In Reply: Phototherapy Effect on the Incidence of Patent Ductus Arteriosus

Abstract

Dr Ward points to two major problems that we discussed in our paper. At the time this study was begun in our neonatal intensive care unit, only M-mode echocardiography was available. We agree our methods were relatively gross estimations of ductal patency, and we are presently studying the effect of phototherapy using two-dimensional and Doppler echocardiography.

The second flaw of nonblinding was an extremely difficult one to solve in our unit. Those physicians involved in the study spent considerable time in the unit and, even if shields were removed during the scheduled daily examination, it would be difficult to truly blind observers because shields would have been replaced.