Distribution and elimination of crystalloid fluid in pre-eclampsia

Abstract

Pre-eclampsia (PE) is a disease of pregnancy associated with peripheral oedema and hypovolaemia, but few details are known about how women with PE handle a volume load of crystalloid fluid compared with healthy pregnant women. To study this issue, Ringer's acetate solution (12.5 ml/kg of body weight) was given by intravenous infusion over 30 min to eight women with PE and to eight healthy pregnant women matched with respect to gestational week (mean, 34 weeks). Venous blood was sampled and excreted urine was collected over 90 min to study the time course of the volume expansion by means of volume kinetic analysis. The results show that the size of the central body fluid space expanded by the infused fluid was smaller in PE (mean, 2940 ml compared with 4240 ml respectively; P<0.04), and the clearance constants for distribution (100 ml/min compared with 43 ml/min; P<0.04) and elimination (125 ml/min compared with 36 ml/min; P<0.02) were higher in the women with PE than in the controls. Less excess volume accumulated in the central body fluid space in the presence of PE, whereas the rates of distribution and elimination were higher during and for 15 min after the infusion. It is concluded that Ringer's acetate solution fluid is both distributed and eliminated faster in women with PE than in matched pregnant controls.

Adrenergic Drugs Alter Both the Fluid Kinetics and the Hemodynamic Responses to Volume Expansion in Sheep

“…The unknown parameters in the kinetic model were estimated individually for each experiment, using Matlab version 4.2 (Math Works Inc., Notich, MA), in which process a non-linear regression analysis was used to fit the solution to the differential equations given above to the data on dilution [9]. The validity of the used model has recently been discussed [5].…”

“…The Hb series was analyzed by volume kinetics, which is pharmacokinetics adapted to fluid infusions [3][4][5]. Volume kinetics implies that fluid infused at the rate k i expands a central body fluid space (v) which is reduced to its baseline size V by two dilution-dependent mechanisms; k r which eliminates fluid by urinary excretion, and k t which translocates fluid to a peripheral body fluid compartment.…”

“…Plasma dilution was used as the measure of intravascular volume expansion and served as a link between fluid therapy and hemodynamic response. Plasma dilution and the urinary excretion were also used as input variables for kinetic calculations to outline the disposition of 0.9% saline [3][4][5].…”

Must hypervolaemia be avoided? A critique of the evidence

“…Interestingly, the kinetics of crystalloid fluids seems to be affected by albuminuria, which indicates damage to the glycocalyces of the glomeruli. For example, minimal albuminuria increased the rate of elimination of crystalloid fluid infused just before major abdominal surgery [39] and preeclamptic women had twice the distribution and elimination rates of Ringer´s acetate when compared to matched pregnant controls [40].…”

Comparison of the hemodynamics and dynamics of fluid shift of Ringer's solution before surgery in children and adults

“…Co-administration of different catecholamines has been demonstrated to induce different effects on the dynamics of volume expansion of crystalloid infusion (3,4). Research has also indicated that the particular illness in the patient may influence the dynamics of volume expansion (5). Additionally, different fluids present different fluid shift (6).…”