A105 CRITICAL CARE: IMPROVING PROGNOSTICATION IN CRITICAL ILLNESS: The Ratio Of Measured To Predicted Compliance: A New Parameter For Assessing Impairment In Mechanics And Prognosis In Acute Respiratory Distress Syndrome

D'Angelo[1] found that compliances were predictable through vital capacity (VC). Since VC can be predicted in healthy subjects[2], we derived data from D'Angelo's study and calculated the predicted Crs, Cl, and Ccw as being 1.6%, 2.9%, and 3.6% of predicted VC (ml) per cmH2O, respectively. ARDS is characterized by lung volume loss[3]. Because aerated lung volume is proportional to the measured Crs or Cl, we propose using the ratio of measured to predicted C or C (C_ _ /C _ ., C. _ /C. .) to assess the severity of lung volume loss.