A preliminary report--heparin counteracts indomethacin effect on ductus arteriosus in very low birthweight infants.

Objective: We report a clinical observation showing that continuous exposure to heparin via a central venous catheter is associated with patent ductus arteriosus treatment failure with indomethacin in very low birthweight infants.

Study Selection: A clinical observational case report in infants weighting <1501 g.

Data Extraction: This study compares the rates of patent ductus arteriosus treatment failure during a) the index period from June 2, 2003, to August 22, 2003, when all very low birthweight infants with a peripherally inserted central venous catheter received continuous infusion of heparinized parenteral nutrition; b) the baseline period of 1 yr before the index period; and c) the postindex period of 1 yr after the index period.

Data Synthesis: The rate of patent ductus arteriosus treatment failure with indomethacin increased significantly during the index period compared with the baseline (odds ratio, 7.0; 95% confidence interval, 1.41-34.7; p = .017) and postindex periods (odds ratio, 33.8; 95% confidence interval, 4.72-243; p = .0005). The result was confirmed in logistic multivariable regression analysis.

Conclusion: This observation, based on a case series and their controls, serves as a basis for a new hypothesis suggesting that continuous exposure to heparin through heparinized central venous infusion significantly increases patent ductus arteriosus treatment failure with indomethacin. This hypothesis needs to be tested in a randomized controlled trial.