The EMShockNet team previously claimed in JAMA that hyperoxia (paO2>300) after cardiac arrest could be deadly (63% in-hospital mortality vs 45% in normoxic patients). After looking at 12,108 database records in Australia/New Zealand, Bellomo et al beg to differ. By applying severity of illness/propensity models, they found no increased risk of death in those with high paO2 after cardiac arrest. Critical Care 2011;15:R90.