We assessed O2 gas deprivation potential of bedding that had actually been used by 26 infants diagnosed with sudden unexpected infant death using FiCO2 time course of baby mannequin model. All cases were the same ones in our poster paper (I). Mathematically, time-FiCO2 (t) graphs were given as FiCO2 (t) = C(1 - eDt). Here, "C" approximates the maximum FiCO2 value, while "D" is the velocity to reach maximum FiCO2. FiO2 in a potential space around the mannequin's nares was estimated using a formula: FiO2 = 0.21-FiCO2/RQ. RQ is the respiratory quotient, and the normal human value is 0.8. The graph pattern of FiO2 is roughly the inverse of the FiCO2 time course. Four cases showed the bottom of estimated FiO2 to be more than 15%, 15 were 15-6%, and the other seven were 6% or less. Considering the minimal tissue stores of O2, changes in FiO2 may be affected by both CO2 production and gas movement around the infant's face. Especially, the latter seven cases may suggest the participation of the role not only of CO2 accumulation but also of the decrease of O2 around the face.
- Sudden death in infancy
ASJC Scopus subject areas
- Pathology and Forensic Medicine
- Issues, ethics and legal aspects