Simple dilution does not explain everything, however, as the haemodilution incurred when treating patients with therapeutic fluids tends to depress coagulation more or less profoundly depending on the fluid used. A larger decrease in coagulation markers than expected from
the dilution itself has been observed for colloid diluted blood, with the impact corresponding in part to molecular size. High dalton-range HES solutions and dextran are generally seen as the worst offenders. The mechanism proposed is interference with fibrin polymerization.
Synthetical colloid fluids in general seem to have a more negative impact compared to crystalloid solutions, although results from some other studies appear to contradict these findings. The confusion may stem from the many separate methodologies used in the
research, amount of dilution, or the choice of analysis . Our hypothesis of fibrinogen correcting or at least ameliorating the dilutive coagulopathy could not be proven correct; no significant changes could be accomplished in any of the three parameters. Previous research by other groups cited above have shown positive results of fibrinogen addition in vitro but only one of these used the Sonoclot and did not use the same methodology surrounding the tests as we have. Our direct ICU-patient approach and use of native blood may account for our inability to reproduce these results.
Ulf SchÃ¶tt, Effects of High Dose Fibrinogen on in vitro Haemodilution with Different
Last date updated on July, 2014