To compare the impact of liberal vs conservative oxygen doses on markers of oxidative stress in patients enrolled in the BLENDER trial.
Extracorporeal membrane oxygen (ECMO) is a heart lung support device used for patients with severe and cardiac and respiratory failure and carries an increased risk of exposure to very high oxygen tensions. Hyperoxia (arterial oxygen \>100mmHg) can lead to the production of reactive oxygen species (ROS). Excess production of ROS and depletion of antioxidant compounds is referred to as oxidative stress and results in inflammation, tissue injury and cell death. The inter-relationship between the production of ROS and end organ dysfunction is complicated and remain unclear. A more detailed assessment of the timing of changes in markers of oxidative stress, inflammatory mediators and tissue injury is warranted to understand the processes and potentially identify therapeutic targets. The BLENDER Trial is a multicentre trial in ECMO patients to determine whether a conservative oxygen strategy during ECMO reduces ICU length of stay and improves patient outcomes compared to a liberal oxygen strategy. Currently there have been no studies that look at the underlying pathophysiological changes that occur in patients on ECMO when subjected to different oxygen concentrations. As such The BLENDER study represents a unique opportunity to understand the mechanisms by which hyperoxia may cause tissue injury in patients receiving ECMO. This nested study seeks to elucidate whether exposure to hyperoxia during ECMO results in increased oxidative stress and whether this is correlated with increased risk of tissue injury and organ dysfunction. A better understanding of the mechanism of hyperoxia induced tissue injury may allow treatment to be optimised for patients exposed to hyperoxia as part of their treatment.
Study Type
OBSERVATIONAL
Enrollment
30
Alfred Hospital
Melbourne, Victoria, Australia
Super oxide dismutase levels U/ml
Plasma levels of superoxide dismutase in patients exposed to either a liberal or conservative oxygen strategy during VA-ECMO
Time frame: Within 24 hours of ECMO commencement
Marker of Cardiac Injury
Troponin ng/ml This will be determined by analysing blood samples routinely collected daily from patient receiving ECMO
Time frame: Day 3 of ECMO
Marker of Cardiac Injury
Troponin I ng/ml This will be determined by analysing blood samples routinely collected daily from patient receiving ECMO
Time frame: Day 7 of ECMO
Markers of Liver Injury
ALT and AST (IU/L) This will be determined by analysing blood samples routinely collected daily from patient receiving ECMO
Time frame: Day 3 of ECMO
Markers of Liver Injury
ALT and AST (IU/L) This will be determined by analysing blood samples routinely collected daily from patient receiving ECMO
Time frame: Day 7 of ECMO
Marker of Neurological Injury
Neuron Specific Enolase (microg/L) This will be determined by analysing blood samples routinely collected daily from patient receiving ECMO
Time frame: Day 3 of ECMO
Marker of Neurological Injury
Neuron Specific Enolase (microg/L) This will be determined by analysing blood samples routinely collected daily from patient receiving ECMO
Time frame: Day 7 of ECMO
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Coagulation Parameters
APTT This will be determined by analysing blood samples routinely collected daily from patient receiving ECMO
Time frame: Day 3 of ECMO
Coagulation Parameters
APTT This will be determined by analysing blood samples routinely collected daily from patient receiving ECMO
Time frame: Day 7 of ECMO
Immune Markers
IL-6, TNFa, IL-10, IL-1B (pg/ml)
Time frame: Day 3 of ECMO
Immune Markers
IL-6, TNFa, IL-10, IL-1B (pg/ml)
Time frame: Day 7 of ECMO
Other Markers of Oxidative Stress
Malondialdehyde, Vitamin C
Time frame: Day 3 of ECMO
Other Markers of Oxidative Stress
Malondialdehyde, Vitamin C
Time frame: Day 7 of ECMO
Superoxide dismutase levels U/ml
Plasma levels of superoxide dismutase in patients exposed to either a liberal or conservative oxygen strategy during VA-ECMO
Time frame: On Day 3 following ECMO commencement
Superoxide dismutase levels
Plasma levels of superoxide dismutase in patients exposed to either a liberal or conservative oxygen strategy during VA-ECMO
Time frame: On Day 7 following ECMO commencement
Markers of Kidney Injury
Creatinine (micromol/L)
Time frame: Day 3 of ECMO
Markers of Kidney Injury
Creatinine (micromol/L)
Time frame: Day 7 of ECMO