To the Editor: I believe that the design of the Lung Open Ventilator Study by Dr Meade and colleagues1 made an error by adjusting PEEP according to FIO2, leading to overdistention of alveoli as evidenced by lower static compliance (tidal volume / [plateau pressure – end-expiratory pressure]) in the high PEEP group than in the lower PEEP group.2 The mean levels of compliance in the high and low PEEP groups were 0.41 and 0.42 mL/kg/cm H2O on day 3 and 0.37 and 0.41 mL/kg/cm H2O on day 7, respectively. Despite a similar protocol, the same phenomenon was not observed in the ALVEOLI study,3 possibly due to the difference in patient population. The protocol change in the middle of the study allowing higher PEEP levels in the Lung Open Ventilator Study might have negatively affected the study results.
Oba Y. Ventilation Strategies for Acute Lung Injury and Acute Respiratory Distress Syndrome. JAMA. 2008;300(1):39-43. doi:10.1001/jama.300.1.39-b