Del Vecchio A, Latini G, Henry E, Christensen R D
Division of Neonatology, Ospedale A Perrino, Brindisi, Italy.
J Perinatol. 2008 Jun;28(6):427-31. doi: 10.1038/jp.2008.10. Epub 2008 Feb 14.
The template bleeding time is a test used to assess the hemostatic effectiveness of platelet/endothelial interactions. A modified template bleeding time, described over 15 years ago by Andrew et al., has been used to test this aspect of hemostasis in term and preterm infants, but questions remain regarding the effect of gestational age and postnatal age on results. The effect of the platelet count (platelets per microliter blood) and the circulating platelet mass (nl platelets per microliter blood) on the bleeding time of neonatal intensive care unit (NICU) patients also require better definition.
We measured template bleeding times on 240 neonates at Ospedale A Perrino, in Brindisi, Italy; studying groups of n=60 at the following gestational ages; <28 weeks, 29 to 32 weeks, 33 to 37 weeks and > or =38 weeks. In each group of 60 neonates, 20 were studied on the first day after birth, 20 were studied on day 10 and 20 were studied on day 30. A multivariate analysis was performed to examine various associations with bleeding time.
Bleeding times, on the first day of life, were shorter as gestational age increased. Those born <33 weeks gestation had bleeding times about twice that of those > or =38 weeks (P<0.001). Bleeding times tended to shorten between days 1 and 10. Little or no further shortening occurred between days 10 and 30, and by day 30 they were not statistically different between the various gestational age groups. No independent effect on bleeding time could be ascribed to gender, platelet count or circulating platelet mass, but independent effects were found for hematocrit (P<0.02) and gestational age (P<0.001).
On the first day of life, preterm neonates have a longer bleeding time than do term neonates. By day of life 10, the bleeding times at all gestational ages are shorter and are indistinguishable on the basis of gestational age at birth. Additionally, since platelet counts as low as 110 000 per microliter did not prolong the bleeding time, we see no benefit of administering a platelet transfusion to a stable, nonbleeding, NICU patient with mild thrombocytopenia (platelet count 100 000 to 150 000 per microliter).
模板出血时间是一项用于评估血小板/内皮细胞相互作用止血效果的检测。15年前安德鲁等人描述的改良模板出血时间，已被用于检测足月儿和早产儿止血的这一方面，但关于胎龄和出生后年龄对结果的影响仍存在疑问。新生儿重症监护病房（NICU）患者的血小板计数（每微升血液中的血小板数）和循环血小板量（每微升血液中的纳升血小板数）对出血时间的影响也需要更明确的界定。
我们在意大利布林迪西的佩里诺医院对240名新生儿进行了模板出血时间测量；研究了以下胎龄组，每组n = 60名；小于28周、29至32周、33至37周以及大于或等于38周。在每组60名新生儿中，20名在出生后第一天进行研究，20名在第10天进行研究，20名在第30天进行研究。进行多变量分析以检查与出血时间的各种关联。
出生第一天，随着胎龄增加出血时间缩短。孕周小于33周出生的婴儿出血时间约为孕周大于或等于38周婴儿的两倍（P < 0.001）。出血时间在第1天至第10天趋于缩短。在第10天至第30天几乎没有或没有进一步缩短，到第30天，不同胎龄组之间在统计学上没有差异。性别、血小板计数或循环血小板量对出血时间没有独立影响，但发现血细胞比容（P < 0.02）和胎龄（P < 0.001）有独立影响。
出生第一天，早产儿的出血时间比足月儿长。到出生后第10天，所有胎龄的出血时间都缩短了，并且根据出生时的胎龄无法区分。此外，由于血小板计数低至每微升110000时并未延长出血时间，我们认为对于血小板轻度减少（血小板计数每微升100000至150000）的稳定、无出血的NICU患者，输注血小板没有益处。
