Effects of dexmedetomidine and xylazine on cardiovascular function during total intravenous anaesthesia with midazolam and ketamine and recovery quality and duration in horses.
Abstract: To compare cardiovascular effects and recovery quality and duration of total intravenous anaesthesia (TIVA) with xylazine-ketamine-midazolam or dexmedetomidine-ketamine-midazolam. Methods: Prospective, randomized experimental cross-over trial. Methods: Eight adult warmblood horses. Methods: After sedation with acepromazine and either xylazine [0.5 mg kg(-1) , intravenously (IV)] or dexmedetomidine (3.5 μg kg(-1) IV) anaesthesia was induced with ketamine and midazolam and maintained with a constant rate infusion (CRI) of xylazine (1 mg kg(-1) hour(-1) ) [XKM] or dexmedetomidine (7 μg kg(-1) hour(-1) ) [DKM] in combination with midazolam (0.1 mg kg(-1) hour(-1) ), and ketamine infusion (initially 3 mg kg(-1) hour(-1) ) for 120 minutes. Ketamine infusion rate was increased in response to positive reactions to electrical nociceptive stimulation performed every 30 minutes. Heart rate (HR), mean arterial blood pressure (MAP) and cardiac output (Q˙t) were measured before treatment (baseline), after sedation (not Q˙t), and during anaesthesia. Xylazine, dexmedetomidine, midazolam and ketamine kinetics were calculated, from plasma drug concentrations. Twenty minutes after end of TIVA, flumazenil (0.01 mg kg(-1) IV) was administered. Recovery quality and duration were assessed. Two-way analysis of variance with repeated measurements or Wilcoxon signed rank test as relevant were used to analyse data with an alpha of 5%. Results: Compared to baseline, MAP did not change, while similar, but limited, decreases in HR and Q˙t were observed in both TIVA's. Mean ketamine doses of 3.7 mg kg(-1) hour(-1) were required with both treatments. Plasma concentrations of dexmedetomidine and xylazine showed high intra- and inter-individual changes with elimination half-lifes of 46 ± 7 minutes and 64 ± 13 minutes, respectively. Recovery quality was good to excellent with mean duration of 37 ± 16 and 46 ± 21 minutes after stopping TIVA with XKM and DKM, respectively. Conclusions: Both drug combinations are suitable to maintain anaesthesia for two hours, with good cardiovascular and good to excellent recovery conditions.
© 2013 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.
Publication Date: 2013-10-15 PubMed ID: 24127757DOI: 10.1111/vaa.12095Google Scholar: Lookup
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- Journal Article
- Randomized Controlled Trial
Summary
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This research compares the cardiovascular effects and recovery quality and duration following total intravenous anaesthesia (TIVA) in horses with either xylazine-ketamine-midazolam or dexmedetomidine-ketamine-midazolam combinations. The study finds that both combinations can effectively maintain anaesthesia for two hours with good cardiovascular condition and excellent recovery quality.
Objective and Methodology
- The objective of the study was to compare the cardiovascular effects and the quality and duration of recovery from total intravenous anaesthesia administered using either xylazine-ketamine-midazolam or dexmedetomidine-ketamine-midazolam.
- In a randomized cross-over trial, eight adult warmblood horses were utilized. After sedation with acepromazine and either xylazine or dexmedetomidine, anaesthesia was initiated with ketamine and midazolam. The anaesthesia was sustained with xylazine (in the XKM group) or dexmedetomidine (in the DKM group) in combination with midazolam and ketamine infusion for 120 minutes.
- Measurements such as heart rate, mean arterial blood pressure, and cardiac output were taken before treatment for baseline, after sedation, and during anaesthesia.
- Plasma drug concentrations were monitored to calculate the kinetics of xylazine, dexmedetomidine, midazolam, and ketamine. Twenty minutes after TIVA was stopped, flumazenil was administered to the horses.
Results
- Similar yet minor decreases in heart rate and cardiac output were observed in both anaesthesia groups when compared to baseline. The mean arterial blood pressure did not significantly change.
- The mean dosage of ketamine required was similar for both groups.
- There were notable intra- and inter-individual changes in the plasma concentrations of dexmedetomidine and xylazine, with elimination half-lives of approximately 46 minutes and 64 minutes respectively.
Recovery Quality and Duration
- The quality of recovery was rated as good to excellent, with the mean duration being 37 minutes for the XKM group and 46 minutes for the DKM group after stopping TIVA.
- The study concluded that both drug combinations are effectively suitable to maintain anaesthesia for two hours in horses, with good cardiovascular conditions and excellent recovery conditions.
Cite This Article
APA
Hopster K, Müller C, Hopster-Iversen C, Stahl J, Rohn K, Kästner S.
(2013).
Effects of dexmedetomidine and xylazine on cardiovascular function during total intravenous anaesthesia with midazolam and ketamine and recovery quality and duration in horses.
Vet Anaesth Analg, 41(1), 25-35.
https://doi.org/10.1111/vaa.12095 Publication
Researcher Affiliations
- Equine Clinic, University of Veterinary Medicine Hanover, Foundation, Hanover, Germany.
MeSH Terms
- Anesthesia Recovery Period
- Anesthetics, Dissociative / administration & dosage
- Anesthetics, Dissociative / pharmacology
- Animals
- Blood Pressure / drug effects
- Cross-Over Studies
- Dexmedetomidine / administration & dosage
- Dexmedetomidine / pharmacology
- Drug Therapy, Combination
- Heart Rate / drug effects
- Horses
- Hypnotics and Sedatives / administration & dosage
- Hypnotics and Sedatives / pharmacology
- Ketamine / administration & dosage
- Ketamine / pharmacology
- Midazolam / administration & dosage
- Midazolam / pharmacology
- Time Factors
- Xylazine / administration & dosage
- Xylazine / pharmacology
Citations
This article has been cited 7 times.- Abass M, Ibrahim H, Salci H, Hamed MA. Evaluation of the effect of different sedative doses of dexmedetomidine on the intestinal motility in clinically healthy donkeys (Equus asinus).. BMC Vet Res 2022 Jul 14;18(1):274.
- Wilkens HL, Neudeck S, Kästner SBR. Nasal and tracheobronchial nitric oxide production and its influence on oxygenation in horses undergoing total intravenous anaesthesia.. BMC Vet Res 2022 Apr 11;18(1):134.
- Tucker L, Almeida D, Wendt-Hornickle E, Baldo CF, Allweiler S, Guedes AGP. Effect of 15° Reverse Trendelenburg Position on Arterial Oxygen Tension during Isoflurane Anesthesia in Horses.. Animals (Basel) 2022 Feb 1;12(3).
- Gozalo-Marcilla M, Ringer SK. Recovery after General Anaesthesia in Adult Horses: A Structured Summary of the Literature.. Animals (Basel) 2021 Jun 14;11(6).
- Hopster K, Wittenberg-Voges L, Geburek F, Hopster-Iversen C, Kästner SBR. Effects of controlled hypoxemia or hypovolemia on global and intestinal oxygenation and perfusion in isoflurane anesthetized horses receiving an alpha-2-agonist infusion.. BMC Vet Res 2017 Nov 28;13(1):361.
- Yavari S, Khraim N, Szura G, Starke A, Engelke E, Pfarrer C, Hopster K, Schmicke M, Kehler W, Heppelmann M, Kästner SBR, Rehage J. Evaluation of intravenous regional anaesthesia and four-point nerve block efficacy in the distal hind limb of dairy cows.. BMC Vet Res 2017 Nov 7;13(1):320.
- Marly-Voquer C, Schwarzwald CC, Bettschart-Wolfensberger R. The use of dexmedetomidine continuous rate infusion for horses undergoing transvenous electrical cardioversion--A case series.. Can Vet J 2016 Jan;57(1):70-5.
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