LAUSR

To the Editor: We thank Drs Shen and Du for their valuable comments1 about our article “EarlyModerate Hyperoxemia Does Not Predict Outcome After Aneurysmal Subarachnoid Hemorrhage.”2 Targeting hyperoxemia in a neurocritical care setting is common practice, but the safety of hyperoxemia has been questioned. In previous studies the definition, the cutoff value, and time of assessment of hyperoxemia vary by study. Bellomo et al3 have shown that the worst PaO2 is more representative of mean PaO2 than the first PaO2. Hyperoxia in the early phase of critical illness may be associated with worse outcome.4 However, in most studies hyperoxia exposure is based on a single value of PaO2. We wanted to study the mean exposure to oxygen and we chose TWA-O2 as an indicator for that. It has been previously shown that there is a significant correlation between TWA-O2 and nPaO25 and similar findings were discovered in our study as presented in Figure. Drs Shen and Du1 suggest a new index, the