Mesenteric Artery Blood Flow Velocity Research Articles

The effect of Daikenchuto on blood flow of the superior mesenteric artery and portal vein in ELBW: A prospective study.

Focal intestinal perforation (FIP) is a devastating complication of premature birth, and extremely low birth weight (ELBW) infants are at highest risk. This study aimed to evaluate the relationship of the superior mesenteric artery (SMA) and portal vein (PV) blood flow velocities to investigate the association between intestinal blood flow and FIP. In addition, the herbal formula Daikenchuto (TJ-100) is expected to improve intestinal blood flow disorders; therefore, we evaluated its effect. We conducted a prospective cohort study of 15 ELBW infants from January 2020 to August 2021. Measured variables included birth weight, 5-minute Apgar score, time of oral feeding initiation, ductus arteriosus (PDA) closure (percent), diastolic and systolic blood pressure, SMA and PV blood flow velocity, and FIP onset data. Fifteen infants were divided into three groups: a non-surgery group (Group I; 6), a surgery group with FIP (Group II; 4), and a TJ-100 administration group (Group III; 5). The main outcome parameters included SMA and PV blood flow velocities with TJ-100. SMA and PV blood flow differed significantly for the SMA of Group I and the SMA and PV of Group III (P < 0.01, P = 0.01, and P = 0.04, respectively). There was a correlation between SMA and PV in Group III (P = 0.03). TJ-100 may increase SMA and PV blood flow and improve intestinal blood flow in ELBW infants at risk of FIP. Therefore, the effects of TJ-100 should undergo further study.

Effects of delayed cord clamping in intrauterine growth-restricted neonates: a randomized controlled trial.

The time of cord clamping in intrauterine growth-restricted (IUGR) neonates remains an area of uncertainty. This assessor-blinded randomized controlled trial compared the effects of delayed cord clamping (DCC) with early cord clamping (ECC) on the systemic blood flow (SBF) and cerebral hemodynamics in IUGR neonates of gestational age ≥28 weeks, not requiring resuscitation. Eligible newborns were randomized to DCC (cord clamping after 60 s; n=55) or ECC (cord clamping within 30 s; n=55) group immediately after delivery. The primary outcome variable was superior vena cava (SVC) blood flow at 24±2 h. The secondary outcome variables were right ventricular output (RVO), anterior cerebral artery (ACA) blood flow velocity (BFV), superior mesenteric artery (SMA)-BFV and venous hematocrit at 24±2 h, peak total serum bilirubin (TSB), incidences of polycythemia, intraventricular hemorrhage, respiratory distress, feeding intolerance, and necrotizing enterocolitis, outcome, duration of hospital stay, screening audiometry, and serum ferritin levels at the postnatal age of 3 months. Compared to ECC, DCC was associated with significantly higher SVC flow (101.22±21.02 and 81.27±19.12 mL/kg/min, in DCC and ECC groups, respectively; p<0.0001), and significantly increased RVO, SMA-BFV, venous hematocrit, and serum ferritin levels. Though peak TSB was significantly higher with DCC, duration of phototherapy was comparable. ACA-BFV, incidence of polycythemia, and other outcomes were comparable between the groups.Conclusions: DCC was a safe and beneficial intervention in IUGR infants with an improved SBF and SMA-BFV and an increased hematocrit and serum ferritin levels without higher incidences of polycythemia and requirement of phototherapy for significant hyperbilirubinemia.Trial registration: Clinical Trials Registry of India (CTRI/2019/05/018904) What is Known: • Delayed cord clamping (DCC) increases superior vena cava (SVC) blood flow in preterm neonates. • DCC increases hematocrit and serum ferritin in intrauterine growth-restricted (IUGR) neonates, but there may be an associated risk of polycythemia and neonatal hyperbilirubinemia. What is New: • DCC increases SVC blood flow, right ventricular output, superior mesenteric artery blood flow velocity, venous hematocrit, and serum ferritin in IUGR neonates. • Incidences of polycythemia and duration of phototherapy for significant neonatal hyperbilirubinemia do not increase with DCC.

Early prediction of feed intolerance in very low birth weight preterm infants using superior mesenteric artery blood flow velocity

Objective: To evaluate the utility of superior mesenteric artery (SMA) flow velocity post feeding for predicting time to achieve full enteral feeds in very low birth weight (VLBW) neonates.Subjects: In this prospective cohort study preterm VLBW infants were followed until they achieved full enteral feeding.Results: There was no significant difference between prefeed and post feed SMA flow measurements in study subjects. At baseline, it was observed that Small for gestational age (SGA) babies had a significantly lower peak systolic velocity. Time-averaged mean velocity (TAMV) was significantly lower in SGA babies at baseline, 15, 30, 45, and 60 min post feed, but there were no within-group differences noted over time.Conclusion: SMA blood flow velocity measured pre-feed and post-feed times do not correlate with the time to achieve full enteral feeding in very low birth weight neonates. The clinical significance of lower Peak systolic velocity (PSV) and TAMV in SGA infants is unclear.

Effect of caffeine on superior mesenteric artery blood flow velocities in preterm neonates

Objective: To investigate the effect of caffeine infusion on superior mesenteric artery (SMA) blood flow velocities (BFV) in preterm infants.Methods: Prospective observational study on 38 preterm neonates 28–33+6 weeks gestation, who developed apnea on their first day of life, and caffeine citrate infusion was initiated at a loading dose of 20 mg/kg, followed by a maintenance dose of 5–10 mg/kg/day. Duplex ultrasound measurements of SMA BFV were recorded: peak systolic velocity (PSV), end diastolic velocity (EDV) and resistive index (RI), at 15 min before, 1-, 2- and 6-h after caffeine loading dose, and 2 h after two maintenance doses.Results: There was a significant reduction in PSV 1-h (p = .008), a significant decrease in EDV 1- and 2-h (p = .000 and p = .005, respectively) and a significant increase in RI 1- and 2-h (p = .003 and p = .005, respectively) following caffeine loading dose, as compared to values before caffeine infusion. No significant effect of caffeine maintenance doses on SMA BFV was observed (p > .05).Conclusion: Blood flow in SMA is significantly reduced after caffeine citrate infusion at a loading dose of 20 mg/kg. This effect continues for at least 2 h. Meanwhile, SMA BFV seems not affected by maintenance doses.

Packed red blood cell transfusion (PRBC) attenuates intestinal blood flow responses to feedings in pre-term neonates with normalization at 24 hours

Objective: To determine whether packed red blood cell (PRBC) transfusion affects post-prandial superior mesenteric artery blood flow velocities (SMA BFVs) in very-low birth weight (VLBW) neonates and if so, at what time point after transfusion restoration of previous SMA BFV patterns occurs.Design/Methods: VLBW pre-term neonates, older than 14 days and tolerating bolus enteral feedings administered every 3 h were enrolled in this prospective observational study. Pulsed Doppler ultrasound was used to measure pre- and post-prandial (at 45 min) time-averaged mean, peak and end diastolic velocities (TAMV, PSV, EDV) immediately before and after 15 ml/kg of PRBC transfusion was given over 3 h; patent ductus arteriosus (PDA) status was also evaluated. Subsequent pre- and post-prandial SMA BFVs were recorded 24 and 48 h after the transfusion.Results: Pre- and post-prandial measurements were obtained for 21 out of 25 enrolled infants. Post-prandial SMA BFVs were attenuated during the feedings immediately after transfusion; at 24 and 48 h after transfusion, changes in post-prandial SMA BFVs were similar to those measured prior to transfusion; the presence of the PDA did not affect results.Conclusions: PRBC transfusion blunted SMA BFV responses to feedings immediately after the transfusion with normalization observed 24 h post-transfusion.

Feeding preterm neonates with patent ductus arteriosus (PDA): intestinal blood flow characteristics and clinical outcomes

Objective: To evaluate the effects of patent ductus arteriosus (PDA) on postprandial superior mesenteric artery blood flow velocities (SMA BFV)s and feeding tolerance in extremely low birth weight (ELBW) neonates.Methods: Appropriate for gestational age, ELBW preterm neonates, tolerating bolus enteral feedings were eligible to participate in this prospective observational study. Pulsed Doppler was used to measure preprandial and postprandial (at 30 and 60 min) time-averaged mean velocity (TAMV), peak systolic velocity (PSV) and end diastolic velocity (EDV) once during the day of life 5–7; at the same time, PDA size was estimated using the PDA: left pulmonary artery (LPA) ratio.Results: A total of 38 infants were studied, 16 in small, 13 in moderate and 9 in large PDA groups. The postprandial SMA BFVs were lower in the large PDA group, although not reaching statistical significance. Importantly, infants in the large PDA group reached full enteral intake later (p = 0.02) and had higher incidence of death secondary of necrotizing enterocolitis (NEC; p = 0.04).Conclusions: ELBW preterm neonates with large PDA may have attenuated intestinal blood flow responses to feedings. There was also an association with higher rates of necrotizing enterocolitis and feeding intolerance in the large PDA group.

Factors that affect the postnatal increase in superior mesenteric artery blood flow velocity in very low birth weight preterm infants

To identify factors related to the postnatal increase in superior mesenteric artery blood flow velocity (SMA BFV). SMA BFV was measured in 35 infants (birth weight 1047±246 g) on day of life (DOL) 1, 3, 5, 7 10 and 14. Latent curve modeling (LCM) was used to measure the longitudinal change in BFV for each subject, and the correlation between changes in BFV and baseline values. Non-parametric correlations were calculated between BFV and variables previously reported to be related to SMA BFV. There was significant variability in SMA BFV on DOL 1, a significant increase from DOL 1-14, and significant variability in the postnatal increase. Infants with higher enteral feeding volumes had greater increases, while infants receiving positive pressure ventilation or hyperalimentation had lower increases. Several clinical factors affect the postnatal increase in SMA BFV. The use of LCM is useful in longitudinal studies of very low birth weight (VLBW) infants, who are clinically and demographically heterogeneous.

Effects of a Patent Ductus Arteriosus on Postprandial Intestinal Blood Flow in Extremely Low Birth Weight (ELBW) Neonates

Background: Patent ductus arteriosus (PDA) affects superior mesenteric artery blood flow velocity (SMA BFV) in fasting neonates. Recently, it has been reported that PDA affects postprandial mesenteric perfusion in premature baboons; however, the effects of PDA on postprandial mesenteric perfusion in preterm neonates have not been evaluated. Aims: To determine whether PDA affects postprandial SMA BFV in ELBW neonates. Methods: Appropriate for gestational age, ELBW preterm neonates, tolerating bolus enteral feedings were enrolled in this prospective observational study. Pulsed Doppler was used to measure preprandial and postprandial (at 30-min and 60-min) time-averaged mean, peak and end diastolic velocities (TAMV, PSV, EDV) once during the day of life 5 to 7; at the same time, PDA size was estimated using the PDA:left pulmonary artery (LPA) ratio : 0.5 (i.e., moderate/large PDA) and < 0.5 (i.e., small/no PDA). Mean values across time were graphed to illustrate relative changes in moderate/large and no/small PDA groups. Repeated measures ANOVA was used to compare SMA BFV changes between the groups from preprandial to 30-min and 60-min postprandial for each type of measured velocity (TAMV, PSV, EDV). Results: Of the38 infants studied, 16 were in the no/small PDA group; 22 were in the moderate/large PDA group. Postprandial TAMV, PSV and EDV were not different between these two groups ( p values were 0.798, 0.315 and 0.59, respectively). Conclusions: Changes in postprandial mesenteric blood velocity did not differ between infants with no/small PDA versus moderate/large PDA in this study's cohort of 38 ELBW neonates.

Effects of Maternal Magnesium Sulfate Administration on Intestinal Blood Flow Velocity in Preterm Neonates

Background: Antenatal MgSO₄ administration is used extensively as a tocolytic agent and to treat preeclampsia. Various effects on the fetus and newborn have been reported, and MgSO₄ has well-documented vasoactive effects. Objective: To determine if antenatal MgSO₄ administration affects intestinal blood flow velocity in newborn preterm infants. Methods: Peak, mean and end-diastolic velocities in the superior mesenteric artery were measured on day 1 of life. Maternal medical records were reviewed to identify infants whose mothers had been administered MgSO₄ for preterm labor or preeclampsia within 24 h of delivery. Result: Fifty-six infants were studied: 27 were exposed and 29 were not exposed to antenatal MgSO₄. Mean birth weight (1,371 ± 349 and 1,401 ± 469 g, respectively), gestational age (29.7 ± 2.0 and 30.0 ± 2.9 weeks, respectively) and infant hemodynamic and clinical variables (other than clinical indication for antenatal MgSO₄ administration) were similar between groups. There were no significant differences between the exposed and unexposed groups in intestinal blood flow velocities. For the exposed group, however, there was a significant negative correlation between mean velocity and the number of hours from birth to the time superior mesenteric artery blood flow velocity measurements were made (p = 0.002); there was no correlation for the unexposed group (p = 0.852). Conclusion: Group mean values indicate that antenatal exposure to MgSO₄ does not significantly affect intestinal blood flow velocity in newborn preterm infants. However, the significant negative relationship between mean blood flow velocity and time from birth to blood flow velocity measurement in exposed infants suggests that there may be measurable effects of MgSO₄ exposure within the hours immediately after birth. Trials that prospectively evaluate the development of intestinal blood flow velocities are needed to further clarify potential effects of antenatal MgSO₄ on the gastrointestinal tract of preterm infants.

Physiological changes in blood flow velocities in the superior mesenteric and coeliac artery in healthy term fetuses and newborns during perinatal period

Objective. The aim was to describe the course of physiological changes in coeliac artery (CA) and superior mesenteric artery (SMA) blood flow velocities (BFVs) during the perinatal period in healthy term fetuses and infants as it has not been studied in detail so far.Methods. This prospective Doppler ultrasound study included 50 infants. The examinations were performed in a fetus after the completion of 36.0 gestation weeks before the onset of labor and in infants postnatally at the ages of 2, 24, and 72 h.Results. The end-diastolic velocity (EDV) in the CA was generally higher than in the SMA (p < 0.001). The EDV in the SMA decreased postnatally (8.4 vs. −7.2, p < 0.001) and showed negative values in 92% of infants. By 24 h of postnatal age, EDV in the SMA had become positive in all of the infants (mean 13.8 cm/s, p < 0.001). The EDV in CA had only positive values. The changes in EDV in both vessels were reflected by changes in the resistance index in inverse manner.Conclusions. BFV in the CA and SMA changed dramatically in the perinatal period; the most remarkable changes occurred within the first 24 h of life.

Blood Transfusion Alters the Superior Mesenteric Artery Blood Flow Velocity Response to Feeding in Premature Infants

Packed red blood cell transfusion may increase the risk of necrotizing enterocolitis in premature infants. We hypothesize that the postprandial increase in mesenteric blood flow velocity (MBFV) would not be altered by a blood transfusion in premature infants. Infants born at 25 to 32 weeks and feeding at least 60 mL/kg/d who required a transfusion were randomized within each of two weight strata to feed or not feed during the transfusion. Mean, peak systolic, and end diastolic Doppler MBFV was measured 30 minutes before and after feedings at baseline (anemic) and with the first feeding posttransfusion. Twenty-two infants (27.3 +/- 2.3 weeks' gestational age; hemoglobin [HgB] 9.3 +/- 1.3 g/dL) were studied on day of life 3 to 71 (mean 31.2 days) and a corrected gestational age of 31.8 +/- 2.9 weeks. In the entire cohort, the peak systolic ( P = 0.02) and the mean ( P = 0.01) MBFV increased in response to feeding in the anemic but not the transfused state. On subgroup analysis, only anemic infants > 1250 g ( N = 12, HgB 8.6 +/- 0.9 g/dL) had an increase in peak systolic ( P = 0.04) and mean ( P = 0.006) MBFV with feeding. In conclusion, the MBFV increases in response to feeding in anemic preterm infants > 1250 g. We speculate that the lack of response to feeding in the immediate posttransfusion state may contribute to the development of transfusion-associated necrotizing enterocolitis.

Systemic and hepatosplanchnic macro- and microcirculatory dose response to arginine vasopressin in endotoxic rabbits

Arginine vasopressin (AVP) is being used increasingly to treat vasodilatory hypotension, although its effects on hepatosplanchnic perfusion have been debated. Prospective study in a university-based experimental research laboratory. We compared the effect of AVP on systemic, gut, and liver blood flow in anesthetized and ventilated rabbits given either saline or endotoxin. Incremental i.v. boluses of AVP ranging from 1 to 1,000[Symbol: see text]ng were administered 90[Symbol: see text]min post-endotoxin or saline. Endotoxin induced a shock state with a transient decrease of mesenteric artery blood flow velocity (pulsed Doppler, in centimeters per second, V(mes)) but had no effect on liver surface microcirculation (laser Doppler in TPU, MicroFl(liver)). Gut microcirculatory (MicroFl(gut)) changes became independent of mean arterial pressure (MAP) after endotoxin. In control rabbits (n = 5), increasing doses of AVP elevated MAP but reduced aortic blood flow (pulsed Doppler, VAo), V(mes), and MicroFl(gut) (p < 0.05). In endotoxic animals (n = 6), AVP produced a similar rise in MAP (p < 0.05), while V(mes) and MicroFl(gut) only decreased for AVP doses above 100[Symbol: see text]ng (p < 0.05). Liver microcirculation was only minimally affected by AVP, although significantly, both in control and endotoxin animals. Preservation of mesenteric blood flow as well as gut and liver microcirculation, with therapeutic doses of AVP during endotoxemia, supports its use as a hemodynamic agent during septic shock.

Intrauterine growth restriction, visceral blood flow velocity and exocrine pancreatic function

BackgroundAnimal models and observations in human neonates suggest fetal exocrine pancreas vulnerability to reduced maternofetal blood flow. We investigated the relationship between superior mesenteric artery blood flow velocity (sma bfv) and exocrine pancreatic function, in a cohort of very low birth weight (VLBW) babies.Group 1: 9 babies < 3rd percentile for birth weight. Antenatally, all had absent or reversed diastolic flow on Doppler ultrasound of the umbilical artery (UA).Group2: 18 babies > 10th percentile for birth weight.FindingsAll had Doppler ultrasound scan of the superior mesenteric artery (sma), by same operator (RMN), on day 1 of life before commencement of enteral feeding. Stool samples assayed for faecal chymotrypsin and weekly serum samples assayed for amylase and lipase (kinetic colorimetric assay) from days 1 to 14 of life.Growth restricted babies had significantly lower sma bfv values compared with appropriately grown preterm babies. Faecal chymotrypsin levels were also lower but this difference did not achieve statistical significance. Both groups had serum lipase levels detectable in adult concentrations. Serum amylase was undetectable in either group.ConclusionBabies with previous in-utero blood flow redistribution may exhibit altered gut ontogeny with re-setting of mesenteric blood flow velocities and altered exocrine pancreatic function.

Effect of single loading dose of intravenous caffeine infusion on superior mesenteric artery blood flow velocities in preterm infants

To evaluate the effects of a single loading dose of caffeine base (10 mg/kg) on superior mesenteric artery (SMA) blood flow velocities (BFV). Eighteen preterm infants of gestational age <or=32 weeks gestation were investigated prospectively. SMA BFV before infusion, 1 h, 2 h and 6 h after a single loading dose of caffeine were measured using Doppler ultrasonography. The peak systolic velocity in SMA decreased by 18% from baseline at 1 h after caffeine infusion and improved towards the baseline by 6 h after the infusion. The reduction in velocity after caffeine infusion was not statistically significant. No significant changes were observed in heart rate, blood pressure and incidence of necrotising enterocolitis. A single 10 mg/kg intravenous loading dose of caffeine does not cause a significant reduction in SMA BFV and therefore does not place the preterm intestine at increased risk of ischemic injury.

Umbilical artery catheters do not affect intestinal blood flow responses to minimal enteral feedings

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. 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. 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. Preprandial SMA BFV and postprandial SMA BFV responses to minimal enteral feedings were not affected by the presence of a UAC.

Ultrasonic Assessment of Hepatic Blood Flow as a Marker of Mouse Hepatocarcinoma

Two-dimensional color-coded pulsed Doppler ultrasonography (US) with a 12-MHz linear transducer was used to follow tumor growth and neoangiogenesis development in 12 transgenic mice developing a whole liver hepatocellular carcinoma (HCC) induced by the expression of SV40-T antigen. In this model, male mice developed HCC at various temporal and histologic stages (hyperplastic, four–eight wk; nodular, 12 wk; diffuse carcinoma, 16–20 wk), whereas female mice remained tumor free. Seven age-matched tumor-free mice were used as controls. Liver volume was calculated from B-mode images of the abdomen. Blood flow waveforms were recorded from the hepatic tumor-feeding artery upstream from the tumor vessels, allowing quantitative blood flow velocity measurements. Measurements were performed every four weeks from four to 20 weeks. As early as the hyperplastic stage (eight weeks), liver volume was increased by 2.7-fold, hepatic artery peak-systolic blood flow velocities (BFV) by 1.5-fold, end-diastolic BFV by 1.6-fold and mean BFV by 2.0-fold compared with control values ( p < 0.001). Differences increased until 20 weeks and peak-systolic reached 90 ± 6, end-diastolic 54 ± 5 and mean BFV 48 ± 5 cm s –1. Successive measurements of BFV were reproducible and intraobserver repeatability coefficient values were <3 cm s –1. In contrast, mesenteric artery BFV, which did not supply tumor region, did not show any significant difference with respect to control values. Thus, an increase in BFV constitutes a functional evaluation of tumor vascularity. In preclinical studies in small animals, measurements of liver volume and blood flow velocities in hepatic tumor-feeding artery provide a useful, reproducible, noninvasive, easy-to-repeat tool to monitor tumor growth and neoangiogenesis in hepatocellular carcinoma in mice. (E-mail: philippe.bonnin@lrb.aphp.fr)

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

To identify demographic and clinical variables that relate to the postnatal increase in intestinal blood flow velocity in preterm infants. 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. 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 = 0.005) from postnatal day 1 to 5. The postnatal increase in TAMV and PSV was attenuated in infants administered CPAP or HAL for > or =3 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. 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.

Dietary Nucleotides and Intestinal Blood Flow Velocity in Term Infants

ABSTRACTObjectives:Two previous studies have shown that the addition of nucleotides to single feedings of formula is associated with increased 90‐minute postprandial superior mesenteric artery (SMA) blood flow velocity (BFV). To assess the effect of chronic feeding of nucleotide‐supplemented formula, we measured pre‐ and postprandial SMA BFV in term infants fed formula with or without added nucleotides for 4 weeks.Methods:At 1 week of age, healthy, term infants were randomized to receive formula with added nucleotides (NT+), or formula without added nucleotides (NT−) from age 1 to 5 weeks. When the infants were 5 weeks of age, SMA BFV was measured by Doppler ultrasound 15 minutes before the assigned feeding (baseline) and 30, 60, and 90 minutes after the start of feeding. A reference group of human milk‐fed infants was studied before and after breast feeding.Results:Thirty formula‐fed (NT+ = 17; NT− = 13) and 10 human milk‐fed infants were studied. Baseline BFV was similar among the three groups. BFV increased in each group from baseline to 30 minutes after initiation of feeding and progressively declined from 30 to 90 minutes in infants fed NT− formula or human milk. In infants fed NT+ formula, BFV decreased between 30 and 60 minutes. However, from 60 to 90 minutes, velocity was unchanged or increased. At 90 minutes, mean and peak systolic velocities were significantly greater in the NT+ group than the NT− group (P &lt; 0.001).Conclusions:These data agree with those of previous studies showing increased 90‐minute postprandial SMA BFV after a feeding with nucleotide‐supplemented formula. The clinical significance of these findings is unknown.

Prediction of early tolerance to enteral feeding by measurement of superior mesenteric artery blood flow velocity: appropriate- versus small-for-gestational-age preterm infants.

To evaluate whether serial Doppler measurements of superior mesenteric artery blood flow velocity could predict early tolerance to enteral feeding in preterm infants. In a prospective study, 54 healthy preterm neonates were assigned to one of the following groups: neonates with birthweight appropriate for gestational age (group 1), neonates small for gestational age without (group 2) and with prenatal haemodynamic disturbances (group 3). We studied Doppler blood flow velocity and resistance index before and after the first feed. Contrary to patients of group 3, infants in groups 1 and 2 showed a significant increase in blood flow velocity and a significant decrease in resistance index from the preprandial values after the first feed. At each postprandial time, we found significant differences in all velocity and resistance measurements between patients of group 3 and patients of both groups 1 and 2. In all patients, we found that the value of mean velocity measured 30 min after the first feed was the most predictive of early feed tolerance, with 95% sensitivity and 94% specificity when mean velocity >0.38 m/s. Small-for-gestational-age preterm infants with prenatal haemodynamic disturbances have an unusual intestinal haemodynamic response to the first feed. In the whole group of preterm infants, the value of mean velocity measured 30 min after the first feed is a good tool for the clinician in predicting early enteral feeding.

Prediction of early tolerance to enteral feeding by measurement of superior mesenteric artery blood flow velocity: appropriate- versus small-for-gestational-age preterm infants

Aim: To evaluate whether serial Doppler measurements of superior mesenteric artery blood flow velocity could predict early tolerance to enteral feeding in preterm infants. Methods: In a prospective study, 54 healthy preterm neonates were assigned to one of the following groups: neonates with birthweight appropriate for gestational age (group 1), neonates small for gestational age without (group 2) and with prenatal haemodynamic disturbances (group 3). We studied Doppler blood flow velocity and resistance index before and after the first feed. Results: Contrary to patients of group 3, infants in groups 1 and 2 showed a significant increase in blood flow velocity and a significant decrease in resistance index from the preprandial values after the first feed. At each postprandial time, we found significant differences in all velocity and resistance measurements between patients of group 3 and patients of both groups 1 and 2. In all patients, we found that the value of mean velocity measured 30 min after the first feed was the most predictive of early feed tolerance, with 95% sensitivity and 94% specificity when mean velocity >0.38 m/s. Conclusion: Small-for-gestational-age preterm infants with prenatal haemodynamic disturbances have an unusual intestinal haemodynamic response to the first feed. In the whole group of preterm infants, the value of mean velocity measured 30 min after the first feed is a good tool for the clinician in predicting early enteral feeding.