Overview
The First Question Is Where Blood Is Going
A newborn may be deeply cyanotic while the lungs sound relatively clear, or may become tachypneic and poorly perfused after appearing well.
A newborn may be deeply cyanotic while the lungs sound relatively clear, or may become tachypneic and poorly perfused after appearing well. Those patterns point to different failures. In transposition, oxygenated and deoxygenated blood travel in parallel and need a connection between circuits; in hypoplastic left heart syndrome, the ductus temporarily supports systemic flow; in truncus arteriosus, falling pulmonary resistance draws excessive blood into the lungs; and in TAPVR, obstruction traps blood behind the lungs. The circulation pattern predicts the first danger and the first action. Pulse oximetry screening of a well newborn occurs at or around 24 hours: the revised algorithm requires at least 95% in both the right hand and either foot, with one retest after a nonpassing initial screen. A symptomatic infant still needs evaluation after a passed screen.