Objective: To study serum creatinine (SCr) levels following indomethacin for patent ductus arteriosus (PDA) closure in extremely preterm neonates in relation to postnatal age at the start of treatment.
Methods: This was a retrospective (January 2000-December 2002) analysis of data on preterm neonates (gestation <29 weeks) who received indomethacin for PDA. Pre-existing renal malformation and/or impairment and high serum levels of nephrotoxic drugs were criteria for exclusion.
Results: Indomethacin was commenced at postnatal age <7 days and >or=7 days in 60 (group 1) and 30 (group 2) neonates, respectively. The median (Q1, Q3) gestational age and birth weight for group 1 and group 2 neonates were 25 (23, 27) vs. 25 (24, 26) weeks and 740 (620, 909) vs. 780 (663, 966) grams, respectively. Postnatal age <7 days at start of indomethacin was associated with higher baseline (0.083 (0.074, 0.090) vs. 0.073 (0.054, 0.083) mmol/L, p=0.001) and peak SCr levels (0.099 (0.089,0.109) vs. 0.090 (0.064, 0.104) mmol/L, p=0.015). Logistic regression analysis controlling for gestational age and baseline SCr level indicated that postnatal age >or=7 days was a risk factor for elevated SCr after indomethacin (OR=13.4, 95% CI: 3.8-46.6, p < 0.001).
Conclusion: Postnatal age >or=7 days at the start of indomethacin is a predictor of a significant rise in SCr in extremely preterm neonates.