Objective: To investigate the effects of umbilical artery catheters (UACs) on superior mesenteric artery (SMA) blood flow velocity (BFV) following enteral feedings in very low birth weight preterm infants.
Study design: Very low birth weight preterm infants who had UACs inserted as part of standard clinical care were enrolled in this prospective study. On the day the UAC was scheduled to be removed, pre- and postprandial SMA BFV (mean, peak systolic and end diastolic velocities) were measured in conjunction with a minimal enteral feeding given while the UAC was in place. The same measurements were made with the next feeding given after the UAC was removed. Preprandial measurements were made at least 3 h after the last enteral feeding, and postprandial measurements were made 30, 45 and 60 min after the feeding began. The same volume and type of feeding were used for both studies.
Results: The birth weight and gestational age of the 19 infants who completed the study were 1014+/-221 g and 27.4+/-1.9 weeks, respectively. Infants were 4.6+/-1.7-days-old when the first SMA BFV measurement was made, the volume of enteral feedings was 1.3+/-0.6 ml, and the time between the two enteral feedings was 4.7+/-3.2 h. Preprandial SMA BFV did not differ with the UAC in place compared with the UAC removed. Peak postprandial velocities were at 45 min after feedings began. The percent increase from baseline was not significantly different with the UAC in place compared with the UAC removed.
Conclusions: Preprandial SMA BFV and postprandial SMA BFV responses to minimal enteral feedings were not affected by the presence of a UAC.