Summary
Twelve patients undergoing total hip replacement, with regional anaesthesia and with
dextran infusion for plasma expansion and thromboprophylaxis, were given the vasopressin
analogue desmopressin (DDAVP) or placebo in a randomized, double-blind prospective
study. In controls (n = 6) we found a prolongation of the bleeding time, low factor VIII (FVIII) and von
Willebrand factor (vWF) and a decrease in antithrombin III to levels known to be at
risk for venous thrombosis. Desmopressin shortened postoperative bleeding time, gave
an early FVIII/vWF complex increase, prevented antithrombin III from falling to critically
low values and appeared to activate the fibrinolytic system, both by tPA increase
and PAI-1 decrease.
Thus in the controls we found changes in both coagulation and fibrinolysis indicating
a haemorrhagic diathesis as well as a risk for thromboembolism. Desmopressin induced
factor changes that possibly reduce both risks.