There was no between-group difference in total protamine dose ( 3.9 0.6 and 4.2 0.7 ; 95 % CI of the difference between means : -0.544 to 0.008 mg/kg ; p = 0.057 ) or protamine : heparin ratios ( 1.3:1 and 1.4:1 ; 95 % CI of the difference between means : -0.05 to 0.03 mg/mg ; p = 0.653 ) .