PaO2/FIO2, leukocyte count, and C-reactive protein during the first 10 days after out-of-hospital cardiac arrest, in subjects with or without early-onset pneumonia. PaO2/FIO2, leukocyte count, and C-reactive protein during the first 10 days after out-of-hospital cardiac arrest, in subjects with or without early-onset pneumonia. For PaO2/FIO2 there were significant differences on day 4 (P = .009), day 5 (P = .003), and day 6 (P = .03). For leukocyte count there were no significant differences. For C-reactive protein there were significant differences on day 3 (P = .006), day 4 (P = .052), and day 7 (P = .02). Dirk Pabst et al. Respir Care 2013;58:1514-1520 (c) 2012 by Daedalus Enterprises, Inc.