Can We Avoid Anticoagulation in Extracorporeal Life Support (ECLS)? The Impact of Anticoagulation Monitoring and Administration Practices
Abstract
When lungs or heart or a combination are severely injured from disease, patients may be unable to support themselves because of the inability in delivering adequate oxygen to their organs to support life. With lung failure, patients often have a condition referred to as acute respiratory distress syndrome, ARDS. In this condition, their lungs are unable to provide normal gas exchange, leading to low levels of oxygen and very high levels of carbon dioxide in their blood. When the lungs fail, patients are treated with escalating measures to help gas exchange, culminating in the placement of a tube in the trachea (windpipe) to allow a machine (mechanical ventilator) to deliver high concentrations of oxygen and help with carbon dioxide removal. When the lung failure is so severe that this fails or the pressures delivered by the mechanical ventilator are so high they cause more damage to the lung, extracorporeal life support (ECLS) can be used. In a similar fashion, if heart failure is so severe that the body does not receive adequate oxygen to the tissues, or the levels of medications to help the heart to pump is so high it contributes to heart failure, ECLS can also be used to provide cardiac support. In ECLS, blood is drained out of a large vein in the body via a plastic tube (cannula) and pumped through an artificial device that functions as an artificial lung, adding oxygen and removing carbon dioxide from the blood. Oxygenated blood is then returned to the body via another large plastic tube (cannula). If the heart is working well and the problem is mainly gas exchange, blood is returned to the right side of the heart and the native heart pumps out the oxygenated blood to the body. This is called venovenous ECLS. When the oxygenated return is directed into the patient’s arterial circulation (most common in heart failure), this is called venoarterial ECLS. When blood is exposed to any artificial surface, cells and clotting factors are activated, and clots can form in the body, blood vessels, and ECLS machine. Thus, giving patients on ECLS anticoagulants, which prevent clotting, is common. Despite much research, the optimal anticoagulant or means of measuring its effects to prevent clotting while not causing excessive bleeding is unknown. Currently, many tests are done to follow the coagulation status of the patient, but these are not readily available in environments such as the battlefield, clinic, during transport, or in other austere sites. Further, new data is finding that these tests do not correlate well with the dose of anticoagulant given or the bleeding and thrombotic events that are observed. New interest in use of viscoelastic testing, which gives a graphic picture of clot formation and breakdown in the body, has arisen as this technology has shown effectiveness in guiding blood product and anticoagulant use in trauma and cardiopulmonary bypass patients. The current commercially available devices for this testing are large, not portable, require specialized training and operators to run, and results are often delayed in getting to the clinician. Validated a new miniature device to perform viscoelastic testing (called the VCM), which is the size of a computer tablet, can be carried around, is easy to use, and gives results that are immediately available to the clinician, would simplify care and allow for improved monitoring of patients both within and without the hospital environment. Our efforts to assess the ability for the electronic medical record to automatically download information from collected data into a research database, which can help answer questions as to how frequent blood clotting or bleeding occurs, what factors associated are with it, and how different lab tests relate to the administered anticoagulant medication as well as what doses are associated with bleeding or thrombosis, which are also an important and underdeveloped area of medicine. Studies are showing, however, that use of data downl
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Dec 28, 2022
- Source ID
- W81XWH2210056
Entities
People
- Heidi Dalton
Organizations
- Inova Fairfax Hospital
- United States Army