Bell Edward F
Department of Pediatrics, University of Iowa, Iowa City, Iowa, USA
Arch Dis Child Fetal Neonatal Ed. 2022 Mar;107(2):126-130. doi: 10.1136/archdischild-2020-320495. Epub 2021 Apr 27.
Extremely low birthweight infants become anaemic during their care in the neonatal intensive care unit because of the physiological anaemia experienced by all newborn infants compounded by early umbilical cord clamping, blood loss by phlebotomy for laboratory monitoring and delayed erythropoiesis. The majority of these infants receive transfusions of packed red blood cells, usually based on haemoglobin values below a certain threshold. The haemoglobin or haematocrit thresholds used to guide transfusion practices vary with infant status and among institutions and practitioners. Previous smaller studies have not given clear guidance with respect to the haemoglobin thresholds that should trigger transfusions or even if this is the best way to decide when to transfuse an infant. Two large clinical trials of similar design comparing higher and lower haemoglobin thresholds for transfusing extremely low birthweight infants were recently published, the ETTNO and TOP trials. These trials found reassuringly conclusive and concordant results. Within the range of haemoglobin transfusion thresholds studied, there was no difference in the primary outcome (which was the same in both studies), neurodevelopmental impairment at 2 years' corrected age or death before assessment, in either study. In addition, there was no difference in either study in either of the components of the primary outcome. In conclusion, haemoglobin transfusion thresholds within the ranges used in these trials, 11-13 g/dL for young critically ill or ventilated infants and 7-10 g/dL for stable infants not requiring significant respiratory support, can be safely used without expecting adverse consequences on survival or neurodevelopment.
极低出生体重儿在新生儿重症监护病房接受治疗期间会出现贫血，这是由于所有新生儿都会经历的生理性贫血，再加上早期脐带结扎、为实验室监测进行静脉穿刺采血导致的失血以及红细胞生成延迟。这些婴儿中的大多数会接受浓缩红细胞输血，通常是基于血红蛋白值低于某个阈值。用于指导输血实践的血红蛋白或血细胞比容阈值因婴儿状况以及不同机构和从业者而有所不同。先前规模较小的研究并未就应触发输血的血红蛋白阈值给出明确指导，甚至也未明确这是否是决定何时为婴儿输血的最佳方式。最近发表了两项设计相似的大型临床试验，即ETTNO试验和TOP试验，比较了极低出生体重儿输血时较高和较低的血红蛋白阈值。这些试验得出了令人安心的确定性且一致的结果。在所研究的血红蛋白输血阈值范围内，两项研究的主要结局（两者相同），即矫正年龄2岁时的神经发育障碍或评估前死亡，均无差异。此外，在主要结局的任何一个组成部分上，两项研究也均无差异。总之，在这些试验中所使用的阈值范围内，对于病情危重或需要通气的婴儿，血红蛋白输血阈值为11 - 13 g/dL，对于不需要显著呼吸支持的稳定婴儿，阈值为7 - 10 g/dL，可以安全使用，而不必担心对生存或神经发育产生不良后果。
