Comparison effect of 6% hydroxyethyl starch with Ringer's solution on splanchnic perfusion in canine with septic shock

Introduction

6% hydroxyethyl starch (HES) is an artificial colloid. HES and Ringer's solution (RS) are usually used to restore adequate volume in patients with septic shock, but their effects on splanchnic perfusion with septic shock were not clear. This prospective and randomized study was therefore to compare the effect of HES with that of RS on splanchnic perfusion in canine with septic shock.

Materials and methods

Twenty-four mongrel dogs with septic shock induced by lipopolysaccharides (LPS) were randomized to be divided into two groups (HES group and RS group). Each group was to receive an intravenous infusion of HES or RS (1 ml/kg/min) for 60 min, followed by normal saline for 180 min at the same rate. Hemodynamic and oxygendynamic and splanchnic perfusion parameters were repeated at 0, 30, 60, 120, 180, 240 min after the basic measurement (pre-LPS).

Results

After LPS infusion, the mean arterial pressure (MAP), cardiac output index (CI), and mesenteric blood flow decreased in all animals (P < 0.05). After fluid resuscitation, the MAP increased to pre-LPS value after 60 min in the HES group significantly, but after 120 min in the RS group. The CI increased significantly in both groups (P < 0.05).

After LPS infusion, the oxygen delivery (DO₂) and mesenteric blood flow decreased in all animals (P < 0.05). Compared with 0 min, DO₂ increased by fluid therapy in both groups. Mesenteric blood flow increased from 70 ± 35 to 100 ± 40 ml/min after 60 min in the HES group, and the intramucosal pH (pHi) also increased, and arterial lactate concentration and Pg-aCO₂ decreased significantly (P < 0.05), but there were no differences in RS group.

Discussion

Our present study showed that both HES and RS could raise arterial pressure and oxygen delivery in canines with septic shock. HES and RS therefore had similar effects on systemic hemodynamics and oxygen delivery.

Pg-a CO₂ and pHi were important signals of intestinal perfusion – low pHi and high Pg-a CO₂ indicated inadequate intestinal perfusion and hypoxia. Therefore the gut has been regarded as the motor of MODS. Compared with baseline values, the mesenteric blood flow increased, and also the intramucosal pH (pHi) increased, and the arterial lactate concentration and Pg-a CO₂ decreased significantly in the HES group, but there were no differences in the RS group. Our results indicated that HES improve splanchnic perfusion.

Conclusion

This work demonstrated both HES and RS could improve the hemodynamic state of canines with septic shock, but on splanchnic perfusion HES was better than RS.