Assessment of intravascular retention of hydroxyethyl starch in mild hemorrhagic shock

Objective

To evaluate the retention of hydroxyethyl starch (HES) in the vessel at the microcirculation using intravital microscopy [1, 2].

Methods

Experiments were performed using a mild hemorrhagic (10% of total blood volume) shock model in rats. The blood vessels (A2 and V2) of the cremaster muscle were observed. One hour after hemorrhage was induced, FITC-labeled L-HES (MW 150,000–200,000) or M-HES (MW 175,000–225,000) or H-HES (MW 550,000–850,000) was administered within 15 min. The retention of HES was evaluated by the contrasting density of the brightness of fluorescence on the image stored on the PC.

Results

A retention ratio of HES inside the blood vessel was different among groups. M-HES and H-HES retained in the vessels longer than L-HES, with no difference between M-HES and H-HES (Fig. 1).

Figure 1

(abstract P172)

Conclusion

M-HES (MW 175,000–225,000) seems to have large molecules, which is enough to maintain the blood volume after hemorrhage.