The role of protein C as an inhibitor of blood clotting during extracorporeal
circulation.
Author(s): Feindt P(1), Volkmer I, Seyfert UT, Haack H.
Affiliation(s): Author information:
(1)Department of Thoracic and Cardiovascular Surgery, Saarland University
Hospital, Homburg/Saar, Germany.
Publication date & source: 1991, Thorac Cardiovasc Surg. , 39(6):338-43
The plasma levels of protein C, AT III, the perioperative administration of fresh
frozen plasma (FFP) and AT III concentrate were compared under the use of various
drugs in a randomized, prospective double-blind study in 40 patients in whom an
aortocoronary bypass operation was carried out. We formed four groups of ten
patients: group A served as a control group, group B received a prostacyclin
(PGI2) infusion of 10 or 20 ng/kg/min, group C high-dose aprotinin substitution,
and group D was treated with a combination of prostacyclin and aprotinin. After
an initial short-term rise in the inhibitors protein C and AT III, there was a
fall in all groups in the further course of extracorporeal circulation. The
initial preoperative values were reached again on the morning of the first
postoperative day. This indicates a raised turnover and in association with this
a raised rate of elimination of these factors caused by an increased thrombin
activation during the extracorporeal circulation which cannot be prevented by the
usual heparinization. Whereas prostacyclin had no effect on our results mediated
by thrombocytic mechanisms, use of aprotinin led to a significant saving in the
requirement for perioperative fresh frozen plasma and AT III substitution
therapy. A clinical advantage of prostacyclin and aprotinin combination was not
observed. In view of our results (individual analyses were mainly in the normal
range), we consider that AT III and fresh frozen plasma should not be substituted
routinely during or after extracorporeal circulation.
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