Transcutaneous blood gas monitoring and tissue perfusion during common femoral thromboendarterectomy

Abstract

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 (tcpO₂) and carbon dioxide (tcpCO₂) 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. TcpO₂ and tcpCO₂ 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 tcpO₂ and tcpCO₂ related to arterial clamping and declamping during the procedure and analyzed by paired statistics.

Results

Femoral artery clamping resulted in a significant decrease in tcpO₂ (−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 tcpCO₂ (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. Clinical Trials identifier: NCT04040478. Registered on July 31, 2019.

Keywords:

• Transcutaneous monitoring
• transcutaneous blood gas
• peripheral perfusion
• microcirculation
• hemodynamic monitoring

Disclosure statement

EKA: Indirect departmental research funding from Norpharma as well as lecture fees from Radiometer. CSM: Direct and indirect departmental research funding from Boehringer Ingelheim and Merck, Sharp & Dohme as well as lecture fees from Radiometer. HBDS: HBDS, EKA and CSM has co-founded a start-up company, WARD247 ApS, with the aim of pursuing the regulatory and commercial activities of the WARD-project (Wireless Assessment of Respiratory and circulatory Distress, a project developing a clinical support system for continuous wireless monitoring of vital signs). WARD247 ApS has obtained license agreement for any WARD-project software and patents. One patent has been filed: “Wireless Assessment of Respiratory and circulatory Distress (WARD) – Clinical Support System (CSS) – an automated clinical support system to improve patient safety and outcomes”. JPE: No relevant conflicts of interests. Other authors report: No conflicts of interests.

Data availability statement

All data are available from the authors upon request.

Additional information

Funding

The study was supported by Radiometer by an unrestricted grant and lending of equipment.