Comparison of circulatory and respiratory effects of isoflurane and halothane anesthesia in horses.
Abstract: Circulatory and respiratory effects of alveolar concentrations of 1.31, 1.97, and 2.62 vol% of isoflurane in oxygen were studied in eight young, healthy horses during spontaneous and controlled ventilation. These isoflurane concentrations were equivalent, respectively, to 1.0, 1.5, and 2.0 times the minimal alveolar concentration of isoflurane, which prevents movement in horses in response to a standard pain stimulus. Results of the isoflurane studies were compared with similarly derived findings in these same horses during equipotent halothane in oxygen anesthesia. Isoflurane, similar to halothane, produced a dose-related depression of cardiovascular function which was less severe during spontaneous ventilation and associated hypercapnia. The two anesthetic agents produced similar circulatory effects during controlled ventilation and constant arterial carbon dioxide tension except for a significantly (P less than 0.05) less depressed cardiac output/kg of body weight and stroke volume that occurred with minimal alveolar concentration 1.5 and 2.0 isoflurane. Total peripheral resistance was greatest when these horses were anesthetized with halothane regardless of the alveolar dose. In horses, isoflurane was, in general, no more depressing than was halothane to circulatory and respiratory function.
Publication Date: 1980-05-01 PubMed ID: 7406305
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- Journal Article
- Research Support
- U.S. Gov't
- P.H.S.
Summary
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This research article compares the circulatory and respiratory impacts of two types of anesthesia, isoflurane and halothane, in horses. The study suggests that isoflurane is generally no more detrimental to circulatory and respiratory function in horses than halothane.
Research Methodology
- The study involved eight young, healthy horses. The animals were subjected to alveolar concentrations of 1.31, 1.97, and 2.62 vol% of isoflurane in oxygen during both spontaneous and controlled ventilation. The chosen isoflurane concentrations were equivalent to 1.0, 1.5, and 2.0 times the minimal alveolar concentration of isoflurane that prevents movement in horses in response to a standard pain stimulus.
- The results obtained from these isoflurane studies were then compared with findings derived from the same group of horses undergoing halothane in oxygen anesthesia.
Key Findings
- The research revealed that isoflurane, similar to halothane, induced a dose-related decline of cardiovascular function. This impact was less severe during spontaneous ventilation and associated hypercapnia.
- The two anesthetic agents induced comparable circulatory effects during controlled ventilation and constant arterial carbon dioxide tension. Still, there was a notably less depressed cardiac output/kg of body weight and stroke volume with isoflurane at minimal alveolar concentration 1.5 and 2.0.
- The total peripheral resistance was highest when the horses were anesthetized with halothane, irrespective of the alveolar dose.
Conclusion
- The research suggests that isoflurane was typically no more depressing to horses’ circulatory and respiratory function than halothane. This insight could be important for veterinary surgical practices, offering an alternative anesthetic agent for use in horses.
Cite This Article
APA
Steffey EP, Howland D.
(1980).
Comparison of circulatory and respiratory effects of isoflurane and halothane anesthesia in horses.
Am J Vet Res, 41(5), 821-825.
Publication
Researcher Affiliations
MeSH Terms
- Anesthesia / veterinary
- Animals
- Cardiovascular System / drug effects
- Female
- Halothane / pharmacology
- Horses / physiology
- Isoflurane / pharmacology
- Male
- Methyl Ethers / pharmacology
- Respiration / drug effects
Citations
This article has been cited 14 times.- Rabbogliatti V, Amari M, Brioschi FA, Di Cesare F, Zani DD, De Zani D, Di Giancamillo M, Cagnardi P, Ravasio G. Use of dexmedetomidine repeated subcutaneous administration for balanced anaesthesia in horses. BMC Vet Res 2022 Jul 11;18(1):269.
- Poon YY, Tsai CY, Huang YH, Wu JCC, Chan SHH, Chan JYH. Disproportional cardiovascular depressive effects of isoflurane: Serendipitous findings from a comprehensive re-visit in mice. Lab Anim (NY) 2021 Jan;50(1):26-31.
- Morris TB, Lumsden JM, Dunlop CI, Locke V, Sommerauer S, Hurcombe SDA. Clinical Assessment of an Ipsilateral Cervical Spinal Nerve Block for Prosthetic Laryngoplasty in Anesthetized Horses. Front Vet Sci 2020;7:284.
- Williams DC, Brosnan RJ, Fletcher DJ, Aleman M, Holliday TA, Tharp B, Kass PH, LeCouteur RA, Steffey EP. Qualitative and Quantitative Characteristics of the Electroencephalogram in Normal Horses during Administration of Inhaled Anesthesia. J Vet Intern Med 2016 Jan-Feb;30(1):289-303.
- Conde Ruiz C, Cruz Benedetti IC, Guillebert I, Portier KG. Effect of Pre- and Postoperative Phenylbutazone and Morphine Administration on the Breathing Response to Skin Incision, Recovery Quality, Behavior, and Cardiorespiratory Variables in Horses Undergoing Fetlock Arthroscopy: A Pilot Study. Front Vet Sci 2015;2:58.
- Umar MA, Fukui S, Kawase K, Itami T, Yamashita K. Cardiovascular effects of total intravenous anesthesia using ketamine-medetomidine-propofol (KMP-TIVA) in horses undergoing surgery. J Vet Med Sci 2015 Mar;77(3):281-8.
- Brosnan RJ. Inhaled anesthetics in horses. Vet Clin North Am Equine Pract 2013 Apr;29(1):69-87.
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- Pascoe PJ, McDonell WN, Trim CM, Van Gorder J. Mortality rates and associated factors in equine colic operations - a retrospective study of 341 operations. Can Vet J 1983 Mar;24(3):76-85.
- Khanna AK, McDonell WN, Dyson DH, Taylor PM. Cardiopulmonary effects of hypercapnia during controlled intermittent positive pressure ventilation in the horse. Can J Vet Res 1995 Jul;59(3):213-21.
- Burrows FA, Klinck JR, Rabinovitch M, Bohn DJ. Pulmonary hypertension in children: perioperative management. Can Anaesth Soc J 1986 Sep;33(5):606-28.
- Gorenberg EB, Slack J, Stefanovski D, Theiss D, Hopster K. Dobutamine improves haemodynamics and oxygen delivery in standing and isoflurane-anaesthetised horses. Equine Vet J 2025 Nov;57(6):1677-1689.
- Lambertini C, Spaccini F, Mazzanti A, Spadari A, Lanci A, Romagnoli N. Lidocaine constant rate infusion in isoflurane anesthetized neonatal foals. Front Vet Sci 2023;10:1304868.
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