Successful Initiation of Veno-Venous ECMO At Teynampet ,APOLLO CHILDRENS HOSPITAL
Successful Initiation of Veno-Venous At Teynampet , APOLLO CHILDRENS HOSPITAL, ECMO Without Systemic Anticoagulation in a Pediatric Patient With Post-Transplant Idiopathic Pulmonary Syndrome and Severe Pulmonary Hemorrhage
Abstract
Background: Idiopathic pulmonary syndrome (IPS) is a rare but life-threatening complication following hematopoietic stem cell transplantation (HSCT), with limited therapeutic options. The use of extracorporeal membrane oxygenation (ECMO) in this population is controversial due to bleeding risk, immunosuppression, and historically poor outcomes.
Case Presentation: We report a 5-year-old girl with beta thalassemia major and significant pre-existing comorbidities who developed severe IPS following autologous HSCT. Her clinical course was complicated by refractory hypoxemic respiratory failure, pulmonary hemorrhage, disseminated intravascular coagulation, and acute kidney injury requiring continuous renal replacement therapy (CRRT). Given progressive hypoxemia despite maximal ventilatory support, she was supported with veno-venous ECMO without systemic anticoagulation. Meticulous circuit surveillance and targeted transfusion strategies were employed. Adequate gas exchange was achieved, allowing lung-protective ventilation.
Conclusion: This case highlights the feasibility of VV ECMO without systemic anticoagulation in a high-risk pediatric post-HSCT patient with severe pulmonary hemorrhage and IPS, emphasizing careful patient selection and multidisciplinary management.
Introduction
Idiopathic pulmonary syndrome (IPS) is a noninfectious pulmonary complication characterized by widespread alveolar injury and hypoxemia occurring after HSCT. Mortality rates exceed 60%, particularly in patients requiring mechanical ventilation. The role of ECMO in this setting remains controversial due to concerns regarding bleeding, infection, graft-versus-host disease (GVHD), and limited survival data. We describe the successful application of veno-venous (VV) ECMO without systemic anticoagulation in a pediatric patient with IPS and life-threatening respiratory failure following HSCT.
Case Presentation
A 5-year-old girl with beta thalassemia major, born to parents who were both thalassemia carriers, had a complex medical history including pulmonary hypertension, acute respiratory distress syndrome, chronic kidney disease, and gastrojejunal tube dependence. She presented with bone marrow failure and underwent autologous hematopoietic stem cell transplantation.
Pre-transplant evaluation demonstrated normal nuclear medicine glomerular filtration rate and preserved cardiac function. Her hematopoietic cell transplant–comorbidity index (HCT-CI) score was 6, with severe baseline pulmonary disease (forced expiratory volume in 1 second [FEV1] 54.5%).
Post-Transplant Course
On day +17 post-transplant, the patient developed adenovirus DNAemia, which was successfully treated with cidofovir and an unmanipulated donor lymphocyte infusion (DLI; CD3⁺ 5 × 10⁴/kg) on day +23.
On day +40, she developed fever, cough, and progressive respiratory distress. Laboratory evaluation showed stable blood counts with mild anemia and a modestly elevated C-reactive protein. She was transferred to the pediatric intensive care unit (PICU) and initially managed with high-flow nasal cannula oxygen. Progressive hypoxemia necessitated endotracheal intubation and mechanical ventilation on day +41.
Chest radiography revealed diffuse bilateral pulmonary infiltrates. Despite escalation to high-frequency oscillatory ventilation (HFOV) with inhaled nitric oxide, oxygenation continued to deteriorate. Bronchoscopy with bronchoalveolar lavage showed no evidence of diffuse alveolar hemorrhage. Echocardiography demonstrated normal biventricular function without worsening pulmonary hypertension.
Given the absence of infection and cardiac dysfunction, IPS was diagnosed, and treatment with intravenous methylprednisolone (1 mg/kg/day) was initiated.
ECMO Initiation
Due to refractory hypoxemia and a persistently elevated oxygenation index (up to 62), ECMO candidacy was discussed. Although the patient was high risk, ECMO was pursued given successful engraftment, absence of GVHD, intact neurologic status, and lack of neutropenia.
On day +42, she was cannulated for VV ECMO via the femoral vein (15-Fr venous cannula; Medtronic) with return via the right internal jugular vein (14-Fr arterial cannula). ECMO support was initiated using a centrifugal pump and polymethylpentene membrane oxygenator (Quadrox; Maquet). Flows were gradually increased to a maximum of 1,650 mL/min (100 mL/kg/min), with sweep gas flow of 2 L/min at 100% oxygen. Oxygenation improved immediately following cannulation.
| Ventilator Parameter | Strategy During ECMO |
| Ventilation Mode | Pressure-controlled ventilation |
| Peak Inspiratory Pressure (PIP) | 20 cmH₂O |
| Positive End-Expiratory Pressure (PEEP) | 8 cmH₂O |
| Respiratory Rate | 10 breaths per minute |
| Pressure Support | 10 cmH₂O |
| Fraction of Inspired Oxygen (FiO₂) | 30% |
| Ventilatory Goal | Minimize ventilator-induced lung injury while maintaining alveolar recruitment |
| Oxygenation Strategy | Primary oxygenation and carbon dioxide removal achieved via VV ECMO |
| Radiologic Monitoring | Serial chest radiographs used to monitor pulmonary disease progression, avoiding computed tomography to limit radiation exposure |
Anticoagulation Strategy and Complications
The patient developed severe pulmonary hemorrhage, disseminated intravascular coagulation, thrombocytopenia, and stage 3 acute kidney injury requiring CRRT while on ECMO. Given the high bleeding risk, ECMO was managed without systemic heparin anticoagulation. The circuit was heparin-bonded, and activated clotting time (ACT) was maintained around 180 seconds without anticoagulant infusion.
Platelet counts were maintained above 40,000/µL, and fibrinogen levels above 200 mg/dL with transfusion support. The ECMO circuit was visually inspected every 12 hours for thrombus formation, and transmembrane pressure gradients were monitored daily and remained within normal limits (<40 mmHg). No circuit thrombosis occurred.
Pulmonary disease progression was monitored primarily with serial chest radiographs to limit radiation exposure.
Discussion
Pulmonary complications are a significant cause of morbidity and mortality following HCT. Our patient developed IPS, leading to acute respiratory distress syndrome (ARDS) and respiratory failure. Most ARDS cases in their cohort developed around the time of engraftment, a period of increased inflammation that can involve immune dysregulation . Our patient was outside the engraftment period. However, she received an unmanipulated DLI which could have contributed to increased inflammation and immune dysregulation.
Previous reports describing poor ECMO outcomes in HCT recipients had resulted in this cohort of patients being considered poor candidates for ECMO. However, previous studies relied on retrospective reports, utilization of database information with potential inherent reporting bias, and limited patient numbers. The paucity of randomized controlled trials in pediatric HCT patients receiving ECMO, relatively limited patient data available for study, and lack of reliable prognostic prediction models have limited the consistency of which ECMO is offered to pediatric HCT patients .
Idiopathic Pulmonary Syndrome remains a devastating complication following HSCT, with limited effective therapies. Corticosteroids remain the mainstay of treatment, though outcomes in severe cases requiring mechanical ventilation are poor. ECMO has traditionally been avoided in post-transplant patients due to bleeding risk, infection, and poor historical survival rates.
Recent case series suggest that carefully selected pediatric patients may benefit from ECMO, particularly when used as a bridge to pulmonary recovery. This case demonstrates that VV ECMO without systemic anticoagulation may be feasible in the setting of active pulmonary hemorrhage, provided that meticulous circuit monitoring and aggressive hemostatic management are employed. Recent pediatric acute lung injury sepsis investigator (PALISI) network survey data showed that 99.5% of respondents stated that they would consider ECMO for pediatric HCT patients, and 95.7% reported that "every HSCT patient is unique; thus candidacy for ECMO should be considered on an individual basis", with only 0.5% considering HCT an absolute contraindication.
Pediatric HCT patients comprise a heterogeneous population with various underlying medical conditions, which complicates the application of uniform recommendations for ECMO utilization in this population. The most crucial considerations during the evaluation of pediatric HCT patients for ECMO candidacy are the reversibility of the underlying etiology causing cardiopulmonary compromise and the ability to initiate ECMO prior to the onset of irreversible organ damage.
The use of heparin-bonded circuits, high ECMO flows, and frequent surveillance allowed adequate oxygenation without thrombotic complications.
Conclusion
This case supports the consideration of VV ECMO as rescue therapy for severe IPS in selected pediatric post-HSCT patients, even in the presence of significant bleeding risk. ECMO without systemic anticoagulation may be a viable strategy when managed by an experienced multidisciplinary team.