plateau pressure minus PEEP) rather than “simple” tidal volume limitation [ 92 ].…”

“…However, for both transpulmonary driving pressure and mechanical power, confirmation in large randomized controlled clinical trials seems required. The optimal level of PEEP should be set individually and should be assessed using either best compliance (e.g., with the help of a pressure volume tool), measured recruitability, and/or through transpulmonary pressure assessment (e.g., with the use of an esophageal balloon) [ 88 , 90 ].…”

“…Prone positioning was shown to be one of the most effective adjunctive therapies in ARDS and is associated with increased survival [ 94 ]. Hence, early prone positioning of patients with moderate to severe CARDS (P/F ratio <150) is recommended [ 88 ]. Proning should be performed for 16 h per day [ 88 ]; however, there is some evidence showing that prone positioning for longer time periods (up to 36 h) might be safe and might have a more substantial impact on oxygenation when compared with 16 h of proning [ 95 ].…”

“…Hence, early prone positioning of patients with moderate to severe CARDS (P/F ratio <150) is recommended [ 88 ]. Proning should be performed for 16 h per day [ 88 ]; however, there is some evidence showing that prone positioning for longer time periods (up to 36 h) might be safe and might have a more substantial impact on oxygenation when compared with 16 h of proning [ 95 ]. Prone positioning reduces the pleural pressure gradient, improves the distribution of ventilation, can contribute to recruitment, and may thus indirectly decrease ventilator-induced lung injury.…”

Twenty articles that critical care clinicians should read about COVID-19

“…Finally, Menk et al . described the evolving standard of care for COVID-19 ARDS [ 17 ]. The authors advocated lung protective ventilation with tidal volumes ≤ 6 mL/kg of predicted body weight, limitation of driving pressure to ≤ 15 cmH 2 O, individualized PEEP titration, conservative fluid management, and veno-venous ECMO for severe, untreatable hypoxemia.…”