'Life-threatening' conditions or refractory
hypoxemia during
mechanical ventilation are more a matter of personal rating than an objective diagnosis based on defined and/or unanimously agreed thresholds that would mandate the use of rescue
therapies. Although the outcome might vary with different rescue procedures, most of them will improve oxygenation. Prone positioning maintains a predominant role as rescue
therapy in severe
hypoxemia and does not only improve oxygenation in but also survival of ARDS patients. Recruitment maneuvers can have temporary positive effects. Inhaled
nitric oxide, as well as high-frequency oscillatory ventilation might acutely improve oxygenation and can be used as a 'bridge' to alternative rescue
therapies, but neither provides any survival advantage by itself and might even be detrimental. Although increasingly employed in other than the rescue indication,
extracorporeal membrane oxygenation should still primarily be used in patients who do not respond to differentiated
mechanical ventilation, which includes a careful evaluation of nonextracorporeal membrane oxygenation rescue
therapies that might be combined in order to overcome the life-threatening situation. Early involvement of an ARDS or
extracorporeal membrane oxygenation center should be considered to ensure optimal care.
SUMMARY: A well timed, multimodal approach is required for patients with ARDS suffering from life-threatening
hypoxemia. Understanding the limits of each type of rescue measure is of vital importance.