Department of Clinical Sciences, Karolinska Institutet at Danderyd Hospital, Stockholm, 182 88, Sweden.
BMC Anesthesiol. 2024 Mar 27;24(1):119. doi: 10.1186/s12871-024-02494-w.
Kinetic analysis of crystalloid fluid yields a central distribution volume (V) of the same size as the expected plasma volume (approximately 3 L) except during general anesthesia during which V might be only half as large. The present study examined whether this difference is due to influence of the intravascular albumin balance.
A population volume kinetic analysis according to a three-compartment model was performed based on retrospective data from 160 infusion experiments during which 1-2.5 L of crystalloid fluid had been infused intravenously over 20-30 min. The plasma dilution based on blood hemoglobin (Hb) and plasma albumin (Alb) was measured on 2,408 occasions and the urine output on 454 occasions. One-third of the infusions were performed on anesthetized patients while two-thirds were given to awake healthy volunteers.
The Hb-Alb dilution difference was four times greater during general anesthesia than in the awake state (+ 0.024 ± 0.060 versus - 0.008 ± 0.050; mean ± SD; P < 0.001) which shows that more albumin entered the plasma than was lost by capillary leakage. The Hb-Alb dilution difference correlated strongly and positively with the kinetic parameters governing the rate of fluid transfer through the fast-exchange interstitial fluid compartment (k and k) and inversely with the size of V. Simulations suggest that approximately 200 mL of fluid might be translocated from the interstitial space to the plasma despite ongoing fluid administration.
Pronounced plasma volume expansion early during general anesthesia is associated with a positive intravascular albumin balance that is due to accelerated lymphatic flow. This phenomenon probably represents adjustment of the body fluid volumes to anesthesia-induced vasodilatation.
晶体液的动力学分析产生了一个与预期血浆体积（约 3 L）相同大小的中央分布容积（V），但在全身麻醉期间，V 可能只有一半大小。本研究旨在探讨这种差异是否是由于血管内白蛋白平衡的影响。
根据 160 例静脉输注实验的回顾性数据，采用三房室模型进行群体容量动力学分析，在 20-30 分钟内静脉输注 1-2.5 L 晶体液。根据血液血红蛋白（Hb）和血浆白蛋白（Alb）进行血浆稀释测量了 2408 次，尿液输出测量了 454 次。三分之一的输液是在麻醉患者中进行的，而三分之二是在清醒的健康志愿者中进行的。
全身麻醉期间的 Hb-Alb 稀释差异是清醒状态下的四倍（+0.024±0.060 与-0.008±0.050；平均值±标准差；P<0.001），这表明更多的白蛋白进入了血浆，而不是通过毛细血管渗漏丢失。Hb-Alb 稀释差异与控制液体通过快速交换间质液室转移速度的动力学参数（k 和 k）呈强烈正相关，与 V 的大小呈负相关。模拟表明，尽管持续输液，仍有约 200 mL 的液体可能从间质空间转移到血浆中。
全身麻醉早期明显的血浆体积扩张与血管内白蛋白平衡呈正相关，这是由于淋巴液流速加快所致。这种现象可能代表了机体液体量对麻醉诱导的血管扩张的调节。
