Review Question - QID 107281

The patient most likely has patent ductus arteriosus (PDA) based on the description of the continuous machine-like murmur and a bounding pulse. In preterm infants, indomethacin can help close the PDA.

PDA is an abnormal vascular connection that causes blood to flow from the aorta to the pulmonary artery. This leads to decreased oxygen delivery to the periphery. PDAs account for about 10% of congenital heart disease. Small PDAs are frequently asymptomatic. PDAs usually close within the first month of life. Aside from indomethacin, PDAs can be closed surgically through ligation or coil embolization.

Saenz et al. note that congenital heart defects are classified into acyanotic and cyanotic lesions. Most common acyanotic lesions include VSD, ASD, atrioventricular canal, pulmonary stenosis, PDA, aortic stenosis, and coarctation of the aorta. Congestive heart failure is the primary concern in these infants. Cyanotic lesions include tetralogy of Fallot and transposition of great arteries. These infants suffer from hypoxia.

Mahony et al. performed a landmark double-blind, controlled study of indomethacin in premature infants with subclinical patent ductus arteriosus. In infants who weighed 1000 grams or less, major ductus shunts developed in 10 out of 12 given the placebo, while indomethacin therapy showed a statistically significant lower incidence in major shunts, reduced surgical ligations, decrease time of oxygen therapy, and fewer days until return of birth weight.

Incorrect answers:
Answer 2: There is no role of thiazide diuretics in this case, although medical management of progressed heart failure can include digoxin and diuretics.
Answer 3: There is no use of aspirin in treating PDA.
Answer 4: There are no signs of infection that would require penicillin.
Answer 5: While the child is asymptomatic at this time, PDA is a cause of acyanotic heart disease which needs to be treated.