Increasing respiratory rate to improve CO2 clearance during mechanical ventilation is not a panacea in acute respiratory failure

recent cooperative study seemsto have closed 10 yrs of contro-versy regarding the efficiency oftidal volume limitation in acuterespiratory failure (ARF) treatment (1). Bydemonstrating a significant reduction inmortality and a significant increase in dayswithout mechanical ventilation, with tidalvolume reduction in a large population ofpatients meeting the criteria for acute lunginjury or acute respiratory distress syn-drome (2), this study confirmed that astrategy limiting lung stretch during me-chanical ventilation is really protective inARF (1). However, some peculiar points ofthis study are intriguing. The authors useda high respiratory rate (RR) during volume-controlled ventilation (30 breaths/min) toimprove CO