Computerized assessment of shunt and Ventilation-Perfusion mismatch in oxygen dependent infants

Hypoxemia is defined as a decrease in the partial pressure of oxygen in the blood. There are various mechanisms of hypoxemia: Ventilation-Perfusion (V/Q)mismatch and shunt are the most common causes of arterial hypoxia in newborns. Neonatologists often treat hypoxic infants in their clinical practice. A simple and rapid tool to evaluate the contribution of shuntand V/Q mismatch in oxygen dependent infants would be useful. We non-invasively studied six preterm infants with bronchopulmonary dysplasia, a condition in which V/Q mismatch and shunt may coexist. Our setup consisted of a high precision oximeter and a computerized algorithm to eliminate inaccurate oxygen saturation data. The relationship between fraction of inspired oxygen (FiO2) andarterial oxygen saturation(SpO2) was assessed using a previously described methodology. Most infants had V/Q mismatch, while one had prevalent shunt.