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Flick, M., Vokuhl, C., Bergholz, A., et al. | J Clin Monit Comput (2025) 39(5):813-820 | Personalized intraoperative arterial pressure management and mitochondrial oxygen tension in patients having major non-cardiac surgery: a pilot substudy of the IMPROVE trial

November 29, 2025

Background: The “Cellular Oxygen METabolism” (COMET) system (Photonics Healthcare, Utrecht, The Netherlands) non-invasively measures mitochondrial oxygen tension (mitoPO₂) in the skin. The effects of general anesthesia and major non-cardiac surgery on mitoPO₂ remain unknown.

Methods: In this pre-planned pilot substudy of the “Intraoperative blood pressure Management based on the individual blood PRessure profile: impact on postOperatiVE organ function” (IMPROVE) trial, mitoPO₂ was measured from induction of general anesthesia until the end of surgery in 19 patients undergoing major non-cardiac surgery (10 assigned to personalized and 9 to routine intraoperative arterial pressure management).

Results: In the overall cohort, the median (25th to 75th percentile) preoperative awake mitoPO₂ was 63 (53 to 82) mmHg, and mitoPO₂ after induction of general anesthesia was 42 (35 to 59) mmHg. The intraoperative average mitoPO₂ was 39 (30 to 50) mmHg. Thirteen patients (68%) had intraoperative mitoPO₂ values below 20 mmHg, and the median percentage of surgical time with mitoPO₂ <20 mmHg was 17 (0 to 31)%. MitoPO₂ was weakly correlated with mean arterial pressure (repeated measures correlation rrm(984)=0.26, 95% confidence interval 0.20 to 0.32; P<0.001), but not meaningfully with heart rate (rrm(984)=-0.05, 95% confidence interval -0.11 to 0.01; P=0.117). There was no important difference in intraoperative average mitoPO₂ between patients assigned to personalized or routine intraoperative arterial pressure management (P=0.653).

Conclusions: MitoPO₂ under general anesthesia was about a quarter lower than preoperative awake mitoPO₂, fluctuated substantially during major non-cardiac surgery, and transiently decreased below 20 mmHg in about two-thirds of the patients. Personalized, compared with routine, intraoperative arterial pressure management did not increase intraoperative mitoPO₂. Whether intraoperative decreases in mitoPO₂ are clinically meaningful warrants further investigation.

Keywords: Anesthesia; Cardiovascular dynamics; Hemodynamic monitoring; Individualized; Microcirculation; Tissue perfusion.