Summary
Vasopressin infusions in normal volunteers that produce concentrations in plasma comparable
to those seen during stress, cause an increase in plasma factor VIII and shortening
of the euglobulin clot lysis time (ECLT). We have investigated the relationship between
endogenous vasopressin (aVP) release and haemostatic function in 7 patients undergoing
major abdominal surgery. Blood samples were taken at nine intervals during the operative
procedure. Plasma aVP levels peaked at median values of 51 pg/ml during bowel manipulation
and remained elevated on the first post-operative day. Following, and in close temporal
relationship with the rise in aVP there were increases in factor VIII coagulant activity,
the ristocetin co-factor, von Willebrand antigen, plasminogen activator activity (106/ECLT2) and fibrinopeptide A concentrations with shortening of the activated partial thromboplastin
time. The relationship was similar to that seen following infusion of a VP in human
volunteers. The results are consistent with the hypothesis that aVP is an important
mediator of changes in haemostatic function which accompany stress and might contribute
to the thrombotic risk associated with surgical operations.
Key words
Abdominal surgery - Vasopressin - Factor VIII - Fibrinolysis - Fibrinopeptide A
