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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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Mühlemann S, Leandri M, Risberg ÅI, Spadavecchia C. Comparison of Threshold and Tolerance Nociceptive Withdrawal Reflexes in Horses. Animals (Basel) 2021; 11:ani11123380. [PMID: 34944157 PMCID: PMC8698093 DOI: 10.3390/ani11123380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/23/2021] [Accepted: 11/25/2021] [Indexed: 11/30/2022] Open
Abstract
Simple Summary Nociception is the physiological basis of the complex experience of pain. An established model for its quantification in equine studies is based on the nociceptive withdrawal reflex evoked by electrical stimulation of a sensory nerve. The reflex is recorded via electromyography and it is common to determine the threshold at which a nociceptive-specific reflex activity can be observed. In the present study, the classical methodology was expanded for a deeper understanding of the physiology of nociceptive reflexes in horses. First, for each individual horse, a threshold was determined as the minimal stimulation intensity able to evoke a nociceptive withdrawal reflex. Second, the stimulation intensity was stepwise increased up to tolerance, which was defined as the stimulus that is able to elicit the maximal tolerable behavioral reaction. The characteristics of the reflex activity on the electromyographic records were compared for threshold and tolerance stimulation intensities. At tolerance, the reflex became faster and wider than at threshold, indicating that either a spinal summation mechanism or the recruitment of faster sensory fibers occurs in response to high-intensity noxious stimuli. A novel endpoint (i.e., tolerance) can now be considered when applying the nociceptive withdrawal reflex model in equine studies. Abstract The nociceptive withdrawal reflex (NWR) is used to investigate nociception in horses. The NWR threshold is a classical model endpoint. The aims of this study were to determine NWR tolerance and to compare threshold and tolerance reflexes in horses. In 12 horses, the NWR was evoked through electrical stimulation of the digital nerve and recorded via electromyography from the deltoid. Behavioral reactions were scored from 0 to 5 (tolerance). First, the individual NWR threshold was defined, then stimulation intensity was increased to tolerance. The median NWR threshold was 7.0 mA, whereas NWR tolerance was 10.7 mA. Upon visual inspection of the records, two main reflex components R1 (median latency 44 ms) and R2 (median latency 81 ms) were identified at threshold. Increasing stimulation intensity to tolerance led to a significant increase in the amplitude and duration of R1 and R2, whereas their latency decreased. At tolerance, a single burst of early, high-amplitude reflex activity, with a median latency of 39 ms, was detected in 15 out of 23 stimulations (65%). The results of this study suggest that (1) it is feasible to determine NWR tolerance in horses and (2) high-intensity stimuli initiate ultrafast bursts of reflex activity, which is well known in practice and has now been quantified using the NWR model.
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Affiliation(s)
- Selina Mühlemann
- Department of Clinical Veterinary Medicine, Anaesthesia Section, Vetsuisse Faculty Bern, 3012 Bern, Switzerland;
| | - Massimo Leandri
- Department of Neuroscience, University of Genova, 16132 Genova, Italy;
| | - Åse Ingvild Risberg
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433 Ås, Norway;
| | - Claudia Spadavecchia
- Department of Clinical Veterinary Medicine, Anaesthesia Section, Vetsuisse Faculty Bern, 3012 Bern, Switzerland;
- Correspondence: ; Tel.: +41-31-684-29-57
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de Oliveira AR, Gozalo-Marcilla M, Ringer SK, Schauvliege S, Fonseca MW, Trindade PHE, Puoli Filho JNP, Luna SPL. Development, Validation, and Reliability of a Sedation Scale in Horses (EquiSed). Front Vet Sci 2021; 8:611729. [PMID: 33665216 PMCID: PMC7921322 DOI: 10.3389/fvets.2021.611729] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 01/15/2021] [Indexed: 12/11/2022] Open
Abstract
The lack of standardization of sedation scales in horses limits the reproducibility between different studies. This prospective, randomized, blinded, horizontal and controlled trial aimed to validate a scale for sedation in horses (EquiSed). Seven horses were treated with intravenous detomidine in low/high doses alone (DL 2.5 μg/kg + 6.25 μg/kg/h; DH 5 μg/kg +12.5 μg/kg/h) or associated with methadone (DLM and DHM, 0.2 mg/kg + 0.05 mg/kg/h) and with low (ACPL 0.02 mg/kg) or high (ACPH 0.09 mg/kg) doses of acepromazine alone. Horses were filmed at (i) baseline (ii) peak, (iii) intermediate, and (iv) end of sedation immediately before auditory, visual and pressure stimuli were applied and postural instability evaluated for another study. Videos were randomized and blindly evaluated by four evaluators in two phases with 1-month interval. Intra- and interobserver reliability of the sum of EquiSed (Intraclass correlation coefficient) ranged between 0.84-0.94 and 0.45-0.88, respectively. The criterion validity was endorsed by the high Spearman correlation between the EquiSed and visual analog (0.77), numerical rating (0.76), and simple descriptive scales (0.70), and average correlation with head height above the ground (HHAG) (-0.52). The Friedman test confirmed the EquiSed responsiveness over time. The principal component analysis showed that all items of the scale had a load factor ≥ 0.50. The item-total Spearman correlation for all items ranged from 0.3 to 0.5, and the internal consistency was good (Cronbach's α = 0.73). The area under the curve of EquiSed HHAG as a predictive diagnostic measure was 0.88. The sensitivity of the EquiSed calculated according to the cut-off point (score 7 of the sum of the EquiSed) determined by the receiver operating characteristic curve, was 96% and specificity was 83%. EquiSed has good intra- and interobserver reliabilities and is valid to evaluate tranquilization and sedation in horses.
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Affiliation(s)
- Alice Rodrigues de Oliveira
- Department of Veterinary Surgery and Animal Reproduction, School of Veterinary Medicine and Animal Science, São Paulo State University Universidade Estadual Paulista (UNESP), Botucatu, Brazil
| | - Miguel Gozalo-Marcilla
- The Royal (Dick) School of Veterinary Studies and The Roslin Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Simone Katja Ringer
- Section Anaesthesiology, Department of Clinical Diagnostics and Services, Vetsuisse Faculty, University of Zürich, Zurich, Switzerland
| | - Stijn Schauvliege
- Department of Surgery and Anaesthesia of Domestic Animals, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Mariana Werneck Fonseca
- Department of Veterinary Surgery and Animal Reproduction, School of Veterinary Medicine and Animal Science, São Paulo State University Universidade Estadual Paulista (UNESP), Botucatu, Brazil
| | - Pedro Henrique Esteves Trindade
- Department of Veterinary Surgery and Animal Reproduction, School of Veterinary Medicine and Animal Science, São Paulo State University Universidade Estadual Paulista (UNESP), Botucatu, Brazil
| | - José Nicolau Prospero Puoli Filho
- Department of Veterinary Surgery and Animal Reproduction, School of Veterinary Medicine and Animal Science, São Paulo State University Universidade Estadual Paulista (UNESP), Botucatu, Brazil
| | - Stelio Pacca Loureiro Luna
- Department of Veterinary Surgery and Animal Reproduction, School of Veterinary Medicine and Animal Science, São Paulo State University Universidade Estadual Paulista (UNESP), Botucatu, Brazil
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Shane SE, Langston VC, Wills RW, Denney WS, Knych H, Fontenot RL, Meyer RE, Natalini CC. Pharmacokinetics and pharmacodynamics of intravenous continuous rate infusion and repeated intramuscular administration of dexmedetomidine in standing horses. J Vet Pharmacol Ther 2021; 44:533-543. [PMID: 33576078 DOI: 10.1111/jvp.12951] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 01/04/2021] [Accepted: 01/19/2021] [Indexed: 11/28/2022]
Abstract
An ideal dexmedetomidine protocol has yet to be determined for standing sedation in horses. It was hypothesized that an IV bolus followed by CRI dexmedetomidine would have a quicker increase in plasma concentrations compared with repeated IM injections. In a crossover design, eight adult, female horses were randomly placed into two groups: the CRI group (IV bolus dexmedetomidine at 0.005 mg/kg followed by a CRI at 0.01 mg/kg/h for 15 min then 0.005 mg/kg/h for 60 min) and the IM group (dexmedetomidine at 0.01 mg/kg, followed by 0.005 mg/kg in 30-min intervals for 60 min). Clearance and elimination half-life were 134 ± 67.4 ml/kg/min and 44.3 ± 26.3 min, respectively, in the CRI group, and apparent clearance and half-life were 412 ± 306 ml/kg/min (Cl/F) and 38.9 ± 18.6 min, respectively, in the IM group. Analgesia was evaluated using mechanical pressure threshold. Intravenous dexmedetomidine produced faster onset of sedation and increased pressure threshold compared with IM administration. Individual horses had a large variability in dexmedetomidine plasma concentrations between CRI and IM administration. The odds of a decreased GI motility following IV administration was 12.34 times greater compared with IM administration.
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Affiliation(s)
- Sarah E Shane
- Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
| | - Vernon C Langston
- Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
| | - Robert W Wills
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
| | | | - Heather Knych
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Robin L Fontenot
- Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
| | - Robert E Meyer
- Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
| | - Claudio C Natalini
- Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
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The effect of regional hypothermia on mechanical nociceptive thresholds in the equine distal forelimb. Vet J 2021; 269:105607. [PMID: 33593491 DOI: 10.1016/j.tvjl.2021.105607] [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: 07/05/2019] [Revised: 11/24/2020] [Accepted: 12/30/2020] [Indexed: 11/24/2022]
Abstract
Regional hypothermia has shown promise as analgesic in horses when used to manage painful conditions of the distal limb such as laminitis. In this prospective study, the analgesic effects of regional hypothermia were assessed using mechanical nociceptive thresholds during distal limb cooling. The study population consisted of eight healthy adult Standardbred horses, selected from a teaching herd. A distal forelimb of each horse was cooled using water immersion at the following sequential target water temperatures: 34 °C, 20 °C, 10 °C, 5 °C, 1 °C, 5 °C, 10 °C, 20 °C. Limb surface temperature was measured after 30 min at each target water temperature and the mechanical force required to elicit a response (mechanical nociceptive threshold) was determined using a pneumatic actuator. Both forelimbs of each horse were tested one week apart. At skin surface temperatures above 7 °C, there was little association between skin surface temperature and the mechanical force required to elicit a response. As the skin surface temperature decreased below 7 °C, there was a rapid increase in the force required to elicit a response (P = 0.036). Skin surface temperatures of <7 °C required water temperatures below 2 °C. The results of this study suggest that hypothermia has potential to provide distal limb analgesia in horses at skin surface temperatures below 7 °C. Further evaluation of the technique is warranted.
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Grady SE, Lescun TB, Moore GE, Cooper BR, Davern AJ, Brunner TJ, Taylor SD. Ketorolac Is Not More Effective Than Flunixin Meglumine or Phenylbutazone in Reducing Foot Pain in Horses. J Equine Vet Sci 2020; 94:103204. [PMID: 33077087 DOI: 10.1016/j.jevs.2020.103204] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 07/18/2020] [Accepted: 07/20/2020] [Indexed: 10/23/2022]
Abstract
The objective was to compare the analgesic efficacy of ketorolac tromethamine (KT) and two other nonsteroidal anti-inflammatory drugs (NSAIDs), including flunixin meglumine (FM) and phenylbutazone (PB), using a heart bar shoe (HBS) model of reversible foot lameness in horses. Nine adult horses were used in a blinded, randomized, placebo-controlled crossover study. After induction of left front limb lameness using a modified HBS model, one of three NSAIDs (KT, 2.0 mg/kg IV; FM, 1.1 mg/kg IV; PB, 4.4 mg/kg IV) or saline (placebo) was administered IV as a single dose. Lameness was assessed every 30 minutes for 2 hours, then every hour up to 12 hours using both a lameness grading scale (lameness score; LS) and a body-mounted inertial sensor system (lameness locator; LL). High-performance liquid chromatography and mass spectrometry were used to measure plasma drug concentration at various time points. There was no difference in percent reduction of LS or LL value between KT and any other group, or between FM and placebo. The PB group showed a significantly higher percentage in LS reduction than the placebo and FM groups. The mean percent reduction in LL value was greater for the PB group than that for the placebo and FM groups. Plasma drug concentration was similar among horses for each drug at each time point, with drug concentrations decreasing over time. Thus, variation in plasma drug concentration did not influence lameness reduction for any drug. Ketorolac tromethamine was not superior to FM or PB in reducing lameness using a HBS model.
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Affiliation(s)
- Shannon E Grady
- Department of Veterinary Teaching Hospital, College of Veterinary Medicine, Purdue University, West Lafayette, IN
| | - Timothy B Lescun
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN
| | - George E Moore
- Department of Veterinary Administration, College of Veterinary Medicine, Purdue University, West Lafayette, IN
| | - Bruce R Cooper
- Bindley Bioscience Center, Purdue University, West Lafayette, IN
| | - Alec J Davern
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN
| | - Timothy J Brunner
- Department of Veterinary Teaching Hospital, College of Veterinary Medicine, Purdue University, West Lafayette, IN
| | - Sandra D Taylor
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN.
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Dexmedetomidine and Bupivacaine Association in Caudal Epidural Injection in Mares. J Equine Vet Sci 2020; 91:103015. [PMID: 32684274 DOI: 10.1016/j.jevs.2020.103015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 03/13/2020] [Accepted: 03/30/2020] [Indexed: 11/23/2022]
Abstract
The objective of the study was to compare the effects of caudal epidural bupivacaine and dexmedetomidine (DEX) combination, with bupivacaine or DEX plain for perineal analgesia in mares. Six healthy saddle mares weighing 330-370 kg and aged 10-15 years were used in this study. Each mare was assigned to receive three treatments: 0.04 mg/kg 0.25% bupivacaine (BP), 2 μg/kg DEX (DX), or 0.02 mg/kg bupivacaine and 1 μg/kg DEX (BPDX). The order of treatments was randomized. All drugs were injected into the caudal epidural space (Co1-Co2) through a 16-G Tuohy epidural needle. After the epidural injections, heart rate, respiratory rate, arterial blood pressures (systolic, diastolic, and mean), and rectal temperature were measured at 5, 10, 15, 30, 60, 90, and 120 minutes, and after this time, every 60 minutes until the end of the experiments. A subjective score system was used to assess analgesia, behavioral and motor blockade at the same time points. The BPDX treatment produced analgesic action with twice the duration (200 minutes) of the BP treatment (97 minutes), but with an analgesic duration shorter than the DX treatment (240 minutes) in the regions of the tail, perineum, and upper hind limbs in mares. All treatments showed mild motor blockade. No behavioral changes were observed in any of the animals. There was hemodynamic stability without significant changes in respiratory rate for all treatments. Epidural analgesia using DEX alone or the combination of DEX and bupivacaine may be an option for painful obstetric and gynecological procedures in mares.
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de Laat MA, Sillence MN. A review of recent developments in the pharmacological prevention and treatment of endocrinopathic laminitis. ANIMAL PRODUCTION SCIENCE 2020. [DOI: 10.1071/an19491] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Despite the prevalence of endocrinopathic laminitis, the pharmacologic options for preventing and treating the disease are severely limited. The present review aims to discuss the spectrum of potential therapeutic agents for the condition, ranging from early experimental compounds to agents nearing registration. There are different pharmacologic targets for, and approaches to, managing laminitis. Reducing hyperinsulinaemia is central to diminishing endocrinopathic laminitis risk, and a detailed understanding of the pathophysiology of insulin dysregulation is necessary to identify pathways that can be targeted to minimise post-prandial insulin secretion and action. This area of research is advancing rapidly, with several exciting prospects, such as sodium-dependent glucose co-transporter-2 inhibitors, on the horizon for the treatment of equine metabolic dysfunction. Drugs that directly target the lamellae and aim to reduce the damage inflicted on the lamellae as part of this condition, are not yet available. Although progress in this area of laminitis therapy is slower, improved understanding of the events that lead to lamellar failure has enabled the investigation of novel drugs that aim to prevent laminitis at the site of the lesion. Finally, a brief review is included of the directions being taken in the management of the chronic and acute pain that accompanies laminitis. Medications for relieving the pain associated with laminitis are currently the most-prescribed drugs for the disease, and range from simple, affordable and thoroughly tested options, such as phenylbutazone, to newer, less-understood applications such as paracetamol and gabapentin. In the future, endocrinopathic laminitis management plans will likely take a multi-faceted approach that still hinge on effective dietary management and exercise, but also include drugs that address foot pathology, pain and underlying endocrine disturbances.
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Gozalo-Marcilla M, Luna SPL, Gasthuys F, Schauvliege S. Thermal, mechanical and electrical stimuli in antinociceptive studies in standing horses: an update. Vet Anaesth Analg 2019; 47:15-27. [PMID: 31813668 DOI: 10.1016/j.vaa.2019.09.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 08/26/2019] [Accepted: 09/02/2019] [Indexed: 12/26/2022]
Abstract
OBJECTIVE To perform a literature review of the thermal and mechanical antinociceptive devices used in pharmacological studies in standing horses published after 2011 (2012-2019). To complete a full literature review about electrical stimulation used for evaluation in similar studies. DATABASES USED PubMed, Google Scholar and Web of Science. CONCLUSIONS A high level of standardization has been reached in antinociceptive studies in standing horses using thermal and mechanical stimuli in most recent years. Commercially available testing devices to deliver thermal, mechanical and electrical stimuli, with observation of aversive responses to these stimuli, are reliable, sensitive and specific. For electrical stimulus testing, there is evidence that the resistance between the electrodes should be measured and should not exceed 3 kΩ to guarantee consistent and reproducible stimuli. The specific analysis of electromyographic activity after an electrical stimulus provides more detailed information about the neurons stimulated.
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Affiliation(s)
- Miguel Gozalo-Marcilla
- The Royal (Dick) School of Veterinary Studies and The Roslin Institute, The University of Edinburgh, Easter Bush Campus, Midlothian, UK.
| | - Stelio Pacca Loureiro Luna
- Department of Surgery and Anaesthesiology, School of Veterinary Medicine and Animal Science, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Frank Gasthuys
- Department of Surgery and Anaesthesia of Domestic Animals, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Stijn Schauvliege
- Department of Surgery and Anaesthesia of Domestic Animals, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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Bettembourg V, Dulgheriu D, Haga HA. Plasma concentrations at two dexmedetomidine constant rate infusions in isoflurane anaesthetized horses: a clinical study. Vet Anaesth Analg 2019; 46:627-635. [PMID: 31395482 DOI: 10.1016/j.vaa.2019.04.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 03/18/2019] [Accepted: 04/24/2019] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To determine dexmedetomidine plasma concentrations at two infusion rates in isoflurane anaesthetized horses and compare cardiovascular effects and anaesthetic recovery between treatments. STUDY DESIGN Prospective, randomized, masked clinical study. ANIMALS Healthy, adult, client-owned, non-food producing horses presented for castration. METHODS Premedication consisted of acepromazine, romifidine and morphine, and anaesthesia was induced with ketamine and midazolam. The horses were randomized to receive dexmedetomidine 0.5 μg kg-1 hour-1 (treatment DL, n = 7) or 1.75 μg kg-1 hour-1 (treatment DH, n = 7) for 90 minutes of isoflurane anaesthesia at an end-tidal concentration of 1.2%. Venous plasma concentrations were determined with liquid chromatography-electrospray-ionization-tandem mass spectrometry. Jugular venous and arterial blood was sampled for blood gas analysis at the start and end of the infusion. Changes in cardiovascular variables from the start to the end of the infusion, and recovery parameters were statistically compared between treatments. RESULTS Fourteen male horses, 2-6 years old, 325-536 kg were included. Mean ± standard deviation dexmedetomidine plasma concentrations at 30, 60 and 90 minutes with treatment DL were 0.22 ± 0.05, 0.29 ± 0.07 and 0.33 ± 0.08 ng mL-1, and with treatment DH were 0.65 ± 0.11, 0.89 ± 0.10 and 1.01 ± 0.10 ng mL-1. The 95% confidence interval for change minute-1 in dexmedetomidine plasma concentrations between 75 and 90 minutes was 0-1% for both treatments. With treatment DH, the heart rate decreased significantly more from the beginning to the end of the infusion compared to DL (p = 0.043). No other significant differences were found between treatments in cardiovascular or recovery parameters. CONCLUSIONS AND CLINICAL RELEVANCE Infusion of dexmedetomidine in isoflurane anaesthetized horses resulted in plasma concentrations with low variation at both infusion rates, approaching stable levels after 75 minutes of infusion. No differences of clinical importance were found when comparing cardiovascular variables and quality of recovery between treatments.
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Affiliation(s)
- Vanessa Bettembourg
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway.
| | - Daniela Dulgheriu
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Henning Andreas Haga
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
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How to score sedation and adjust the administration rate of sedatives in horses: a literature review and introduction of the Ghent Sedation Algorithm. Vet Anaesth Analg 2018; 46:4-13. [PMID: 30528671 DOI: 10.1016/j.vaa.2018.08.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 07/20/2018] [Accepted: 08/23/2018] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To summarize the different methods used to assess sedation and/or adjust the dose or administration rate of alpha-2 agonists in horses and to propose an algorithm to adjust the administration rate of a constant rate infusion of an alpha-2 agonist in horses. DATABASES USED PubMed and Web of Science; search terms: horse, sedation and score. CONCLUSIONS Most authors distinguish between sedation depth, sedation quality and degree of ataxia. These three features are evaluated using scoring systems similar to those classically used to assess pain, i.e. simple descriptive scales, numerical rating scales (NRS), visual analogue scales and/or multifactorial sedation scales. In addition, head height above the ground is often used as a measure of the depth of sedation. Very few authors have described how to adjust the administration rate or dose of alpha-2 agonists. Based on the available literature, the Ghent Sedation Algorithm was developed, which assigns scores (NRS) for degree of ataxia, sedation depth and surgical conditions, and uses these to prescribe changes in the administration rate of constant rate infusions of alpha-2 agonists. Studies are needed to validate this algorithm.
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Lervik A, Raszplewicz J, Ranheim B, Solbak S, Toverud SF, Haga HA. Dexmedetomidine or fentanyl? Cardiovascular stability and analgesia during propofol-ketamine total intravenous anaesthesia in experimental pigs. Vet Anaesth Analg 2018; 45:295-308. [DOI: 10.1016/j.vaa.2017.08.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 07/13/2017] [Accepted: 08/29/2017] [Indexed: 10/18/2022]
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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 2017; 41:205-217. [PMID: 29226340 DOI: 10.1111/jvp.12474] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 11/17/2017] [Indexed: 12/26/2022]
Abstract
The objective of this review was to perform a literature compilation of all the equine publications that used dexmedetomidine as the first article on this topic was published, in 2005. We also aimed to answer the question whether the use of dexmedetomidine can currently be justified. For that, we compiled information from databases, such as PubMed, Google Scholar and Web of Science and the proceedings of the last veterinary anaesthesiology meetings. Dexmedetomidine is an attractive drug to be used in horses, mainly due to its pharmacokinetic profile and pharmacodynamics that favour its use as intravenous constant rate infusion (CRI). Nowadays, its clinical use is popular for sedation in prolonged standing procedures and during partial intravenous anaesthesia (PIVA) and total intravenous anaesthesia (TIVA). However, legal requirements for its use should be taken into account.
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Affiliation(s)
- M Gozalo-Marcilla
- Department of Veterinary Surgery and Anaesthesiology, School of Veterinary Medicine and Animal Science, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - F Gasthuys
- Department of Surgery and Anaesthesia of Domestic Animals, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - S P L Luna
- Department of Veterinary Surgery and Anaesthesiology, School of Veterinary Medicine and Animal Science, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - S Schauvliege
- Department of Surgery and Anaesthesia of Domestic Animals, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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Gozalo-Marcilla M, Luna SPL, Crosignani N, Puoli Filho JNP, Pelligand L, Taylor PM. The importance of measuring skin resistance for electrical nociceptive stimulation in standing horses. Equine Vet J 2017; 49:836. [DOI: 10.1111/evj.12700] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- M. Gozalo-Marcilla
- Department of Veterinary Surgery and Anaesthesiology; Faculty of Veterinary Medicine and Animal Science; UNESP - Univ. Estadual Paulista; Botucatu Sao Paulo Brazil
| | - S. P. L. Luna
- Department of Veterinary Surgery and Anaesthesiology; Faculty of Veterinary Medicine and Animal Science; UNESP - Univ. Estadual Paulista; Botucatu Sao Paulo Brazil
| | - N. Crosignani
- Department of Veterinary Surgery and Anaesthesiology; Faculty of Veterinary Medicine and Animal Science; UNESP - Univ. Estadual Paulista; Botucatu Sao Paulo Brazil
| | - J. N. P. Puoli Filho
- Department of Veterinary Surgery and Anaesthesiology; Faculty of Veterinary Medicine and Animal Science; UNESP - Univ. Estadual Paulista; Botucatu Sao Paulo Brazil
| | - L. Pelligand
- Departments of Clinical Services and Sciences and Comparative Biomedical Sciences; Royal Veterinary College; North Mymms, Hatfield Hertfordshire UK
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Medeiros LQ, Gozalo-Marcilla M, Taylor PM, Campagnol D, de Oliveira FA, Watanabe MJ, de Araujo Aguiar AJ. Sedative and cardiopulmonary effects of dexmedetomidine infusions randomly receiving, or not, butorphanol in standing horses. Vet Rec 2017; 181:402. [PMID: 28822974 DOI: 10.1136/vr.104359] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Revised: 06/22/2017] [Accepted: 07/24/2017] [Indexed: 11/04/2022]
Abstract
Dexmedetomidine (DEX) alone, or combined with butorphanol (BUT), may be administered by constant rate infusions (CRIs) in standing horses. This blinded, randomised, crossover study in six healthy adult horses aimed to determine the sedative and cardiopulmonary effects of DEX (dexmedetomidine (3.5 µg/kg+5 µg/kg/hour CRI) and DEX/BUT (dexmedetomidine (3.5 µg/kg+3.5 µg/kg/hour CRI) and butorphanol (20 µg/kg+24 µg/kg/hour CRI)). Head height above ground (HHAG), ataxia, responses to tactile/auditory stimuli and cardiopulmonary variables were recorded before, at 5/15/30/60/90 minutes and after CRIs terminated (15/30/60 minutes). Repeated measures analysis of variance with Tukey-Kramer test were used for cardiopulmonary values (mean±SD) and HHAG reduction (per cent), and Friedman's and Dunn's for non-parametric data (P<0.05). Maximum HHAG reductions of 54 per cent (DEX) and 58 per cent (DEX/BUT) occurred at 15 minutes, with ataxia for 15 minutes in both treatments. Responses to stimuli were reduced for 30 minutes in both treatments, and auditory up to 60 minutes in DEX. Cardiopulmonary effects typical of α2-agonists were observed, with no differences between treatments. At the doses and rates reported here, both regimens provided clinically sufficient sedation for only 30 minutes.
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Affiliation(s)
- Luíza Quintão Medeiros
- Graduate Program in Anaesthesiology, Medical School of Botucatu, UNESP-Univ Estadual Paulista, Botucatu-SP, Brazil
| | - Miguel Gozalo-Marcilla
- Department of Veterinary Surgery and Anaestesiology, Faculty of Veterinary Medicine and Animal Science, UNESP - Univ Estadual Paulista, Botucatu-SP, Brazil
| | | | - Daniela Campagnol
- Graduate Program in Anaesthesiology, Medical School of Botucatu, UNESP-Univ Estadual Paulista, Botucatu-SP, Brazil
| | - Flávia Augusta de Oliveira
- Graduate Program in Anaesthesiology, Medical School of Botucatu, UNESP-Univ Estadual Paulista, Botucatu-SP, Brazil
| | - Marcos Jun Watanabe
- Department of Veterinary Surgery and Anaestesiology, Faculty of Veterinary Medicine and Animal Science, UNESP - Univ Estadual Paulista, Botucatu-SP, Brazil
| | - Antonio José de Araujo Aguiar
- Department of Veterinary Surgery and Anaestesiology, Faculty of Veterinary Medicine and Animal Science, UNESP - Univ Estadual Paulista, Botucatu-SP, Brazil
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Comparison of sedation and mechanical antinociception induced by intravenous administration of acepromazine and four dose rates of dexmedetomidine in donkeys. Vet Anaesth Analg 2017; 44:509-517. [DOI: 10.1016/j.vaa.2016.08.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 08/24/2016] [Accepted: 08/25/2016] [Indexed: 12/18/2022]
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Gozalo-Marcilla M, Luna SP, Crosignani N, Filho JNP, Possebon FS, Pelligand L, Taylor PM. Sedative and antinociceptive effects of different combinations of detomidine and methadone in standing horses. Vet Anaesth Analg 2017; 44:1116-1127. [PMID: 29050998 DOI: 10.1016/j.vaa.2017.03.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 03/05/2017] [Accepted: 03/06/2017] [Indexed: 12/26/2022]
Abstract
OBJECTIVE To evaluate intravenous (IV) detomidine with methadone in horses to identify a combination which provides sedation and antinociception without adverse effects. STUDY DESIGN Randomized, placebo-controlled, blinded, crossover. ANIMALS A group of eight adult healthy horses aged (mean ± standard deviation) 7 ± 2 years and 372 ± 27 kg. METHODS A total of six treatments were administered IV: saline (SAL); detomidine (5 μg kg-1; DET); methadone (0.2 mg kg-1; MET) alone or combined with detomidine [2.5 (MLD), 5 (MMD) or 10 (MHD) μg kg-1]. Thermal, mechanical and electrical nociceptive thresholds were measured, and sedation, head height above ground (HHAG), cardiopulmonary variables and intestinal motility were evaluated at 5, 15, 30, 45, 60, 75, 90, 120 and 180 minutes. Normal data were analyzed by mixed-model analysis of variance and non-normal by Kruskal-Wallis (p < 0.05). RESULTS Nociceptive thresholds in horses administered methadone with the higher doses of detomidine (MMD, MHD) were increased above baseline to a greater degree and for longer duration (MMD: 15-30 minutes, MHD: 30-60 minutes) than in horses administered low dose with methadone or detomidine alone (MLD, DET: 5-15 minutes). No increases in nociceptive thresholds were recorded in SAL or MET. Compared with baseline, HHAG was lower for 30 minutes in MMD and DET, and for 45 minutes in MHD. No significant sedation was observed in SAL, MET or MLD. Intestinal motility was reduced for 75 minutes in MHD and for 30 minutes in all other treatments. CONCLUSIONS Methadone (0.2 mg kg-1) potentiated the antinociception produced by detomidine (5 μg kg-1), with minimal sedative effects. CLINICAL RELEVANCE Detomidine (5 μg kg-1) with methadone (0.2 mg kg-1) produced antinociception without the adverse effects of higher doses of detomidine.
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Affiliation(s)
- Miguel Gozalo-Marcilla
- Department of Veterinary Surgery and Anaesthesiology, School of Veterinary Medicine and Animal Science, São Paulo State University (UNESP), Botucatu, SP, Brazil.
| | - Stelio Pl Luna
- Department of Veterinary Surgery and Anaesthesiology, School of Veterinary Medicine and Animal Science, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Nadia Crosignani
- Department of Veterinary Surgery and Anaesthesiology, School of Veterinary Medicine and Animal Science, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - José Np Puoli Filho
- Department of Animal Production, School of Veterinary Medicine and Animal Science, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Fábio S Possebon
- Department of Veterinary Hygiene and Public Health, School of Veterinary Medicine and Animal Science, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Ludovic Pelligand
- Departments of Clinical Services and Sciences and Comparative Biomedical Sciences, Royal Veterinary College, Hatfield, UK
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Di Giminiani P, Sandercock DA, Malcolm EM, Leach MC, Herskin MS, Edwards SA. Application of a handheld Pressure Application Measurement device for the characterisation of mechanical nociceptive thresholds in intact pig tails. Physiol Behav 2016; 165:119-26. [PMID: 27422675 PMCID: PMC5038977 DOI: 10.1016/j.physbeh.2016.07.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 06/30/2016] [Accepted: 07/11/2016] [Indexed: 11/29/2022]
Abstract
The assessment of nociceptive thresholds is employed in animals and humans to evaluate changes in sensitivity potentially arising from tissue damage. Its application on the intact pig tail might represent a suitable method to assess changes in nociceptive thresholds arising from tail injury, such as tail docking or tail biting. The Pressure Application Measurement (PAM) device is used here for the first time on the tail of pigs to determine the reliability of the methods and to provide novel data on mechanical nociceptive thresholds (MNT) associated with four different age groups (9, 17, 24 and 32 weeks) and with proximity of the target region to the body of the animal. We recorded an overall acceptable level of intra-individual reliability, with mean values of CV ranging between 30.1 and 32.6%. Across all age groups, the first single measurement of MNT recorded at region 1 (proximal) was significantly higher (P < 0.05) than the following two. This was not observed at tail regions 2 and 3 (more distal). Age had a significant effect (P < 0.05) on the mean thresholds of nociception with increasing age corresponding to higher thresholds. Furthermore, a significant effect of proximity of tail region to the body was observed (P < 0.05), with MNT being higher in the proximal tail region in pigs of 9, 17 and 24 weeks of age. There was also a significant positive correlation (P < 0.05) between mechanical nociceptive thresholds and age/body size of the animals. To the best of our knowledge, no other investigation of tail nociceptive thresholds has been performed with the PAM device or alternative methods to obtain mechanical nociceptive thresholds in intact tails of pigs of different age/body size. The reliability of the data obtained with the PAM device support its use in the measurement of mechanical nociceptive threshold in pig tails. This methodological approach is possibly suitable for assessing changes in tail stump MNTs after tail injury caused by tail docking and biting. Mechanical nociceptive thresholds were quantified for the first time in pig tails. The PAM device allowed determining anatomical and age-specific thresholds in pigs. A platform for the assessment of painful conditions in pigs is proposed.
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Affiliation(s)
- Pierpaolo Di Giminiani
- School of Agriculture, Food and Rural Development, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom.
| | - Dale A Sandercock
- Aarhus University, Department of Animal Science, AU-FOULUM, Tjele, Denmark
| | - Emma M Malcolm
- School of Agriculture, Food and Rural Development, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - Matthew C Leach
- School of Agriculture, Food and Rural Development, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - Mette S Herskin
- Animal and Veterinary Science Research Group, Scotland's Rural College (SRUC), West Mains Road, Edinburgh EH16 4SA, United Kingdom
| | - Sandra A Edwards
- School of Agriculture, Food and Rural Development, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
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Risberg ÅI, Ranheim B, Krontveit RI, Lervik A, Haga HA. The cardiovascular status of isoflurane-anaesthetized horses with and without dexmedetomidine constant rate infusion evaluated at equivalent depths of anaesthesia. Vet Anaesth Analg 2016; 43:412-23. [DOI: 10.1111/vaa.12315] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 02/10/2015] [Indexed: 11/29/2022]
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Wright S. Highlights of recent clinically relevant papers. EQUINE VET EDUC 2015. [DOI: 10.1111/eve.12327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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