Effect of indomethacin infused over 30 minutes on cerebral fractional tissue oxygen extraction in preterm newborns with a patent ductus arteriosus.

BACKGROUND

A significant patent ductus arteriosus (PDA) is a common finding in the first days of life and, if persistent, is associated with an increased morbidity and mortality in the preterm newborn.

OBJECTIVES

Our aim was to investigate, using near-infrared spectroscopy, the effect of indomethacin on the fractional tissue (cerebral) oxygen extraction (FT(c)OE) in a group of preterm newborns undergoing medical treatment for a PDA.

METHODS

This is a prospective, observational study. A cohort of 18 preterm newborns (<32 weeks) undergoing treatment for a PDA with indomethacin were monitored continuously for mean arterial blood pressure, arterial oxygen saturation (SpO(2)) and regional cerebral oxygen saturation (r(c)SO(2)). Measurements were started 1 h before and continued for 4 h after the first indomethacin dose. A final measurement (1 h) was made within 24 h of completing the full course. FT(c)OE = [SpO(2) - r(c)SO(2)]/SpO(2) was then calculated. To analyze the data, we chose to average the measurements over 1-hour periods.

RESULTS

There was a significant increase in the FT(c)OE (0.06, 95% CI 0.04-0.09, p < 0.001) noticeable within the 1st hour after the start of indomethacin administration, which peaked in the 2nd hour (FT(c)OE increased by 0.08, 95% CI 0.04-0.11, p < 0.001) and lasted for the full 4-hour period measured.

CONCLUSION

Indomethacin, infused over 30 min, significantly increased the FT(c)OE in the preterm newborn, the effect lasting at least 4 h. This may represent a protective response to the indomethacin-induced reduction in cerebral blood flow demonstrated by others and warrants further investigation.