Effects on cardiac function of a novel low viscosity plasma expander based on polyethylene glycol conjugated albumin.

BACKGROUND

Plasma expanders have become increasingly advantageous when compared to blood transfusion, due to their long shelf-life and cost-effectiveness. A new generation of plasma expander based on polyethylene glycol (PEG) conjugated to human serum albumin (PEG-HSA) has shown positive microvascular effects during extreme hemodilution and fluid resuscitation from severe hemorrhagic shock. PEG conjugation increases uniformly albumin molecular weight (MW) and colloidal osmotic pressure, with minor effects on viscosity.

METHODS

This study was designed to test the hypothesis that PEG-HSA improves and maintains cardiac function during anemic condition, independently of its lower viscosity, compared to plasma expanders with higher viscosity. To accomplish this objective, we compared PEG-HSA to colloids of different MWs and viscosities, dextran 70 kDa (moderate viscosity plasma expander, MVPE) and dextran 2000 kDa (high viscosity plasma expander, HVPE). Cardiac function was analyzed using indices derived from left ventricular pressure volume, and were assessed using a miniaturized conductance catheter, in two experimental models: 1) hemodilution and 2) resuscitation from hemorrhagic shock.

RESULTS

After hemodilution, PEG-HSA increased cardiac output compared to MVPE through the entire observation period, and HVPE increased stroke work compared to MVPE. After resuscitation, PEG-HSA increased stroke work compared to HVPE through the entire observation period. In both experimental protocols, cardiac functional changes induced by PEG-HSA were sustained over the observation time.

CONCLUSION

PEG-HSA, a low viscosity plasma expander, had beneficial effects on cardiac function when compared to conventional colloidal plasma expanders with higher viscosities. Maintenance of homeostasis during hemodilution and resuscitation from hemorrhagic shock using PEG-HSA will lead to a significant decrease of the use of blood, thus alleviating in part, forecasted blood shortages, and significantly reducing morbidity and mortality associated with the use of blood in transfusion medicine.