Chapter 45

1. Problem. During a physical examination, an infant appears blue. Cyanosis becomes visible when there is >3g of desaturated hemoglobin/dL. Therefore, the degree of cyanosis depends on both oxygen saturation and hemoglobin concentration. Cyanosis is visible with much less degree of hypoxemia in the polycythemic compared with the anemic infant. Cyanosis can be a sign of severe cardiac, respiratory, or neurologic compromise.

2. Immediate questions

1. Does the infant have respiratory distress? If the infant has increased respiratory effort with increased rate, retractions, and nasal flaring, respiratory disease should be high on the list of differential diagnoses. Cyanotic heart disease usually presents without respiratory symptoms but can have effortless tachypnea (rapid respiratory rate without retractions). Blood disorders usually present without respiratory or cardiac symptoms.

1. Does the infant have a murmur? A murmur usually implies heart disease. Transposition of the great vessels can present without a murmur (~60%).One study revealed that in infants with congenital heart malformation, <50% have a murmur in the newborn period. Unfortunately, murmurs are not any more common in more severe heart defects.

1. Is the cyanosis continuous, intermittent, sudden in onset, or occurring only with feeding or crying? Intermittent cyanosis is more common with neurologic disorders; these infants may have apneic spells alternating with periods of normal breathing. Continuous cyanosis is usually associated with intrinsic lung disease or heart disease. Cyanosis with feeding may occur with esophageal atresia and severe esophageal reflux. Sudden onset of cyanosis may occur with an air leak, such as pneumothorax. Cyanosis that disappears with crying may signify choanal atresia. Infants with Tetralogy of Fallot may have clinical cyanosis only with crying.

1. Is there differential cyanosis? Cyanosis of the upper or lower part of the body only usually signifies serious heart disease. The more common pattern is cyanosis restricted to the lower half of the body, which is seen in patients with patent ductus arteriosus with a left-to-right shunt. Cyanosis restricted to the upper half of the body is seen occasionally in patients with pulmonary hypertension, patent ductus arteriosus, coarctation of the aorta, and D-transposition of the great arteries.

1. What is the prenatal and delivery history? An infant of a diabetic mother has an increased risk of hypoglycemia, polycythemia, respiratory distress syndrome, and heart disease. Infection, such as that which can occur with premature rupture of membranes, may cause shock and hypotension with resultant cyanosis. Amniotic fluid abnormalities, such as oligohydramnios (associated with hypoplastic lungs) or polyhydramnios (associated with esophageal atresia), may suggest a cause for the cyanosis. Cesarean section is associated with increased respiratory distress. Certain perinatal conditions increase the incidence of congenital heart disease. Examples of these include the following:

1. Maternal diabetes or cocaine: D-transposition of the great arteries.

1. Maternal use of lithium: Ebstein anomaly.

1. Use of phenytoin: Atrial septal defect, ventricular septal defect, Tetralogy of Fallot.

1. Maternal lupus: AV block.

1. Maternal congenital heart disease and/or congenital heart disease in a first-degree relative: Increased incidence of heart disease in the child.

3. Differential diagnosis. The causes of cyanosis can be classified as arising from respiratory, cardiac, central nervous system (CNS), or other disorders.

1. Respiratory diseases

1. Lung diseases

1. Hyaline membrane disease.

1. Transient tachypnea ...

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