Optimization of General Anesthesia Monitoring Methods Used in Laboratory Animals during Development and Experimental Study of Veterinary Drugs

Introduction. Giving general anesthesia to animals is an important element of experimental research during the development and study of new veterinary drugs. Due to specific nature of general anesthesia and the need to use the potent sedatives and hypnotics, it has always been posing a risk to laboratory animals. In the frame of present-day veterinary research, the problem of proficient monitoring of anesthesia is extremely relevant, especially with regard to research involving laboratory rodents. The aim of the study is to develop and optimize laboratory monitoring methods of general anesthesia in animals during experimental studies of new veterinary drugs.
Materials and Methods. The study was conducted at the research laboratory of the Institute of Living Systems, DSTU, from January to May 2024. The experiment involved 20 Wistar rats of both sexes weighing 300–400 g that were subjected to inhalation anesthesia with isoflurane, using an RWD R520 anesthesia machine. The laboratory monitoring protocols were developed based on the electroencephalography (EEG), electrocardiography (ECG), respiratory rate, blood pressure, and body temperature parameters. The condition of animal organs and systems was assessed by means of biochemical blood and urine tests, as well as excretory function tests.
Results. An inhalation chamber connected to an anesthesia machine was designed for the study in rats. It allowed labor-atory monitoring of animals’ condition during inhalation anesthesia by electrophysiological and functional methods. A trial mode of the chamber using 2.0% isoflurane gas supply, at a flow rate of 2.0 l/min, and a withdrawal rate of 8.0 l/min had proved to be the optimal protocol for administering general anesthesia to laboratory rats. Electrophysiological, biochemical, and functional parameters demonstrated high tolerability of the anesthesia protocol used.
Discussion and Conclusion. The development proposed by the authors optimizes laboratory monitoring in animals during general anesthesia, contributes to improvement of quality of experimental research results, facilitates the work of re-searchers, and can be used during the development of new veterinary drugs.

1. Betshart-Wolfensberger R, Stekolnikov AA, Plemyashov KV, Nechaev AYu. General Anesthesia and Euthanasia In Veterinary Medicine: A Textbook. Saint Petersburg: Prospect Nauki; 2024. 376 p. (In Russ.).

2. Bille C, Auvigne V, Bomassi E, Durieux P, Libermann S, Rattez E. An Evidence-Based Medicine Approach to Small Animal Anaesthetic Mortality in a Referral Practice: The Influence of Initiating three Recommendations on Subsequent Anaesthetic Deaths. Veterinary Anaesthesia and Analgesia. 2014;41(3):249–258. https://doi.org/10.1111/vaa.12116

3. Baetge CL, Matthews NS. Anesthesia and Analgesia for Geriatric Veterinary Patients. Veterinary Clinics of North America: Small Animal Practice. 2012;42(4):643–653. https://doi.org/10.1016/j.cvsm.2012.05.001

4. Bille C, Auvigne V, Libermann S, Bomassi E, Durieux P, Rattez E. Risk of Anaesthetic Mortality in Dogs and Cats: An Observational Cohort Study of 3546 Cases. Veterinary Anaesthesia and Analgesia. 2012:39(1):59–68. https://doi:10.1111/j.1467-2995.2011.00686.x

5. Grubb T, Sager J, Gaynor JS, Montgomery E, Parker JA, Shafford H, Tearney C. 2020 AAHA Anesthesia and Monitoring Guidelines for Dogs and Cats. Journal of American Animal Hospital Association. 2020;56(2):59–82. https://doi.org/10.5326/jaaha-ms-7055

6. Pinho RH, Nasr-Esfahani M, Pang DSJ. Medication Errors in Veterinary Anesthesia: A Literature Review. Veteri-nary Anaesthesia and Analgesia. 2024;51(3):203–226. https://doi.org/10.1016/j.vaa.2024.01.003

7. Jones H, Robson K, Maddox T, Alderson B. Incidence of and Risk Factors for Poor Recovery Quality in Dogs Recovering from General Anaesthesia-A Prospective Case Control Study. Veterinary Anaesthesia and Analgesia. 2024;51(3):227–234. https://doi.org/10.1016/j.vaa.2023.12.002

8. Varkoulis K, Savvas I, Anagnostou T, Kazakos G, Pavlidou K. A Retrospective Study on Canine and Feline Mortality during Anaesthesia at a University Clinic in Greece. Animals. 2023;13(15):2486. https://doi.org/10.3390/ani13152486

9. Brodbelt DC, Blissitt KJ, Hammond RA, Neath PJ, Young LE, Pfeiffer DU, Pfeiffer DU. The Risk of Death: The Confidential Enquiry into Perioperative Small Animal Fatalities. Veterinary Anaesthesia and Analgesia. 2008;35(5):365–373. https://doi.org/10.1111/j.1467-2995.2008.00397.x

10. Reiser K, Schroers M, Reese S, Meyer-Lindenberg A. Gängige veterinärmedizinische Praxis in der Kleintieranästhesie – eine Onlineumfrage unter Kleintierpraktikern in Europa [Common Veterinary Practice in Small Animal Anesthesia — An Online Survey among Small Animal Practitioners in Europe]. Tierärztliche Praxis Ausgabe K: Kleintiere Heimtiere. 2021;49(5):325–334. https://doi.org/10.1055/a-1543-5167

11. Truchetti G, Otis C, Brisville AC, Beauchamp G, Pang D, Troncy E. Management of Veterinary Anesthesia in Small Animals: A Survey of Current Practice in Quebec. PLoS One. 2020;15(1):e0227204. https://doi.org/10.1371/journal.pone.0227204

12. Bennett K, Lewis K. Sedation and Anesthesia in Rodents. Vetterinary Clinics of North America Exotic Animal Practice. 2022;25(1):211–255. https://doi.org/10.1016/j.cvex.2021.08.013

13. GOST 33216-2014. Guidelines for the Care and Maintenance of Laboratory Animals. Rules for the Care and Mainte-nance of Laboratory Rodents and Rabbits. Official Edition. Moscow: Standartinform; 2016. 16 p. (In Russ.).

14. Kalkan KK, Kekecoglu M. Ethical Principles and Rules in Experimental Animal Studies: A Comprehensive Re-view. Duzce Medical Journal. 2024;26(S1):1–13. https://doi.org/10.18678/dtfd.1497730

15. Directive 2010/63/EU of the European Parliament and of the Council of 22 September 2010 on the Protection of Animals Used for Scientific Purposes. Official Journal of the European Union. 2010; Document 32010L0063. URL: https://eur-lex.europa.eu/eli/dir/2010/63/oj

16. Flecknell P. Laboratory Animal Anesthesia. 4th Ed. London: Academic Press, 2015. 350р.

17. Lycheva NA, Makarova MN, Makarov VG, Rybakova AV. Effect of Different Species of Anesthesia on Electrocardiogram Parameters in Rats. Laboratory Animals for Science. 2018;2:16–23. (In Russ.). https://10.29296/2618723X-2018-02-02

18. Caracciolo SF, Bertran GC, Arini PD. Electrocardiography in Wistar Rat Experimental Model: Analysis and Characterization. Sistema Nacional de Repositorios Digitales. 2018. URL: https://repositoriosdigitales.min-cyt.gob.ar/vufind/Record/CONICETDig_3359662e317b0cc411c85e6d4108a7da

19. Allen PS, Dell’Italia LJ, Esvelt M, Conte ML, Cadillac JM, Myers DD. Cardiovascular Research. In: Suckow MA, Hankenson FC, Wilson RP, Foley PL (Eds). The Laboratory Rat. 3rd Ed: Elsevier; 2020. P. 927–965. https://doi.org/10.1016/B978-0-12-814338-4.00025-8

20. Karkischenko NN, Grachev SV. Handbook on Laboratory Animals and Alternative Models in Biomedical Technologies. Moscow; 2010. 344 p. (In Russ.).

21. Rifai N, Horvath AR, Wittwer CT. Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics. 8th Ed. St. Louis: Elsevier Health Science; 2019. 1062 p.

22. Koeppen BM, Stanton BA. Renal Physiology. 6th Ed. Philadelphia: Elsevier; 2019. 248 р.

23. Islam MA, Al-Shiha A. Foundations of Biostatistics. Singapore: Springer; 2018. 474 р.

24. Pokhrel LR, Grady KD. Risk Assessment of Occupational Exposure to Anesthesia Isoflurane in the Hospital and Veterinary Settings. Science of the Total Environment. 2021;783:146894. https://doi.org/10.1016/j.sci-totenv.2021.146894