Effect of fluid resuscitation with balanced solutions on platelets: In vitro simulation of 20% volume substitution.

BACKGROUND Fluid resuscitation in massive bleeding may cause coagulation disorders by dilution of platelets and clotting factors or by the definite influence on theirfunction. The aim of this study was to investigate the effects of balanced crystalloid and colloid solutions on platelets (PLT) in vitro using complex assessment of coagulation. METHODS The study group was comprised of 32 American Society of Anesthesiologists physical status class I male volunteers, aged 21-35 (29 ± 4) years, weighting 59-103 (81.2 ± 9.8) kg. Whole blood samples were diluted at a 4:1 ratio with the following fluids: balanced crystalloid (Plasmalyte®), 6% hydroxyethyl starch 130/0.4 (Volulyte®) and succinylated gelatin (Geloplasma®). Coagulation was assessed using standard morphology, rotational thromboelastometry and aggregometry. RESULTS Dilution with all fluids caused statistically significant drop in the number of platelets (p < 0.01) but the effect did not differ between solutions (p > 0.05 for all). Other platelet parameters, such as platelet distribution width, mean platelet volume and platelet-large cell ratio were not affected by the solutions. Haemodilution had no effect on platelet function (p = 0.1). Decreased platelet component of clot strength was found for all three fluids (p < 0.05), although the effect for colloids was more pronounced. CONCLUSIONS The effect of balanced crystalloids and colloids on platelet aggregation was insignificant, even after 20% volume substitution with the resuscitation fluids.