Persistent Doppler flow predicts lack of response to multiple courses of indomethacin in premature infants with recurrent patent ductus arteriosus

Objective. Although indomethacin produces ductus arteriosus constriction in extremely premature newborns, a recurrent symptomatic patent ductus arteriosus (PDA) frequently develops after the initial course of indomethacin. Currently, there is little information available to determine the effectiveness of a second course of indomethacin in producing permanent ductus closure. The objective of this study was to determine the rate of permanent ductus closure after a second course of indomethacin for a recurrent, symptomatic PDA and to identify the factors associated with permanent ductus closure. Methods. We identified 32 infants ( Results. After the second course of indomethacin, 56% (18 of 32) of the infants had persistent or recurrent PDA-related symptoms that were considered to be hemodynamically significant. The only significant predictor of failure of the second indomethacin course was the demonstration (by Doppler echocardiogram) of persistent ductus flow within 24 hours of completing the initial indomethacin course. All of the 9 newborns with persistent Doppler ductus flow after the initial indomethacin course failed the second course of indomethacin. In contrast, only 39% (9 of 23) of newborns with absent Doppler flow after the initial indomethacin course failed the second course of indomethacin. Conclusions. Newborns who are