The Silent Patent Ductus Arteriosus

In Reply.— We appreciate the comments of Kashani, Swensson and Merritt. We are cognizant of the pioneering work done through the years at the University of California at San Diego in relation to the management of respiratory distress syndrome (RDS). The multicenter trial1 established diagnostic criteria for patent ductus arteriosus (PDA) in 1978. In view of the unknown toxicity of indomethacin at that time, high specificity rather than maximum sensitivity was of prime concern. We wanted to enroll in our trial only those infants in whom the degree of ductal shunting was leading to sufficient cardiopulmonary compromise to cause a threat to the infant and to warrant the use of a potentially toxic drug or surgery.