Experience of NovoSeven administration in management of coagulopathic bleedings after surgical interventions with extracorporeal circulation

Objective

To analyze the clinical experience of administration of recombinant activated factor VII (rFVIIa) (NovoSeven) in post-surgical bleedings refractory to the traditional haemostatic therapy in patients who underwent surgical interventions with extra-corporeal circulation (EC).

Materials and methods

Assessment of 17 patients (age 31–53, 44.3 ± 2.9 years) who underwent surgical interventions on the heart with EC (prosthetic repair of one or two heart valves, coronary artery bypass graft, prosthetic repair of the ascending aorta with a valvular conduit, etc.) was performed. Duration of EC was 172 ± 34 min. The aorta was occluded for 107 ± 19 min. Indications for administration of the rFVIIa were considered when there was a postsurgical bleeding (exceeding 750 ml/hour) in the absence of surgical sources of the bleeding and lack of efficacy of the conventional hemostatic procedures: adequate neutralization of heparin with protamine sulfate, high doses of aprotinin, aminocaproic acid, fresh frozen plasma transfusion. NovoSeven was administered 44–158 (105 ± 24) min after neutralization of heparin with protamine sulfate. The dosage of the agent was 1.8 ± 0.3 mg, or 22 ± 3 μg/kg. The data were statistically processed, with evaluation of the significance of the differences using Student's t test.

Results

For 2 hours immediately after the administration of rFVIIa, the rate of the bleeding decreased from 1270 ± 240 to 182 ± 26 ml/hour. During the following hours of observation it was no different from the values acceptable for cardiosurgical interventions (125 ± 17–35 ± 7 ml/hour) (Table 1).

Table 1

Conclusion

The depletion of factor VII plasma activity that occurs during cardiosurgical interventions may cause coagulopathic bleeding refractory to the standard therapy. There are several possible mechanisms for the impairment of the factor VII activity during the EC surgeries: hemodilution; hypothermia; contact activation of the components of the haemostasis system due to interaction of the blood with foreign surface of the EC-device contour; consumption of the factor and depletion of its plasma concentration due to ingress of the tissue factors into the systemic circulation after aspiration of the wound contents into the cardiotomic reservoir of the EC device. NovoSeven produces a potent haemostatic effect in bleeding events refractory to the conventional therapy complicating the cardiosurgical interventions and substantially decreases the demand for blood transfusion.