There are two recently completed large randomized clinical trials of blood transfusions in the preterm infants most at risk of requiring them. Liberal and restrictive strategies were compared with composite primary outcome measures of death and neurodevelopmental impairment. Infants managed under restrictive guidelines fared no worse in regard to mortality and neurodevelopment in early life. The studies had remarkably similar demographics and used similar transfusion guidelines. In both, there were fewer transfusions in the restrictive arm. Nevertheless, there were large differences between the studies in regard to transfusion exposure with almost 3 times the number of transfusions per participant in the transfusion of prematures (TOP) study. Associated with this, there were differences between the studies in various outcomes. For example, the combined primary outcome of death or neurodevelopmental impairment was more likely to occur in the TOP study and the mortality rate itself was considerably higher. Whilst the reasons for these differences are likely multifactorial, it does raise the question as to whether they could be related to the transfusions themselves? Clearly, every effort should be made to reduce exposure to transfusions and this was more successful in the Effects of Transfusion Thresholds on Neurocognitive Outcomes (ETTNO) study. In this review, we look at factors which may explain these transfusion differences and the differences in outcomes, in particular neurodevelopment at age 2 years. In choosing which guidelines to follow, centers using liberal guidelines should be encouraged to adopt more restrictive ones. However, should centers with more restrictive guidelines change to ones similar to those in the studies? The evidence for this is less compelling, particularly given the wide range of transfusion exposure between studies. Individual centers already using restrictive guidelines should assess the validity of the findings in light of their own transfusion experience. In addition, it should be remembered that the study guidelines were pragmatic and acceptable to a large number of centers. The major focus in these guidelines was on hemoglobin levels which do not necessarily reflect tissue oxygenation. Other factors such as the level of erythropoiesis should also be taken into account before deciding whether to transfuse.

最近完成了两项针对最有可能需要输血的早产儿输血的大型随机临床试验。将自由和限制性策略与死亡和神经发育障碍的复合主要结果指标进行比较。在限制性指南下管理的婴儿在早期死亡率和神经发育方面的表现并不差。这些研究具有非常相似的人口统计数据并使用了相似的输血指南。在这两种情况下，限制性手臂的输血次数都较少。然而，在输血暴露方面的研究之间存在很大差异，几乎是早产儿输血 (TOP) 研究中每位参与者的输血次数的 3 倍。与此相关的是，研究在各种结果方面存在差异。例如，在 TOP 研究中，死亡或神经发育障碍的综合主要结果更有可能发生，死亡率本身也相当高。虽然造成这些差异的原因可能是多方面的，但它确实提出了一个问题，即它们是否与输血本身有关？显然，应尽一切努力减少输血，这在输血阈值对神经认知结果 (ETTNO) 的影响研究中更为成功。在这篇综述中，我们着眼于可以解释这些输血差异和结果差异的因素，特别是 2 岁时的神经发育。在选择遵循哪些指南时，应鼓励使用宽松指南的中心采用更具限制性的指南。然而，具有更严格指南的中心是否应该更改为与研究中相似的中心？这方面的证据不太令人信服，特别是考虑到研究之间的输血暴露范围很广。已经使用限制性指南的各个中心应根据自己的输血经验评估结果的有效性。此外，应该记住，研究指南是实用的，并且为大量中心所接受。这些指南的主要焦点是血红蛋白水平，它不一定反映组织氧合。在决定是否输血之前，还应考虑红细胞生成水平等其他因素。特别是考虑到研究之间的输血暴露范围很广。已经使用限制性指南的各个中心应根据自己的输血经验评估结果的有效性。此外，应该记住，研究指南是实用的，并且为大量中心所接受。这些指南的主要焦点是血红蛋白水平，它不一定反映组织氧合。在决定是否输血之前，还应考虑红细胞生成水平等其他因素。特别是考虑到研究之间的输血暴露范围很广。已经使用限制性指南的各个中心应根据自己的输血经验评估结果的有效性。此外，应该记住，研究指南是实用的，并且为大量中心所接受。这些指南的主要焦点是血红蛋白水平，它不一定反映组织氧合。在决定是否输血之前，还应考虑红细胞生成水平等其他因素。应该记住，研究指南是务实的，并且为许多中心所接受。这些指南的主要焦点是血红蛋白水平，它不一定反映组织氧合。在决定是否输血之前，还应考虑红细胞生成水平等其他因素。应该记住，研究指南是务实的，并且为许多中心所接受。这些指南的主要焦点是血红蛋白水平，它不一定反映组织氧合。在决定是否输血之前，还应考虑红细胞生成水平等其他因素。