Factors that influence mesenteric artery blood flow velocity in newborn preterm infants

Abstract

Objectives: To identify demographic and clinical variables that relate to the postnatal increase in intestinal blood flow velocity in preterm infants.Study design: Fasting or preprandial peak systolic velocity (PSV) and time-averaged mean velocity (TAMV) in the superior mesenteric artery were measured once each day for the first 5 days of life. We investigated the relationship between blood flow velocity and the following variables: birth weight, gestational age, feeding volumes, number of days to reach full feeding volumes, type of feeding given, continuous positive airway pressure (CPAP) administration and hyperalimentation (HAL) administration.Results: Twenty-five infants with a mean birth weight of 1740 g and mean gestational age of 31.8 weeks were studied. There were significant increases in PSV (P<0.001) and TAMV (P ¼ 0.005) from postnatal day 1 to 5. The postnatal increase in TAMV and PSV was attenuated in infants administered CPAP or HAL for X3 days; the results remained significant after controlling for birth weight and gestational age. There was a significant correlation (P<0.02) between volume of enteral feedings given on 2 of 5 days for TAMV, and on 1 of 5 days for PSV.Conclusions: These data support previous findings of significant increases in intestinal blood flow in preterm infants during the first week of life, and of inconsistent effects of enteral feeding volumes on fasting or preprandial intestinal blood flow. The reasons for, and the clinical implications of, attenuated increases in postnatal intestinal blood flow in infants on CPAP or HAL require further investigation.

Nasal continuous positive airway pressure affects pre- and postprandial intestinal blood flow velocity in preterm infants

“…5 An additional finding of the present study is that the increase in SMA BFV from 0 to 30 min after feeding was greater when infants were on CPAP versus off CPAP. To our knowledge, these are the only reports of CPAP effects on intestinal blood flow velocity.…”

“…5,[9][10][11][12][13][14][15] Other extrinsic factors that affect intestinal blood flow velocity in preterm infants include the type and volume of enteral feeding given, 10,13 -17 various pharmacologic agents 18,19 -21 and phototherapy. 22,23 Greater increases in postnatal and postprandial SMA BFV in preterm neonates are associated with less intestinal dysmotility 6 and with better tolerance to enteral feedings.…”

“…4 We previously reported that CPAP administration was associated with an attenuation of the postnatal increase in superior mesenteric artery blood flow velocity (SMA BFV) in preterm infants. 5 Attenuated increases in postnatal SMA BFV are reportedly associated with intestinal dysmotility 6 and with feeding intolerance. 7 Our objective was to further investigate the effect of CPAP on intestinal blood flow velocity by measuring pre-and postprandial SMA BFV in preterm infants when they were receiving CPAP ('on CPAP') and after CPAP was discontinued ('off CPAP').…”

Regional tissue oxygenation in preterm born infants in association with echocardiographically significant patent ductus arteriosus

“…Significantly lower mesenteric tissue oxygenation was recorded in infants with a large PDA on NCPAP, but not in the mechanically ventilated neonates. Large transductal size and NCPAP, which is a known factor that influences mesenteric artery blood flow velocity in preterm infants, 29,30 is one possible explanation for this finding, although reduction in mesenteric blood flow does not always impair Regional tissue oxygenation in infants with PDA A Petrova et al mesenteric tissue oxygenation. 31 We did not find a decrease in mesenteric tissue oxygenation in infants with moderate PDA on NCPAP, maybe because of the inadequate number of observed cases with moderate PDA on CPAP (n ¼ 2).…”

Early Nasal Continuous Positive Airway Pressure and Necrotizing Enterocolitis in Preterm Infants

“…Blood flow in the superior mesenteric artery is decreased in infants supported with NCPAP when compared with those off NCPAP. 11 This finding suggests that the blood velocity may not be adequate to support the tremendous intestinal growth that occurs soon after birth, leaving the intestine more vulnerable to developing NEC. On the other hand, experimental studies demonstrated mechanical ventilation to create a significant cascade of inflammation leading to severe capillary leak that is not limited to the lungs.…”