Oxidant stress mediates inflammation and apoptosis in ventilator-induced lung injury. SIR-We read with many interest the article by Victoria Karlsson et al.[1] "Randomized controlled trial of low vs high oxygen during neonatal anesthesia: Oxygenation, feasibility, and oxidative stress" and congratulate the authors on their informative study. Moreover, We focused on the occurrence of postoperative atelectasis in the HIOX group because F2-soprostane was significantly increased in ventilator-induced lung injury which include alveolar atelectasis.[4] Neonates are vulnerable to atelectasis. [Extracted from the article]