新生儿排尿特性及血浆尿液渗透压变化

目的：探讨新生儿昼夜排尿特性、膀胱容量及血浆、尿液渗透压变化。方法：42例新生儿(男22例，女20例)，根据日龄分为A，B，C 3组，3组日龄分别为～3 d，～7 d，>7d。记录昼夜排尿时间、尿量，以膀胱B超机测量膀胱残余尿量，以FM-6型全自动冰点渗透压仪测量血浆、尿液渗透压。结果：①A组昼夜尿量，排尿次数与B，C组比较，差异有显著性意义(P0.05)。③以逐步回归分析法建立估测膀胱最大容量的最优回归方程，膀胱最大容量=42±0.17X(ml)，X为10 AM～6 PM尿量，F=15.561(P<0.01)。结论：正常新生儿膀胱稳定，几乎完全排空。新生儿肾脏浓缩功能无昼夜差异。

Characteristics of Micturition and Changes of Plasma and Urine Osmolarity in Neonates

Objective To assess micturition characteristics, bladder capacity and plasma and urine osmolarity in neonates. Methods Forty five neonates were divided into three groups according to post natal ages (Group A=～3 d, Group B=～7 d, Group C=>7 d). The time of micturition and voided volume were recorded. The residual urine volume was detected using a bladder volume instrument (BladderScan BVI 2500). Plasma and urine osmolarity were measured using the FM 6 pattern freezing point osmometer. Results ① There were significant differences (P< 0.05 ) in the day night voided volume and voided frequency between Group A and Groups B and C. ② The bladder emptying rates, maxium bladder capacity(MBC) and plasma urine osmolarity of Groups A, B and C were 0.80 ± 0.07 , 0.82 ± 0.09 , 0.79 ± 0.10 ; 56±6, 65±14, 61±15 (ml); 285±5, 287±7, 286±8 (mOsm/L); 202±59, 185±65, 216±92 (mOsm/L) respectively and there was no significant difference between the 3 groups. ③ The multiple stepwise regression method was used to estabilish the best regression equation for predicting the MBC, which was 42± 0.17 X (ml) [X=8 hours (10 Am～6 Pm) voided volume, F= 15.561 (P< 0.01 )]. Conclusions The bladder of normal neonates empties almost completely and its function is stable. There is no difference in the renal concentration function of neonates between day and night.