Doppler analysis of superior mesenteric artery blood flow in preterm infants

Abstract

Transcutaneous Doppler ultrasound measurements were made of the superior mesenteric artery of 22 preterm infants (mean birth weight 600-2580 g) to investigate the response of intestinal blood flow to feeding. Analysis of the data in relation to milk intake showed a significant change in peak velocity and mean velocity; peak velocity before feeding increased from a mean baseline value of 34 cm/s in fasting infants to 46 cm/s when less than 50 g milk/kg body weight a day were given, and up to 56 cm/s when 50 g or more of milk/kg body weight a day were given. The corresponding values for mean velocity were 10, 15, and 22 cm/s, respectively. The pulsatility index decreased from 0.94 to 0.90 and 0.86 as milk volumes were increased. This investigation showed characteristic changes in the response of intestinal blood flow to feeding: 15 minute peak velocity and mean velocity rose significantly 15, 45, and 90 minutes after feeding, whereas the pulsatility index fell. Flow rate peaked 45 minutes after feeding.