Funding: the study was funded by the Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology state budgetary institution of science as a part of research project "Anesthetic neuroprotection with xenon and sevoflurane in severe brain damage. Clinical and experimental study" (No. 0427-2019-0035).

Author contribution: Krukov IA — study design, concept development and research algorithm establishment; Ershov AV — experimental part, statistical analysis of the data; Cherpakov RA — manuscript writing and editing; Grebenchikov OA — scientific editing of the final version.

Compliance with ethical standards: the study was approved by Ethical Review Board at the Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology (Protocol № 4/21/2 of 29 September 2021) and conducted in compliance with the European Convention for the Protection of Vertebrate Animals used for Experimental and other Scientific Purposes (ETS № 123, Strasbourg 18/03/1986, with the Appendix of 2006), Guide for the Care and Use of Laboratory Animals, 8th ed. (2010), Directive 2010/63/EU of the European Parliament and the Council on the Protection of Animals Used for Scientific Purposes (2010) and the Good Laboratory Practice Guidelines (2016).