Clinical Trial Comparing Heparin and Protamine Fixed and Titrated Doses in Cardiac Surgery With Cardiopulmonary Bypass
Status:
Completed
Trial end date:
2010-11-01
Target enrollment:
Participant gender:
Summary
There are currently several schemes described for anticoagulation with heparin and its
reversal with protamine during cardiac surgery with CPB. The oldest, and most used in our
routine environment, is the scheme of fixed doses, in which a bolus dose of heparin at the
start of CPB is established in IU/kg of body weight and the dose of protamine at the end of
CPB is calculated based on the initial dose of heparin administered.
These schemes do not take into account the variability inter-patients and can result in
overdose or sub-doses of one or both drugs.
The titration schedule of doses of heparin and protamine through the principle of
dose-response curve of Bull promotes individualization of dosage according to the response of
each patient. This scheme has been associated with an effective reversal of the effect of
heparin after CPB and with reduction of post-operatory bleeding and transfusion.
The restoration of a state of anticoagulation by heparin after its reversal by protamine is
called "rebound effect". It is a phenomenon explained by the recirculation of heparin stored
in the reticulum-endothelial system and connective tissue, or by free residual concentration
of heparin after clearance of protamine. This effect may be present for more than 6 hours of
post-operatory and may contribute to increase post-operatory bleeding.
Phase:
Phase 4
Details
Lead Sponsor:
SANE-Society of Anesthesiology
Collaborators:
Fundação Universitária de Cardiologia (University Foundation of Cardiology) Instituto de Cardiologia do Rio Grande do Sul