Treatment of severe pulmonary hemorrhage with activated recombinant factor VII (rFVIIa) in very low birth weight infants

Advances in pulmonary management and weaning from ECLS

ECMO for neonatal and pediatric respiratory failure provides gas exchange to allow lung recovery from reversible pulmonary ailments. This is a comprehensive discussion on the various strategies and advances utilized by pediatric ECLS specialists today. ECMO patients require continual monitoring, serial gasses and radiographs, near-infrared spectroscopy (NIRS - to monitor oxygen delivery to regional tissue beds), and more quality ECLS directed care. As the foundation to lung recovery, good EMCO closely monitors ECLS flow rates, sweep gasses, and membrane lung function. Mixed venous oxygen saturation (Sv02) greater than 65% indicates good oxygen delivery and sweep gas adjustments maintain PaCO2 of 40-45 mm Hg. Lung recovery ventilatory settings do not fully rest the lungs but maintain normal or nontoxic pressure and oxygen levels. Neonatal recovery settings are PIP (cm H20) of 15-20, PEEP of 5-10, ventilator rate of 12-20 and an inspiratory time of 0.5-1 s, and FiO2 of 0.3-0.5. Pediatric recovery settings are PIP (cm H20) < 25, PEEP of 5-15, ventilator rate of 10-20 and an inspiratory time of 0.8-1 s, and FiO2 of <0.5. Some studies demonstrate a higher recovery PEEP level decreases duration of ECMO, but do not demonstrate a mortality difference. Multiple adjunctive therapies such as surfactant, routine pulmonary clearance and respiratory physiotherapy, iNO, prone positioning, bronchoscopy, POCUS, CT imaging, and extubation or "awake ECLS" can significantly affect pulmonary recovery. Patience is necessary as lung recovery may take weeks or even months on the nontoxic settings. On these settings, dynamic recovery will be revealed by improvement in tidal volume, minute ventilation and radiographic pulmonary aeration, prompting discussion about weaning. When this pulmonary compliance recovery becomes evident, decreasing ECLS flow while also decreasing circuit FiO2 and/or sweep gas are common components to ECMO weaning strategies.

Treatment of Diffuse Alveolar Hemorrhage: Controlling Inflammation and Obtaining Rapid and Effective Hemostasis

Diffuse alveolar hemorrhage (DAH) is a life-threatening pulmonary complication in patients with hematologic malignancies or systemic autoimmune disorders. Pathologic findings show pulmonary capillaritis, bland hemorrhage, diffuse alveolar damage, and hemosiderin-laden macrophages, but in the majority of cases, pathogenesis remains unclear. Despite the severity and high mortality, the current treatment options for DAH remain empirical. Systemic treatment to control inflammatory activity including high-dose corticosteroids, cyclophosphamide, and rituximab and supportive care have been applied, but largely unsuccessful in critical cases. Activated recombinant factor VII (FVIIa) can achieve rapid local hemostasis and has been administered either systemically or intrapulmonary for the treatment of DAH. However, there is no randomized controlled study to evaluate the efficacy and safety, and the use of FVIIa for DAH remains open to debate. This review discusses the pathogenesis, diverse etiologies causing DAH, diagnosis, and treatments focusing on hemostasis using FVIIa. In addition, the risks and benefits of the off-label use of FVIIa in pediatric patients will be discussed in detail.

Recombinant Activated Factor VIIa (rFVIIa) Treatment in Very-Low-Birth-Weight (VLBW) Premature Infants with Acute Pulmonary Hemorrhage: A Single-Center, Retrospective Study

AIM

We aimed to evaluate the efficacy of intravenous administration of recombinant activated factor VIIa (rFVIIa) for acute pulmonary hemorrhage treatment in very-low-birth-weight (VLBW) premature infants.

PATIENTS AND METHODS

This study was carried out retrospectively in premature infants with pulmonary hemorrhage that were ≤30 weeks gestational age or <1250 g birth weight. The data of all VLBW premature infants with pulmonary hemorrhage who were hospitalized in our neonatal intensive care unit between 01 January 2013 and 31 December 2015 were evaluated. Group 1 (n = 21) received rFVIIa support within the first 30 min of pulmonary hemorrhage plus conventional treatment, while Group 2 (n = 21) received conventional treatment only.

RESULTS

The number of patients whose pulmonary hemorrhage was stopped within the first 2 h was significantly higher in Group 1 than Group 2 (n = 14 vs n = 4; p = 0.002). After pulmonary hemorrhage, hemoglobin values of Group 1 were higher than Group 2 (11.12 ± 1.06 vs 10.14 ± 1.59 g/dL; p = 0.024). Erythrocyte suspension (1.43 ± 4.51 vs 5.71 ± 7.46 mL/kg; p = 0.030) and fresh frozen plasma use (5.71 ± 8.10 vs 19.52 ± 12.44 mL/kg; p < 0.001) in Group 1 were lower than those of Group 2. Prothrombin time, activated partial thromboplastin time, and international normalized ratio values in Group 1 were lower than those of Group 2 (p < 0.05). No statistically significant difference was identified in recurrence of pulmonary hemorrhage after 72 h, overall mortality, mortality from pulmonary hemorrhage, surfactant use, intubation time, hospitalization duration, intraventricular hemorrhage (IVH), severe IVH, patent ductus arteriosus rates, or short-term complication rates.

CONCLUSION

rFVIIa administration was observed to be effective in stopping pulmonary hemorrhage, reducing blood product requirement, and improving coagulation test parameters. Prospective studies are needed to evaluate the efficacy, reliability, and long-term results of rFVIIa in the prevention and treatment of pulmonary hemorrhage in premature infants.

Diffuse alveolar hemorrhage and recombinant factor VIIa treatment in pediatric patients

Diffuse alveolar hemorrhage (DAH) is a life-threatening pulmonary complication in patients with hematologic malignancies or autoimmune disorders. The current treatment options, which include corticosteroids, transfusions, extracorporeal membrane oxygenation (ECMO), and immunosuppressants, have been limited and largely unsuccessful. Recombinant activated factor VII (rFVIIa) has been successfully administered, either systemically or bronchoscopically, to adults for the treatment of DAH, but there are few data on its use in pediatric patients. The current literature in the PubMed database was reviewed to evaluate the efficacy and risk of rFVIIa treatment for DAH in pediatric patients. This review discusses the diagnosis and treatment of DAH, as well as a new treatment paradigm that includes rFVIIa. Additionally, the risks and benefits of off-label use of rFVIIa in pediatric patients are discussed.

Predicting response to rFVIIa in neonates with intractable bleeding or severe coagulation disturbances

BACKGROUND

To date, clinical experience with recombinant factor VIIa (rFVIIa) in neonates is rather limited because of the lack of controlled studies. ΑIM: The objective of this study was to present further experience from our center with regard to the use of rFVIIa in newborns with severe bleeding or coagulopathy resistant to conventional therapy and to determine factors affecting the clinical outcome.

METHODOLOGY

We performed a retrospective data analysis of 29 neonates with intractable bleeding or severe coagulation disturbances. All patients received 100 μg/kg of rFVIIa per dose bolus intravenously (maximum of 23 doses), as rescue procedure after other interventions had failed to achieve hemostasis.

RESULTS

Fourteen neonates survived (group A), whereas 15 died (group B). There was no difference in birth weight, gestational age, and bleeding site and causes between the 2 groups. In the neonates who survived, rFVIIa had been administered earlier in the disease process (<24 h of beginning of bleeding) compared with those who died (P=0.009). In all 29 neonates, international normalized ratio was directly restored (from 2.99±1.4 before rFVIIa administration to 1.6±1.1 afterward, P<0.001) and prothrombin time and activated partial thromboplastin time were significantly decreased after administration of rFVIIa (from 28 to 16.4 and from 180 to 67, respectively; P=0.001 and 0.05, respectively). Blood products administered were significantly less in group A than in group B, as time from the beginning of bleeding to the administration of rFVIIa was significantly less in group A than in group B. Neither acute adverse events nor thromboembolic complications were observed.

CONCLUSIONS

In this neonatal group with intractable bleeding and/or severe coagulation disturbances, rFVIIa was more effective in early intervention as rescue therapy, without any adverse events in all neonates. Upon failure to achieve hemostasis with initial administration of blood products, fast intervention with rFVIIa could be considered in neonates with serious bleeding and coagulation disorders.

Recombinant activated factor VII for diffuse alveolar hemorrhage in microscopic polyangiitis

Diffuse alveolar hemorrhage is a serious complication of the small vessel vasculitis syndromes and carries a high mortality. Recombinant activated factor VII (rFVIIa) is a powerful hemostatic agent developed for treatment of bleeding in patients with hemophilia and antibodies to factors VIII or IX. It has been used increasingly in life-threatening hemorrhage in a variety of other settings in which conventional medical or surgical therapy is unsuccessful. We report the successful use of rFVIIa for massive pulmonary hemorrhage in a patient of microscopic polyangiitis, which was later complicated by thrombotic microangiopathy and posterior reversible encephalopathy syndrome.

Recombinant activated factor VII usage in life threatening hemorrhage: a pediatric experience

OBJECTIVE

To determine the safety and efficacy of off label usage of Recombinant activated factor VII (rFVIIa) in children with severe bleeding in non-hemophiliac children with diverse etiologies like leukemia, post hematopoietic stem cell transplantation, dengue shock syndrome and Glanzmann thrombasthenia.

METHOD

Medical records of 16 non-hemophiliac children with 20 bleeding episodes where rFVIIa was administered only after failure of standard measures to control bleeding were retrospectively reviewed and data collected regarding patient demographics, diagnosis and location of bleeding. Blood counts, coagulation and other lab parameters, both pre and post rFVIIa, were also noted. Severity of bleeding was assessed using a scoring system used previously by Nevo S et al. A record of usage of the amount of blood components (red blood cells, platelets, fresh frozen plasma, and cryoprecipitate) 24 h pre and post rFVIIa was also made. The dose of rFVIIa and any adverse side effects were recorded.

RESULTS

Bleeding sites were gastrointestinal (13/20), pulmonary hemorrhage (6/20) and intracranial hemorrhage (1/20). Thrombocytopenia (platelet count <50,000/cumm) was present in 50% episodes and five had refractory low platelets. Usage of packed red cells and platelets was significantly less after usage of rFVIIa (p value 0.001 and 0.006, respectively). Mean dosage of rFVIIa was 77 μgm/kg/dose (range 60 to 90 μgm/kg/dose). The bleeding stopped completely in 11(55%), decreased to minimal in 2 (10%), reduced but transfusions needed in 4 (20%) and did not stop in 3 (15%) episodes. Five patients (31%) did not survive the bleeding episode. None of the patients developed thrombosis.

CONCLUSIONS

rFVIIa appears to be safe and effective in controlling life-threatening bleed in non-hemophiliac children.

Recombinant activated factor VIIa treatment for refractory hemorrhage in infants

OBJECTIVE

Report clinical response to recombinant factor VIIa in a cohort of critically ill infants.

STUDY DESIGN

We identified all infants who received factor VIIa in the Duke Neonatal Intensive Care Unit between January 2005 and July 2008. Hematological data and volume of blood transfusions before and after factor VIIa treatment were compared. The precipitating diagnosis for each factor VIIa use, and the ensuing clinical outcomes of bleeding, thrombosis and mortality were noted.

RESULT

We identified 18 infants with median birth weight of 880 g and median gestational age of 26 weeks. One to six doses of factor VIIa (90 mcg kg(-1) per dose) were administered, with 13 (72%) infants receiving a single dose. Hemostasis was achieved in 13 (72%) of the infants. Prothrombin time and activated partial thromboplastin time significantly decreased following treatment with factor VIIa. Volume of plasma transfusions significantly decreased following treatment with factor VIIa (P=0.02). Thrombosis occurred in one (11%) infant. Six (33%) infants died within 72 h of treatment, and overall mortality was 10/18 (56%).

CONCLUSION

Treatment with factor VIIa at doses of 90 mcg kg(-1) improved coagulation studies and decreased the need for plasma transfusions in a group of critically ill infants without significant risk. Factor VIIa may be an effective addition to current treatment modalities for refractory hemorrhage in infants.

Thrombotic events in neonates receiving recombinant factor VIIa or fresh frozen plasma

BACKGROUND

Numerous recent reports have described the use of recombinant factor VIIa (rFVIIa) in non-hemophilia bleeding situations for achievement of hemostasis. However, its use in clinical situations other than hemophilia patients with inhibitors has been complicated by some reports of thrombotic events. rFVIIa has been used successfully to treat coagulopathic and/or bleeding neonates. The prevalence of thrombotic events in these neonates is completely unknown. This study was initiated to determine the risk of thrombotic events associated with rFVIIa use in neonates.

PROCEDURE

All published literature in non-hemophilic, non-congenital factor VII deficient neonates receiving rFVIIa was reviewed. In addition, all data submitted to the SeveN Bleep Registry, a web-based registry of rFVIIa uses in non-hemophilic children was analyzed. As the baseline risk of thrombotic events in bleeding and/or coagulopathic neonates is not known, we also reviewed the records of 100 consecutive neonates from a single institution who received fresh frozen plasma (FFP) alone to treat their coagulopathy and/or bleeding episode.

RESULTS

A total of 134 neonates received rFVIIa. Of these, 10 (7.5%) had a thrombotic event. The baseline risk of thrombotic events in neonates receiving FFP was 7%.

CONCLUSIONS

Overall the prevalence of thrombotic events in bleeding and/or coagulopathic neonates appears to be around 7%, whether or not they receive rFVIIa.

Fresh frozen plasma and recombinant factor VIIa use in neonates

BACKGROUND

Little recent data are available describing fresh frozen plasma (FFP) use in neonates. The purpose of this study was to determine the outcomes of FFP transfusions in neonates.

PATIENTS AND METHODS

A single institution, observational, and retrospective review of each transfusion of FFP given to neonates admitted to a neonatal intensive care unit over a 2-year period.

RESULTS

One hundred and seventy-three neonates were identified as having received FFP, giving a prevalence of FFP use at 12%. By far the most common determining factor for FFP use was an association with an abnormal activated partial thromboplastin time or prothrombin time (52%). Other factors included bleeding, invasive procedures, volume expansion, necrotizing enterocolitis, cardiopulmonary bypass, and hydrops fetalis. Of objectively accessible responses, FFP was able to correct abnormal coagulation tests into the normal range only 40% of the time. Twenty-four neonates received recombinant factor VIIa (rFVIIa) after first receiving FFP. The prevalence of thrombotic events was not higher in neonates receiving rFVIIa than those receiving FFP alone.

CONCLUSIONS

FFP was widely used in this neonatal unit. As data showing the predictive value of coagulation tests in neonates are discrepant, it is unclear if FFP was being appropriately used. Prospective, controlled data are required.

Coagulopathy screening and early plasma treatment for the prevention of intraventricular hemorrhage in preterm infants

BACKGROUND

Despite the improvement in the assistance and treatment of preterm infants, intraventricular hemorrhage (IVH) remains a frequent complication in these patients. Our aim was to demonstrate the hypothesis that a coagulopathy screening and the early treatment with fresh-frozen plasma (FFP) of proven coagulopathy may contribute to decrease the occurrence of IVH in infants with gestational age of less than 29 weeks.

STUDY DESIGN AND METHODS

This study compared two cohorts of infants who received FFP (10 mL/kg) after the evidence of pathologic coagulation tests performed within 2 hours after birth (screening group, n = 127) or after the development of bleedings and evidence of pathologic coagulation tests (no-screening group, n = 91).

RESULTS

The screening strategy decreased the relative risk (RR) of developing IVH (RR = 0.65; 95% confidence interval, 0.44-0.98) compared to no-screening strategy, but the effect was limited to infants born at 23 to 26 weeks of gestation in whom screening strategy lowered IVH occurrence (34.5% vs. 61.1%, p = 0.008).

CONCLUSIONS

A coagulopathy screening strategy decreases the risk of developing IVH in preterm infants but this effect is limited to infants born at 23 to 26 weeks of gestation.

Recombinant activated Factor VII as a hemostatic agent in very low birth weight preterms with gastrointestinal hemorrhage and disseminated intravascular coagulation

OBJECTIVE

Acute hemorrhage in preterm infants leads immediately to a life-threatening event because of the small circulating blood volume. The beneficial use of recombinant activated Factor VII (rFVIIa; NovoSeven, NovoNordisk, Gentofte, Denmark) as hemostatic treatment in neonates with hemorrhagic shock has been described. Necrotizing enterocolitis is a challenge in neonatology as the disease represents one of the leading causes of mortality in preterm infants. We report on the use of rFVIIa in very low birth weight (<1500 g), preterms with intestinal hemorrhage, and disseminated intravascular coagulation (DIC).

DESIGN

Retrospective analysis of 5 cases.

PATIENTS

Five preterm infants <or=28 weeks gestational age with DIC and hemorrhagic shock due to severe diffuse gastrointestinal bleeding.

INTERVENTION

Intravenous bolus administration of 100 to 180-microg/kg rFVIIa (total of 9 doses) as rescue procedure after other interventions (substitution of platelets, fresh frozen plasma, red packed cells, surgery) failed to achieve hemostasis.

RESULTS

Two patients with severe acidosis, hypothermia, and thrombopenia died in hemorrhagic shock, treatment with rFVIIa was unsuccessful. In 3 patients, rFVIIa was effective and gastrointestinal bleeding could be stopped. No acute adverse event, increasing bowel necrosis, increasing platelet consumption, or thromboembolic complications were observed.

CONCLUSIONS

In this small group of preterms with DIC, intestinal hemorrhage, and persistent hemorrhagic shock, rFVIIa was effective as a rescue therapy but failed in patients with severe acidosis, hypothermia, and thrombopenia.

Acquired Nonneoplastic Neonatal and Pediatric Diseases

The lung biopsy is an established procedure to procure a pathologic diagnosis in a child with a suspected pneumonic process of undetermined etiology. Improvements in pediatric anesthesia and surgery have reduced the operative complications to a minimum. A biopsy can usually be taken through a small intercostal incision when localization is not especially important in a patient with diffuse changes (see Chapter 1). The alternative method for tissue sampling is the endoscopic transbronchial biopsy. There is less risk to the patient, but the specimen is smaller and crush artifacts from the instrument are more common.

Is the use of rFVIIa safe and effective in bleeding neonates? A retrospective series of 8 cases

BACKGROUND

Recombinant activated factor VII (rFVIIa), originally developed for the treatment of life-threatening bleeding in hemophilic patients with inhibitors to factors VIII or IX, has been increasingly used to control hemorrhage unresponsive to conventional treatment, in the absence of a defined coagulopathy or thrombocytopathy. To date, clinical experience of rFVIIa administration in neonates, especially preterms, is rather limited, because of the lack of controlled studies and based solely on some published case reports and 1 prospective pilot study. The objective of this study was to retrospectively evaluate the clinical outcome of newborns treated with recombinant activated factor VII for intractable bleeding or severe coagulation disturbances, resistant to conventional hemostatic therapy.

METHODS

The medical records of 8 neonates treated with rFVIIa (100 micro g/kg) were retrospectively reviewed for the course of hemorrhage and the hemostatic interventions performed before and up to 24 hours after the administration rFVIIa. Coagulation parameters of 3 different time-points were assessed and compared: before administration of any blood product (time-point 1), before administration of the first dose of rFVIIa (time-point 2), and 4 hours after the administration of the last dose of rFVIIa (time-point 3). The safety and tolerability profile of rFVIIa in bleeding neonates was also evaluated.

RESULTS

Six preterm and 2 term patients were included in the study. Seven patients presented with refractory bleeding and 1 was diagnosed with severe coagulopathy unresponsive to the conventional treatment. Prompt hemostasis was achieved in half of the patients with their coagulation profile being restored within 4 hours after the administration of the first dose of rFVIIa. Improvement in prothrombin time, activated partial thromboplastin time, and fibrinogen after rFVIIa administration was statistically significant, as compared with that observed after conventional treatment. No major safety issues were observed during the study. All 8 patients survived and had their hemorrhage or coagulopathy controlled within 4 hours after transfusion of the last dose of rFVIIa.

CONCLUSIONS

In this study, the hemostatic agent rFVIIa was well-tolerated and behaved in a safe and efficacious manner in all infants treated for life-threatening bleeding and coagulation disorders. Future prospective controlled trials are needed to determine the efficacy, safety, tolerability, and possibly the optimal dose and timing of rFVIIa administration.

Recombinant activated factor seven in acute life-threatening bleeding in neonates: report on three cases and review of literature

INTRODUCTION

Acute bleeding of different genesis can be a severe, life-threatening problem in neonatology. Recombinant factor seven (rFVIIa) is known to have unique hemostatic properties in adults and older children.

CASE PRESENTATION

Three cases of acute life-threatening peri- and postnatal hemorrhage were successfully controlled after the application of fFVIIa. All infants were first treated with vitamin K, fresh-frozen plasma and platelet transfusion.

CONCLUSION

The cases substantiate other reports that rFVIIa is an effective treatment for acute, refractory and life-threatening bleeding in neonates and premature infants.

Recombinant factor VIIa for treatment of massive liver fracture in a premature infant

Recombinant factor VIIa (rFVIIa) is a highly efficacious therapy initially used to treat the bleeding diathesis of hemophiliac patients that has recently gained a wider role in the treatment of liver disease, thrombocytopenia, and intracerebral and traumatic hemorrhage. Data with regard to the use of rFVIIa within the pediatric population for the treatment of liver injury, however, are limited. We present a case report of successful treatment using rFVIIa of an iatrogenic liver injury in a 1200-g infant who was undergoing resection of a large sacrococcygeal teratoma. In addition, we review the issues of surgical relevance to the pediatric surgeon relating to rFVIIa's mechanism of action and dosages for clinical application.

Recombinant activated factor VII (rFVIIa) treatment in infants with hemorrhage

BACKGROUND

Recombinant activated factor VII (rFVIIa) is approved by the FDA for the treatment of bleeding episodes in patients with hemophilia A or B with inhibitors to factor VIII or factor IX. In addition to the FDA-approved indications, rFVIIa has been anecdotally reported effective for profound bleeding episodes in adult patients without hemophilia, and proven beneficial for adults with intracranial hemorrhage. In the pediatric literature, case reports have been made with apparent clinical improvement seen after the use of rFVIIa for acute life-threatening bleeding; however, there are limited data regarding its use in infants<4 months of age. We report our experience with rFVIIa in nine infants with severe hemorrhage of diverse etiologies.

METHODS

This case series of infants under 4 months with coagulopathy and bleeding treated with rFVIIa was collected from two institutions. We report the age, weight and pre-rFVIIa laboratory values of the patients as well as the clinical scenario and outcomes.

RESULTS

The nine infants all suffered acute life-threatening hemorrhage. Two patients were postoperative from cardiac surgery, two with Vitamin K deficiency and intracranial hemorrhage, three with suspected necrotizing enterocolitis and abdominal hemorrhage, and two with pulmonary hemorrhage. The patients ranged in age from 2 days to 4 months, (average age 1 month and average weight 3.3+/-1.0 kg). Seven of the nine patients had frozen plasma, cryoprecipitate, or platelet administration in failed attempts to correct the coagulation defect prior to receiving rFVIIa. The dose range used in this series was 90-100 microg.kg-1, with 90 microg.kg-1 being the most commonly used dose. The average pre-rFVIIa INR was 8.7+/-5.1. Four patients had an immeasurably high INR. All patients had clinical resolution of bleeding after receiving rFVIIa, and seven of nine patients survived.

CONCLUSIONS

rFVIIa is a powerful hemostatic drug whose mechanism of action provides a theoretical specificity to sites of tissue injury. In addition to its FDA-approved uses in hemophiliac patients, this drug has a potential role in the treatment of life-threatening hemorrhage from multiple causes.

Recombinant factor VIIa in paediatric bleeding disorders ? a 2006 review

Recombinant factor VIIa (rFVIIa) has been used in haemophilia bleeding since its introduction in 1996. It has been found to be safe and effective in the majority of patients with haemophilia who have developed inhibitors. There is increasing use of rFVIIa in many off-label bleeding conditions, but there is a paucity of randomized studies regarding the use of rFVIIa in children. This review will attempt to address and summarize the studies focusing on the role of rFVIIa in both haemophilia and non-haemophilia bleeding conditions in children. rFVIIa has been administered as both bolus and continuous infusions, and at varying doses. Furthermore, adverse events have not reportedly increased in children despite growing experience with its use in the paediatric population.

Prevention of intraventricular haemorrhage: a role for recombinant activated factor VII?

As the survival from extreme prematurity continues to improve, focus on the quality of this survival becomes increasingly important. Prevention of intraventricular haemorrhage (IVH) and its potential long-term sequelae remains one of the major challenges in the early management of these infants. Recombinant activated factor VII (rVIIa), a novel haemostatic agent with an ever-expanding list of potential applications, warrants consideration for use in this setting. This review examines the pathogenesis and prevention of IVH, current concepts of haemostasis both in adults and neonates, and the postulated mechanism of action and various uses of rVIIa. Published data specifically relating to use of rVIIa in neonates is summarised. The hypothesis that early (prophylactic) administration of rVIIa to extremely preterm infants (<28 weeks) would reduce the incidence of severe IVH is explored.

A prospective pilot study of prophylactic treatment of preterm neonates with recombinant activated factor VII during the first 72 hours of life

OBJECTIVE

Intraventricular hemorrhage (IVH) in the preterm infant is a devastating complication, causing marked mortality and morbidity. A general hemostatic agent such as recombinant activated factor VII (rFVIIa) might have the potential to reduce the extent of severe IVH.

DESIGN

Prospective, single-arm pilot study.

SETTING

Level III neonatal intensive care unit.

PATIENTS

Ten preterm infants between 23 and 28 wks of gestation.

INTERVENTION

Administration of a 100-microg/kg rFVIIa bolus injection within the first 2 hrs of life, followed by 100 microg/kg rFVIIa every 4 hrs, for the first 72 hrs of life.

MEASUREMENTS AND MAIN RESULTS

Cranial ultrasonography and flow studies of the major arteries and the venae cava, aorta, vena portae, and venae renales, was performed at study enrollment and at 12 hrs, 24 hrs, 48 hrs, and 72 hrs. Blood cell counts and coagulation studies were performed. End points of the study were occurrences of adverse events, with an emphasis on thrombotic events or disseminated intravascular coagulation (DIC). Ten preterm infants with a gestational age of 23 wks 1 day to 28 wks 3 days were included. None had venous thrombosis or cerebral infarction during or after the treatment. Neither platelet consumption nor DIC was observed. Two infants with an umbilical artery catheter had a thrombus at the catheter tip (one during infusion of the study drug), which was successfully treated with heparin. One had grade III IVH and died on day 6 of life; in another, grade II IVH progressed to grade III after termination of the drug.

CONCLUSION

One hundred microg/kg rFVIIa does not accumulate if administered prophylactically to preterm infants of <28 wks of gestation every 4 hrs in the first 72 hrs of life. In this population, rFVIIa does not cause DIC. Thrombus formation was observed in two infants with umbilical artery catheters but in none of the infants with venous catheters. Embolic events were not observed. In this pilot study, which did not provide the sample size to assess any effect of rFVIIa on the incidence of IVH, 20% of the neonates went on to have grade III or IV IVH, which is similar to the rate in studies in which rFVIIa was not given.

Platelet function in term and preterm neonates

Platelet dysfunction likely contributes to the pathophysiology of catastrophic hemorrhages in preterm neonates. In vitro studies have demonstrated that platelets of both term and preterm neonates are hyporesponsive to a variety of agonists. In contrast,template bleeding times of term neonates are shorter than those from adults. Very little is known about this and other tests of primary hemostasis in premature and sick neonates in the neonatal intensive care unit (NICU). This article covers the current knowledge of platelet function in preterm and term neonates and review show new agents (such as recombinant thrombopoietin and recombinant factor VIIa) may enhance neonatal platelet function.

Safety profile of recombinant factor VIIa

Recombinant factor VIIa (rFVIIa; NovoSeven(R), Novo Nordisk, Bagsvaerd, Denmark) has been used for many years in the successful management of bleeding episodes in patients with hemophilia and inhibitors. More recently, rFVIIa has also shown considerable success as a hemostatic agent in trauma and surgery patients without pre-existing coagulopathy. Despite extensive and varied usage of rFVIIa, the incidence of serious adverse events associated with its use is less than 1%; however, there remain concerns regarding the agent's potential to induce thrombosis. This paper will review the safety profile of rFVIIa by examining existing clinical evidence, and will demonstrate that the isolated thrombotic events reported following rFVIIa treatment are due primarily to an improvement in the coagulation mechanism rather than rFVIIa treatment per se. The demonstrated safety of rFVIIa is probably due to its localization to injured areas of the vascular tree by binding to tissue factor (TF) and activated platelets at the bleeding site, thus avoiding systemic activation of coagulation. Finally, those situations in which rFVIIa therapy may not be safe, such as disseminated intravascular coagulation (DIC) and sepsis, will also be discussed.