Effects of two different hydroxyethylstarch solutions on colloid osmotic pressure and renal function in ovine endotoxemic shock

Introduction

The purpose of the present study was to directly compare the impact of two different hydroxyethylstarch solutions (HES 6% 130/0.4, Voluven^® 6%; and HES 10% 200/0.5, Hemohes^® 10%) and a balanced crystalloid (Sterofundin^® ISO) on the colloid-osmotic pressure (COP) and renal function in fulminant ovine endotoxemia.

Methods

Thirty healthy ewes received a continuous infusion of Salmonella typhosa endotoxin started at 5 ng/kg/min, which was doubled every hour until the mean arterial pressure fell below 65 mmHg. Thereafter, sheep were randomized (each group n = 10) to either receive repeated bolus infusions of 5 ml/kg HES 130 or HES 200, or 10 ml/kg crystalloid to increase the central venous pressure (8–12 mmHg), pulmonary arterial occlusion pressure (12–15 mmHg) and mixed-venous oxygen saturation (≥ 65%). Following infusion of the maximum colloid dose (20 ml/kg), all groups received only crystalloid infusions (10 ml/kg), if necessary. Animals surviving the 12-hour intervention period were anesthetized and killed. Data are expressed as means ± SEM. Statistics were performed using two-way ANOVA with Student–Newman–Keuls post-hoc comparisons.

Results

The colloid groups needed less total fluids than the crystalloid group. Apart from significantly higher systemic oxygen delivery index and stroke volume index in sheep treated with HES 130, the hemodynamics were comparable between groups. COP was higher in both colloid-treated groups as compared with the crystalloid group (12.5 ± 0.6 and 14.7 ± 1.0 vs 8.4 ± 1.7; P < 0.05 for HES 130 and HES 200 vs crystalloids). However, there was no significant difference in COP between the two colloid groups (P = 0.429). Urinary output was markedly reduced in the HES 200 group (2.5 ± 0.9 vs 5.7 ± 1.3 and 7.2 ± 1.2 ml/kg/hour; P < 0.05 for HES 200 vs HES 130 and crystalloids). Plasma creatinine was highest in sheep treated with HES 200 (1.4 ± 0.1 vs 1.0 ± 0.0 and 1.0 ± 0.1 mg/dl; P < 0.05 for HES 200 vs HES 130 and crystalloids).

Conclusion

In ovine endotoxemia, treatment with HES 200 may compromise oxygen transport and renal function as compared with HES 130 and crystalloids. The underlying mechanisms remain to be elucidated but appear to be independent of COP.