EFFECTS OF GELATIN-BASED RESUSCITATION FLUIDS ON PLATELET-AGGREGATION

Fluid resuscitation aims to maintain intravenous volume without signif icant effects on haemostasis. Several different types of i.v. fluid ar e available for use in a patient who has suffered trauma, but there is evidence that some resuscitation fluids may affect primary haemostasi s. We have compared the effects of two resuscitation fluids, Haemaccel and Gelofusine, on platelet aggregation in vitro. These resuscitation fluids are both based on gelatin but Haemaccel contains a high concen tration of Ca2+ whereas Gelofusine does not. Their effects on platelet aggregation in whole blood, induced by a range of different agents, w ere determined using a platelet-counting technique. Both Haemaccel and Gelofusine prevented platelet aggregation induced by ristocetin (P<0. 05, Mann-Whitney). in addition, Haemaccel proved to be a potent inhibi tor of the platelet aggregation that occurred in response to all of th e other agonists investigated: adenosine diphosphate, platelet-activat ing factor, collagen, a thromboxane A(2) mimetic (U46619) and epinephr ine. The additional inhibitory effects of Haemaccel were largely, but not completely, attributable to its high Ca2+ content. Inhibition of p latelet aggregation by ristocetin may indicate a mechanism by which Ha emaccel or Gelofusine may contribute to impaired haemostasis. The pres ence in Haemaccel of high concentrations of Ca2+, which is largely res ponsible for inhibition of the aggregation induced by other agents, ma y provide an additional means by which haemostasis could be impaired.