International Observational Study on BLood Management for Mechanical Circulatory Support Using Extracorporeal Membrane Oxygenation (OBLEX)
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Enrollment
- 561
- Locations
- 1
- Primary Endpoint
- Hospital mortality
Study Overview
Brief Summary
Extracorporeal membrane oxygenation (ECMO) is a lifesaving procedure used to treat severe forms of heart and/or lung failure. It works by the principal of replacing the function of these organs by taking blood from the patient, provide it with oxygen outside the body and return it to the patient in one continuous circuit. Because of the evaluability of better technology, the use of ECMO has exponentially risen over the last decade. This treatment is very invasive and carries a number of risks. It is mostly used in situations where it seems likely that the patient would otherwise die and no other less invasive measure could change this. Still in large registries 50-60% of patients die which is often due to complications associated with the treatment.
One of the most important complication is caused by the activation of clotting factors during the contact with the artificial surfaces of the device. This can lead to clot formation inside the patient or the device. To counterbalance this anticoagulation is needed. Because of the consumption of clotting factors and the heparin therapy bleeding complications are also very common in ECMO.
Clinicians are challenged to balance these competing risks and are often forced to transfuse blood products to treat these conditions, which comes with additional risks for the patient. Many experienced centres have reported thromboembolic and bleeding events as the most important contributor to a poor outcome of this procedure. However, no international study combining the experience of multiple centres to compare their practice and identify risk factors which can be altered to reduce these risks.
This study has been endorsed by the international ECMONet and aims to observe the practice in up to 50 centres and 500 patients worldwide to generate the largest ever published database on this topic. It will concentrate on patients with severe heart failure and will be able to identify specific risk factors for thromboembolic and bleeding events. Some of these factors may be modifiable by change in practice and can subsequently be evaluated in clinical trials. Some of these factors may include target values for heparin therapy and infusion of clotting factors.
This study will directly improve patient management by informing clinicians which measures are associated with the best outcome and indirectly helps building trials to increase the evidence further.
Detailed Description
Background:
Extracorporeal Membrane Oxygenation (ECMO) is the most frequently used mechanical circulatory support (MCS) for severe forms of cardiogenic shock (CS) when simpler measures like inotropes and the intra-aortic balloon pump fail. Despite improvements in technology and growing clinical experience mortality among patients supported with ECMO remains above 40%. In addition to bloodstream infections and circuit-related complications, disorders of coagulation which can result in life-threatening hemorrhage, thrombosis and thromboembolic events remain the most frequent and dangerous complications.
Significant perturbations in hemostatic function are seen during extracorporeal therapies. The mechanisms of these are complex and relate to underlying pathology, blood-surface contact and pump mechanics. They are evidenced by platelet dysfunction and consumption, hyperfibrinolysis or coagulopathy secondary to disseminated intravascular coagulation (DIC).
Given the multifactorial disturbances of hemostasis that can result in hemorrhage during ECMO, standard laboratory hemostatic testing may not enable the clinician to specify the underlying cause of the bleeding. Consequently, bleeding events are typically managed with transfusion of coagulation factors guided by clinician judgment.
Anticoagulation practice itself may also determine the bleeding risk and it has been noted that practice is variable. Heparin dosage and titration as well as stopping rules are not well defined and vary vastly in the literature.
Study Design
- Study Type
- Observational
- Observational Model
- Cohort
- Time Perspective
- Prospective
Eligibility Criteria
- Ages
- 18 Years to — (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •ECMO for mechanical circulatory support
- •ECMO using a temporary device containing an oxygenator and an active blood pump.
Exclusion Criteria
- •ECMO for respiratory support only
- •ECMO treatment outside the participating centre for >24 hours
- •Previous enrolment in OBLEX during the same hospital admission
- •ECMO treatment outside the intensive care unit only (e.g. theatre or angiography)
- •Enrolment in other studies where a randomized intervention is targeting anticoagulation or blood management.
Outcomes
Primary Outcomes
Hospital mortality
Time Frame: Till the end of the index hospital admission, on average 30 days
Fraction of patients not surviving the index hospital admission
Secondary Outcomes
- ECMO free days(28 days after the start of the treatment)
- Ventilator free days(28 days after the start of the treatment)
- Anticoagulation management(For 7 days after the start of ECMO or till the end of treatment (whatever comes first))
- ICU free days(28 days after the start of the treatment)
- Hemorrhagic complications(For 7 days after the start of ECMO or till the end of treatment (whatever comes first))
- Thromboembolic complications(For 7 days after the start of ECMO or till the end of treatment (whatever comes first))
Investigators
Hergen Buscher
Principal Investigator
St Vincent's Hospital, Sydney