Christensen Robert D, Henry Erick, Del Vecchio Antonio
Women and Newborns Program, Intermountain Healthcare, Salt Lake City, Utah, UT 84403, USA.
J Matern Fetal Neonatal Med. 2012 Oct;25 Suppl 4:15-7. doi: 10.3109/14767058.2012.715027.
Quantitative and qualitative platelet abnormalities of neonates must be defined using evidence-based reference ranges, constructed according to gestational and postnatal age.
Platelet counts, and demographic and outcome data, were obtained from neonates in the Intermountain Healthcare system in the western USA and template bleeding times were determined from neonates in Italy.
Reference ranges were constructed by excluding values from neonates with diagnoses associated with abnormal platelet counts (small for gestational age (SGA), pregnancy-induced hypertension (PIH), infection and necrotizing enterocolitis (NEC)). Values remaining in the database after excluding these diagnoses were organized into 5th to 95th percentile ranges. At 23-25 weeks gestation, thrombocytopenia (<5th percentile) was defined by a platelet count <100,000/µl. Severe thrombocytopenia (platelet count <50,000/µl) occurred in 2.4% of neonatal intensive care unit (NICU) admissions and was largely due to acquired consumptive causes (bacterial and fungal sepsis, NEC and extracorporeal membrane oxygenation). No correlation was found between platelet count and subsequent central nervous system (CNS), pulmonary or gastrointestinal (GI) bleeding. The mortality rate did not correlate with the lowest platelet count but was proportionate to the number of platelet transfusions received. Platelet transfusions, administered according to guidelines, were given to 7% of NICU admissions, but a change in the guidelines from "count-based" to "mass-based" was associated with a reduction to 4%, with no increase in CNS, pulmonary, GI or cutaneous haemorrhage. Bleeding times were twice as long in neonates <33 weeks gestation as in term neonates, and shortened to term values by day of life ten.
When reference ranges for platelets, appropriate to gestational and postnatal ages, are used, more uniformity occurs in definitions. This uniformity will foster consistency in diagnosis, treatment and outcomes-reporting.
必须使用基于证据的参考范围来定义新生儿血小板的定量和定性异常，这些参考范围是根据胎龄和出生后年龄构建的。
从美国西部山间医疗保健系统的新生儿中获取血小板计数、人口统计学和结局数据，并从意大利的新生儿中测定模板出血时间。
通过排除患有与血小板计数异常相关诊断（小于胎龄儿（SGA）、妊娠高血压综合征（PIH）、感染和坏死性小肠结肠炎（NEC））的新生儿的值来构建参考范围。排除这些诊断后数据库中剩余的值被整理成第5至第95百分位数范围。在妊娠23 - 25周时，血小板减少症（<第5百分位数）定义为血小板计数<100,000/µl。严重血小板减少症（血小板计数<50,000/µl）发生在2.4%的新生儿重症监护病房（NICU）入院病例中，主要是由于获得性消耗性原因（细菌和真菌败血症、NEC和体外膜肺氧合）。未发现血小板计数与随后的中枢神经系统（CNS）、肺部或胃肠道（GI）出血之间存在相关性。死亡率与最低血小板计数无关，但与接受的血小板输注次数成比例。按照指南进行血小板输注的情况发生在7%的NICU入院病例中，但指南从“基于计数”改为“基于质量”与降至4%相关，且CNS、肺部、GI或皮肤出血均未增加。妊娠<33周的新生儿出血时间是足月儿的两倍，到出生后第10天时缩短至足月儿水平。
当使用适合胎龄和出生后年龄的血小板参考范围时，定义会更加统一。这种统一将促进诊断、治疗和结局报告的一致性。
