Department of Pediatrics, Division of Neonatal and Developmental Medicine, Stanford University School of Medicine and Lucile Packard Children's Hospital, Palo Alto, CA, USA.
Social, Statistical and Environmental Sciences Unit, RTI International, Research Triangle Park, Rockville, NC, USA.
Pediatr Res. 2022 Oct;92(4):1034-1041. doi: 10.1038/s41390-022-02082-z. Epub 2022 May 5.
Extremely low birth weight (ELBW) infants are at risk for end-organ hypoxia and ischemia. Regional tissue oxygenation of the brain and gut as monitored with near-infrared spectroscopy (NIRS) may change with postnatal age, but normal ranges are not well defined.
A prospective study of ELBW preterm infants utilized NIRS monitoring to assess changes in cerebral and mesenteric saturation (Csat and Msat) over the first week after birth. This secondary study of a multicenter trial comparing hemoglobin transfusion thresholds assessed cerebral and mesenteric fractional tissue oxygen extraction (cFTOE and mFTOE) and relationships with perinatal variables.
In 124 infants, both Csat and Msat declined over the first week, with a corresponding increase in oxygen extraction. With lower gestational age, lower birth weight, and 5-min Apgar score ≤5, there was a greater increase in oxygen extraction in the brain compared to the gut. Infants managed with a lower hemoglobin transfusion threshold receiving ≥2 transfusions in the first week had the lowest Csat and highest cFTOE (p < 0.001).
Brain oxygen extraction preferentially increased in more immature and anemic preterm infants. NIRS monitoring may enhance understanding of cerebral and mesenteric oxygenation patterns and inform future protective strategies in the preterm ELBW population.
Simultaneous monitoring of cerebral and mesenteric tissue saturation demonstrates the balance of oxygenation between preterm brain and gut and may inform protective strategies. Over the first week, oxygen saturation of the brain and gut declines as oxygen extraction increases. A low hemoglobin transfusion threshold is associated with lower cerebral saturation and higher cerebral oxygen extraction compared to a high hemoglobin transfusion threshold, although this did not translate into clinically relevant differences in the TOP trial primary outcome. Greater oxygen extraction by the brain compared to the gut occurs with lower gestational age, lower birth weight, and 5-min Apgar score ≤5.
极低出生体重（ELBW）婴儿有终末器官缺氧和缺血的风险。近红外光谱（NIRS）监测的脑和肠道局部组织氧合可能随出生后年龄而变化，但正常范围尚未明确界定。
一项前瞻性研究纳入了 ELBW 早产儿，使用 NIRS 监测评估出生后第一周脑和肠系膜饱和度（Csat 和 Msat）的变化。这项多中心试验的二次研究比较了血红蛋白输血阈值，评估了脑和肠系膜组织氧摄取分数（cFTOE 和 mFTOE）及其与围产期变量的关系。
在 124 名婴儿中，Csat 和 Msat 在第一周内均下降，氧摄取相应增加。胎龄越小、出生体重越低、5 分钟 Apgar 评分≤5 时，脑氧摄取的增加大于肠道。在第一周接受 2 次或以上输血且血红蛋白输血阈值较低的婴儿，Csat 最低而 cFTOE 最高（p<0.001）。
在较不成熟和贫血的早产儿中，脑氧摄取优先增加。NIRS 监测可能有助于深入了解脑和肠系膜的氧合模式，并为早产儿 ELBW 人群提供未来的保护策略。
同时监测脑和肠系膜组织饱和度可显示早产儿脑和肠道之间的氧合平衡，并为保护策略提供信息。在第一周，脑和肠道的氧饱和度随着氧摄取的增加而下降。与高血红蛋白输血阈值相比，低血红蛋白输血阈值与较低的脑饱和度和较高的脑氧摄取相关，但这并未转化为 TOP 试验主要结局的临床相关差异。与高血红蛋白输血阈值相比，胎龄越小、出生体重越低、5 分钟 Apgar 评分≤5 时，脑的氧摄取大于肠道。
