Persistent pulmonary hypertension of the newborn (PPHN)
Congenital heart syndromes
Transposition of the great vessels
Tetraology of Fallot
Total anomalous pulmonary venous return
Hypoplastic left heart
Truncus arteriosus
Tricuspid atresia
Pulmonary atresia
Atrioventricular canal defect
Airway conditions
Airway foreign body
Diaphragmatic hernia
Croup
Pneumonia
Bronchiolitis
Reactive airway disease
Choanal atresia
Laryngomalacia
Vocal cord paralysis
Tracheal stenosis
Cystic hygroma
Hemangioma
Metabolic abnormalities
Polycythemia
Methemoglobinemia
Transposition of the great vessels
Tetraology of Fallot
Total anomalous pulmonary venous return
Hypoplastic left heart
Truncus arteriosus
Tricuspid atresia
Pulmonary atresia
Atrioventricular canal defect
Airway foreign body
Diaphragmatic hernia
Croup
Pneumonia
Bronchiolitis
Reactive airway disease
Choanal atresia
Laryngomalacia
Vocal cord paralysis
Tracheal stenosis
Cystic hygroma
Hemangioma
Polycythemia
Methemoglobinemia
Hypoxia
Hypopnea / Hypoventilation
Pneumonia
Valvular heart disease
ASD / VSD
Pulmonary embolism / DVT
Myocardial infarction
Vascular disease
Pulmonary HTN
COPD
Pneumothorax
Hypoperfusion
CHF
Methemoglobinemia
Polycythemia
Sulfhemoglobinemia
Raynauds
Administration of methylene blue
Cyanosis
Polycythemia
Phimosis
Hematuria
Hematuria 
Hepatomegaly
Polyuria
Dyshemoglobinemia