In Reply.—Dr Sepkowitz has raised some questions with respect to a change in diagnostic or inclusion criteria in our retrospective study. The criteria outlined in our report did not change from 1980 to 1981.1 We did note an increased number of patients in 1981 and speculated that this could be related to a higher index of suspicion.
More aggressive intervention was used in those infants who did not respond to conservative therapy after the diagnosis of PPHN was established. We were able to make the diagnosis of PPHN earlier in the inborn infants and therefore initiate appropriate therapy at an earlier time in their course.
Death in patients with PPHN was thought to be related to the severity of coexisting pulmonary parenchymal disease, eg, meconium aspiration, or pulmonary hypoplasia, eg, congenital diaphragmatic hernia. However, recent data have suggested that the pulmonary vascular disease may be a more important