ABSTRACT
Aim: Post-operative bleeding remains a significant risk after
cardiac surgery. Despite adequate protamine reversal of heparin
intraoperatively, protein-bound heparin causes anticoagulant effect,
leading to bleeding in the post-operative period. The aim of this study
is to whether the use of a four-hour, low dose protamine infusion in
intensive care would reduce post-operative bleeding and hence, blood
transfusion requirements.
Methods: A retrospective cohort study of seven hundred and two
patients, who underwent elective or urgent coronary artery bypass
grafting from April 2014 and January 2017, were divided into two groups
based on who received post-operative protamine infusion (Group A, 472
patients) versus those who did not (Group B, 230 patients). They were
assessed for amount of post-operative mediastinal and pleural drainage
for the first 24 hours, use of post-operative transfusion of blood
products, postoperative hospital stay, and re-exploration.
Results: We found no significant difference between the rate of
bleeding in either of the groups. No significant difference was observed
in blood product requirements as well. In the sub-group consisting of
patients with high BMI (BMI ≥30), who received protamine infusion,
post-operative platelets transfusion was found to be significantly less.
Conclusions: Our results suggest that a low dose protamine
infusion given in the immediate postoperative period does not lead to
any significant clinical benefits. Both patients receiving and not
receiving the infusion had similar postoperative drainage, transfusion
requirements, haemorrhagic morbidity, mortality and length of hospital
stay.
Key words: Protamine infusion, bleeding, heparin rebound,
transfusion