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Journal of veterinary emergency and critical care (San Antonio, Tex. : 2001)2021; 31(4); 476-482; doi: 10.1111/vec.13083

The effect of xylazine on intracranial pressure in anesthetized and standing horses.

Abstract: To determine the effect of xylazine on intracranial pressure (ICP) in standing compared to isoflurane-anesthetized horses. Methods: Prospective, crossover study design. Methods: University Teaching Hospital. Methods: Six adult horses donated to the University. Horses were determined to be healthy via physical examination, complete blood count, and neurological evaluation. Methods: Horses were anesthetized, maintained on isoflurane in oxygen in left lateral recumbency, and ventilated to normocapnia. Horses were instrumented for intraparenchymal measurement of ICP, invasive blood pressure, pulse oximetry, and end tidal gas analyzer. Xylazine 1 mg/kg was administered IV and ICP, systolic arterial pressure, mean arterial pressure (MAP), diastolic arterial pressure, and heart rate were recorded and cerebral perfusion pressure (CPP) was calculated for the following 15 minutes. Twenty-four to 36 hours following anesthetic recovery, xylazine 1 mg/kg was administered IV and ICP, heart rate, and Doppler blood pressure (BPdop) on the tail were monitored for 15 minutes. Results: There was a decrease in ICP following administration of xylazine in anesthetized horses (P < 0.003) but not standing horses (P = 0.227). There was an increase in systolic arterial pressure, MAP, diastolic arterial pressure (P < 0.001), and BPdop (P = 0.001) following administration of xylazine. As a result, CPP increased in anesthetized horses (P < 0.03). There was a negative association between ICP and MAP in anesthetized horses (P = 0.007) but not ICP and BPdop conscious horses (P = 0.379). Conclusions: Administration of xylazine to anesthetized horses resulted in an increased CPP due to decreased ICP with concurrent increased MAP. Administration of xylazine to standing horses did not result in a change in ICP. However, with the increase in BPdop found in awake horses, it is likely that CPP would also increase in awake horses following xylazine administration.
© Veterinary Emergency and Critical Care Society 2021.
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Publication Date: 2021-06-18 PubMed ID: 34143942DOI: 10.1111/vec.13083Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research studied the impact of xylazine on the intracranial pressure (ICP) in horses. The study found that xylazine decreases ICP in anesthetized horses, but not in standing horses, and that blood pressure increases after xylazine administration in both cases.

Research Methodology

  • The researchers conducted a prospective, crossover study using six adult horses in good health, as confirmed through physical exams, complete blood counts, and neurological evaluations.
  • The horses were anesthetized with isoflurane in oxygen and placed in left lateral recumbency. They were ventilated to a state of normocapnia (normal blood carbon dioxide levels).
  • In order to measure the effect of xylazine, various instruments were installed to measure ICP, invasive blood pressure, pulse oximetry (oxygen saturation level in blood), and end tidal gas volume (amount of exhaled carbon dioxide).
  • Xylazine was administered intravenously at a dose of 1 mg/kg. ICP, along with systolic arterial pressure, mean arterial pressure (MAP), diastolic arterial pressure, and heart rate, were recorded and cerebral perfusion pressure (CPP – blood flow to the brain) was calculated over the next 15 minutes.
  • The procedure was repeated after 24 to 36 hours, this time with the horses standing. ICP, heart rate, and Doppler blood pressure on the tail were monitored for 15 minutes following xylazine administration.

Research Findings

  • The research found that xylazine decreased ICP in anesthetized horses significantly (P < 0.003), but the same did not occur in standing horses (P = 0.227).
  • There was an increase in systolic arterial pressure, MAP, diastolic arterial pressure, and Doppler blood pressure after the administration of xylazine, both in anesthetized and standing horses (P < 0.001).
  • Consequently, CPP increased in anesthetized horses (P < 0.03).
  • A significant negative correlation was found between ICP and MAP in anesthetized horses (P = 0.007), but the same correlation was not found between ICP and Doppler blood pressure in standing horses (P = 0.379).

Conclusion

  • The administration of xylazine to anesthetized horses resulted in increased cerebral perfusion pressure due to decreased intracranial pressure and concurrent increase in mean arterial pressure.
  • In contrast, the administration of xylazine to standing horses did not change their intracranial pressure. However, the observed increase in Doppler blood pressure suggests that cerebral perfusion pressure would likely also increase in awake horses following the administration of xylazine.

Cite This Article

APA
Reed RA, Epstein KL, Bramski JH, Diehl KA, Ryan CA. (2021). The effect of xylazine on intracranial pressure in anesthetized and standing horses. J Vet Emerg Crit Care (San Antonio), 31(4), 476-482. https://doi.org/10.1111/vec.13083

Publication

Journal of veterinary emergency and critical care (San Antonio, Tex. : 2001)
ISSN: 1476-4431
NlmUniqueID: 101152804
Country: United States
Language: English
Volume: 31
Issue: 4
Pages: 476-482

Researcher Affiliations

Reed, Rachel A
  • Department of Large Animal Medicine, University of Georgia College of Veterinary Medicine, Athens, Georgia, USA.
Epstein, Kira L
  • Department of Large Animal Medicine, University of Georgia College of Veterinary Medicine, Athens, Georgia, USA.
Bramski, Jessica H
  • Department of Large Animal Medicine, University of Georgia College of Veterinary Medicine, Athens, Georgia, USA.
Diehl, Kathryn A
  • Department of Small Animal Medicine and Surgery, University of Georgia College of Veterinary Medicine, Athens, Georgia, USA.
Ryan, Clare A
  • Department of Large Animal Medicine, University of Georgia College of Veterinary Medicine, Athens, Georgia, USA.

MeSH Terms

  • Animals
  • Blood Pressure
  • Cross-Over Studies
  • Heart Rate
  • Horses
  • Intracranial Pressure
  • Isoflurane
  • Prospective Studies
  • Xylazine / pharmacology

References

This article includes 36 references
  1. Feige K, Fürst A, Kaser-Hotz B, Ossent P. Traumatic injury to the central nervous system in horses: occurrence, diagnosis and outcome.. Equine Vet Educ 2000;12(4):220-224.
  2. Tyler CM, Davis RE, Begg AP. A survey of neurological diseases in horses.. Aust Vet J 1993;70(12):445-449.
  3. Mount CA, MD J. Cerebral Perfusion Pressure.. Treasure Island, FL: StatPearls; 2019.
  4. Brosnan RJ, LeCouteur RA, Steffey EP. Direct measurement of intracranial pressure in adult horses.. Am J Vet Res 2002;63(9):1252-1256.
  5. Rangel-Castilla L, Gopinath S, Robertson CS. Management of intracranial hypertension.. Neurol Clin 2008;26(2):521-541.
  6. Fatima N, Shuaib A, Chughtai TS. The role of transcranial doppler in traumatic brain injury: a systemic review and meta-analysis.. Asian J Neuros 2019;14(3):626-633.
  7. Kim H, Lee HJ, Kim YT. Novel index for predicting mortality during the first 24 hours after traumatic brain injury.. J Neurosurg 2018;131(6):1887-1895.
  8. Ziegler D, Cravens G, Poche G. Use of transcranial Doppler in patients with severe traumatic brain injuries.. J Neurotrauma 2017;34(1):121-127.
  9. Aryan HE, Box KW, Ibrahim D. Safety and efficacy of dexmedetomidine in neurosurgical patients.. Brain Inj 2006;20(8):791-798.
  10. Shehabi Y, Ruettimann U, Adamson H. Dexmedetomidine infusion for more than 24 hours in critically ill patients: sedative and cardiovascular effects.. Intensive Care Med 2004;30(12):2188-2196.
  11. James ML, Olson DM, Graffagnino C. A pilot study of cerebral and haemodynamic physiological changes during sedation with dexmedetomidine or propofol in patients with acute brain injury.. Anaesth Intensive Care 2012;40(6):949-957.
  12. Schomer KJ, Sebat CM, Adams JY. Dexmedetomidine for refractory intracranial hypertension.. J Intensive Care Med 2019;34(1):62-66.
  13. Wang X, Ji J, Fen L, Wang A. Effects of dexmedetomidine on cerebral blood flow in critically ill patients with or without traumatic brain injury: a prospective controlled trial.. Brain Inj 2013;27(13-14):1617-1622.
  14. Flower O, Hellings S. Sedation in traumatic brain injury.. Emerg Med Int 2012;2012:637171.
  15. Moore RM, Trim CM. Effect of hypercapnia or xylazine on lateral ventricle and lumbosacral cerebrospinal fluid pressures in pentobarbital-anesthetized horses.. Vet Surg 1993;22(2):151-158.
  16. Moore RM, Trims CM. Effect of xylazine on cerebrospinal fluid pressure in conscious horses.. Am J Vet Res 1992;53(9):1558-1561.
  17. Brosnan RJ, Steffey EP, LeCouteur RA. Effects of body position on intracranial and cerebral perfusion pressures in isoflurane-anesthetized horses.. J Appl Physiol 2002;92(6):2542-2546.
  18. Brosnan RJ, Esteller-Vico A, Steffey EP. Effects of head-down positioning on regional central nervous system perfusion in isoflurane-anesthetized horses.. Am J Vet Res 2008;69(6):737-743.
  19. Brosnan RJ, Steffey EP, LeCouteur RA. Effects of isoflurane anesthesia on cerebrovascular autoregulation in horses.. Am J Vet Res 2011;72(1):18-24.
  20. Brosnan RJ, Steffey EP, LeCouteur RA. Effects of duration of isoflurane anesthesia and mode of ventilation on intracranial and cerebral perfusion pressures in horses.. Am J Vet Res 2003;64(11):1444-1448.
  21. Brosnan RJ, Steffey EP, LeCouteur RA. Effects of ventilation and isoflurane end-tidal concentration on intracranial and cerebral perfusion pressures in horses.. Am J Vet Res 2003;64(1):21-25.
  22. Bedford RF, Persing JA, Pobereskin L, Butler A. Lidocaine or thiopental for rapid control of intracranial hypertension?. Anesth Analg 1980;59(6):435-437.
  23. Hoffman WE, Edelman G, Kochs E. Cerebral autoregulation in awake versus isoflurane-anesthetized rats.. Anesth Analg 1991;73(6):753-757.
  24. Manohar M, Parks C. Regional distribution of brain and myocardial perfusion in swine while awake and during 1.0 and 1.5 MAC isoflurane anaesthesia produced without or with 50% nitrous oxide.. Cardiovasc Res 1984;18(6):344-353.
  25. McPherson RW, Traystman RJ. Effects of isoflurane on cerebral autoregulation in dogs.. Anesthesiology 1988;69(4):493-499.
  26. Mutch WA, Patel PM, Ruta TS. A comparison of the cerebral pressure-flow relationship for halothane and isoflurane at haemodynamically equivalent end-tidal concentrations in the rabbit.. Can J Anaesth 1990;37(2):223-230.
  27. Todd MM, Drummond JC. A comparison of the cerebrovascular and metabolic effects of halothane and isoflurane in the cat.. Anesthesiology 1984;60(4):276-282.
  28. Berlin T, Murray-Krezan C, Yonas H. Comparison of parenchymal and ventricular intracranial pressure readings utilizing a novel multi-parameter intracranial access system.. SpringerPlus 2015;4:10.
  29. Khan SH, Kureshi IU, Mulgrew T. Comparison of percutaneous ventriculostomies and intraparenchymal monitor: a retrospective evaluation of 156 patients.. Acta Neurochir Suppl 1998;71:50-52.
  30. Olson DM, Ortega Perez S, Ramsay J. Differentiate the source and site of intracranial pressure measurements using more precise nomenclature.. Neurocrit care 2019;30(2):239-243.
  31. Vender J, Waller J, Dhandapani K, McDonnell D. An evaluation and comparison of intraventricular, intraparenchymal, and fluid-coupled techniques for intracranial pressure monitoring in patients with severe traumatic brain injury.. J Clin Monit Comput 2011;25(4):231-236.
  32. Lawrence CJ, Prinzen FW, de Lange S. The effect of dexmedetomidine on nutrient organ blood flow.. Anesth Analg 1996;83(6):1160-1165.
  33. Yamashita K, Tsubakishita S, Futaok S. Cardiovascular effects of medetomidine, detomidine and xylazine in horses.. J Vet Med Sci 2000;62(10):1025-1032.
  34. McCormick JM, McCormick PW, Zabramski JM, Spetzler RF. Intracranial pressure reduction by a central alpha-2 adrenoreceptor agonist after subarachnoid hemorrhage.. Neurosurgery 1993;32(6):974-979.
  35. Kollias-Baker CA, Court MH, Williams LL. Influence of yohimbine and tolazoline on the cardiovascular, respiratory, and sedative effects of xylazine in the horse.. J Vet Pharmacol Ther 1993;16(3):350-358.
  36. Bailey JE, Dunlop CI, Chapman PL. Indirect Doppler ultrasonic measurement of arterial blood pressure results in a large measurement error in dorsally recumbent anaesthetised horses.. Equine Vet J 1994;26(1):70-73.

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