A Comparison of 4% Succinylated Gelatin Solution versus Normal Saline in Stable Normovolaemic Sheep: Global Haemodynamic, Regional Blood Flow and Oxygen Delivery Effects

Abstract

The objective of this study was to compare the effects on regional blood flow and regional oxygen delivery of 4% succinylated gelatin solution (Gelofusine, B. Braun) with those of normal saline. This was a randomised, controlled, cross-over large animal study, which took place at the animal laboratory of university physiology institute. The subjects were seven merino cross-ewes. We implanted flow probes around the aorta, coronary, renal and mesenteric arteries. We randomised animals to observation (control), normal saline (one litre over 15 minutes) or Gelofusine (one litre over 15 minutes). We measured central haemodynamics, organ blood flows, arterial blood gases and haemoglobin every 30 minutes for 210 minutes. Compared to control, both Gelofusine and normal saline significantly and similarly increased mean arterial pressure, stroke volume, cardiac output and central venous pressure in the first hour (P < 0.05). Such changes, however, were transient except for the increase in cardiac output seen with Gelofusine. Normal saline significantly increased mesenteric blood flow in the first hour (P < 0.05), while Gelofusine caused a specific, sustained and progressive increase in renal blood flow and conductance (P < 0.05). Both fluids increased urine output and creatinine clearance (P < 0.05), but, due to haemodilution, both decreased renal oxygen delivery in the first hour (P < 0.05). Normal saline and Gelofusine have transient, volume expansion-related systemic haemodynamic effects, which are greater for Gelofusine. Saline had a more pronounced early effect on mesenteric blood flow, while Gelofusine had a sustained and progressive greater effect on renal blood flow. The transient increase in urine output and creatinine clearance seen with both fluids occurred while renal oxygen delivery decreased.