ABSTRACT
From the time of its inception, the role of mechanical ventilation in acute respiratory failure has been duplicitous-life saving on one hand, while injury promoting on the other. Before the use of positive pressure ventilation became widespread, mortality from acute hypoxemic respiratory failure was nearly 100%. Mortality was still nearly 60% in 1971, when Petty and Ashbaugh (1) first reported on the use of positive pressure ventilation for the treatment of ARDS. At that time, clinicians had already raised concerns about the potential harmful effects of mechanical ventilation. For example, in 1968 Sladen and coworkers (2) reported that prolonged mechanical ventilation resulted in worsening oxygenation, increased lung water, and decreased compliance in patients with ventilatory failure. Similar findings had been reported in animal models as early as the 1940s (3-5).
