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Frontiers in veterinary science2021; 8; 603695; doi: 10.3389/fvets.2021.603695

Clinical Randomized Comparison of Medetomidine and Xylazine for Isoflurane Balanced Anesthesia in Horses.

Abstract: To assess drug plasma levels, preanesthetic sedation, cardiopulmonary effects during anesthesia and recovery in horses anesthetized with isoflurane combined with medetomidine or xylazine. Prospective blinded randomized clinical study. Sixty horses undergoing elective surgery. Thirty minutes after administration of antibiotics, flunixine meglumine or phenylbutazone and acepromazine horses received medetomidine 7 μg kg (group MED) or xylazine 1.1 mg kg (group XYL) slowly intravenously (IV) and sedation was assessed 3 min later. Anesthesia was induced with ketamine/diazepam and maintained with isoflurane in oxygen/air and medetomidine 3.5 μg kg h or xylazine 0.69 mg kg h. Ringer's acetate 10 mL kg h and dobutamine were administered to maintain normotension. All horses were mechanically ventilated to maintain end-tidal carbon dioxide pressures at 45 ± 5 mmHg (5.3-6.7 kPa). Heart rate (HR), invasive arterial blood pressures, inspired and expired gas compositions, pH, arterial blood gases, electrolytes, lactate and glucose were measured. For recovery all horses received intramuscular morphine 0.1 mg kg and medetomidine 2 μg kg or xylazine 0.3 mg kg IV. Recovery was timed and scored using three different scoring systems. Plasma samples to measure medetomidine and xylazine concentrations were collected at predetermined timepoints. Repeatedly measured parameters were analyzed using a two-way repeated-measures analysis of variance for differences between groups and over time; < 0.05 was considered statistically significant. Mean arterial blood pressures (MAP) stayed within normal ranges but were higher ( = 0.011) in group XYL despite significant lower dobutamine doses ( = 0.0003). Other measured parameters were within clinically acceptable ranges. Plasma levels were at steady state during anesthesia (MED 2.194 ± 0.073; XYL 708 ± 18.791 ng mL). During recovery lateral recumbency (MED 42.7 ± 2.51; XYL 34.3 ± 2.63 min; = 0.027) and time to standing (MED 62.0 ± 2.86; XYL 48.8 ± 3.01 min; = 0.002) were significantly shorter in group XYL compared to group MED. Recovery scores did not differ significantly between groups. In horses anesthetized with isoflurane and medetomidine or xylazine, xylazine maintained higher MAP, reduced the dobutamine consumption and recovery time, whilst overall recovery quality was unaffected.
Publication Date: 2021-04-20 PubMed ID: 33959647PubMed Central: PMC8093396DOI: 10.3389/fvets.2021.603695Google Scholar: Lookup
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  • Journal Article

Summary

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The study looks into a comparison of effects between two drugs, Medetomidine and Xylazine, when used in combination with Isoflurane for anesthesia during horse surgery. It mainly focuses on the effects of the two drugs on sedation, cardiopulmonary actions, and recovery in horses.

Study Design

  • The research is a prospective blinded randomized clinical study, involving 60 horses that were set to undergo elective surgery.
  • Both drugs were applied intravenously, 30 minutes after the administration of antibiotics, flunixine meglumine or phenylbutazone and acepromazine, and sedation was observed 3 min later.
  • Anesthesia was induced with ketamine/diazepam and maintained with isoflurane in oxygen/air and either medetomidine or xylazine. To maintain normotension, Ringer’s acetate and dobutamine were applied.
  • All horses were mechanically ventilated to maintain end-tidal carbon dioxide pressures at optimal levels. Different parameters were measured including heart rate, arterial blood pressures, pH, electrolytes, lactate and glucose among others.
  • During recovery, all horses received intramuscular morphine and either medetomidine or xylazine. Recovery was timed and scored using three different scoring systems.
  • Plasma samples were collected at predetermined timepoints to measure the concentrations of medetomidine and xylazine.

Results

  • Mean arterial blood pressures remained in normal ranges but were higher in the xylazine group even though they received significantly lower dobutamine doses.
  • All other parameters were in the clinically acceptable ranges.
  • During anesthesia, plasma levels were steady for both groups.
  • Different measures of recovery time including lateral recumbency and time to standing were found to be significantly shorter in the xylazine group.
  • However, recovery scores did not differ significantly between the groups.

Conclusions

  • The findings suggest that using xylazine with isoflurane for anesthesia in horses provides better results than medetomidine. Xylazine was found to maintain higher mean arterial blood pressures, reduce the consumption of dobutamine and shorten recovery time.
  • However, the overall recovery quality, judged by recovery scores, was similar in both groups.

Cite This Article

APA
Wiederkehr A, Barbarossa A, Ringer SK, Jörger FB, Bryner M, Bettschart-Wolfensberger R. (2021). Clinical Randomized Comparison of Medetomidine and Xylazine for Isoflurane Balanced Anesthesia in Horses. Front Vet Sci, 8, 603695. https://doi.org/10.3389/fvets.2021.603695

Publication

ISSN: 2297-1769
NlmUniqueID: 101666658
Country: Switzerland
Language: English
Volume: 8
Pages: 603695
PII: 603695

Researcher Affiliations

Wiederkehr, Alexandra
  • Section Anesthesiology, Department of Clinical Diagnostics and Services, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
Barbarossa, Andrea
  • Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.
Ringer, Simone K
  • Section Anesthesiology, Department of Clinical Diagnostics and Services, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
Jörger, Fabiola B
  • Section Anesthesiology, Department of Clinical Diagnostics and Services, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
Bryner, Marco
  • Clinic for Equine Surgery, Equine Department, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
Bettschart-Wolfensberger, Regula
  • Section Anesthesiology, Department of Clinical Diagnostics and Services, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.

Conflict of Interest Statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

References

This article includes 46 references
  1. Steffey EP, Howland D Jr. Cardiovascular effects of halothane in the horse.. Am J Vet Res 1978 Apr;39(4):611-5.
    pubmed: 646195
  2. Dugdale AH, Taylor PM. Equine anaesthesia-associated mortality: where are we now?. Vet Anaesth Analg 2016 May;43(3):242-55.
    doi: 10.1111/vaa.12372pubmed: 26970940google scholar: lookup
  3. Johnston GM, Eastment JK, Wood J, Taylor PM. The confidential enquiry into perioperative equine fatalities (CEPEF): mortality results of Phases 1 and 2.. Vet Anaesth Analg 2002 Oct;29(4):159-170.
  4. Gozalo-Marcilla M, Gasthuys F, Schauvliege S. Partial intravenous anaesthesia in the horse: a review of intravenous agents used to supplement equine inhalation anaesthesia. Part 1: lidocaine and ketamine.. Vet Anaesth Analg 2014 Jul;41(4):335-45.
    doi: 10.1111/vaa.12179pubmed: 24815750google scholar: lookup
  5. Gozalo-Marcilla M, Gasthuys F, Schauvliege S. Partial intravenous anaesthesia in the horse: a review of intravenous agents used to supplement equine inhalation anaesthesia. Part 2: opioids and alpha-2 adrenoceptor agonists.. Vet Anaesth Analg 2015 Jan;42(1):1-16.
    doi: 10.1111/vaa.12196pubmed: 24984895google scholar: lookup
  6. Sacks M, Ringer SK, Bischofberger AS, Berchtold SM, Bettschart-Wolfensberger R. Clinical comparison of dexmedetomidine and medetomidine for isoflurane balanced anaesthesia in horses.. Vet Anaesth Analg 2017 Sep;44(5):1128-1138.
    doi: 10.1016/j.vaa.2016.12.061pubmed: 29037800google scholar: lookup
  7. Nannarone S, Spadavecchia C. Evaluation of the clinical efficacy of two partial intravenous anesthetic protocols, compared with isoflurane alone, to maintain general anesthesia in horses.. Am J Vet Res 2012 Jul;73(7):959-67.
    doi: 10.2460/ajvr.73.7.959pubmed: 22738046google scholar: lookup
  8. Bettschart-Wolfensberger R, Larenza Menzies MP. Balanced anesthesia in the equine. Clin Tech Equine Pract (2007) 6:104–10.
  9. Devisscher L, Schauvliege S, Dewulf J, Gasthuys F. Romifidine as a constant rate infusion in isoflurane anaesthetized horses: a clinical study.. Vet Anaesth Analg 2010 Sep;37(5):425-33.
  10. Marcilla MG, Schauvliege S, Segaert S, Duchateau L, Gasthuys F. Influence of a constant rate infusion of dexmedetomidine on cardiopulmonary function and recovery quality in isoflurane anaesthetized horses.. Vet Anaesth Analg 2012 Jan;39(1):49-58.
  11. Pöppel N, Hopster K, Geburek F, Kästner S. Influence of ketamine or xylazine supplementation on isoflurane anaesthetized horses--a controlled clinical trial.. Vet Anaesth Analg 2015 Jan;42(1):30-8.
    doi: 10.1111/vaa.12176pubmed: 24815552google scholar: lookup
  12. Ringer SK, Kalchofner K, Boller J, Fürst A, Bettschart-Wolfensberger R. A clinical comparison of two anaesthetic protocols using lidocaine or medetomidine in horses.. Vet Anaesth Analg 2007 Jul;34(4):257-68.
  13. Schauvliege S, Marcilla MG, Verryken K, Duchateau L, Devisscher L, Gasthuys F. Effects of a constant rate infusion of detomidine on cardiovascular function, isoflurane requirements and recovery quality in horses.. Vet Anaesth Analg 2011 Nov;38(6):544-54.
  14. Grimsrud KN, Mama KR, Steffey EP, Stanley SD. Pharmacokinetics and pharmacodynamics of intravenous medetomidine in the horse.. Vet Anaesth Analg 2012 Jan;39(1):38-48.
  15. Garcia-Villar R, Toutain PL, Alvinerie M, Ruckebusch Y. The pharmacokinetics of xylazine hydrochloride: an interspecific study.. J Vet Pharmacol Ther 1981 Jun;4(2):87-92.
  16. Virtanen R, Savola JM, Saano V, Nyman L. Characterization of the selectivity, specificity and potency of medetomidine as an alpha 2-adrenoceptor agonist.. Eur J Pharmacol 1988 May 20;150(1-2):9-14.
    doi: 10.1016/0014-2999(88)90744-3pubmed: 2900154google scholar: lookup
  17. Kamerling S, Keowen M, Bagwell C. Pharmacological profile of medetomidine in the equine. Acta Vet Scand (1991) 161–2.
  18. Creighton CM, Lemke KA, Lamont LA, Horney BS, Riley CB. Comparison of the effects of xylazine bolus versus medetomidine constant rate infusion on cardiopulmonary function and depth of anesthesia in horses anesthetized with isoflurane.. J Am Vet Med Assoc 2012 Apr 15;240(8):991-7.
    doi: 10.2460/javma.240.8.991pubmed: 22471829google scholar: lookup
  19. Bettschart-Wolfensberger R, Bettschart RW, Vainio O, Marlin D, Clarke KW. Cardiopulmonary effects of a two hour medetomidine infusion and its antagonism by atipamezole in horses and ponies. J Vet Anaesth (1999) 26:8–12.
  20. Yamashita K, Tsubakishita S, Futaok S, Ueda I, Hamaguchi H, Seno T, Katoh S, Izumisawa Y, Kotani T, Muir WW. Cardiovascular effects of medetomidine, detomidine and xylazine in horses.. J Vet Med Sci 2000 Oct;62(10):1025-32.
    doi: 10.1292/jvms.62.1025pubmed: 11073071google scholar: lookup
  21. Kalchofner KS, Picek S, Ringer SK, Jackson M, Hässig M, Bettschart-Wolfensberger R. A study of cardiovascular function under controlled and spontaneous ventilation in isoflurane-medetomidine anaesthetized horses.. Vet Anaesth Analg 2009 Sep;36(5):426-35.
  22. Yamashita K, Muir WW 3rd, Tsubakishita S, Abrahamsen E, Lerch P, Hubbell JA, Bednarski RM, Skarda RT, Izumisawa Y, Kotani T. Clinical comparison of xylazine and medetomidine for premedication of horses.. J Am Vet Med Assoc 2002 Oct 15;221(8):1144-9.
    doi: 10.2460/javma.2002.221.1144pubmed: 12387384google scholar: lookup
  23. Menzies MP, Ringer SK, Conrot A, Theurillat R, Kluge K, Kutter AP, Jackson M, Thormann W, Bettschart-Wolfensberger R. Cardiopulmonary effects and anaesthesia recovery quality in horses anaesthetized with isoflurane and low-dose S-ketamine or medetomidine infusions.. Vet Anaesth Analg 2016 Nov;43(6):623-634.
    doi: 10.1111/vaa.12359pubmed: 26915545google scholar: lookup
  24. Daunt DA, Steffey EP. Alpha-2 adrenergic agonists as analgesics in horses.. Vet Clin North Am Equine Pract 2002 Apr;18(1):39-46, vi.
    doi: 10.1016/S0749-0739(02)00004-4pubmed: 12064181google scholar: lookup
  25. England GC, Clarke KW. Alpha 2 adrenoceptor agonists in the horse--a review.. Br Vet J 1996 Nov;152(6):641-57.
    doi: 10.1016/S0007-1935(96)80118-7pubmed: 8979422google scholar: lookup
  26. Ringer SK, Portier KG, Fourel I, Bettschart-Wolfensberger R. Development of a xylazine constant rate infusion with or without butorphanol for standing sedation of horses.. Vet Anaesth Analg 2012 Jan;39(1):1-11.
  27. Bryant CE, Clarke KW, Thompson J. Cardiopulmonary effects of medetomidine in sheep and in ponies.. Res Vet Sci 1996 May;60(3):267-71.
    doi: 10.1016/S0034-5288(96)90052-1pubmed: 8735520google scholar: lookup
  28. Steffey EP, Pascoe PJ, Woliner MJ, Berryman ER. Effects of xylazine hydrochloride during isoflurane-induced anesthesia in horses.. Am J Vet Res 2000 Oct;61(10):1225-31.
    doi: 10.2460/ajvr.2000.61.1225pubmed: 11039552google scholar: lookup
  29. Taylor P, Coumbe K, Henson F, Scott D, Taylor A. Evaluation of sedation for standing clinical procedures in horses using detomidine combined with buprenorphine.. Vet Anaesth Analg 2014 Jan;41(1):14-24.
    doi: 10.1111/vaa.12055pubmed: 23742694google scholar: lookup
  30. Leece EA, Corletto F, Brearley JC. A comparison of recovery times and characteristics with sevoflurane and isoflurane anaesthesia in horses undergoing magnetic resonance imaging.. Vet Anaesth Analg 2008 Sep;35(5):383-91.
  31. Valverde A, Black B, Cribb NC, Hathway A, Daw A. Assessment of unassisted recovery from repeated general isoflurane anesthesia in horses following post-anesthetic administration of xylazine or acepromazine or a combination of xylazine and ketamine.. Vet Anaesth Analg 2013 Jan;40(1):3-12.
  32. Wohlfender FD, Doherr MG, Driessen B, Hartnack S, Johnston GM, Bettschart-Wolfensberger R. International online survey to assess current practice in equine anaesthesia.. Equine Vet J 2015 Jan;47(1):65-71.
    doi: 10.1111/evj.12257pubmed: 24593298google scholar: lookup
  33. Laurenza C, Ansart L, Portier K. Risk Factors of Anesthesia-Related Mortality and Morbidity in One Equine Hospital: A Retrospective Study on 1,161 Cases Undergoing Elective or Emergency Surgeries.. Front Vet Sci 2019;6:514.
    doi: 10.3389/fvets.2019.00514pmc: PMC6990105pubmed: 32039253google scholar: lookup
  34. Bettschart-Wolfensberger R, Jäggin-Schmucker N, Lendl C, Bettschart RW, Clarke KW. Minimal alveolar concentration of desflurane in combination with an infusion of medetomidine for the anaesthesia of ponies.. Vet Rec 2001 Mar 3;148(9):264-7.
    doi: 10.1136/vr.148.9.264pubmed: 11292086google scholar: lookup
  35. Kalchofner KS, Ringer SK, Boller J, Kästner SBR, Lischer C, Bettschart-Wolfensberger R. Clinical assessment of anesthesia with isoflurane and medetomidine in 300 equidae. Pferdeheilkunde (2006) 22:301–8.
    doi: 10.21836/PEM20060309google scholar: lookup
  36. Bettschart-Wolfensberger R, Clarke KW, Vainio O, Aliabadi F, Demuth D. Pharmacokinetics of medetomidine in ponies and elaboration of a medetomidine infusion regime which provides a constant level of sedation.. Res Vet Sci 1999 Aug;67(1):41-6.
    doi: 10.1053/rvsc.1998.0274pubmed: 10425239google scholar: lookup
  37. Bettschart-Wolfensberger R, Freeman SL, Bowen IM, Aliabadi FS, Weller R, Huhtinen M, Clarke KW. Cardiopulmonary effects and pharmacokinetics of i.v. dexmedetomidine in ponies.. Equine Vet J 2005 Jan;37(1):60-4.
    doi: 10.2746/0425164054406801pubmed: 15651736google scholar: lookup
  38. Larenza MP, Ringer SK, Kutter AP, Conrot A, Theurillat R, Kummer M, Thormann W, Bettschart-Wolfensberger R. Evaluation of anesthesia recovery quality after low-dose racemic or S-ketamine infusions during anesthesia with isoflurane in horses.. Am J Vet Res 2009 Jun;70(6):710-8.
    doi: 10.2460/ajvr.70.6.710pubmed: 19496659google scholar: lookup
  39. Bryant CE, England GC, Clarke KW. Comparison of the sedative effects of medetomidine and xylazine in horses.. Vet Rec 1991 Nov 9;129(19):421-3.
  40. Bueno AC, Cornick-Seahorn J, Seahorn TL, Hosgood G, Moore RM. Cardiopulmonary and sedative effects of intravenous administration of low doses of medetomidine and xylazine to adult horses.. Am J Vet Res 1999 Nov;60(11):1371-6.
    pubmed: 10566811
  41. Knych HK, Stanley SD, McKemie DS, Arthur RM, Kass PH. Pharmacokinetic and pharmacodynamics of xylazine administered to exercised thoroughbred horses.. Drug Test Anal 2017 May;9(5):713-720.
    doi: 10.1002/dta.2047pubmed: 27492623google scholar: lookup
  42. Ringer SK, Schwarzwald CC, Portier KG, Ritter A, Bettschart-Wolfensberger R. Effects on cardiopulmonary function and oxygen delivery of doses of romifidine and xylazine followed by constant rate infusions in standing horses.. Vet J 2013 Feb;195(2):228-34.
    doi: 10.1016/j.tvjl.2012.06.036pubmed: 22841452google scholar: lookup
  43. Gozalo-Marcilla M, Gasthuys F, Luna SPL, Schauvliege S. Is there a place for dexmedetomidine in equine anaesthesia and analgesia? A systematic review (2005-2017).. J Vet Pharmacol Ther 2018 Apr;41(2):205-217.
    doi: 10.1111/jvp.12474pubmed: 29226340google scholar: lookup
  44. Ambrisko TD, Kabes R, Moens Y. Influence of drugs on the response characteristics of the LiDCO sensor: an in vitro study.. Br J Anaesth 2013 Feb;110(2):305-10.
    doi: 10.1093/bja/aes380pubmed: 23166148google scholar: lookup
  45. Hubbell J, Muir W. Considerations for induction, maintenance, and recovery. Equine Anesth (2009) 381–96.
  46. Wagner AE. Complications in equine anesthesia.. Vet Clin North Am Equine Pract 2008 Dec;24(3):735-52, x.
    doi: 10.1016/j.cveq.2008.10.002pubmed: 19203709google scholar: lookup

Citations

This article has been cited 2 times.
  1. Kälin I, Henze IS, Ringer SK, Torgerson PR, Bettschart-Wolfensberger R. Comparison of Recovery Quality Following Medetomidine versus Xylazine Balanced Isoflurane Anaesthesia in Horses: A Retrospective Analysis.. Animals (Basel) 2021 Aug 19;11(8).
    doi: 10.3390/ani11082440pubmed: 34438896google scholar: lookup
  2. Cunneen A, Pratt S, Perkins N, McEwen M, Truchetti G, Rainger J, Farry T, Kidd L, Goodwin W. Total Intravenous Anaesthesia with Ketamine, Medetomidine and Midazolam as Part of a Balanced Anaesthesia Technique in Horses Undergoing Castration.. Vet Sci 2021 Jul 26;8(8).
    doi: 10.3390/vetsci8080142pubmed: 34437464google scholar: lookup