Mark Wefers Bettink

Chapter 8 146 Abstract Introduction The newly introduced Cellular Oxygen METabolism (COMET ® ) monitor provides a means to measure mitochondrial oxygenation (mitoPO 2 ) using the protoporphyrin IX triple state lifetime technique (PpIX-TSLT). In this study we aim to investigate the feasibility and applicability of the COMET ® measurements in the operating theatreduring stable operating conditions. Furthermore, two cases arepresentedwherein the characteristics of the mitoPO 2 measurements are shown in unstable conditions. Methods: In this observational study mitochondrial oxygenation was measured in 20 patients during neurosurgery using the COMET ® measuring device. Tissue oxygenation and local blood flow were measured by the Oxygen to See (O2C). Primary outcomes included mitochondrial oxygen tension, skin temperature, mean arterial blood pressure, local blood flow and tissue oxygenation. Results: Mean application time of the ALA plaster was 17 ± 3.3 hours. Mean baseline mitoPO 2 was 60 ± 17 mmHg, mean mitoPO 2 remained between 40-60 mmHg during surgery. Conclusion: This study has presented mitochondrial oxygenation measurements during both stable and unstable hemodynamic conditions in the operating theatre. The results demonstrate the reliability of mitochondrial oxygenation as measured by the COMET ® monitor and provide the first step for future research into their added value during major surgery.