新生儿成熟度和产后日龄对血清钾水平的影响

目的　探讨新生儿成熟度和产后日龄对血清钾浓度的影响。方法　回顾性分析了胎龄为 2 4～ 2 8周 (A组 ) ,2 9～ 3 2周 (B组 ) ,3 3～ 3 6周 (C组 )和 3 7～ 4 2周 (D组 )新生儿生后 1～ 72h内的血清钾水平及其变化。结果　①新生儿的胎龄、体重和尿量与血清钾水平存在着线性关系。②生后 1～ 2 4h ,A组新生儿的血清钾水平最高 ,B组次之 ,C和D组相当 ,为最低。生后 4 8h内 ,A和B组的血清钾水平开始下降 ,并于 72h内下降至C和D组新生儿水平。C和D组新生儿生后 72h内的血清钾水平无明显变化。③A ,B和C组早产儿生后 2 4h内高钾血症 (≥7.0mmol/L)发生率分别为 2 0 .0 % ,12 .5%和 4 .0 % ;2 4例高钾血症患儿经常规治疗后 ,14例 (58.3 % )于 72h内血钾降至 7.0mmol/L以下并存活 ;10例 (4 1.7% )高钾血症状态持续存在 ,其中 7例死亡。D组足月儿于生后 72h内未出现高钾血症。结论　新生儿的成熟度和产后胎龄影响血清钾水平 ;极不成熟新生儿 (2 4～ 3 2周 )在生后 2 4h内具有较高的血清钾水平 ,继之随生后日龄的增加而降低 ;早产儿可有致命性高钾血症存在 ,常规治疗仅部分有效。

Effect of maturity and postnatal age on serum potassium concentration in neonates

Objective To explore the effect of neonatal maturity and postnatal age on serum potassium concentration ([K +]). Methods Serum [K +] in neonates with gestational ages of 24～28 weeks (group A), 29～32 weeks (group B), 33～36 weeks (group C) and 37～42 weeks (group D) were retrospectively analyzed at 1～72 hours after birth. Results ①There was a linear correlation between serum [K +] and the gestational age, birth weight, and urine output in newborns. ②Serum [K +] of group A and B was higher than that of group C and D during the first 24 hours after birth, decreased during the second 24 hours, and reached that of group C and D during the third 24 hours. Serum [K +] in groups C and D did not change significantly during 72 hours after birth. ③Twenty four of the premature infants in groups A, B and C developed hyperkalemia (≥7.0 mmol/L) during the first 24 hours, with an incidence of 20.0%, 12.5% and 4.0%, respectively. After conventional therapy, serum [K +] in 14(58.3%) decreased to less than 7.0 mmol/L within 72 hours (all infants survived), whereas hyperkalemia persisted in 10 infants (41.7%) remained, and 7 died. There was no hyperkalemia in group D during 72 hours after birth. Conclusions Neonatal maturity and postnatal age affect serum potassium concentration. Higher potassium concentration decreases with the increasing of gestational and postnatal age in very premature infants. Critical hyperkalemia exists in premature infants, and conventional therapy is partially effective for the survival of the infants.