Table 5.

Differentiation of Cyanotic Heart Disease From Pulmonary Disease Among Infants in Respiratory Distress^a

Variable	Cyanotic Heart Disease	Pulmonary Disease
History	Previous sibling with congenital heart disease	Maternal fever
	Diagnosis of congenital heart disease by prenatal ultrasonography	MSAF
		Preterm delivery
Physical examination	Cyanosis	Cyanosis
	Gallop rhythm or murmur	Severe retractions
	Single second heart sound	Split second heart sound
	Large liver	Temperature instability
	Mild respiratory distress
Chest radiograph	Increased heart size	Normal heart size
	Decreased pulmonary vascularity (except in transposition of the great vessels or total anomalous pulmonary venous return)	Abnormal pulmonary parenchyma, such as total whiteout or patches of consolidation in pneumonia, fluid in the fissures in TTN or ground glass appearance in RDS
Arterial blood gas	Normal or decreased Paco2	Increased Paco2
	Decreased Pao2	Decreased Pao2
Hyperoxia test	Pao2 <150 mm Hg	Pao2 >150 mm Hg (except in severe PPHN)
Echocardiography	Abnormal heart or vessels	Normal heart and vessels

MSAF=meconium-stained amniotic fluid; PPHN=persistent pulmonary hypertension of the newborn; RDS=respiratory distress syndrome; TTN=transient tachypnea of the newborn.

^aReproduced with permission from Aly et al. (23) Copyright 2014 by the American Academy of Pediatrics.