Symptomatic patent ductus arteriosus following prophylactic indomethacin. A clinical and biochemical appraisal.

Seven of 36 premature infants with birth weight less than 1,250 g who had been randomly assigned to either high-frequency ventilatory ventilation or conventional mechanical ventilation developed symptomatic patent ductus arteriosus (PDA) after receiving prophylactic indomethacin, 0.2 mg/kg, i.v. 24 h after birth. Infants who developed symptomatic PDA were more likely to be white and male and have more severe pulmonary insufficiency than infants who did not develop symptomatic PDA. Serum indomethacin levels were similar in both groups of patients. There was no difference in the degree of suppression or subsequent recovery of endogenous eicosanoid biosynthesis between infants who did and did not develop symptomatic PDA. Compared to conventional mechanical ventilation, high-frequency oscillatory ventilation had no significant effect on endogenous eicosanoid biosynthesis. The susceptibility of white male infants to symptomatic PDA following prophylactic indomethacin may represent the influence of maturational factors on ductus patency. Cyclooxygenase products do not appear to be involved in mediating ductus patency when symptomatic PDA occurs immediately following administration of prophylactic indomethacin.