Reasons for performing study: Adverse effects on renal health and haemostasis have been documented in human patients administered hydroxyethyl starches (HESs). Gelatins could provide useful substitutes should similar adverse effects be identified in horses.
Objectives: To compare the effects of a 4% modified fluid gelatin (MFG) with a 6% (130/0.4) HES on haemodilution, colloid osmotic pressure (COP), haemostasis and renal parameters in healthy ponies.
Study Design: Randomised crossover experiment. Methods: Three treatments (A=10 ml/kg bwt HES, B=10 ml/kg bwt MFG and C=20 ml/kg bwt MFG) were administered to 6 healthy ponies with a 1-week washout period. Haematocrit, platelet count, total serum protein, COP, thromboelastography (TEG), prothrombin time (PT), activated partial thromboplastin time (aPTT) and fibrinogen were measured at baseline and at multiple time points up to 24 h post-infusion. Serum creatinine, urine specific gravity (USG), urine protein: creatinine ratio (UPC), urine gamma glutamyltransferase:creatinine ratio (UGC) and urine sediment examination (USE) were performed before and 24 h after each treatment, as well as one week after the final treatment.
Results: All treatments resulted in significant haemodilution and increases in COP, with treatment C having a significantly greater effect on haematocrit than other treatments. The platelet count decreased with all treatments and was significantly lower following treatment C compared with treatment B. No clinically relevant differences were observed in any of the TEG parameters within or between treatments. No significant differences in PT, aPTT or fibrinogen were observed between treatments. Serum creatinine, UPC and UGC did not change significantly between pre- and post-study measurements. USG and USE remained within normal limits.
Conclusions: MFG could be considered as an alternative to HES for volume expansion and oncotic support. Neither MFG nor HES were associated with clinically significant adverse effects on haemostasis or renal parameters.