Mitochondrial Oxygenation During Cardiopulmonary Bypass: A Pilot Study
Floor A Harms1, Rinse Ubbink1, Calvin J de Wijs1
1Department of Anesthesiology, Erasmus Medical Center, Erasmus University Rotterdam, Rotterdam, Netherlands.
Frontiers in Medicine
|August 4, 2022
Summary
This pilot study shows that measuring cutaneous mitochondrial oxygen tension (mitoPO2) during cardiac surgery is feasible. The COMET® monitor effectively tracked oxygenation changes, unlike standard tissue oxygenation (StO2) monitoring.
Area of Science:
- Cardiology
- Anesthesiology
- Biomedical Engineering
Background:
- Adequate oxygenation is critical during cardiac surgery and cardiopulmonary bypass (CPB) to maintain organ function.
- Both hypoxia and hyperoxia can lead to adverse outcomes, highlighting the need for precise oxygen monitoring.
- Current monitoring methods may not fully capture perioperative oxygenation status.
Purpose of the Study:
- To assess the feasibility of using the non-invasive COMET® monitor to measure cutaneous mitochondrial oxygen tension (mitoPO2) during cardiothoracic procedures.
- To compare cutaneous mitoPO2 measurements with tissue oxygenation (StO2) monitored by near-infrared spectroscopy.
- To evaluate the correlation between perioperative mitoPO2 levels and the incidence of acute kidney insufficiency (AKI).
Main Methods:
- A single-center, observational pilot study involving 41 cardiac surgery patients undergoing CPB.
- Preoperative application of a 5-aminolevulinic acid plaster to enable cutaneous mitoPO2 measurements.
- Continuous monitoring of cutaneous mitoPO2 and StO2 throughout the procedure, with follow-up for AKI development.
Main Results:
- Cutaneous mitoPO2 was successfully measured in all patients, showing a significant decrease from 63.5 mmHg at surgery start to 36.4 mmHg by the end of CPB (p < 0.01).
- StO2 levels did not change significantly during the procedure.
- Aortic cross-clamping and non-pulsatile flow led to significant decreases in mitoPO2, which partially recovered upon clamp release (p < 0.01).
- Four patients developed AKI; they spent significantly more time with mitoPO2 < 20 mmHg compared to the non-AKI group.
Conclusions:
- The COMET® monitor is a feasible tool for measuring cutaneous mitoPO2 during cardiothoracic surgery.
- Cutaneous mitoPO2 demonstrated greater sensitivity to hemodynamic and microcirculatory changes during CPB and aortic cross-clamping compared to StO2.
- Lower perioperative mitoPO2 may be associated with an increased risk of AKI following cardiac surgery.
