The Annals of Thoracic Surgery, Vol 42, 168-171, Copyright © 1986 by The Society of Thoracic Surgeons
Platelet damage by protamine and the protective effect of prostacyclin: an experimental study in dogs
AJ Velders and CR Wildevuur
Protamine is given after cardiopulmonary bypass to reverse the effect of
heparin. However, the adverse effects of an overdose have not been fully
evaluated. In this canine study, a standard dose of one bolus of heparin
(300 IU per kilogram of body weight) was neutralized by an infusion of
protamine hydrochloride in a 1:2 ratio. Platelet number and function were
severely reduced by this overdose of protamine, and this finding correlated
with a prolongation of the bleeding time. Giving a titrated dose of
protamine hydrochloride to reverse heparin activity, measured by the
activated clotting time, affected neither platelet number nor function.
When prostacyclin (0.5 microgram/kg/min) was infused during administration
of an overdose of protamine, platelets again were not affected by the
excess of protamine.
