Intrabronchial administration of activated recombinant factor VII in a young child with diffuse alveolar hemorrhage

Intrapulmonary administration of recombinant activated factor VII in pediatric, adolescent, and young adult oncology and hematopoietic cell transplant patients with pulmonary hemorrhage

Introduction

Diffuse alveolar hemorrhage (DAH) is a devastating disease process with 50-100% mortality in oncology and hematopoietic cell transplant (HCT) recipients. High concentrations of tissue factors have been demonstrated in the alveolar wall in acute respiratory distress syndrome and DAH, along with elevated levels of tissue factor pathway inhibitors. Activated recombinant factor VII (rFVIIa) activates the tissue factor pathway, successfully overcoming the tissue factor pathway inhibitor (TFPI) inhibition of activation of Factor X. Intrapulmonary administration (IP) of rFVIIa in DAH is described in small case series with successful hemostasis and minimal complications.

Methods

We completed a single center retrospective descriptive study of treatment with rFVIIa and outcomes in pediatric oncology and HCT patients with pulmonary hemorrhage at a quaternary hematology/oncology hospital between 2011 and 2019. We aimed to assess the safety and survival of patients with pulmonary hemorrhage who received of IP rFVIIa.

Results

We identified 31 patients with pulmonary hemorrhage requiring ICU care. Thirteen patients received intrapulmonary rFVIIa, while eighteen patients did not. Overall, 13 of 31 patients (41.9%) survived ICU discharge. ICU survival (n=6) amongst those in the IP rFVIIa group was 46.2% compared to 38.9% (n=7) in those who did not receive IP therapy (p=0.69). Hospital survival was 46.2% in the IP group and 27.8% in the non-IP group (p=0.45). There were no adverse events noted from use of IP FVIIa.

Conclusions

Intrapulmonary rFVIIa can be safely administered in pediatric oncology patients with pulmonary hemorrhage and should be considered a viable treatment option for these patients.

Life-Threatening Subglottic Thrombus Formation after Administration of Nebulized Tranexamic Acid

We present a case of subglottic thrombus formation after administration of nebulized tranexamic acid (TXA) for postoperative hemoptysis following CO2 laser wedge excision of subglottic stenosis. Although other factors certainly could have resulted in postoperative bleeding and subsequent thrombus formation, the patient's rapid decompensation following administration of nebulized TXA suggests a direct effect. We recommend implementing an airway action plan regarding TXA use for patients presenting to the emergency department with postoperative hemorrhage following otolaryngology procedures. Laryngoscope, 134:1356-1358, 2024.

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.

Diffuse Alveolar Hemorrhage After Pediatric Hematopoietic Stem Cell Transplantation

Pulmonary complications are common following hematopoietic cell transplantation (HCT) and contribute significantly to its morbidity and mortality. Diffuse alveolar hemorrhage is a devastating non-infectious complication that occurs in up to 5% of patients post-HCT. Historically, it carries a high mortality burden of 60–100%. The etiology remains ill-defined but is thought to be due to lung injury from conditioning regimens, total body irradiation, occult infections, and other comorbidities such as graft vs. host disease, thrombotic microangiopathy, and subsequent cytokine release and inflammation. Clinically, patients present with hypoxemia, dyspnea, and diffuse opacities consistent with an alveolar disease process on chest radiography. Diagnosis is most commonly confirmed with bronchoscopy findings of progressively bloodier bronchoalveolar lavage or the presence of hemosiderin-laden macrophages on microscopy. Treatment with glucocorticoids is common though dosing and duration of therapy remains variable. Other agents, such as aminocaproic acid, tranexamic acid, and activated recombinant factor VIIa have also been tried with mixed results. We present a review of diffuse alveolar hemorrhage with a focus on its pathogenesis and treatment options.

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.

Pilot trial of a novel two-step therapy protocol using nebulized tranexamic acid and recombinant factor VIIa in children with intractable diffuse alveolar hemorrhage

BACKGROUND AND OBJECTIVES

Diffuse alveolar hemorrhage (DAH) is a life threatening condition with very limited, often unsuccessful, therapeutic options. This study aimed at exploring the feasibility and efficacy of nebulized tranexamic acid TXA (n-TXA) and nebulized recombinant factor VIIa (n-rFVIIa) when used in a two-step therapy protocol in children with intractable DAH in a pediatric intensive care unit.

METHODS

In a prospective trial, n-TXA (250 mg/dose for children < 25 kg and 500 mg/dose for children > 25 kg) was administered to 18 children (median age [interquartile range]; 24.0 months [11.3, 58.5]) with intractable DAH. N-rFVIIa (35 micro g/kg/dose for children < 25 kg, and 50 micro g/kg/dose for children > 25 kg) was added if no or minimal response was seen after 3 to 4 doses (18 to 24 hours) of n-TXA.

RESULTS

DAH was stopped in 10 (55.6%) children with n-TXA alone within 24 hours of therapy. Documented concomitant respiratory infection showed a significant negative association with response to n-TXA in a step.wise regression analysis (OR=0.06; 95% CI=0.01-0.74). In the other 8 (44.4%) children, n-rFVIIa was added due to n-TXA failure. Six (75.0%) showed complete cessation of DAH, while two children failed to respond with the addition of n-rFVIIa (25.0%). None of the children who responded to therapy showed recurrence of DAH after therapy termination. No complications related to therapy were recorded.

CONCLUSIONS

n-TXA and n-rFVIIa were effective and safe when used in a two-step-therapy protocol to control intractable DAH in pediatric patients in intensive care settings. This therapy modality warrants further exploration through larger multicenter clinical trials.