Impact of different dosage of protamine on heparin reversal during off-pump coronary artery bypass: a clinical study.
BACKGROUND
Currently, a dose of protamine equal to 1 mg for each 100 units of heparin given is used to reverse the residual heparin activity following off-pump coronary artery bypass. We hypothesized that a 1:1 ratio (ratio of protamine to heparin) could be higher than necessary inducing post-operative disturbance of hemostasis.


METHODS
Between January and March 2014 in 9 patients undergoing off-pump coronary artery bypass, we evaluated the effect of a dose of protamine equal to 1 mg per 100 units of heparin (Total Calculated Dose) on hemostasis as evaluated by means of thromboelastomery. Two data analyses were performed: the first after the administration of 2/3 of the Total Calculated Dose of protamine and the second after the administration of the Total Calculated Dose of protamine.


RESULTS
We found that the administration of 2/3 of Total Calculated Dose of protamine was always able to reverse the anticoagulant effect of heparin and that a significant clotting time elongation was induced by the infusion of the second part of the Total Calculated Dose of protamine. No modification in clot firmness was observed.


CONCLUSIONS
The present study seems to suggest that the commonly applied ratio equal to 1:1 (ratio of protamine to heparin) could be higher than needed with potential and hazardous impacts on the efficacy of the coagulation system.
Department of Surgical, Microsurgical and Medical Sciences, University of Sassari, Italy.
Salvatore
S
Suelzu
Anesthesia and Intensive Care Unit, Azienda Ospedaliero-Universitaria, Sassari, Italy.
Andrea
A
Cossu
Anesthesia and Intensive Care Unit, Santissima Annunziata Hospital, Sassari, Italy.
Giovanni
G
Pala
Cardiosurgery Unit, Santissima Annunziata Hospital, Italy.
Michele
M
Portoghese
Department of Surgical, Microsurgical and Medical Sciences, University of Sassari, Italy.
Valeria
V
Columbanu
Department of Surgical, Microsurgical and Medical Sciences, University of Sassari, Italy.
Gabriele
G
Sales
Anesthesia and Intensive Care Unit, Santissima Annunziata Hospital, Sassari, Italy.
Luigi
L
Solinas
Department of Surgical, Microsurgical and Medical Sciences, University of Sassari, Italy ; Anesthesia and Intensive Care Unit, Azienda Ospedaliero-Universitaria, Sassari, Italy.
Luca
L
Brazzi
heparin; off-pump coronary artery bypass (OPCAB); protamine; thromboelastography