Cyanotic lesions comprise approximately one-third of potentially fatal forms of congenital heart disease (CHD) [1,2]. Early recognition, emergent stabilization, and transport to an appropriate cardiac care center are critically important in the outcome of newborns with these lesions.
The evaluation and initial management of cyanotic CHD in the newborn are presented here. The causes of neonatal cyanotic cardiac lesions are discussed separately. (See "Cardiac causes of cyanosis in the newborn".)
Prenatal sonograms often identify structural malformations including CHD, diaphragmatic hernia, and congenital cystic adenomatoid malformation; however, the sensitivity of CHD detection is highly variable depending on operator expertise, gestational age, fetal position, and type of defect. As a result, prenatal sonography will miss some patients with cyanotic CHD. (See "Prenatal sonographic diagnosis of fetal cardiac anomalies", section on 'Efficacy' and "Congenital heart disease (CHD) in the newborn: Presentation and screening for critical CHD", section on 'Variability of prenatal ultrasound'.)
In affected neonates who are not identified by prenatal sonography, a clinical diagnosis of cyanotic CHD is based on history, physical findings, chest radiography, and hyperoxia test. The diagnosis is confirmed by echocardiography.
Central cyanosis caused by reduced arterial oxygen saturation is generally perceptible when the reduced hemoglobin level exceeds 3 g/dL (figure 1) . It can result from several different pathologic mechanisms that are caused by cardiac disorders, pulmonary abnormalities, or hemoglobinopathies (table 1) . (See "Cardiac causes of cyanosis in the newborn", section on 'Etiology' and "Overview of cyanosis in the newborn", section on 'Hemoglobin concentration' and "Overview of cyanosis in the newborn", section on 'Central cyanosis'.)