Summary
Dextran fractions of different molecular weights were given to dogs in order to ascertain
at which molecular weight dextran interferes with the coagulation factors.
1. Infusions of dextran with an average molecular weight of 130,000 (Intradex®) and
in doses of 1.5 g dextran per kg body weight induced a moderate coagulation defect.
There was a slight prolongation of the bleeding time and a slight drop in platelet
count. Values for AHF, factor V, prothrombin and factor VII, and fibrinogen declined
by 10 to 40% of the original values.
2. Infusions of dextran with an average molecular weight of 75,000 (Macrodex®) in
doses of 1.5 g per kg body weight did not produce any significant changes in bleeding
time and platelet count. The AHF level decreased by 40% and the levels of prothrombin
and factor VII, factor V and fibrinogen by about 10% of the original values. In a
dose of 2 g per kg body weight this fraction produced a significant coagulation defect
with a fall of the various coagulation factors by about 40 to 50%.
3. A dextran fraction with an average molecular weight of 60,000 in doses of 1.5 g
per kg body weight did not prolong the bleeding time and caused only a very slight
decrease in platelet count. There were no changes in the values for AHF, factor V,
prothrombin and factor VII but a slight drop occurred in the fibrinogen levels.
4. Dextran with an average molecualr weight of 40,000 (Rheomacrodex ® ) in doses of
1.5 g per kg body weight did not affect the bleeding time or the platelet count. Nor
did any significant decline occur in the amounts of the other coagulation factors.
No changes in the Duke or in the Ivy bleeding times were observed in human beings
given Macrodex® and Rheomacrodex® in doses of 1 g per kg body weight.
Intradex® and Macrodex® in doses of up to 1-1.5 g per kg bodyweight to persons with
normal blood coagulation are considered not associated with any appreciable risk of
haemorrhage, but they are contraindicated in patients with haemorrhagic diathesis.
The experiments indicate that Rheomacrodex® in similar doses does not incur any risk
of haemorrhage.
