[The effect of antithrombin iii concentrations during cardiopulmonary surgery]

Evaluation of influence of pre-op continuous e.v. heparin infusion in patients undergoing urgent myocardial surgical revascularization, on the anticoagulation threshold needed for cardiopulmonary bypass. Analysis of the efficacy of ATIII substitutional therapy to allow best ACT values during extracorporeal circulation, and to reduce intra and post-op bleeding and need for homologus transfusion.

Operative room and ICU of a cardiac surgery unit in a regional hospital.

Two groups of coronary patients in preoperative treatment with heparin were randomized in a prospective double blind study for an intraoperative treatment with heparin and ATIII (Group A) and heparin plus placebo (Group B). An investigation was made on the influence of preoperative heparin treatment regarding extracorporeal circulation, the variation of the coagulation parameters in CEC with substitutive therapy of ATIII and the reduction of the therapeutic strength of heparin during perfusion, the problem of bleeding and the incidence of blood transfusions and lastly the economic questions of the two procedures.

The study showed the necessity of repeated bolus of heparin during CEC and the rapid loss of its effect in the group not subjected ATIII therapy. A less incidence of bleeding in Group A was observed; for this reason the patients received significantly less packed red cells and FFP and a discrete number of patients of this group were not transfused. Surely the method of using the ATIII is much more expensive from the economic point of view, but the benefits of avoiding the problems of a blood transfusion (infections, immunodepression etc.), of the reduced stay in the Intensive Care Unit, of the riduced risk involved with problems of bleeding and the need of repeated operative procedures make this method fundamental in patients with reduced plasma levels of ATIII such as coronary patients who are under heparin treatment for several days.

Intraoperative administration of ATIII can reduce most problems due to heparinization of the extracorporeal circuit, such as onset of fibrinolysis, CID and platelets depletion or inactivation causing intra and post-op massive bleeding.