Cerebral Tissue Oxygenation Index and SIDS

* Abbreviations: SIDS — : sudden infant death syndrome SUID — : sudden unexpected infant death TOI — : tissue oxygenation index In this issue of Pediatrics , Fyfe et al present convincing evidence that cerebral tissue oxygenation index (TOI) is lower in habitually supine-sleeping preterm infants placed prone rather than supine, and that the cerebral TOI for preterm infants placed prone is lower than the TOI for term infants placed prone. Increased rates of sudden infant death syndrome (SIDS) among all infants sleeping prone, and even higher rates among preterm infants placed prone, provide the epidemiologic rationale for their physiologic studies.1,2 An established approach in attempting to understand sudden unexpected infant deaths (SUID), including SIDS, is the Triple Risk Model: a susceptible infant at a susceptible developmental stage is exposed to a stressor that cannot be overcome.3 The susceptible infants investigated by Fyfe et al were born before term and were studied at 2 to 4 weeks, 2 to 3 months, and 5 to 6 months post-term age, and compared with a group of infants born at term. Much recent study of SUID has focused on the interaction between sleep position and sleep microenvironment. This group from Australia has carried the torch in trying … Address correspondence to James S. Kemp, MD, St Louis Children’s Hospital, 1 Children’s Place, St Louis, MO 63130. E-mail: kemp_j{at}kids.wustl.edu