I recently highlighted this as one of the top issues in hospital medicine for last year. Although I missed this review in JAMA from December 8 when preparing that post, many of the same points were made. The review is in a Johns Hopkins Grand Rounds format and the full text (which is unfortunately behind access control) is worth reading in its entirety. It provides a nice overview of ARDS.
ARDS is hypoxemic respiratory failure. Despite this, as is pointed out in the article, only a small minority, on the order of 10-15%, of the mortality is attributable to refractory hypoxemia. The remainder is due to failure of other organs.
General supportive care is the mainstay of management of ARDS with only one specific modality known from research evidence to decrease mortality: low tidal volume ventilation. Multiple other modalities which in studies have not been shown to decrease overall mortality but can improve oxygenation are considered rescue therapies, examples of which are prone positioning, heavy sedation with paralysis, high frequency modalities, high peep and recruitment maneuvers. Rescue therapies, while not “evidence based” in the strict sense, may offer the patient's only chance for survival in desperate situations involving refractory hypoxemia.
Which rescue therapies to implement depend in part on local expertise. Provision of rescue therapy will require some preparation, particularly if the patient requires transfer to another facility. This underscores the importance of early severity assessment which facilitates planning for possible rescue therapy.