Fatal thrombosis with activated factor VII in a paediatric patient on extracorporeal membrane oxygenation

Intraoperative Management of Adult Patients on Extracorporeal Membrane Oxygenation: An Expert Consensus Statement From the Society of Cardiovascular Anesthesiologists-Part II, Intraoperative Management and Troubleshooting

In the second part of the Society of Cardiovascular Anesthesiologists Extracorporeal Membrane Oxygenation (ECMO) working group expert consensus statement, venoarterial (VA) and venovenous (VV) ECMO management and troubleshooting in the operating room are discussed. Expert consensus statements are provided about intraoperative monitoring, anesthetic drug dosing, and management of intraoperative problems in VA and VV ECMO patients.

Challenges with Navigating the Precarious Hemostatic Balance during Extracorporeal Life Support: Implications for Coagulation and Transfusion Management

For the past four decades, extracorporeal life support (ECLS) has been used to treat critically ill adult and pediatric patients with cardiac and/or respiratory failure, and there are increasingly numbers of centers worldwide performing ECLS for numerous indications. Despite the progress with advancing the technology, hemorrhagic and thrombotic complications are frequently reported and associated with worse outcomes, but the exact cause is often elusive or multifactorial. As a result of the interaction between blood and an artificial circuit, anticoagulation is necessary and there is resultant activation of coagulation, fibrinolysis, as well as, an increased inflammatory response. While unfractionated heparin (UFH) remains the mainstay anticoagulant used during ECLS, there is a paucity of published data to develop a universal anticoagulation guideline and centers are forced to create individualized protocols to guide anticoagulation management while lacking expertise. From an international survey, centers often use a combination of tests, which in turn result in discordant results and confused management. Studies are urgently needed to investigate optimization of current anticoagulation strategies with UFH, as well as, use of alternative anticoagulants and non-thrombogenic biomaterials. Blood transfusion during extracorporeal support typically occurs for several reasons, which includes circuit priming, restoration of oxygen carrying capacity, maintenance of a hemostatic balance, and treatment of hemorrhagic complications. As a result, the majority of patients will have been exposed to at least one blood product during extracorporeal support and transfusion utilization is high. ECLS Centers have adopted transfusion thresholds based upon practice rather than evidence as there have been no prospective studies investigating the efficacy of red cell (RBC) transfusion in patients receiving extracorporeal support. In addition, RBC transfusion has been associated with increased mortality in ECLS in several retrospective studies. Additional studies are needed to establish evidence based thresholds for transfusion support and diagnostics to guide transfusion therapy to assess efficacy of transfusion in this population, as well as, exploration of alternatives to transfusion.

Extracorporeal membrane oxygenation-hemostatic complications

The use of extracorporeal membrane oxygenation (ECMO) support for cardiac and respiratory failure has increased in recent years. Improvements in ECMO oxygenator and pump technologies have aided this increase in utilization. Additionally, reports of successful outcomes in supporting patients with respiratory failure during the 2009 H1N1 pandemic and reports of ECMO during cardiopulmonary resuscitation have led to increased uptake of ECMO. Patients requiring ECMO are a heterogenous group of critically ill patients with cardiac and respiratory failure. Bleeding and thrombotic complications remain a leading cause of morbidity and mortality in patients on ECMO. In this review, we describe the mechanisms and management of hemostatic, thrombotic and hemolytic complications during ECMO support.

[Use of rFVIIa in intractable hemorrhage in patients on central veno-arterial ECMO]

OBJECTIVE

The purpose of our study is to describe the use of recombinant factor VIIa (rFVIIa) in patients on central veno-arterial ECMO with a particular attention on associated thrombotic complications.

STUDY DESIGN

Monocentric retrospective study.

PATIENTS AND METHODS

We examined 91 files of patients on ECMO between 2005 and 2010. During this period, eight patients presented refractory bleeding and benefited from rFVIIa treatment.

RESULTS

In six of the eight patients, the bleeding stopped. A decrease of the bleeding was noticed after the treatment of rFVIIa (before rFVIIa: 40.1±33.1mL/kg per 3 hours after rFVIIa: 5.4±3.2mL/kg per 3 hours (P=0.01). The transfusional needs were decreased after administration of rFVIIa. No thrombotic event was detected. Fibrinogen, d-dimers, platelet count and lactate were not modified by the treatment. Two patients were weaned from ECMO. One patient died 17 days after the weaning. The other patient survived without neurological damages.

CONCLUSION

The rFVIIa is a treatment of exception for patients on central veno-arterial ECMO and could be a last-resort treatment in the presence of a not curable massive bleeding.

Safety and efficacy of recombinant activated factor VII for refractory hemorrhage in pediatric patients on extracorporeal membrane oxygenation: a single center review

Background:

Medically refractory hemorrhage in patients on ECMO (extracorporeal membrane oxygenation) support can have catastrophic complications. Recombinant-Activated Factor VII (rFVIIa; NovoSeven®) may provide lifesaving hemostasis; however, there are reports of catastrophic thrombosis related to its administration.

Objective:

This review attempts to add safety and efficacy data to existing literature regarding the use of rFVIIa for refractory hemorrhage in pediatric patients on ECMO support.

Design/Methods:

A retrospective chart review was performed for all pediatric patients on ECMO who received rFVIIa for refractory hemorrhage from 2004 to 2009. Data was extracted for each refractory bleeding event, including patient blood loss and transfused blood products in the 6 hours before the first dose, between rFVIIa doses and in the 6 hours after the final dose. For purposes of data collection, a hemorrhagic event was defined as new onset hemorrhage or a hemorrhage occurring at least 12 hours after the most recent dose of rFVIIa.

Results:

In total, seven patients aged 1 month to 15 years received rFVIIa for 14 different hemorrhagic events. There was no significant difference in blood loss or blood product transfusion associated with rFVIIa administration. There was one patient-related and one ECMO-related complication temporally associated with rFVIIa administration: decreased ECMO circuit oxygenator efficiency and the development of an intra-gastric clot requiring surgical evacuation.

Conclusion:

These data suggest limited efficacy for rFVIIa use for refractory hemorrhage in pediatric patients on ECMO support. There were two non-catastrophic complications temporally associated with its administration.

Recombinant factor VIIa for uncontrollable bleeding in patients with extracorporeal membrane oxygenation: report on 15 cases and literature review

Introduction

Bleeding is the most frequent complication in patients receiving venoarterial or venovenous extracorporeal membrane oxygenation (ECMO). Recombinant activated factor VII (rFVIIa) has been used in these patients with conflicting results. We describe our experience with rFVIIa for refractory bleeding in this setting and review the cases reported in the literature.

Methods

Clinical characteristics, demographics, bleeding, thrombotic complications, mortality, and rFVIIa administration were retrospectively collected for analysis from the electronic charts of the 15 patients in our intensive care unit who received rFVIIa while being given ECMO from January 2006 to March 2011.

Results

Fifteen patients received rFVIIa for persistent bleeding under venoarterial (n = 11) or venovenous (n = 4) ECMO. Bleeding dramatically decreased in 14 patients, without a major thrombotic event, except in one patient in whom a major stroke could not be ruled out. Two circuits were changed within the 48 hours after rFVIIa administration for clots in the membrane and decreased oxygenation but without massive clotting. The mortality rate was 60%.

Conclusions

rFVIIa use for intractable hemorrhaging in patients receiving ECMO controlled bleeding, without major thrombotic events, and with 60% dying. Hence, its use warrants discussion, and clinicians should be aware of the possibility of potentially life-threatening systemic thrombosis, emboli, or circuit clotting. Whether rFVIIa can save the lives of such patients remains to be determined.

Controlling intrathoracic hemorrhage on ECMO: help from Factor VIIa and Virchow

Objective:

Thoracentesis with chest tube placement is often needed to decompress a clinically significant pneumothorax or pleural effusion. The risks of such a procedure may be considered too great to perform on a systemically anticoagulated patient supported by extracorporeal membrane oxygenation (ECMO).

Results:

An 8-year-old child with respiratory failure due to necrotizing pneumonia and autoimmune vasculitis, on veno-venous ECMO, developed a severe tension pneumothorax that required emergent decompression with a chest tube. Post-procedure, the patient developed a hemothorax that was approaching non-sustainability. We developed a strategy based on Virchow’s triad to favor homeostasis in the patient while avoiding thrombosis in the ECMO circuit. We employed selective lung ventilation, passive pleural drainage, high flow ECMO, and aggressive coagulation cascade control, including the use of aminocaproic acid and activated factor VIIa. Following this strategy, the hemorrhage was controlled and, later, the patient was able to successfully come off ECMO.

Conclusions:

With careful coagulation cascade manipulation, complete lung rest for the affected lung, control of ECMO blood flow, and prudent hemothorax drainage, we were able to facilitate hemostasis that was required for the successful recovery of our patient while avoiding critical ECMO circuit thrombosis. Even with today’s highly advanced medical technologies, centuries-old basic medical principles can still assist in the care of our sickest and most complex patients. Chest tube placement while on ECMO is rare and, although necessary, may be a risky procedure. With precise coagulation control, it can be a successful procedure on ECMO.

Defining the role of recombinant activated factor VII in pediatric cardiac surgery: where should we go from here?

OBJECTIVES

Postoperative hemorrhage is a recognized complication of pediatric cardiac surgery. Both the immature coagulation system and increased susceptibility to hemodilution increase the likelihood of pediatric patients developing coagulopathy when compared with adult counterparts. Treatment options remain limited. Recombinant factor VII (rFVIIa) is a hemostatic agent increasingly used to reduce hemorrhage in other surgical settings, the role of which is unclear in this population. This article systematically reviews the published literature on the use of rFVIIa in pediatric cardiac surgery.

DATA SOURCES AND STUDY SELECTION

A systematic literature search identified reports of rFVIIa administration in pediatric patients undergoing cardiac surgery. Where possible, individual patient-specific data were extracted and pooled statistical analysis was performed.

DATA EXTRACTION AND SYNTHESIS

Twenty-nine articles reporting on the administration of rFVIIa to 169 patients were identified. rFVIIa has been administered to patients with predefined congenital abnormalities of hemostasis to arrest hemorrhage refractory to other interventions and prophylactically in the hope of reducing blood loss. Treatment regimens vary widely, in terms of both first and cumulative dose. Data on chest tube blood loss and two markers of coagulation were pooled and analyzed, and significant improvements were demonstrated. Mortality was 4.4% for the entire cohort but 20% of patients on extracorporeal membrane oxygenation suffered significant thromboembolic complications.

CONCLUSIONS

rFVIIa has an increasingly accepted role in the management of patients with congenital coagulopathies undergoing major surgery. However, randomized trials are required to define the role of rFVIIa as an adjunct to control major hemorrhage in the pediatric cardiac surgical population. Any future work must focus not only on benefits but also on patient safety, particularly, risk of morbid thromboembolic complication.

How to replace an extracorporeal life support without interruption of the cardiopulmonary assistance

The extracorporeal life support (ECLS) allows a maximum of a few weeks of cardio-respiratory assistance. Using standard ECLS, the circuit must be replaced after a few days or sometimes more frequently, in case of dysfunction. Classically, the replacement needs the interruption of the support inducing a temporarily hemodynamic instability. We report a simple technique, allowing this replacement without interruption of the assistance, based on the implantation of a new circuit in parallel. We describe the original modification, the complete procedure and our results. This method has been used in 34 ECLS replacements in 14 patients without any incident or thrombo-embolic events. This simple technique is safe, reliable, and avoids the hemodynamic instability induced by classical replacements.