RT Book, Section A1 Leone, Tina A. A2 Siassi, Bijan A2 Noori, Shahab A2 Acherman, Ruben J. A2 Wong, Pierre C. SR Print(0) ID 1161424770 T1 Desaturation and Cyanosis in the Newborn Infant without Congenital Heart Disease* T2 Practical Neonatal Echocardiography YR 2018 FD 2018 PB McGraw-Hill Education PP New York, NY SN 9781260123135 LK accesspediatrics.mhmedical.com/content.aspx?aid=1161424770 RD 2024/10/03 AB The physical signs of cyanosis and decreased oxygen saturation are usually the result of hypoxemia, and can be found in newborn infants with a variety of pathologies. Hypoxemia can be the result of shunting of deoxygenated blood from the venous to the arterial circulation. This can occur at many levels including intracardiac, extracardiac, and intrapulmonary locations. The primary causes of hypoxemia in infants without congenital heart disease vary and include pulmonary problems such as pneumonia, respiratory distress syndrome (RDS), congenital anomalies, pneumothorax, and meconium aspiration syndrome (MAS). Additionally, the primary cause of hypoxemia could be persistent pulmonary hypertension of the newborn (PPHN), a failure or delay in making the circulatory transition from fetal to newborn life leading to persistently elevated pulmonary vascular resistance, and continued shunting through the fetal channels. In most cases, PPHN is secondary to another respiratory disease, and therefore these findings do not usually occur in isolation. Certain conditions predispose infants to having a more prolonged circulatory transition. Infants at higher risk include infants of diabetic mothers, infants with trisomy 21, and fetal exposure to nonsteroidal anti-inflammatory agents or selective serotonin reuptake inhibitors. Preterm infants may have a variety of transitional problems after birth leading to hypoxemia. Both RDS and prolonged premature rupture of membranes (PPROM) are associated with PPHN. Additionally, a significant patent ductus arteriosus (PDA) is often associated with increasing oxygen and ventilator requirements. Echocardiography can be helpful in the diagnosis and management of many of these problems.