Response to prophylactic indomethacin varied with birth weight: A retrospective chart review

This study was designed to evaluate the benefits reported in previous trials of using prophylactic indomethacin in high-risk neonates to improve outcome. The medical records of 217 infants with maximum birth weights of 1250 grams born between May 1995 and May 1997 were reviewed. These infants were either delivered at University Hospital, San Antonio, Texas or were transferred from affiliated hospitals within twenty-four hours of life. Drug administration records were surveyed for the doses and times of administration of indomethacin. Radiology reports of routine head ultrasounds (HUS) were used to determine the incidence of intraventricular hemorrhage (IVH). The Papille grading system was used to classify IVH. Daily progress notes were reviewed for specific known common side effects of intravenous indomethacin administration, including necrotizing enterocolitis (NEC), bowel perforation, periventricular leukomalacia (PVL), and renal compromise. Those infants receiving three or more doses, with the first dose given within the first twenty-four hours of life and before the onset of symptoms of a PDA were classified in the prophylactic group. Those who received indomethacin for medical management of PDA, an incomplete course (less than 3 doses), or did not receive indomethacin were placed in the non- prophylactic indomethacin group. The groups were stratified by birth weights between 500 and 800 grams and those between 801 and 1250 grams. Statistical analyses were done using the paired t-test and chi square analysis. Twenty-nine of the 217 (13.2%) neonates met the criteria of prophylactic indomethacin use, while 188 (87%) of the neonates were considered as not receiving prophylactic indomethacin. The mean birth weights and gestational ages for the two groups were not significantly different (p<0.05). There was no statistical difference in the incidence of mortality or morbidity associated with the use of prophylactic indomethacin in the extremely low birth weight (500-800 grams) patients. There was not a significant difference in the incidence of IVH (low or high grade) in these two groups. In both stratified groups of infants receiving prophylactic indomethacin, there was a significant reduction in the diagnosis of PDA (p<0.01). However, a statistically significant increase was seen in the prophylactic group in the incidence of NEC (P<0.01) and PVL (p<0.01), in the 801 to 1250 gram neonates. This increase was not seen in the 500-800 gram birth weight neonate. Our findings suggest the need for further prospective randomized trials for the use of prophylactic indomethacin with particular emphasis in the extremely low birth weight infants.