The effect of dextran on the coagulation of blood; a preliminary report

[Effects of plasma substitutes on hemostasis]

OBJECTIVE

Data synthesis on haemostasis effects of cristalloids and colloids and clinical implications for their use for plasma volume replacement.

DATA SOURCES

Data were searched in the Medline database from 1954 to 2000 using the following key-words: cristalloids, colloids, albumin, gelatin, dextran, hydroxyethyl starch, haemostasis, von Willebrand disease, haemodilution.

DATA EXTRACTION

Publications from 1954 to 1990 were selected depending on the quality of their methodology. Most of articles published after 1990 and all types including case report were accepted.

DATA SYNTHESIS

Cristalloids induces a moderate hypercoagulable state with 10 to 30% haemodilution. Hypocoagulation is observed above 50% haemodilution. Albumin does not impair hemostasis except with a 50% or more haemodilution where hypocoagulation is observed. Dextran dramatically impairs haemostasis and fibrinolysis. With increasing dose, a progressive decrease of all von Willebrand multimers, mostly the largest, is observed. Till 50% haemodilution, gelatin has a moderate impact on hemostasis, but platelet aggregation is moderately modified. However this moderate impairment of haemostasis may potentiate the haemostatic effect of other colloids when used in association with gelatin. More than 30% haemodilution with hydroxyethyl starch (HES) has a serious effect in vitro on platelet function and fibrinoformation. In most studies in human, less than 20 ml.kg-1 plasma volume replacement has no clinical impact, but in some evaluations postoperative bleeding is more important with HES, particularly HES 450, in comparison to other colloids. With HES 450 and HES 200 highly substituted (0.6 of degree of substitution) intravascular cumulation of large molecules leads to type I von Willebrand syndrome when doses overtake 80 ml.kg-1. Dextran and HES are prohibited in patients with impaired haemostasis due to congenital disease (haemophilia and von Willebrand disease) or acquired defect (thrombocytopenia). Caution is required in patients with renal failure or receiving antithrombotic or non-steroidal anti-inflammatory agents. Patients without a haemorrhagic diathesis must not received more than 1.5 g.kg-1.j-1 of dextran and restrictive conditions of use must be respected with HES.

CONCLUSION

Except isotonic cristalloids, all colloids induce haemostastic changes particularly for haemodilution over 30%. Effects are more pronounced with HES and dextran.

The rate of blood loss from skin punctures during the Ivy bleeding time test

The rate of blood loss from skin punctures during the performance of the Ivy bleeding time test has been measured by a simple technique in normal individuals, in patients without defects of the haemostatic or coagulation system, and in patients with known haemorrhagic disorders.A wide range was found in normal individuals, but repeated tests on a single individual showed a smaller variation. Nearly half of the tests on patients with von Willebrand's disease, thrombocytopenia, ;capillary type' of bleeding, or haemorrhagic renal failure gave abnormally high rates of blood loss. Haemophilic, Christmas disease, and Dinedevan-treated patients gave low volumes and rates of blood loss.A group of patients has been encountered in whom the bleeding time was normal but the rate of blood loss was increased. The majority of these had haemorrhagic symptoms and other evidence of a defective haemostatic or coagulation system. It is suggested that a consideration of the rate of blood loss in those patients with a normal bleeding time gives additional help in interpreting the Ivy test. A high rate may indicate the need for further investigation of the haemostatic and coagulation system.

Acute and subacute toxicity of 7.5% hypertonic saline-6% dextran-70 (HSD) in dogs. 2. Biochemical and behavioral responses

7.5% Hypertonic saline-6% Dextran-70 (HSD) is currently being evaluated in our laboratory as a resuscitation solution for the treatment of hypovolemia at a dose of 4 ml kg-1 body weight. A few reports of dextran toxicity, particularly of the kidney, have been cited in the literature, so the present study evaluated the acute and subacute toxicity of HSD administered i.v. to beagle dogs. In the acute toxicity studies animals were infused with a single dose of HSD, or its components of hypertonic saline (HS) or Dextran-70 (D-70), at the maximum tolerated dose (MTD: 20 ml kg-1). Controls received Ringers lactate (RL). In the HSD-infused dogs, transient but significant increases in serum alanine (ala) aminotransferase (AT), aspartate (asp) AT and alkaline phosphatase (AP) were observed for the first 72 h. In most cases this increase was also observed in the HS group. In the subacute studies, dogs were infused daily with the MTD of the above test solutions. Serum ala AT activity was 2-3-fold higher in the HSD than the RL group for the first 3 days. Again, a similar effect was observed in the HS group. Slight, transient increases in asp AT and AP activity were also observed in the HSD group. Higher lactate dehydrogenase (LDH) activity was only observed at Day 14 in dogs infused with the MTD of HSD or HS. In both studies, no adverse effects on blood urea nitrogen (BUN) or serum creatinine were observed and other transient changes in serum parameters were attributable to hemodilution induced by HSD.(ABSTRACT TRUNCATED AT 250 WORDS)

Hydroxyethyl starch as an experimental adjunct to leukocyte separation by centrifugal means: review of safety and efficacy

A total of 1,921 leukapheresis procedures have been performed on 532 normal and CML donors at six research institutions, for the purpose of supporting granulocytopenic leukemia patients during infectious episodes. The addition of HES alone or in combination with either etiocholanolone or dexamethasone, resulted in a significant increase in the numbers of leukocytes (granulocytes) harvested by continuous and noncontinuous flow centrifugation. Normal donors participating in these programs were monitored prior to and immediately following each procedure by standard laboratory methods which revealed no serious or abnormal changes occurring as a result of the procedure in those undergoing single or multiple donations with these agents. CML donors tolerated the addition of only HES well, as evidenced by the lack of toxic reactions in three donors undergoing 101 to 121 procedures.

Disordered blood coagulation in burned children receiving high molecular weight dextran

Coagulation studies were performed on nine children with burns. Four of these children received treatment which included intravenous dextran; all four showed abnormalities of coagulation and two of them developed a bleeding state. No abnormalities of haemostasis were detected in the remaining five children who had comparable degrees of burns but whose treatment did not include intravenous dextran.