Effects of crystalloids and colloids on microcirculation, central venous oxygen saturation, and central venous-to-arterial carbon dioxide gap in a rabbit model of hemorrhagic shock

Abstract

Objective The effects of hydroxyethyl starch (HES) on microcirculation, central venous oxygen saturation (ScvO 2 ), and the central venous-to-arterial carbon dioxide gap (dCO 2 ) are studied in a rabbit model of hemorrhagic shock for elucidating the advantages and drawbacks of resuscitation with HES compared with crystalloids. Methods An ear chamber and sublingual mucosa were used to examine blood vessels by intravital microscopy. Hemorrhagic shock was induced by removing nearly half of the blood volume. Twenty-two rabbits received 20 mL of HES by intravenous infusion immediately after bloodletting. Additional HES was then administered intravenously to a total volume of 100 mL. The other 22 rabbits (control) were intravenously given 40 mL of normal saline solution (NSS), followed by additional NSS to a total volume of 200 mL, administered under the same conditions as HES. Results After the infusion, the vessel density and perfusion rate of the sublingual microcirculation recovered in the HES group. The arteriolar diameter, blood flow velocity, and blood flow rate of the ear microcirculation were maintained in this group, and microcirculatory failure did not develop. In the NSS group, however, all 5 of the aforementioned measured variables were significantly smaller than those in the HES group after the completion of infusion. The recovery of ScvO 2 and dCO 2 to the respective baseline values was significantly better in the HES group than in the NSS group. Conclusion Intravenous infusion of HES effectively maintains adequate tissue oxygenation and perfusion in hemorrhagic shock.

Fluid resuscitation with hydroxyethyl starch in perioperative acute hemorrhagic shock

“…Previous studies have pointed out harmful effects of older generation of HES on the kidneys in various patients [12]. However, recent evidences have shown that a third-generation HES did not contribute to the renal dysfunction in subjects with hemorrhagic shock [6][7][8] and in surgical patients [24,25], it preserved renal function through maintenance of microvascular oxygenation [6,26].…”

“…However, the use of FFP may be limited in emergent situations since it can cause several adverse effects [23]. Recent studies have shown that fluid resuscitation with a third-generation HES (HES 130/0.4) in acute hemorrhagic shock can preserve micro-vessel integrity [8] and protect the glycocalyx layer, leading to better outcomes in animal models of acute hemorrhage [9]. Komori et al have demonstrated that fluid resuscitation with HES 130/0.4 effectively maintained adequate tissue oxygenation and peripheral perfusion compared to that with crystalloids in a rabbit model of hemorrhagic shock [8].…”

“…Recent studies have shown that fluid resuscitation with a third-generation HES (HES 130/0.4) in acute hemorrhagic shock can preserve micro-vessel integrity [8] and protect the glycocalyx layer, leading to better outcomes in animal models of acute hemorrhage [9]. Komori et al have demonstrated that fluid resuscitation with HES 130/0.4 effectively maintained adequate tissue oxygenation and peripheral perfusion compared to that with crystalloids in a rabbit model of hemorrhagic shock [8]. By examining the micro-vessel and perfusion status of the sublingual mucosa and an ear chamber using intravital microscopy, their study clearly showed that HES rather than crystalloids preserved hemodynamics and the microcirculation.…”

“…Several studies have demonstrated that fluid resuscitation with colloids compared to crystalloids might improve the outcomes of acute hemorrhagic shock [6,7]. Moreover, recent studies have elucidated the detailed effects of fluid resuscitation with hydroxyethyl starch (HES) on microcirculation and micro-vessels in subjects with acute hemorrhagic shock [8,9]. These studies have shown that fluid resuscitation with HES can maintain adequate tissue oxygenation and peripheral perfusion [8], and suppress vascular permeability via protection of glycocalyx layer in acute hemorrhagic shock [9].…”

“…Moreover, recent studies have elucidated the detailed effects of fluid resuscitation with hydroxyethyl starch (HES) on microcirculation and micro-vessels in subjects with acute hemorrhagic shock [8,9]. These studies have shown that fluid resuscitation with HES can maintain adequate tissue oxygenation and peripheral perfusion [8], and suppress vascular permeability via protection of glycocalyx layer in acute hemorrhagic shock [9]. Conversely, many randomized controlled studies focusing on patients with septic shock have shown that the advantages of fluid resuscitation with colloids, including HES and albumin, remain controversial [10,11].…”