UMBILICAL ARTERY CATHETERS AND BLOOD-FLOW VELOCITIES IN THE SUPERIOR MESENTERIC-ARTERY - EFFECT OF ENTERAL FEEDING

Objective: Enteral feeding in neonates with umbilical artery catheters is thought to be a factor in bowel ischemia and in the pathogenesis o f necrotizing enterocolitis. This study was designed to determine whet her the presence of umbilical artery catheters affects the expected ch anges in blood flow velocities in the superior mesenteric artery after enteral feeding. Methods: Duplex pulsed Doppler ultrasound was used t o measure peak systolic, end diastolic, and mean blood flow velocities in the superior mesenteric artery. Resistance index and pulsatility i ndex were calculated from these data. Eighteen infants of birth weight s 1060-4130 g and gestational age 27-41 weeks were studied. Nine infan ts with indwelling umbilical artery catheters (UAC group) and nine inf ants without umbilical artery catheters (control group) were studied. Babies were studied immediately before and 45 min after enteral feedin g. Results: Blood flow velocities, resistance index, and pulsatility i ndex before feeding in the control and umbilical artery catheter group s were similar, Blood flow velocities increased significantly after fe eding when compared with the flow rate before feeding. The increases i n blood flow velocities were similar for both groups. In both groups, resistance index and pulsatility index did not change significantly af ter feeding. Conclusions: The effect of enteral feeding on blood flow velocities and vascular resistance of the superior mesenteric artery a re similar in babies with and without umbilical artery catheters.