Unidad de Hematología y Oncología Médica, Hospital Universitario Morales-Meseguer, Centro de Hemodonacion, Murcia, Spain; Department of Haematology/Transfusion Medicine, NHS Blood & Transplant/Oxford University Hospitals NHS Trust, Oxford, UK; Center for Transfusion and Cellular Therapies, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia; Division of Newborn Medicine, Children's Hospital Boston, Boston, Massachusetts.
Transfusion. 2013 Nov;53(11):2814-21; quiz 2813. doi: 10.1111/trf.12343. Epub 2013 Jul 25.
Thrombocytopenia is a common problem among sick neonates admitted to the neonatal intensive care unit. Among neonates, preterm infants are the subgroup at highest risk for thrombocytopenia and hemorrhage, which is frequently intracranial. Although there is no evidence of a relationship between platelet (PLT) count and occurrence of major hemorrhage, preterm infants are commonly transfused prophylactically when PLT counts fall below an arbitrary limit, and this threshold is usually higher than for older infants or adults. This liberal practice has been influenced by the observation that, in vitro, neonatal PLTs are hyporeactive in response to multiple agonists. However, full-term infants exhibit normal to increased primary hemostasis due to factors in neonatal blood that enhance the PLT-vessel wall interaction. Additionally, cardiorespiratory problems are considered the main etiologic factors in the development of neonatal intraventricular hemorrhage. In this review, we will discuss the developmental differences that exist in regard to PLT production and function, as well as in primary hemostasis in preterm and term neonates, and the implications of these developmental differences to transfusion medicine. PLT transfusions are not exempt of risk, and a better understanding of the PLT function and the hemostatic profile of premature infants and their changes over time and in response to illness is the starting point to design randomized controlled trials to define optimal use of PLT transfusions in premature neonates. Without these future trials, the marked disparities in PLT transfusion practice in neonates between hospitals and countries will remain over time.
血小板减少症是入住新生儿重症监护病房的患病新生儿的常见问题。在新生儿中，早产儿是血小板减少症和出血风险最高的亚组，而且通常是颅内出血。尽管没有证据表明血小板 (PLT) 计数与大出血的发生之间存在关系，但当 PLT 计数下降到任意下限以下时，早产儿通常会预防性输注，而这个阈值通常高于年龄较大的婴儿或成年人。这种宽松的做法受到以下观察结果的影响：在体外，新生儿 PLT 对多种激动剂的反应呈低反应性。然而，由于新生儿血液中的因素增强了 PLT-血管壁相互作用，足月婴儿表现出正常至增加的初级止血功能。此外，心肺问题被认为是导致新生儿脑室出血发展的主要病因。在这篇综述中，我们将讨论早产儿和足月儿在 PLT 生成和功能以及初级止血方面存在的发育差异，以及这些发育差异对输血医学的影响。PLT 输注并非没有风险，更好地了解 PLT 功能以及早产儿的止血概况及其随时间和疾病变化的情况，是设计随机对照试验以确定早产儿 PLT 输注最佳用途的起点。如果没有这些未来的试验，医院和国家之间在新生儿 PLT 输注实践方面的明显差异将随着时间的推移而持续存在。
