Kalhoff H, Wiese B, Kunz C, Diekmann L, Stock G J, Manz F
Children's Hospital, Dortmund, Germany.
Biol Neonate. 1994;66(1):10-5. doi: 10.1159/000244084.
In 76 low birth weight infants with an actual body weight ranging from 1,210 to 2,540 g and fed a commercial preterm formula, urine samples were collected and blood acid base status was measured on day 38 (+/- 17, mean +/- SD) of life. Infants with an actual body weight below 1,600 g demonstrated a higher daily weight gain (22 +/- 3 vs. 14 +/- 5 g/kg/day), lower blood pCO2 (35.4 +/- 5.0 vs. 38.9 +/- 3.8 mm Hg), lower urine pH (5.8 +/- 0.5 vs. 6.5 +/- 0.3), higher renal net acid (1.86 +/- 0.38 vs. 1.28 +/- 0.55 mmol/kg/day) and higher phosphorus excretion (0.67 vs. 0.52 mmol/kg/day) than infants with an actual body weight above 2,100 g. Urinary ionogram data of these 2 groups of infants show that the increased renal net acid excretion of the smaller prematures is the result of a lower urinary excretion of sodium, potassium and chloride, due to a higher daily weight gain, probably a higher retention of these minerals, and a higher urinary phosphorus excretion probably due to an age-specific lower intestinal calcium absorption, and therefore a lower rate of calcium and phosphorus retention. Considering the low renal capacity for hydrogen ion excretion, very low birth weight infants still run a considerable risk for disturbances of acid base metabolism due to the high mean level of net acid excretion in nutrition with preterm formulas and an additional age-specific augmentation of renal acid load.
对76名实际体重在1210至2540克之间、喂食市售早产配方奶粉的低出生体重婴儿，在出生后第38天（±17，均值±标准差）采集尿液样本并测量血液酸碱状态。实际体重低于1600克的婴儿每日体重增加更高（22±3 vs. 14±5克/千克/天），血液pCO2更低（35.4±5.0 vs. 38.9±3.8毫米汞柱），尿液pH更低（5.8±0.5 vs. 6.5±0.3），肾净酸更高（1.86±0.38 vs. 1.28±0.55毫摩尔/千克/天），磷排泄更高（0.67 vs. 0.52毫摩尔/千克/天），高于实际体重高于2100克的婴儿。这两组婴儿的尿液离子图谱数据显示，较小早产婴儿肾净酸排泄增加是由于钠、钾和氯的尿排泄减少，这是因为每日体重增加更高，可能这些矿物质的潴留更高，以及尿磷排泄更高，可能是由于特定年龄的肠道钙吸收较低，因此钙和磷的潴留率较低。考虑到肾脏排氢离子能力较低，极低出生体重婴儿因早产配方奶粉营养中净酸排泄的平均水平较高以及肾酸负荷的额外特定年龄增加，酸碱代谢紊乱的风险仍然相当大。
