Reduced quality of clot formation with gelatin-based plasma substitutes.
(25/27)
We have studied, over a wide range of dilutions using techniques of clot weight, thrombelastography and scanning electron microscopy, the physical properties of a blood clot formed in vitro when fresh blood was diluted with gelatin-based colloid solutions compared with crystalloid controls. The colloid solutions tested (3.5% polygeline (Haemaccel) and 4% succinylated gelatin (Gelofusine)) produced clots that had reduced median weight (P < 0.001 and P = 0.018, respectively) and reduced mean shear modulus (P < 0.001) compared with crystalloid controls. Scanning electron microscopy showed that the fibrin formed a less extensive mesh in the presence of the gelatin-based colloids compared with crystalloid. Reduction in clot quality with gelatin-based colloids has not been noted previously and further work is needed to ascertain if this occurs in vivo as these solutions are used frequently in patients who require full haemostatic competence. (+info)
Effects of colloidal resuscitation fluids on reticuloendothelial function and resistance to infection after hemorrhage.
(26/27)
The effects of three resuscitation fluids, hydroxyethyl starch (HES), Haemaccel, and fresh autologous blood, on reticuloendothelial system phagocytic and catabolic functions and resistance to infection after 40% hemorrhages in BALB/c mice were studied. The mice, anesthetized with isoflurane, were bled over a 10-min period, left hypovolemic for 30 min, and then resuscitated with their shed blood or the same volume of asanguineous fluid. Normothermia was maintained throughout the experiments. The uptake and catabolism of intravenously injected double-labelled sheep erythrocytes (51Cr-125I-SRBC) in liver and spleen were determined at 1 and 48 h after hemorrhage. No significant changes in the uptake or catabolism of SRBC in liver or spleen were found at 1 h after hemorrhage and resuscitation with any of the fluids. However, at 48 h a significant increase in liver uptake of SRBC was seen in animals resuscitated with either Haemaccel or HES compared to that in animals resuscitated with shed blood or in animals subjected to a sham operation. The increase in liver uptake was accompanied by a small decrease in spleen uptake in animals resuscitated with Haemaccel but not with HES. No great changes in catabolic activity were seen at 48 h, although activity levels tended to be higher in animals resuscitated with Haemaccel. Separate groups of animals were challenged by an intraperitoneal injection with live Escherichia coli at 1 or 48 h after hemorrhage and resuscitation. Sixty-four percent of the animals resuscitated with shed blood survived the challenge with E. coli at 1 h after hemorrhage, whereas only 10 and 0% survival was seen for animals resuscitated with Haemaccel and HES, respectively. At 48 h survival was 80% for shed-blood-resuscitated animals and 60 and 70% for Haemaccel- and HES-resuscitated animals, respectively. (+info)
Effects of gelatin-based resuscitation fluids on platelet aggregation.
(27/27)
Fluid resuscitation aims to maintain intravenous volume without significant effects on haemostasis. Several different types of i.v. fluid are available for use in a patient who has suffered trauma, but there is evidence that some resuscitation fluids may affect primary haemostasis. We have compared the effects of two resuscitation fluids, Haemaccel and Gelofusin, on platelet aggregation in vitro. These resuscitation fluids are both based on gelatin but Haemaccel contains a high concentration of Ca2+ whereas Gelofusin does not. Their effects on platelet aggregation in whole blood, induced by a range of different agents, were determined using a platelet-counting technique. Both Haemaccel and Gelofusin prevented platelet aggregation induced by ristocetin (P < 0.05, Mann-Whitney). In addition, Haemaccel proved to be a potent inhibitor of the platelet aggregation that occurred in response to all of the other agonists investigated: adenosine diphosphate, platelet-activating factor, collagen, a thromboxane A2 mimetic (U46619) and epinephrine. The additional inhibitory effects of Haemaccel were largely, but not completely, attributable to its high Ca2+ content. Inhibition of platelet aggregation by ristocetin may indicate a mechanism by which Haemaccel or Gelofusin may contribute to impaired haemostasis. The presence in Haemaccel of high concentrations of Ca2+, which is largely responsible for inhibition of the aggregation induced by other agents, may provide an additional means by which haemostasis could be impaired. (+info)