Shields L E, Moore T R, Brace R A
Department of Reproductive Medicine, University of California San Diego, La Jolla, California 92093-0802, USA.
J Soc Gynecol Investig. 1995 Jul-Aug;2(4):602-8. doi: 10.1016/1071-5576(95)00005-y.
We hypothesized that amnioinfusion with normal saline would increase fetal plasma sodium and chloride concentrations, resulting in a hyperchloremic acidosis, and that these alterations would not occur after amnioinfusion with lactated Ringer's solution.
Chronically catheterized fetal sheep (137 +/- 1 days' gestation; mean +/- SE) were divided into three groups: control (n = 8), infused with normal saline (n = 10), and infused with lactated Ringer's solution (n = 10). The protocol consisted of a 30-minute pre-infusion period, a 1-hour amnioinfusion, and a 1-hour recovery period. During amnioinfusion, warmed solution was infused at a rate of 100 mL/minute for 1 hour. Fetal plasma and amniotic fluid electrolyte concentrations and osmolalities were measured every 20 minutes. Statistical analysis was by analysis of variance and linear regression.
Amniotic fluid electrolyte concentrations changed significantly (P < .001) in both amnioinfusion groups, resulting in amniotic fluid compositions that were essentially the same as the infused fluid 20 minutes after starting the amnioinfusion. Significant increases in fetal plasma Na+ and CI- concentrations (2-3 mEq/L) occurred in the normal-saline infusion group relative to both the control and lactated Ringer's groups (P < .001). The lactated Ringer's group demonstrated only a modest increase in plasma Na+ (P = .04) and no change in plasma Cl- concentration. Fetal arterial pH decreased (-0.015 U) in the normal-saline group, and the change in fetal pH was linearly related to the change in plasma Cl- concentration (r = -0.532, P = .004).
Normal-saline amnioinfusion can significantly alter fetal plasma electrolyte concentrations and blood pH, whereas amnioinfusion with lactated Ringer's solution results in minimal changes in fetal electrolytes and acid-base balance. The fetal plasma changes that occur during saline infusion are in the physiologic but not the pathologic range.
我们推测，用生理盐水进行羊膜腔灌注会增加胎儿血浆钠和氯的浓度，导致高氯性酸中毒，而用乳酸林格氏液进行羊膜腔灌注后不会出现这些改变。
将慢性插管的胎羊（妊娠137±1天；均值±标准误）分为三组：对照组（n = 8）、输注生理盐水组（n = 10）和输注乳酸林格氏液组（n = 10）。实验方案包括30分钟的灌注前期、1小时的羊膜腔灌注期和1小时的恢复期。在羊膜腔灌注期间，以100毫升/分钟的速度输注温热溶液，持续1小时。每20分钟测量一次胎儿血浆和羊水的电解质浓度及渗透压。采用方差分析和线性回归进行统计分析。
两个羊膜腔灌注组的羊水电解质浓度均发生了显著变化（P <.001），在开始羊膜腔灌注20分钟后，羊水成分与输注的液体基本相同。与对照组和乳酸林格氏液组相比，生理盐水输注组胎儿血浆Na⁺和Cl⁻浓度显著升高（2 - 3 mEq/L）（P <.001）。乳酸林格氏液组血浆Na⁺仅略有升高（P =.04），血浆Cl⁻浓度无变化。生理盐水组胎儿动脉pH值下降（-0.015 U），胎儿pH值的变化与血浆Cl⁻浓度的变化呈线性相关（r = -0.532，P =.004）。
生理盐水羊膜腔灌注可显著改变胎儿血浆电解质浓度和血液pH值，而乳酸林格氏液羊膜腔灌注对胎儿电解质和酸碱平衡的影响最小。生理盐水灌注期间胎儿血浆的变化处于生理范围内而非病理范围内。
