脐血心钠素在监测高危新生儿水钠平衡中的意义

目的：心钠素(ANP)是一种具有多种功能的内分泌激素,其过度分泌可造成低钠血症。该文探讨脐血ANP测定在监测高危新生儿水钠平衡中的作用和临床意义。方法：选择117例高危新生儿依据Apgar评分的不同分为两大组,即单纯窒息组及评分正常组。单纯窒息组又分为轻度窒息组和重度窒息组,评分正常组又分为感染组和非感染组,另设40例正常新生儿为对照组。各组均在新生儿娩出后立即抽取脐血,应用放射免疫法测定ANP水平,同时抽取静脉血测定患儿的血清钠含量,并分别与对照组比较。结果：高危新生儿的脐血ANP水平明显高于正常新生儿,尤以早产儿1.46±0.39 ng/mL、严重感染新生儿1.16±0.35 ng/mL及重度窒息新生儿2.12±0.46 ng/mL增高最为明显(P<0.01)。而与其相对应的则是血清钠水平的下降,两者呈显著负相关。结论：高危新生儿脐血心钠素增高明显,易致低钠血症,早期测定可对新生儿抢救与治疗起到指导作用。

Levels of atrial natriuretic peptide in umbilical cord blood of high risk neonates

OBJECTIVE: Atrial natriuretic peptide (ANP) is a cardiac hormone with many biological effects. Hypersecretion may lead to hyponatremia. This study examined the umbilical ANP levels in high risk neonates. METHODS: A total of 117 high risk neonates born between June, 2004 and June, 2005 were divided into Simple asphyxia and Normal score groups according to their Apgar's scores. The Simple asphyxia group was subdivided into Mild (n=20) and Severe asphyxia groups (n=17), and the Normal score group was subdivided into Infection (n=25) and Non-infection groups (n=55). Forty normal neonates were used as the Control group. The samples of umbilical cord blood were collected at delivery and the umbilical ANP levels were measured by radioimmunoassay. Meanwhile the sodium levels in the peripheral vein were measured. RESULTS: The mean umbilical ANP levels in high risk neonates were significantly higher than those in the normal neonates. A more significant increase of the umbilical ANP level was observed in premature infants (1.46 +/- 0.39 ng/mL), and neonates with serious infection (1.16 +/- 0.35 ng/mL) and with severe asphyxia (2.12 +/- 0.46 ng/mL) compared with the normal neonates (0.62 +/- 0.33 ng/mL; P < 0.01). The serum sodium level was negatively correlated with the umbilical ANP level (r=-0.99, P < 0.01). CONCLUSIONS: The umbilical ANP levels increased significantly in the high risk neonates, suggesting high risk neonates are susceptible to hyponatremia.