Transcutaneous blood gas monitoring and tissue perfusion during common femoral thromboendarterectomy

Background Improving tissue perfusion can improve clinical outcomes in surgical patients, where monitoring may aid clinicians in detecting adverse conditions and guide interventions. Transcutaneous monitoring (TCM) of oxygen (tcpO(2)) and carbon dioxide (tcpCO(2)) is a well-proven technology and could potentially serve as a measure of local circulation, perfusion and metabolism, but the clinical use is not thoroughly explored. The purpose of this proof-of-concept study was to investigate whether TCM of blood gasses could detect changes in perfusion during major vascular surgery. Methods Ten patients with peripheral arterial disease scheduled for lower limb major arterial revascularization under general anaesthesia were consecutively included. TcpO(2) and tcpCO(2) were continuously recorded from anaesthesia induction until skin closure with a TCM monitor placed on both legs and the thorax. Peripheral oxygen saturation was kept >= 94% and mean arterial blood pressure >= 65 mmHg. The primary outcomes were changes in tcpO(2) and tcpCO(2) related to arterial clamping and declamping during the procedure and analyzed by paired statistics. Results Femoral artery clamping resulted in a significant decrease in tcpO(2) (-2.1 kPa, IQR-4.2; -0.8), p=.017)), followed by a significant increase in response to arterial declamping (5.5 kPa, IQR 0-7.3), p=.017)). Arterial clamping resulted in a statistically significant increase in tcpCO(2) (0.9 kPa, IQR 0.3-5.4), p=.008)) and a significant decrease following declamping (-0.7 kPa, IQR -2.6; -0.2), p=.011)). Conclusion Transcutaneous monitoring of oxygen and carbon dioxide is a feasible method for detection of extreme changes in tissue perfusion during arterial clamping and declamping, and its use for improving patient outcomes should be explored.