Omar S A, DeCristofaro J D, Agarwal B I, La Gamma E F
Department of Pediatrics, University Hospital, Stony Brook, New York 11794-8111, USA.
Pediatrics. 1999 Sep;104(3 Pt 1):482-8. doi: 10.1542/peds.104.3.482.
We sought to determine if prenatal steroid (PNS) treatment affects water and sodium (Na) balance in extremely low birth weight infants (<1000 g).
PNS treatment enhances lung maturation in preterm infants and induces maturation of renal tubular function and adenylate cyclase activity in animals. We compared water and Na homeostasis for the first week of life in those infants whose mothers received steroids before delivery (PNS: n = 16) to those who did not (nonsteroid group [NSG]: n = 14). The data were collected prospectively, but PNS treatment was not given in a randomized manner. Fluids were initiated at 100 to 125 mL/kg/d and adjusted every 8 to 12 hours to allow a daily weight loss of </=4% of birth weight and to maintain normal serum electrolytes. Weight, serum and urine electrolytes, and urine output were frequently measured and fluid intake was adjusted by increasing the amount of free water to achieve these goals.
When using our fluid management protocol, the percent weight loss in both groups was equivalent during each of the 7 days (15% PNS vs 17% NSG maximum loss) as well as the cumulative urine output at 1 week of age (663 mL/kg/wk PNS vs 681 mL/kg/wk NSG). PNS infants had a higher urine output on the first 2 days of life and a lower daily fluid intake for the first week. PNS infants also had significantly less insensible water loss for each of the first 4 days of life. The PNS group had a significantly lower mean peak serum Na of 138 +/- 1 mmol/L vs 144 +/- 2 mmol/L and none had a peak serum Na >150 mmol/L compared with 36% of the NSG infants. PNS infants had a higher cumulative Na excretion at day 2 of life (10 +/- 2 mmol/kg vs 6 +/- 1 mmol/kg) but a less negative cumulative Na balance at 1 week (-10 mmol/kg vs -14 mmol/kg).
PNS treatment was associated with lower estimated insensible water loss, a decreased incidence of hypernatremia, and an earlier diuresis and natriuresis in extremely low birth weight neonates. We speculate that PNS effects these changes through enhancement of epithelial cell maturation improving skin barrier function. PNS treatment may also enhance lung Na, K-ATPase activity leading to an earlier postnatal reabsorption of fetal lung fluid increasing extracellular volume expansion to help prevent hypernatremia.
我们试图确定产前类固醇（PNS）治疗是否会影响极低出生体重儿（<1000克）的水和钠平衡。
PNS治疗可促进早产儿肺成熟，并诱导动物肾小管功能和腺苷酸环化酶活性成熟。我们比较了母亲在分娩前接受类固醇治疗的婴儿（PNS组：n = 16）和未接受治疗的婴儿（非类固醇组[NSG]：n = 14）出生后第一周的水和钠稳态。数据是前瞻性收集的，但PNS治疗并非随机给予。液体起始量为100至125毫升/千克/天，每8至12小时调整一次，以使每日体重减轻≤出生体重的4%，并维持血清电解质正常。经常测量体重、血清和尿液电解质以及尿量，并通过增加自由水量来调整液体摄入量以实现这些目标。
采用我们的液体管理方案时，两组在7天中的每一天体重减轻百分比相当（PNS组最大减轻15%，NSG组最大减轻17%），1周龄时的累积尿量也相当（PNS组为663毫升/千克/周，NSG组为681毫升/千克/周）。PNS组婴儿在出生后前两天尿量较高，第一周每日液体摄入量较低。PNS组婴儿在出生后前4天中每天的不显性失水量也显著较少。PNS组的平均血清钠峰值显著较低，为138±1毫摩尔/升，而NSG组为144±2毫摩尔/升，且PNS组无血清钠峰值>150毫摩尔/升，而NSG组有36%的婴儿血清钠峰值>150毫摩尔/升。PNS组婴儿在出生后第2天的累积钠排泄量较高（10±2毫摩尔/千克，而NSG组为6±1毫摩尔/千克），但在1周时累积钠平衡的负值较小（-10毫摩尔/千克，而NSG组为-14毫摩尔/千克）。
PNS治疗与极低出生体重新生儿较低的估计不显性失水量、高钠血症发生率降低以及更早的利尿和利钠有关。我们推测PNS通过增强上皮细胞成熟改善皮肤屏障功能来影响这些变化。PNS治疗还可能增强肺钠钾ATP酶活性，导致出生后胎儿肺液的再吸收提前，增加细胞外液量扩张，有助于预防高钠血症。
