Blood volume redistribution on fluid treatments after burn-blast combined injury, especially with respect to the regulation role of microcirculation due to the Fåhraeus effect.

Considering the Fåhraeus effect and the blood volume regulation role of the microcirculation, we used a new method for calculating the blood volume change in microcirculation, macrocirculation as well as the whole circulation (delta Vmic, delta Vmac, delta Vb), to compare fluid therapy effects of hypertonic saline dextran solution (HSD) and lactic Ringer's solution at the early stage after burn-blast combined injury (BBI). The measurement of plasma viscosity was used in this calculation. The results showed that, with calculation of the blood volume change in microcirculation and macrocirculation, this method could more exactly and distinctly display the change and distribution of blood volume during the therapy. It confirms that HSD treatment can increase blood pressure and attenuate tissue edema, by significantly increasing total blood volume, recouping delta Vmac. The study suggests that a desirable and practical clinical method for blood volume change can be developed based on the present study.