In Response: We thank the editor for giving us the opportunity to reply to aggressive criticisms about our letter "Preoxygenation in Children" [1]. Although Biddle and Hinkle impeach our methodology, as well as the ethics and purpose of such a study, we note that the study was done by senior anesthesiologists, with the permission of our ethical committee and with the informed consent of the parents. Of course, it has been known "for many decades" that desaturation is not uncommon, and that hypoxemia is more frequent in children than in adult patients during the induction of anesthesia. Indeed, it had been well described by Morray et al. [2], who published a review of closed malpractice claims and reported that, in pediatric anesthesia, the more frequent damages concern inadequate ventilation. But, before 1992, the safe time for anesthesiologists to intubate the trachea of infants and children after preoxygenation during apnea without hypoxemia had never been studied despite a previous description in adults [3]. The purpose of our study was to evaluate the safety time for anesthesiologists to intubate the trachea of infants and children after they had received a muscle relaxant. Our primary results had been published [4], and soon after Kinouchi et al. [5] published a similar study. Despite previous publications [5,6] and because of the importance of our conclusions, Dr. Miller, the Editor-in-Chief agreed to publish a short version of our study. Indeed, concerning dramatic risks of severe hypoxemia after 75-90 s of apnea in infants, we recommended that endotracheal intubation should be carried out by skilled anesthesiologists, with a pulse oximetry and alarms in place, and that when the saturation value was 94%, oxygen must be given before endotracheal intubation could be performed. We are not in agreement with Biddle and Hinkle, who feel that our philosophical and methodologic approach was inappropriate. First, for our study, we had received the approval of the local ethical committee and the informed consent of each child's parents. Second, when saturation was 90%, patients were previously intubated and manual ventilation was immediately given with 100% oxygen without any complication. It was very different from Cote et al.'s studies [7,8] about the frequency and severity of desaturation events during pediatric anesthesia when they evaluated the usefulness of monitoring with oximetry and capnography. Anesthesiologists were blinded about the oximetry data, and some children and infants developed major events with saturation less than 85% for more than 30 s. Despite those low values, those studies had been approved by an ethical committee, and informed written consent from parents was obtained for all patients. Incidentally, we were very surprised that Biddle and Hinkle were not up to date on those two famous American studies. The purpose of our letter was just to public a short version of our serious study to help anesthesiologists in their daily practice. In France, as in the United States, rigorous ethical standards, the clinical benefits to patients, and informed consent govern every clinical study. Alice Dupeyrat, MD Marc Dubreuil, MD Claude Ecoffey, MD Departement d'Anesthesie et de Reanimation, Universite Paris-sud, Hopital de Bicetre, 94 275 Le Kremlin Bicetre, France