Volume-replacement ratio for crystalloids and colloids during bleeding and resuscitation: an animal experiment

Abstract

BackgroundFluid resuscitation remains a cornerstone in the management of acute bleeding. According to Starling's “Three-compartment model”, four-times more crystalloids have the same volume effect as colloids. However, this volume-replacement ratio remains a controversial issue as it may be affected by the degradation of the endothelial glycocalyx layer, a situation often found in the critically ill. Our aim was to compare colloid and crystalloid based fluid resuscitation during an experimental stroke volume index (SVI) guided hemorrhage and resuscitation animal model.MethodsAnesthetized and mechanically ventilated pigs were randomized to receive a colloid (Voluven®,HES, n=15) or crystalloid (Ringerfundin®,RF, n=15) infusion. Animals were bled till baseline SVI (Tbsl) dropped by 50% (T0), followed by resuscitation until initial SVI was reached (T4) in four steps. Invasive hemodynamic measurements, blood gas analyses and laboratory tests were performed at each assessment points. Glycocalyx degradation markers (Syndecan-1/hematocrit ratio, Glypican/hematocrit ratio) were determined at Tbsl, T0 and T4.ResultsSimilar amounts of blood were shed in both groups (HES group: 506±159 mls blood, RF group: 470±127 mls blood). Hemodynamic changes followed the same pattern without significant difference between the groups. Animals received significantly less resuscitation fluid in the HES compared to the RF-group: 425 [320-665], vs 1390 [884-1585] mls, p <0.001. The volume replacement ratio was 0.92 [0.79-1.54] for HES; and 3.03 [2.00-4.23] for the RF-group (p <0.001). There was no significant difference between the groups in the glycocalyx degradation markers.ConclusionIn this moderate bleeding-resuscitation animal model the volume-replacement ratio for crystalloids and colloids followed similar patterns as predicted by Starling's principle, and the glycocalyx remained intact. This indicates that in acute bleeding events, such as trauma or during surgery, colloids may be beneficial as hemodynamic stability may be achieved more rapidly than with crystalloids.

Population-based volume kinetics of crystalloids and colloids in healthy volunteers

“…Theoretically, a crystalloid solution should have one-fourth the volume-expanding capacity as the same volume of colloid solution 23,24 . In one study, rapid infusion of the colloid solution was more effective than a crystalloid solution in increasing the blood volume in moderate hypovolemia 1 .…”

Perioperatives Flüssigkeitsmanagement bei großen viszeralchirurgischen Eingriffen

“…So wurde gezeigt, dass abhängig von der Intaktheit der Gefäßbarriere und dem Flüssigkeits‑/Volumenstatus des Patienten teilweise bereits innerhalb der ersten Stunde nach Applikation lediglich 20 % des infundierten Volumens im Gefäßsystem verbleiben, während der Rest in das Interstitium diffundiert [ 50 ]. Sollen beispielsweise Blut- oder anderweitige Flüssigkeitsverluste ausgeglichen werden, wird häufig ein Ersatz des Blutverlustes im Verhältnis 3:1 mit Kristalloiden empfohlen [ 68 , 117 ]. Als Konsequenz kann eine „Überwässerung“ mit Flüssigkeitsverschiebungen und den bereits erwähnten Nebenwirkungen resultieren.…”

Immune response in fluid therapy with crystalloids of different ratios or colloid for rats in haemorrhagic shock

“…The lack of a significant difference in syndecan-1 levels might be explained as follows. László I et al reported that volume replacement ratios for haemodynamic restoration were 0.92 with colloid and 3.03 with crystalloid, respectively, in moderate bleeding animal, but there was no significant difference for glycocalyx degradation between the groups 20 . Torres et al reported that 75 mL/kg (above three fold for blood loss) lactated Ringer's solution and 15 mL/kg hetastarch restores haemodynamic parameters with similar expression of syndecan-1 levels in the sera of rats in haemorrhagic shock 21 .…”