The effect of low molecular weight heparin (Fraxiparine = Nadroparine calcium) on full heparinization. An experimental study

Purpose: Standard (unfractionated) heparin is still the only agent to perform extracorporeal circulation in open heart surgery. There are some important side effects of heparin like post-operative bleeding and adverse reactions while protamine reversal. Dose of heparin necessary for extracorporeal circulation was searched whether it could be decreased by using low molecular weight heparin (Fraxiparine*)(*Nadroparine calcium from Choay/Sanafi, Paris, France). Methods: An experimental animal study group was created with 12 pigs which had blood coagulation test values in normal limits. Fraxiparine 0.3 cc in prefilled syringes was administered subcutaneously into pigs twice a day for five days. Then the pigs were heparinized intravenously and the dose of standard heparin needed to get sufficient anticoagulant effect to perform extracorporeal circulation was calculated. Results: Although coagulation and activated coagulation times were slightly increased, these were not statistically significant. Pigs were full heparinized at the 5th day of the trial when compared to control values, these were not statistically significant (p > 0.05). Standard heparin dose to get sufficient anticoagulant effect was 4 mg/kg and this was not less than the dose found for the control group. Conclusion: According to these results, we reported preoperatively low molecular weight heparin use did not change the amount of heparin enough for extracorporeal circulation. We suggested that using low molecular weight heparin could be helpful to achieve the desired antithrombotic effect in the very early post-operative periods of coronary bypass and prosthetic heart valve operations