Recombinant Activated Factor VIIa Use in Massive Transfusion and Coagulopathy Unresponsive to Conventional Therapy

Vascular Injury and Thrombotic Potential: A Note of Caution About Recombinant Factor VIIa

Postoperative hemorrhage following cardiac surgery increases morbidity, mortality, and costs. Several case reports have described the successful use of recombinant factor VIIa to decrease or stop bleeding in patients undergoing cardiac surgery. The mechanism of action of recombinant factor VIIa is thought to be increased site-specific thrombin generation by tissue factor—mediated activation of coagulation or from activated platelets. However, there have also been many reports of thrombotic complications after recombinant factor VIIa administration. Randomized clinical trials and further laboratory studies should help better clarify the efficacy, safety, cost-effectiveness, and optimal dosing of recombinant factor VIIa in the cardiac surgical setting.

Preliminary experience with use of recombinant activated factor VII to control postpartum hemorrhage in acute fatty liver of pregnancy and other pregnancy-related liver disorders

Control of postpartum hemorrhage is difficult in patients with coagulopathy due to acute liver failure. Recombinant activated factor VII (rFVIIa) can help in control of bleed; however, it has short duration of action (2-4 h). The study aimed to report the use of rFVIIa in this setting. We retrospectively analyzed all patients with acute liver failure secondary to pregnancy-related liver disorders who received rFVIIa for control of postpartum hemorrhage (six patients, all six met diagnostic criteria for acute fatty liver of pregnancy). One dose of rFVIIa achieved adequate control of bleeding in five patients, while one patient needed a second dose. rFVIIa administration corrected coagulopathy and significantly reduced requirement of packed red cells and other blood products. No patient had thrombotic complications. In conclusion, rFVIIa was a useful adjunct to standard management in postpartum hemorrhage secondary to acute liver failure of pregnancy-related liver disorders.

Successful management by recombinant activated factor VII in a case of disseminated intravascular coagulopathy caused by obstetric hemorrhage

Postpartum hemorrhage (PPH) is a life-threatening emergency in obstetrics. Although recombinant activated factor VII (rFVIIa) has become used for the treatment of some cases of massive hemorrhage, its applications in the field of obstetrics are still limited. We describe a case of successful treatment with rFVIIa for PPH due to placenta accreta. The patient was a 33-year-old woman with placental previa. Cesarean section (CS) was performed at gestational week 35. During CS, there was massive hemorrhage due to placenta accreta. After CS, disseminated intravascular coagulopathy and hypovolemic shock were diagnosed. The PPH was not controlled by transfusion therapy. On the fourth day after CS, rFVIIa (90 microg/kg x 2) was given because of the persistent PPH. Bleeding decreased and no further transfusion was required from 2 days after administration. rFVIIa was useful in the treatment of this case of obstetric hemorrhage.

In vitro effect of activated recombinant factor VII (rFVIIa) on coagulation properties of human blood at hypothermic temperatures

BACKGROUND

Recombinant activated factor VII (rFVIIa) is currently administered off-label to control diffuse coagulopathic bleeding of patients with traumatic injuries. These patients are often cold, acidotic, and coagulopathic upon arrival and each responds differently to rFVIIa therapy. This study investigated the effects of hypothermia on clotting and the potential benefit of rFVIIa administration on blood coagulation at different hypothermic temperatures.

METHOD

Citrated blood samples were collected from eight healthy volunteers (20-45 years old) and incubated at 37 degrees C, 34 degrees C, 31 degrees C, and 28 degrees C for 30 minutes. rFVIIa (1.26 microg/mL equivalent to 90 microg/kg in vivo dose) or vehicle solution (saline) was added to each blood sample, incubated (10 minutes), and analyzed at the respective temperatures by standard coagulation tests and thrombelastography.

RESULTS

The clot reaction time of blood samples, measured as prothrombin time, activated partial thromboplastin time, and R time (thrombelastography analysis), was significantly prolonged at 31 degrees C or below compared with at 37 degrees C. The clot formation rate ([alpha] angle, maximum clotting velocity [Vmax]) was decreased at all cold temperatures. Maximum clot strength (maximum amplitude) was only affected (reduced) at 28 degrees C. Addition of rFVIIa shortened the prothrombin time, activated partial thromboplastin time, and R times at every temperature, surpassing the normal (37 degrees C) temperature values in 31 degrees C and 34 degrees C cold samples. Similarly, clot formation rate parameters (clotting time, [alpha] angle, Vmax) were also improved by rFVIIa addition and normothermic values were restored in 31 degrees C and 34 degrees C cold blood samples. rFVIIa did not affect maximum amplitude at any temperature.

CONCLUSIONS

Mild to moderate hypothermia delayed the initial clot reaction and reduced clot formation rate without affecting ultimate clot strength. FVIIa effectively compensated for the adverse effects of hypothermia except in severe cases. These results suggest that administration of FVIIa should be beneficial in enhancing hemostasis in hypothermic trauma patients without the need for prior correction of the patient's body temperature.

Use of recombinant activated factor VII to arrest uncontrolled bleeding: a case series

A retrospective analysis is described to assess the effects of using recombinant activated factor VII to control bleeding in a series of patients who had failed to respond to conventional hemostatic measures. In all, 18 patients (aged 16-65 years) with a range of conditions resulting in bleeding refractory to conventional methods of control were treated with recombinant activated factor VII (60-120 Amicrog/kg; 1-4 doses). The effects of recombinant activated factor VII on bleeding were noted together with the patients' transfusion requirements and hematological parameters. Administration of recombinant activated factor VII successfully stopped bleeding in 17 of the 18 patients. Therapy with recombinant activated factor VII significantly decreased transfusion requirements for packed red blood cells, fresh frozen plasma, platelets, and cryoprecipitate compared with pretreatment values along with significant improvement in hemostasis. In various serious bleeding situations, treatment with recombinant activated factor VII may effectively arrest bleeding, which has remained refractory to conventional methods of control.

Safety and efficiency of recombinant activated factor VII in postcardiotomy massive hemorrhage

Postoperative massive hemorrhage is a difficult clinical situation after cardiac surgery. Recombinant activated factor VII (rf-VIIa) can be a useful adjunct to surgical hemostasis and blood product transfusion. Four cases of massive hemorrhage treated with rf-VIIa after complex cardiac surgery are reported. A review of the literature and possible guidelines for the use of rf-VIIa in cardiac surgery are provided.

Blood management

CONTEXT

We provide an overview of the principles of blood management: the appropriate use of blood and blood components, with a goal of minimizing their use.

OBJECTIVE

To review the strategies that exploit combinations of surgical and medical techniques, technologic devices, and pharmaceuticals, along with an interdisciplinary team approach that combines specialists who are expert at minimizing allogeneic blood transfusion.

DATA SOURCES

A search on Medline and PubMed for the terms English and humans used in articles published within the last 20 years.

CONCLUSIONS

Blood management is most successful when multidisciplinary, proactive programs are in place so that these strategies can be individualized to specific patients.

Use of activated recombinant factor VII for severe coagulopathy post ventricular assist device or orthotopic heart transplant

BACKGROUND

Ventricular assist devices(VAD) implantation/removal is a complex surgical procedure with perioperative bleeding complications occurring in nearly half of the cases. Recombinant activated factor VII (rFVIIa) has been used off-label to control severe hemorrhage in surgery and trauma. We report here our experience with rFVIIa as a rescue therapy to achieve hemostasis in patients undergoing orthotopic heart transplant (OHT) and/or VAD implantation.

METHODS

A retrospective review was conducted from Jan 03 to Aug 05 for patients who received rFVIIa for the management of intractable bleeding unresponsive to standard hemostatic blood component therapy. Blood loss and the quantity of blood products, prior to, and for at least 12 hours after, administration of rFVIIa were recorded.

RESULTS

Mean patient age was 53, (38-64 yrs), mean dose of rFVIIa administered was 78.3 microg/kg (24-189 microg/kg) in 1-3 doses. All patients received the drug either intraoperatively or within 6 hours of arrival in ICU. Mean transfusion requirements and blood loss were significantly reduced after rFVIIa administration (PRBC's; 16.9 +/- 13.3 to 7.1 +/- 6.9 units, FFP; 13.1 +/- 8.2 to 4.1 +/- 4.9 units, platelets; 4.0 +/- 2.8 to 2.1 +/- 2.2 units, p < 0.04 for all). 5 patients expired including 3 with thromboembolic cause. One patient developed a lower extremity arterial thrombus, and another deep vein thrombosis.

CONCLUSION

In this review, there was a significant decrease in transfusion requirement and blood loss after rFVIIa administration. Although, 5/17 developed thromboembolic complications, these patients may have been at higher risk based on the multiple modality therapy used to manage intractable bleeding. Nevertheless, the exact role of rFVIIa with respect to development of thromboembolic complications cannot be clearly determined. Further investigation is needed to determine rFVIIa's safety and its effectiveness in improving postoperative morbidity and mortality.

Recombinant Activated Factor VII in Cardiac Surgery: A Systematic Review

Postoperative hemorrhage is a common complication in cardiac surgery, and it is associated with a considerable increase in morbidity, mortality, and cost. Recombinant activated factor VII (rFVIIa) is an emerging hemostatic agent, increasingly used in cardiac surgery. This article systematically reviews the evidence regarding the efficacy, safety, and cost of rFVIIa in this setting. Although definitive evidence from randomized controlled trials is lacking, the use of rFVIIa in patients experiencing refractory postoperative hemorrhage seems promising and relatively safe. However further research is required to definitively establish its clinical utility in the postoperative cardiac patient.

Recombinant activated coagulation factor VII and bleeding trauma patients

BACKGROUND

Recombinant activated coagulation factor VII (rFVIIa) is increasingly being administered to massively bleeding trauma patients. rFVIIa has been shown to correct coagulopathy and to decrease transfusion requirements. However, there is no conclusive evidence to suggest that rFVIIa improves the survival of these patients. The purpose of this study was to determine whether or not rFVIIa has an effect on the in-hospital survival of massively bleeding trauma patients.

METHODS

A retrospective cohort study was conducted from January 1, 2000 to January 31, 2005, at a Level I trauma center in Toronto, Canada. Inclusion criteria included trauma patients requiring transfusion of 8 or more units of packed red cells within the first 12 hours of admission. The primary exposure of interest was the administration of rFVIIa. Primary outcome was a 24-hour survival and secondary outcome was overall in-hospital survival.

RESULTS

There were 242 trauma patients identified who met inclusion criteria; 38 received rFVIIa. rFVIIa patients were younger, had more penetrating injuries, and fewer head injuries. However, rFVIIa patients required more red cell transfusions initially, and were more acidotic. Administering rFVIIa was associated with improved 24-hour survival, after adjusting for baseline demographics and injury factors. The odds ratio (OR) for survival was 3.4 (1.2-9.8). Furthermore, there was a strong trend toward increased overall in-hospital survival. The OR of in-hospital survival was 2.5 (0.8-7.6). Also, subgroup analysis of rFVIIa patients showed that 24-hour survivors required a slower initial rate of red cell transfusion (4.5 vs. 2.9 units/hr, p = 0.002), had higher platelet counts (175 vs. 121 [x10(-9)/L], p = 0.05) and smaller base deficits (7.1 vs. 14.3, p = 0.001) compared with rFVIIa patients who died during the first 24 hours.

CONCLUSION

rFVIIa may be able to improve the early survival of massively bleeding trauma patients. However, surgical control of massive hemorrhage still has primacy, as rFVIIa did not appear efficacious if extremely high red cell transfusion rates were required. Also, correction of acidosis and thrombocytopenia may be important for rFVIIa efficacy. Prospective studies are required.

Transfusion therapy in the intensive care unit

PURPOSE OF REVIEW

Transfusion therapy in the intensive care unit is an ever-growing field, with new understanding of potential complications, new drug therapies to reduce the need for transfusion, and new additions in component therapy. In addition to the risks of sepsis, ABO blood group mismatch, and other complications associated with transfusion, the intensivist needs to be familiar with alternative therapies to minimize transfusion.

RECENT FINDINGS

Transfusion-related acute lung injury and immunosuppression are two newly recognized complications in transfusion. Transfusion-related acute lung injury can lead to respiratory failure in an acute respiratory distress syndrome-like picture, often necessitating intubation and critical care services. Immunosuppression following transfusion has been linked to cytokine and complement activation. Recombinant erythropoietin (rHuEPO, Epogen, Procrit), by maximizing red cell counts, and aprotinin (Trasylol), by inhibiting fibrinolysis, are two old drugs being used with increasing frequency in a new setting: the intensive care unit. A new component therapy, recombinant factor VIIa (rFVIIa, NovoSeven), assists in turning on the extrinsic pathway of the coagulation cascade.

SUMMARY

Recognizing early signs of transfusion-related acute lung injury may aid in the treatment and reporting of this entity. Realizing the mechanism and severity of immunosuppression associated with transfusion may alter transfusion triggers in the intensive care unit. rHuEPO and aprotinin are now being used with increasing frequency to increase red cell counts and minimize the need for transfusion. Recombinant factor FVIIa targets coagulation cascade activation which helps to reduce the number of units of blood products transfused in the actively bleeding patient.

Massive Transfusion Coagulopathy

Coagulopathy following massive transfusion is a consequence of post-traumatic and surgical hemorrhage. Bleeding following massive transfusion can occur due to hypothermia, dilutional coagulopathy, platelet dysfunction, fibrinolysis, or hypofibrinogenemia. Transfusion of 15 to 20 units of blood products causes dilutional thrombocytopenia, and both antiplatelet agents (eg, clopidogrel [Plavix, Sanofi, Bridgewater, NJ]) and hemostatic inhibitors (eg, low-molecular-weight heparins, pentasaccharides, and direct thrombin inhibitors) are contributing factors to bleeding. Tests for platelet dysfunction are not readily available. Excessive fibrinolysis and low fibrinogen are also causes of bleeding in these patients. Currently, however, there are several agents that have been reported to be effective for the prophylaxis of hemorrhage in surgical patients, including aprotinin for cardiac surgery, orthopedic surgery, and hepatic transplantation, and the off-label use of recombinant activated factor VII (NovoSeven, Novo Nordisk, Bagsvaerd, Denmark) as rescue therapy for life-threatening hemorrhage.