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Verhaar N, Kopp V, Pfarrer C, Neudeck S, König K, Rohn K, Kästner S. Alpha 2 Antagonist Vatinoxan Does Not Abolish the Preconditioning Effect of Dexmedetomidine on Experimental Ischaemia-Reperfusion Injury in the Equine Small Intestine. Animals (Basel) 2023; 13:2755. [PMID: 37685019 PMCID: PMC10486550 DOI: 10.3390/ani13172755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 08/25/2023] [Accepted: 08/28/2023] [Indexed: 09/10/2023] Open
Abstract
Pharmacological preconditioning with dexmedetomidine has been shown to ameliorate intestinal ischaemia reperfusion injury in different species, including horses. However, it remains unknown if this effect is related to alpha2 adrenoreceptor activity. Therefore, the aim of this study was to determine the effect of dexmedetomidine preconditioning with and without the administration of the peripheral alpha2 antagonist vatinoxan. This prospective randomized experimental trial included 12 horses equally divided between two treatment groups. Horses in group Dex received a bolus of dexmedetomidine followed by a continuous rate infusion (CRI), while group DexV additionally received vatinoxan as bolus and CRI. A median laparotomy was performed under general anaesthesia, and jejunal ischaemia was applied for 90 min, followed by 30 min of reperfusion. Mucosal damage was evaluated in full thickness biopsies by use of a semiquantitative mucosal injury score and by determining the apoptotic cell counts with immunohistochemical staining for cleaved caspase-3 and TUNEL. Comparisons between the groups and time points were performed using non-parametric tests (p < 0.05). During pre-ischaemia and ischaemia, no differences could be found in mucosal injury between the groups. After reperfusion, group DexV showed lower mucosal injury scores compared to group Dex. The apoptotic cell counts did not differ between the groups. In conclusion, antagonizing the peripheral alpha2 adrenoreceptors did not negatively affect dexmedetomidine preconditioning.
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Affiliation(s)
- Nicole Verhaar
- Clinic for Horses, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Veronika Kopp
- Clinic for Horses, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Christiane Pfarrer
- Institute for Anatomy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Stephan Neudeck
- Small Animal Clinic, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Kathrin König
- Clinic for Horses, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Karl Rohn
- Department of Biometry, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Sabine Kästner
- Clinic for Horses, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
- Small Animal Clinic, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
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Dexmedetomidine Has Differential Effects on the Contractility of Equine Jejunal Smooth Muscle Layers In Vitro. Animals (Basel) 2023; 13:ani13061021. [PMID: 36978562 PMCID: PMC10044630 DOI: 10.3390/ani13061021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 02/24/2023] [Accepted: 03/07/2023] [Indexed: 03/18/2023] Open
Abstract
α2 agonists are frequently used in horses with colic, even though they have been shown to inhibit gastrointestinal motility. The aim of this study was to determine the effect of dexmedetomidine on small intestinal in vitro contractility during different phases of ischaemia. Experimental segmental jejunal ischaemia was induced in 12 horses under general anaesthesia, and intestinal samples were taken pre-ischaemia and following ischaemia and reperfusion. Spontaneous and electrically evoked contractile activity of the circular and longitudinal smooth muscles were determined in each sample with and without the addition of dexmedetomidine. During a second experiment, tetrodotoxin was added to determine if the effect was neurogenic. We found that the circular smooth muscle (CSM) contractility was not affected by ischaemia, whereas the longitudinal smooth muscle (LSM) showed an increase in both spontaneous and induced contractile activity. The addition of dexmedetomidine caused a decrease in the spontaneous contractile activity of CSM, but an increase in that of LSM, which was not mediated by the enteric nervous system. During ischaemia, dexmedetomidine also mildly increased the electrically induced contractile activity in LSM. These results may indicate a stimulatory effect of dexmedetomidine on small intestinal contractility. However, the influence of dexmedetomidine administration on intestinal motility in vivo needs to be further investigated.
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Effects of detomidine or romifidine during maintenance and recovery from isoflurane anaesthesia in horses. Vet Anaesth Analg 2022; 49:624-633. [DOI: 10.1016/j.vaa.2022.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 03/23/2022] [Accepted: 07/12/2022] [Indexed: 11/20/2022]
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Niemann L, Kutter A, Joerger F, Wieser M, Hartnack S, Steblaj B. The impact of vatinoxan on microcirculation after intramuscular coadministration with medetomidine in Beagle dogs – a blinded cross-over study. Vet Anaesth Analg 2022; 49:336-343. [DOI: 10.1016/j.vaa.2021.07.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 04/17/2021] [Accepted: 07/15/2021] [Indexed: 10/19/2022]
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Redmond JS, Stang BV, Schlipf JW, Christensen JM. Pharmacokinetics of diphenhydramine following single-dose intravenous and oral administration in non-fasted adult horses. J Vet Pharmacol Ther 2021; 45:188-195. [PMID: 34921427 DOI: 10.1111/jvp.13041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 11/14/2021] [Accepted: 12/12/2021] [Indexed: 11/30/2022]
Abstract
Diphenhydramine is an H1 receptor antagonist used to control urticaria and other allergic signs caused by type I hypersensitivity reactions in horses (Equus caballus). Limited studies have been conducted on pharmacokinetics of this drug in horses, with no studies involving oral formulations. Our study investigated pharmacokinetics of an oral diphenhydramine formulation compared to intravenous administration in non-fasted adult horses. Six healthy horses underwent a single administration of three different doses of diphenhydramine (1 mg/kg intravenously, 1 mg/kg intragastrically, and 5 mg/kg intragastrically) with a two-week washout period between doses. Bioavailability of intragastric diphenhydramine was less than one percent and six percent for 1 mg/kg and 5 mg/kg intragastric doses, respectively. This poor bioavailability is similar to what is reported in dogs. Two of six horses experienced transient side effects after intravenous diphenhydramine administration, emphasizing the need for determining therapeutic plasma levels in efforts to determine the lowest effective dose minimizing risk of adverse effects. The main conclusion of our study was that oral diphenhydramine at doses up to 5 mg/kg are unlikely to achieve therapeutic plasma levels in adult horses.
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Affiliation(s)
- Jeremy S Redmond
- Department of Clinical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, Oregon, USA
| | - Bernadette V Stang
- Department of Clinical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, Oregon, USA
| | - John W Schlipf
- Department of Clinical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, Oregon, USA
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Neudeck S, Twele L, Kopp V, Kästner S. Pharmacodynamics and plasma concentrations of dexmedetomidine with or without vatinoxan as a constant-rate infusion in horses anaesthetized with isoflurane-A pilot study. J Vet Pharmacol Ther 2021; 44:754-765. [PMID: 34159620 DOI: 10.1111/jvp.12992] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 05/13/2021] [Accepted: 06/06/2021] [Indexed: 11/26/2022]
Abstract
The aim was to determine the effects of vatinoxan on dexmedetomidine plasma concentrations and effects on cardiovascular and intestinal tissue pharmacodynamics. In a prospective randomized study, six horses were premedicated intravenously with dexmedetomidine 3.5 µg kg-1 followed by a constant-rate infusion of 7 µg kg-1 h-1 (group DEX) and six horses with dexmedetomidine of the same dose (bolus and constant-rate infusion) combined with vatinoxan 130 µg kg-1 followed by 40 µg kg-1 h-1 (group VAT). Anaesthesia was induced with ketamine and diazepam and maintained with isoflurane. Venous blood samples were withdrawn before and at predefined points in time after drug application. During sedation and anaesthesia, cardiopulmonary variables, gastrointestinal tissue perfusion and oxygenation were recorded. Data were analysed using two-way-ANOVA, unpaired-t-test and Dunnett's-t-test (p < 0.05). Group VAT had significantly higher oxygen delivery and lower oxygen extraction ratio, venous admixture, alveolar dead space and alveolar-arterial-oxygen difference. Tissue perfusion of buccal mucosa was reduced during anaesthesia in group DEX. Plasma concentrations of dexmedetomidine in group VAT (n = 6) and group DEX (n = 5) were comparable between groups. In the present pilot study, co-administration of vatinoxan with dexmedetomidine did not alter plasma concentrations of dexmedetomidine but ameliorated tissue perfusion and global oxygenation variables.
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Affiliation(s)
- Stephan Neudeck
- Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Lara Twele
- Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Veronika Kopp
- Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Sabine Kästner
- Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany.,Clinic for Small Animals, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
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VanderBroek AR, Engiles JB, Kästner SBR, Kopp V, Verhaar N, Hopster K. Protective effects of dexmedetomidine on small intestinal ischaemia-reperfusion injury in horses. Equine Vet J 2020; 53:569-578. [PMID: 32862437 DOI: 10.1111/evj.13337] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 07/06/2020] [Accepted: 08/13/2020] [Indexed: 12/26/2022]
Abstract
BACKGROUND Strangulating small intestinal lesions in the horse have increased morbidity and mortality compared to nonstrangulating obstructions due to mucosal barrier disruption and subsequent endotoxaemia. OBJECTIVES To investigate protective effects of dexmedetomidine on small intestinal ischaemia-reperfusion injury in the horse. STUDY DESIGN Randomised, controlled, experimental study. METHODS Eighteen systemically healthy horses were randomly assigned to three groups: control, preconditioning, and post-conditioning. During isoflurane anaesthesia, complete ischaemia was induced in a 1-m segment of jejunum for 90 minutes. Horses in the preconditioning and post-conditioning groups received dexmedetomidine (3.5 µg/kg followed by 7 µg/kg/h) before (preconditioning) or after beginning ischaemia (post-conditioning), and during reperfusion. Jejunal biopsies were collected before ischaemia (baseline-1), at the end of the ischaemic period (ischaemia), and 30 minutes after reperfusion (reperfusion-1). Additional biopsies were taken 24 hours after reperfusion from ischaemia-reperfusion-injured jejunum (reperfusion-2). Epithelial injury was scored histologically, and morphometric analyses were used to calculate villus surface area (VSA) denuded of epithelium. Data were analysed using analysis of variance, Kruskal-Wallis and Wilcoxon two-sample tests. RESULTS In the control group, epithelial injury scores and percentage of VSA denudation for ischaemia-reperfusion-injured jejunum were higher compared to baseline-1 at all time points. The ischaemia and both reperfusion samples from the pre- and post-conditioning groups had lower epithelial injury scores and percentage of VSA epithelial denudation compared to the control group, with no difference from baseline-1 at any time point for the preconditioning group. MAIN LIMITATIONS Preconditioning has limited application in the clinical setting with naturally occurring strangulating small intestinal lesions. CONCLUSIONS Dexmedetomidine was protective for small intestinal ischaemia-reperfusion injury in the horse when administered before or during ischaemia.
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Affiliation(s)
- Ashley R VanderBroek
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
| | - Julie B Engiles
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA, USA
| | - Sabine B R Kästner
- Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Veronika Kopp
- Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Nicole Verhaar
- Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Klaus Hopster
- Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA, USA
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Boustead KJ, Steyl J, Joubert K. Fatal post‐anaesthetic pulmonary haemorrhage in a horse suffering from chronic‐active exercise‐induced pulmonary haemorrhage. EQUINE VET EDUC 2020. [DOI: 10.1111/eve.13292] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- K. J. Boustead
- Companion Animal Clinical Studies Faculty of Veterinary Sciences University of Pretoria Pretoria South Africa
- Anaesthesia and Critical Care Service Valley Farm Animal Hospital Pretoria South Africa
| | - J. Steyl
- Paraclinical Sciences Section of Pathology Faculty of Veterinary Sciences University of Pretoria Pretoria South Africa
| | - K. Joubert
- Companion Animal Clinical Studies Faculty of Veterinary Sciences University of Pretoria Pretoria South Africa
- Veterinary Anaesthesia Analgesia and Critical Care Service Johannesburg South Africa
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König KS, Verhaar N, Hopster K, Pfarrer C, Neudeck S, Rohn K, Kästner SBR. Ischaemic preconditioning and pharmacological preconditioning with dexmedetomidine in an equine model of small intestinal ischaemia-reperfusion. PLoS One 2020; 15:e0224720. [PMID: 32348301 PMCID: PMC7190151 DOI: 10.1371/journal.pone.0224720] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 04/08/2020] [Indexed: 02/06/2023] Open
Abstract
Small intestinal strangulation associated with ischaemia-reperfusion injury (IRI) is common in horses. In laboratory animals IRI can be ameliorated by ischaemic preconditioning (IPC) and pharmacological preconditioning (PPC) with dexmedetomidine. The aim of this study was to determine the effect of PPC with dexmedetomidine or IPC in an equine model of small intestinal ischaemia-reperfusion (IR). In a randomized controlled experimental trial, 15 horses were assigned to three groups: control (C), IPC, and PPC with dexmedetomidine (DEX). All horses were placed under general anaesthesia and 90% jejunal ischaemia was induced for 90 minutes, followed 30 minutes of reperfusion. In group IPC, three short bouts of ischaemia and reperfusion were implemented, and group DEX received a continuous rate infusion of dexmedetomidine prior to the main ischaemia. Jejunal biopsies were collected before ischaemia (P), and at the end of ischaemia (I) and reperfusion (R). Mucosal injury was assessed by the Chiu-Score, inflammatory cells were stained by cytosolic calprotectin. The degree of apoptosis and cell necrosis was assessed by cleaved-caspase-3 and TUNEL. Parametric data were analyzed by two-way ANOVA for repeated measurements followed by Dunnetts t-test. Non parametric data were compared between groups at the different time points by a Kruskal-Wallis-Test and a Wilcoxon-2-Sample-test. The mucosal injury score increased during I in all groups. After reperfusion, IRI further progressed in group C, but not in IPC and DEX. In all groups the number of cleaved caspase-3 and TUNEL positive cells increased from P to I. The number of TUNEL positive cells were lower in group DEX compared to group C after I and R. Infiltration with calprotectin positive cells was less pronounced in group DEX compared to group C, whereas in group IPC more calprotectin positive cells were seen. In conclusion, IPC and DEX exert protective effects in experimental small intestinal ischaemia in horses.
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Affiliation(s)
- Kathrin S. König
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Nicole Verhaar
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Klaus Hopster
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Christiane Pfarrer
- Institute for Anatomy, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Stephan Neudeck
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Karl Rohn
- Department of Biometry, Epidemiology and Information Processing, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Sabine B. R. Kästner
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
- Clinic for Small Animals, University of Veterinary Medicine Hannover, Hannover, Germany
- * E-mail:
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Verhaar N, Pfarrer C, Neudeck S, König K, Rohn K, Twele L, Kästner S. Preconditioning with lidocaine and xylazine in experimental equine jejunal ischaemia. Equine Vet J 2020; 53:125-133. [PMID: 32119148 DOI: 10.1111/evj.13251] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 12/17/2019] [Accepted: 02/20/2020] [Indexed: 01/01/2023]
Abstract
BACKGROUND Pharmacological preconditioning of dexmedetomidine on small intestinal ischaemia/reperfusion injury has been reported in different animal models including horses. OBJECTIVES The objective was to assess if xylazine and lidocaine have a preconditioning effect in an experimental model of equine jejunal ischaemia. STUDY DESIGN Terminal in vivo experiment. METHODS Ten horses under general anaesthesia were either preconditioned with xylazine (group X; n = 5) or lidocaine (group L; n = 5). A historical untreated control group (group C; n = 5) was used for comparison. An established experimental model of equine jejunal ischaemia was applied, and intestinal samples were taken pre-ischaemia, after ischaemia and following reperfusion. Histomorphological examination was performed based on a modified Chiu score. Immunohistochemical staining for cleaved caspase-3, TUNEL and calprotectin was performed, and positive cell counts were expressed in cells/mm2 . RESULTS There was no progression of histomorphological mucosal injury from ischaemia to reperfusion, and there were no differences in histomorphology between the groups. After ischaemia, group X had significantly less caspase-positive cells compared to the control group with a median difference of 227% (P = .01). After reperfusion, group X exhibited significantly lower calprotectin-positive cell counts compared to the control group, with a median difference of 6.8 cells/mm2 in the mucosa and 44 cells in the serosa (P = .02 and .05 respectively). All groups showed an increase in caspase- and calprotectin-positive cells during reperfusion (P < .05). TUNEL-positive cells increased during ischaemia, followed by a decrease after reperfusion (P < .05). MAIN LIMITATIONS The small sample size and the use of a historical control group. Preconditioning effects of the tested drugs may be masked by the protective effects of isoflurane in the anaesthetic protocol. CONCLUSIONS Preconditioning with lidocaine did not have any effect on the tested variables. The lower cell counts of caspase- and calprotectin-positive cells in group X may indicate a beneficial effect of xylazine on ischaemia/reperfusion injury. Due to the absence of a concurrent reduction of histomorphological injury, the clinical significance remains uncertain.
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Affiliation(s)
- Nicole Verhaar
- Clinic for Horses, University of Veterinary Medicine, Hannover, Germany
| | - Christiane Pfarrer
- Institute for Anatomy, University of Veterinary Medicine, Hannover, Germany
| | - Stephan Neudeck
- Clinic for Horses, University of Veterinary Medicine, Hannover, Germany
| | - Kathrin König
- Clinic for Horses, University of Veterinary Medicine, Hannover, Germany
| | - Karl Rohn
- Department of Biometry, University of Veterinary Medicine, Hannover, Germany
| | - Lara Twele
- Clinic for Horses, University of Veterinary Medicine, Hannover, Germany
| | - Sabine Kästner
- Clinic for Horses, University of Veterinary Medicine, Hannover, Germany
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Tapio HA, Raekallio MR, Mykkänen AK, Al-Ramahi D, Scheinin M, Hautajärvi HJ, Männikkö S, Vainio O. Effects of vatinoxan on cardiorespiratory function, fecal output and plasma drug concentrations in horses anesthetized with isoflurane and infusion of medetomidine. Vet J 2019; 251:105345. [PMID: 31492389 DOI: 10.1016/j.tvjl.2019.105345] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 07/21/2019] [Accepted: 07/23/2019] [Indexed: 11/17/2022]
Abstract
A constant rate infusion (CRI) of medetomidine is used to balance equine inhalation anesthesia, but its cardiovascular side effects are a concern. This experimental crossover study aimed to evaluate the effects of vatinoxan (a peripheral α2-adrenoceptor antagonist) on cardiorespiratory and gastrointestinal function in anesthetized healthy horses. Six horses received medetomidine hydrochloride 7μg/kg IV alone (MED) or with vatinoxan hydrochloride 140μg/kg IV (MED+V). Anesthesia was induced with midazolam and ketamine and maintained with isoflurane and medetomidine CRI for 60min. Heart rate, carotid and pulmonary arterial pressures, central venous pressure, cardiac output and arterial and mixed venous blood gases were measured. Selected cardiopulmonary parameters were calculated. Plasma drug concentrations were determined. Fecal output was measured over 24h. For statistical comparisons, repeated measures analysis of covariance and paired t-tests were applied. Heart rate decreased slightly from baseline in the MED group. Arterial blood pressures decreased with both treatments, but significantly more dobutamine was needed to maintain normotension with MED+V (P=0.018). Cardiac index (CI) and oxygen delivery index (DO2I) decreased significantly more with MED, with the largest difference observed at 20min: CI was 39±2 and 73±18 (P=0.009) and DO2I 7.4±1.2 and 15.3±4.8 (P=0.014)mL/min/kg with MED and MED+V, respectively. Fecal output or plasma concentrations of dexmedetomidine did not differ between the treatments. In conclusion, premedication with vatinoxan induced hypotension, thus its use in anesthetized horses warrants further studies. Even though heart rate and arterial blood pressures remained clinically acceptable with MED, cardiac performance and oxygen delivery were lower than with MED+V.
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Affiliation(s)
- H A Tapio
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 57, 00014, Finland.
| | - M R Raekallio
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 57, 00014, Finland
| | - A K Mykkänen
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 57, 00014, Finland
| | - D Al-Ramahi
- Bioanalytical Laboratory, Institute of Biomedicine, Kiinamyllynkatu 10, 20520 Turku, Finland; Unit of Clinical Pharmacology, Turku University Hospital, P.O. Box 52, 20521 Turku, Finland
| | - M Scheinin
- Bioanalytical Laboratory, Institute of Biomedicine, Kiinamyllynkatu 10, 20520 Turku, Finland; Unit of Clinical Pharmacology, Turku University Hospital, P.O. Box 52, 20521 Turku, Finland
| | | | - S Männikkö
- 4Pharma Ltd., Tykistökatu 4D, 20520 Turku, Finland
| | - O Vainio
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 57, 00014, Finland
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