High molecular weight hydroxyethyl starch solutions are not more effective than a low wmolecular weight hydroxyethyl starch solution in a porcine model of septic shock.

BACKGROUND: There is evidence that suggests that early fluid resuscitation is beneficial in the treatment of sepsis. We previously demonstrated that hydroxyethyl starch (HES) 130/0.42 attenuated capillary leakage better than HES 200/0.5. Using a similar porcine fecal sepsis model, we tested the effects of two new synthetic high molecular weight (700 kDa) hydroxyethyl starches with the same molar substitution of 0.42 but with a different C2/C6 ratio compared to 6% HES 130/0.42 on plasma volume (PV), systemic and tissue oxygenation.

METHODS: This was a prospective, randomized, controlled animal study. Twenty-five anesthetized and mechanically ventilated pigs (28.4±2.3 kg) were observed over 8 h. Septic shock was induced with fecal peritonitis. Animals were randomized for volume-replacement therapy with HES 700/0.42 C2/C6/2.5:1 (N.=5), HES 700/0.42 C2/C6/6:1 (N.=5), HES 130/0.42 C2/C6/5:1 (N.=5) or Ringer’s Solution (RS, N.=5), and compared to non-septic controls receiving RS (N.=5). The albumin escape rate (AER) was calculated and plasma volume was determined at the end of the study. Tissue Oxygen Saturation was measured with the InSpectra™ Device (InSpectra Tissue Spectrometer, Hutchinson Technology Inc., Hutchinson, MN, USA).

RESULTS: The AER increased in all groups compared to control. All colloids (HES 700/6:1 68±15; HES 130 67±4; HES 700/2.5:1 71±12; P<0.05) but not RS (44±7) stabilized PV (mL/kg BW) after eight hours of sepsis. Systemic oxygenation was significantly lower in the RS group (44±17%; P<0.05) compared to all other groups at study end (P<0.05).

CONCLUSION: In this porcine fecal peritonitis model, the high molecular weight artificial colloids HES 700/2.5:1 and HES 700/6:1 were not more effective in maintaining plasma volume and systemic and tissue oxygenation than HES 130. In comparison to crystalloid RS, all HES solutions were more effective at maintaining plasma volume, mean arterial pressure (MAP), and systemic and tissue oxygenation.