Are oxygen indices effective for predicting pathological intrapulmonary shunt in mechanically ventilated children?
GROUND: This study was undertaken to evaluate whether oxygen indices accurately predict pathological intrapulmonary shunt (Qsp/Qt), and to evaluate the sensitivity and specificity of the FiO2-required formula to obtain a desired arterial oxygen tension (PaO2) in mechanically ventilated children. METHODS: A prospective, hospital-based, comparative study was conducted on 50 mechanically ventilated children at the Intensive Care Units of the National Institute of Pediatrics (INP) in Mexico City. Blood gas data were prospectively collected from 50 critically ill, mechanically ventilated children, 50 taken before and 40 after FiO2 change. Assessment of Qsp/Qt, P(A-a)O2, PaO2/FiO2, PaO2/PAO2, and P(A-a)O2/PaO2 was carried out before and after FiO2 change. RESULTS: In first blood gas data, 31 patients were hypoxemic (PaO2 < 90 Torr), 10 were normal, and 9 were hyperoxemic (PaO2 > 100 Torr). Forty patients required FiO2 modifications that were carried out according to Maxwell’s formula. Five c
