The early postnatal blood flow characteristics in the superior mesenteric and coeliac arteries in late preterm neonates

Maturation of Intestinal Oxygenation: A Review of Mechanisms and Clinical Implications for Preterm Neonates

Nutrient requirements of preterm neonates may be substantial, to support growth and maturation processes in the presence of challenging post-natal circumstances. This may be accompanied by substantial intestinal oxygen requirements. Preterm neonates may not be able to meet these oxygen requirements, due to a developmental delay in intestinal oxygenation regulation mechanisms. This review summarizes the available literature on post-natal maturation of intestinal oxygenation mechanisms and translates these changes into clinical observations and potential implications for preterm neonates. The different mechanisms that may be involved in regulation of intestinal oxygenation, regardless of post-natal age, are first discussed. The contribution of these mechanisms to intestinal oxygenation regulation is then evaluated in newborn and mature intestine. Finally, the course of clinical observations is used to translate these findings to potential implications for preterm neonates.

Early Doppler Ultrasound in the Superior Mesenteric Artery and the Prediction of Necrotizing Enterocolitis in Preterm Neonates

OBJECTIVES

The purpose of this study was to reveal the correlation between superior mesenteric artery (SMA) blood flow in the first 12 hours of life and the risk of necrotizing enterocolitis (NEC) in preterm neonates.

METHODS

We conducted a prospective study. There were 104 preterm neonates included in our study. The SMA blood flow of each neonate was measured during the first 12 hours of life if the hemodynamic situation was stable. The results of Doppler ultrasound were confidential to the neonatologists and nurses. All of the demographics, comorbidities, and outcomes were recorded and analyzed.

RESULTS

Among all of the demographics and comorbidities, the gestational age was related to the measurements of SMA blood flow. We conducted a single-factor analysis of the occurrence of NEC, including the peak systolic velocity (PSV), end-diastolic velocity, time-averaged mean velocity, differential velocity (DV), resistive index, and pulsatility index. A higher PSV (median [interquartile range], 54.165 [42.423-68.463] versus 42.195 [34.278-48.553] cm/s; P = .027) and DV (median [interquartile range], 47.445 [35.010-60.043] versus 32.565 [27.545-39.073] cm/s; P = .020) were significantly related to the risk of NEC. In the logistic analysis including gestational age, PSV, and DV, NEC was significantly associated with gestational age (odds ratio [95% confidence interval], 0.644 [0.456-0.908]; P = .012) and DV (odds ratio [95% confidence interval], 1.144 [1.058-1.237]; P < .01). The area under the receiver operating characteristic curve for the DV was 0.768, with sensitivity 0.875 and specificity 0.604. The cutoff value of the DV was 34.835 cm/s.

CONCLUSIONS

From this single-center study, we can see the promising value of Doppler ultrasound for the prediction of NEC, but further research is needed.