Changes in cerebral, renal and mesenteric blood flow velocity during continuous and bolus infusion of indomethacin

Abstract

Vasoconstriction induced by bolus injection of indomethacin reduces organ perfusion and has been related to the well‐known side effects of indomethacin given for closure of the patent ductus arteriosus (PDA). The aim of the study was to compare the changes in cerebral, renal and mesenteric blood flow velocities after continuous infusion versus bolus injection of indomethacin for closure of the PDA. Thirty‐two preterm infants (range 26–35 wk gestational age) with PDA were randomly assigned to receive the same amount of indomethacin either as three bolus injections (n= 14) or as a continuous infusion (n= 18) over 36 h. Blood flow velocities were measured in the internal carotid, right renal and superior mesenteric arteries at baseline and serially at 10, 30, 60 and 120 min and 12, 24, 36 and 48 h after the start of indomethacin treatment. There were no differences in blood flow velocities between both groups at baseline. During continuous infusion of indomethacin there was no significant change in the cerebral, renal and mesenteric blood flow velocities, whereas the flow velocities in the infants receiving bolus injections decreased significantly during the first 2 h after indomethacin administration in all arteries measured. There was a transient, but significant reduction in urine output after bolus injection of indomethacin. Conclusion: In contrast to bolus injections, decrease of organ blood flow and impairment of urine output do not accompany continuous infusion of indomethacin over 36 h.