Why do newborn infants have a high plasma creatinine?
Why do newborn infants have a high plasma creatinine?
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DOI：
10.1542/peds.103.4.e49
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发表时间：
1999-04-01
期刊：
影响因子：
8
通讯作者：
Drukker, A
中科院分区：
文献类型：
--
作者：
Guignard, JP;Drukker, A
背景资料。与新生儿的大小(和肌肉质量)有关，出生时血浆肌酐(PCr)水平显著升高，并持续1至2周，尤其耐人寻味的是，早产儿的PCr水平高于足月儿，且出生后时间较长。出生体重越小，PCR值越高。这不能用母体的聚合酶链式反应转移或新生儿肾小球滤过率的绝对和相对(相对于成人身体表面积)降低来解释。也许这涉及到肾脏对肌酐的处理。设计。在522对母亲和胎儿中，比较了从妊娠16周到足月的母婴PER。对66例不同出生体重的新生儿进行PER测量，并随访1个月。同时测定成年新西兰白兔(n=8)和新生新西兰白兔(n=20)的肌酐清除量(Ccr)和菊粉清除量(Cin)。在后者中，肾脏在出生后继续发生，因此它们是研究早产儿肾功能的良好动物模型。本文报告一例早产男婴(孕周：29周；出生体重：1410克)，怀疑因胎膜早破和产后母体发热而患上败血症。这一怀疑没有得到证实，血生化检测显示出生时的PER很高(0.85 mg/dL，75MU/L)，甚至高于母亲的PER值(0.77 mg/dL，68MU/L)。PCR值在接近1周后开始下降，但在整个1个月的随访期内仍保持升高。从母体-胎儿的聚合酶链式反应的测量中可以明显看出，在妊娠的后半期，母体和胎儿的小分子肌酸(113道尔顿，0.3 nm半径)在所有母体的聚合酶链式反应水平上是平衡的。新生儿的PCR值不仅在出生时就很高，而且持续了3周以上。研究还表明，婴儿越小，其聚合酶链式反应水平越高。动物实验结果表明，成年兔存在Ccr高估Cin(Ccr/Cin比值1.0)的正常生理模式。相反，新生兔的结果显示Ccr对Cin(Ccr/Cin比率)被意外低估
Background. Plasma creatinine (Pcr) levels at birth are greatly elevated in relation tb the size (and the muscle mass) of the newborn infant and remain so for 1 to 2 weeks, particularly intriguing is the fact that Pcr levels are higher in preterm than in term infants and for a longer postnatal period. The smaller the birth weight, the higher the Pcr. This cannot be explained by maternal transfer of Pcr or by the absolute and relative (to adult body surface area) reduced glomerular filtration rate of the newborn. Perhaps the renal handling of creatinine is involved.Design. In 522 pairs of mothers and fetuses, maternal and fetal Per were compared from 16 weeks of gestation until term. Per was measured in 66 newborns of various birth weights and followed for 1 month. Creatinine clearance (Ccr) and inulin clearance (Cin) were measured simultaneously in adult (n = 8) and newborn (n = 20) New Zealand White rabbits. In the latter, nephrogenesis continues after birth and they are therefore a good animal model for the study of the renal function in premature infants.Patient. A case of a premature male infant is presented (gestation: 29 weeks; birth weight: 1410 g) suspected of having sepsis because of premature rupture of membranes and postpartum maternal fever. This suspicion was not confirmed, blood chemistry evaluation showed a high Per at birth (0.85 mg/dL, 75 mu mol/L), even higher than that of the mother (0.77 mg/dL, 68 mu mol/L). The Pcr started to decrease after similar to 1 week but remained elevated throughout 1 month of follow-up.Results. From the maternal-fetal Pcr measurements it was quite evident that during the second half of gestation the small molecular weight creatinine (113 dalton, 0.3 nm radius) of the mother and fetus equilibrates at all maternal Pcr levels. The newborn Pcr levels were not only high at the time of birth but remained so for more than 3 weeks. It was also shown that the smaller the infant the higher the Pcr levels. The results of the animal experimental data showed that adult rabbits had the normal physiologic pattern in which Ccr overestimates Cin (Ccr/Cin ratio >1.0). In contrast, the results in the newborn rabbits showed an unexpected underestimation of the Ccr vis-a-vis Cin (Ccr/Cin ratio