1
|
Verhaar N, Grages AM, Bienert-Zeit A, Schwieder A, Reineking W, Hewicker-Trautwein M, Kästner S, Geburek F. Flowmetry and spectrophotometry for the assessment of intestinal viability in horses with naturally occurring strangulating small intestinal lesions. Equine Vet J 2024. [PMID: 38888520 DOI: 10.1111/evj.14118] [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: 09/05/2023] [Accepted: 05/16/2024] [Indexed: 06/20/2024]
Abstract
BACKGROUND Ancillary diagnostic methods to enhance the accuracy of viability assessment have not been established for use in clinical practice. OBJECTIVES To assess intestinal microperfusion measured by Laser Doppler Flowmetry and Spectrophotometry (LDFS) in naturally occurring small intestinal strangulations of different origins and to compare this between viable and non-viable segments. STUDY DESIGN Prospective clinical trial. METHODS Forty horses undergoing colic surgery for naturally occurring small intestinal strangulations were included. Tissue oxygen saturation (tSO2), haemoglobin (tHB) and blood flow (tBF) were determined by LDFS before and after release of the strangulation. Intestinal biopsies were taken in cases that underwent intestinal resection or intraoperative euthanasia and assessed using a semi-quantitative mucosal injury score (MIS). The LDFS measurements were compared between the different categories of strangulation causes and histopathological injury using parametric and non-parametric tests (p < 0.05). RESULTS Strangulations by pedunculated lipomas had lower tBF (13.9 ± 18 arbitrary units [AU]) than epiploic foramen entrapments (65.2 ± 61 AU; CI -1.697 to -0.2498; p = 0.005). Segments with MIS > 5 showed lower tBF during strangulation than segments with MIS < 4 (mean difference 61.1 AU; CI -1.119 to -0.07361; p = 0.03). This did not differ significantly following release of strangulation. Furthermore, there was a positive correlation between the inflammatory cell count and tBF during strangulation (r 0.34; CI 0.01 to 0.60; p = 0.04). The tSO2 and tHB did not differ between the different categories of lesions or injury. MAIN LIMITATIONS No biopsies could be taken from the intestinal segments that did not undergo resection. The duration of strangulation could not reliably be ascertained. CONCLUSIONS Blood flow measurements in naturally occurring strangulating lesions show a varying degree of ischaemia in different causes of strangulation. Intestinal blood flow measurements prior to release of the strangulation could potentially contribute to the identification of mucosal injury, yet a high individual variability and other contributing factors need to be considered.
Collapse
Affiliation(s)
- Nicole Verhaar
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Anna Marei Grages
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Astrid Bienert-Zeit
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Alexander Schwieder
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Wencke Reineking
- Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany
| | | | - Sabine Kästner
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
- Clinic for Small Animals, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Florian Geburek
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
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.
Collapse
|
4
|
Dengler F, Sternberg F, Grages M, Kästner SBR, Verhaar N. Adaptive mechanisms in no flow vs. low flow ischemia in equine jejunum epithelium: Different paths to the same destination. Front Vet Sci 2022; 9:947482. [PMID: 36157182 PMCID: PMC9493374 DOI: 10.3389/fvets.2022.947482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 08/17/2022] [Indexed: 01/18/2023] Open
Abstract
Intestinal ischemia reperfusion injury (IRI) is a frequent complication of equine colic. Several mechanisms may be involved in adaptation of the intestinal epithelium to IRI and might infer therapeutic potential, including hypoxia-inducible factor (HIF) 1α, AMP-activated protein kinase (AMPK), nuclear factor-erythroid 2-related factor 2 (NRF2), and induction of autophagy. However, the mechanisms supporting adaptation and thus cellular survival are not completely understood yet. We investigated the activation of specific adaptation mechanisms in both no and low flow ischemia and reperfusion simulated in equine jejunum epithelium in vivo. We found an activation of HIF1α in no and low flow ischemia as indicated by increased levels of HIF1α target genes and phosphorylation of AMPKα tended to increase during ischemia. Furthermore, the protein expression of the autophagy marker LC3B in combination with decreased expression of nuclear-encoded mitochondrial genes indicates an increased rate of mitophagy in equine intestinal IRI, possibly preventing damage by mitochondria-derived reactive oxygen species (ROS). Interestingly, ROS levels were increased only shortly after the onset of low flow ischemia, which may be explained by an increased antioxidative defense, although NFR2 was not activated in this setup. In conclusion, we could demonstrate that a variety of adaptation mechanisms manipulating different aspects of cellular homeostasis are activated in IRI irrespective of the ischemia model, and that mitophagy might be an important factor for epithelial survival following small intestinal ischemia in horses that should be investigated further.
Collapse
Affiliation(s)
- Franziska Dengler
- Department of Biochemical Sciences, Institute of Physiology, Pathophysiology and Biophysics, University of Veterinary Medicine, Vienna, Austria
- *Correspondence: Franziska Dengler
| | - Felix Sternberg
- Department of Biochemical Sciences, Institute of Physiology, Pathophysiology and Biophysics, University of Veterinary Medicine, Vienna, Austria
| | - Marei Grages
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Sabine BR Kästner
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
- Small Animal Clinic, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Nicole Verhaar
- Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany
| |
Collapse
|
5
|
Atorvastatin Attenuates Radiotherapy-Induced Intestinal Damage through Activation of Autophagy and Antioxidant Effects. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:7957255. [PMID: 36092168 PMCID: PMC9459441 DOI: 10.1155/2022/7957255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 07/06/2022] [Accepted: 08/12/2022] [Indexed: 11/17/2022]
Abstract
Abdominal or pelvic radiotherapy (RT) often results in small intestinal injury, such as apoptosis of epithelial cells and shortening of the villi. Atorvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, has many biological effects including cholesterol reduction, protection from cell damage, and autophagy activation. To reduce the extent of radiotherapy- (RT-) induced enteritis, we investigated the protective effects of atorvastatin against RT-induced damage of the intestinal tract. In this study, C57BL/6 mice were randomly distributed into the following groups (n = 8 per group): (1) control group: mice were fed water only, (2) atorvastatin group (Ator): mice were administered atorvastatin, (3) irradiation group (IR): mice received abdominal RT, (4) Ator+IR group: mice received abdominal RT following atorvastatin administration, and (5) Ator+IR+3-MA group: abdominal RT following atorvastatin and 3-methyladenine (an autophagy inhibitor) administration. Based on the assessment of modified Chiu's injury score and villus/crypt ratio, we found that atorvastatin administration significantly reduced intestinal mucosal damage induced by RT. Atorvastatin treatment reduced apoptosis (cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase), DNA damage (γH2AX and 53BP1), oxidative stress (OS, 4-hydroxynonenal), inflammatory molecules (phospho-NF-κB p65 and TGF-β), fibrosis (collagen I and collagen III), barrier leakage (claudin-2 and fluorescein isothiocyanate-dextran), disintegrity (fatty acid-binding protein 2), and dysfunction (lipopolysaccharide) caused by RT in small intestinal tissue. In addition, atorvastatin upregulated the expression of autophagy-active molecules (LC3B), antioxidants (heme oxygenase 1 and thioredoxin 1), and tight junction proteins (occludin and zonula occludens 1). However, the biological functions of atorvastatin in decreasing RT-induced enteritis were reversed after the administration of 3-MA; the function of antioxidant molecules and activity of thioredoxin reductase were independent of autophagy activation. Our results indicate that atorvastatin can effectively relieve RT-induced enteritis through autophagy activation and associated biological functions, including maintaining integrity and function and decreasing apoptosis, DNA damage, inflammation, OS, and fibrosis. It also acts via its antioxidative capabilities.
Collapse
|
6
|
Low Flow versus No Flow: Ischaemia Reperfusion Injury Following Different Experimental Models in the Equine Small Intestine. Animals (Basel) 2022; 12:ani12162158. [PMID: 36009747 PMCID: PMC9405230 DOI: 10.3390/ani12162158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 08/17/2022] [Accepted: 08/19/2022] [Indexed: 11/17/2022] Open
Abstract
Simple Summary One of the main causes of colic in horses is the occlusion of the intestinal blood vessels after displacement or entrapment of the small intestine. In search of new therapies to treat this lethal disease, experimental models have been used to simulate the clinical situation. Both low flow (LF) models with partial blood flow occlusion as well as no flow (NF) models with complete occlusion have been implemented in different studies. This has led to conflicting results and comparative studies are lacking. The objective of this study was to characterize the development of intestinal injury over time in two different experimental models implementing either partial or complete vessel occlusion. Under general anaesthesia, local intestinal blood flow was reduced by 80% in seven horses (LF), and by 100% in another seven horses (NF). The LF group exhibited more bleeding in the intestinal wall and a relatively high variability in intestinal oxygen levels and tissue damage. The NF group showed lower oxygen levels and decreased barrier function of the intestinal wall. These results aid in the selection of the suitable experimental model for future studies. The high variability following LF suggests that an NF model may produce more consistent intestinal damage. Abstract In experimental studies investigating strangulating intestinal lesions in horses, different ischaemia models have been used with diverging results. Therefore, the aim was to comparatively describe ischaemia reperfusion injury (IRI) in a low flow (LF) and no flow (NF) model. Under general anaesthesia, 120 min of jejunal ischaemia followed by 120 min of reperfusion was induced in 14 warmbloods. During ischaemia, blood flow was reduced by 80% (LF, n = 7) or by 100% (NF, n = 7). Intestinal blood flow and oxygen saturation were measured by Laser Doppler fluxmetry and spectrophotometry. Clinical, histological, immunohistochemical and Ussing chamber analyses were performed on intestinal samples collected hourly. Tissue oxygen saturation was significantly lower in NF ischaemia. The LF group exhibited high variability in oxygen saturation and mucosal damage. Histologically, more haemorrhage was found in the LF group at all time points. Cleaved-caspase-3 and calprotectin-stained cells increased during reperfusion in both groups. After NF ischaemia, the tissue conductance was significantly higher during reperfusion. These results aid in the selection of suitable experimental models for future studies. Although the LF model has been suggested to be more representative for clinical strangulating small intestinal disease, the NF model produced more consistent IRI.
Collapse
|
7
|
Lean NE, Zedler ST, Van Eps AW, Engiles JB, Ford M, Stefanovski D, Walsh DM, Pollitt CC. Evaluation of locking compression plate fixation of the distal phalanx to the hoof wall as a potential therapy for laminitis. Equine Vet J 2022. [DOI: 10.1111/evj.13877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 08/11/2022] [Indexed: 11/28/2022]
Affiliation(s)
- N. E. Lean
- School of Veterinary Science University of Queensland Gatton QLD Australia
| | - S. T. Zedler
- School of Veterinary Science University of Queensland Gatton QLD Australia
| | - A. W. Van Eps
- New Bolton Centre, Department of Clinical Studies, School of Veterinary Medicine University of Pennsylvania Kennett Square PA USA
| | - J. B. Engiles
- New Bolton Centre, Department of Clinical Studies, School of Veterinary Medicine University of Pennsylvania Kennett Square PA USA
| | - M. Ford
- New Bolton Centre, Department of Clinical Studies, School of Veterinary Medicine University of Pennsylvania Kennett Square PA USA
| | - D. Stefanovski
- New Bolton Centre, Department of Clinical Studies, School of Veterinary Medicine University of Pennsylvania Kennett Square PA USA
| | | | - C. C. Pollitt
- School of Veterinary Science University of Queensland Gatton QLD Australia
| |
Collapse
|
8
|
d'Anselme O, Robel M, Schwarzwald C, Ringer SK. Anaesthesia management of transvenous implantation of a single‐chamber, rate‐adaptive pacemaker in a donkey with high‐grade second and third degree atrioventricular block. VETERINARY RECORD CASE REPORTS 2022. [DOI: 10.1002/vrc2.363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Olivia d'Anselme
- Section of Anaesthesiology Department of Clinical Diagnostics and Services Vetsuisse Faculty University of Zurich Zurich Switzerland
| | - Matthias Robel
- Clinic for Equine Internal Medicine Equine Department Vetsuisse Faculty University of Zurich Zurich Switzerland
| | - Colin Schwarzwald
- Clinic for Equine Internal Medicine Equine Department Vetsuisse Faculty University of Zurich Zurich Switzerland
| | - Simone Katja Ringer
- Section of Anaesthesiology Department of Clinical Diagnostics and Services Vetsuisse Faculty University of Zurich Zurich Switzerland
| |
Collapse
|
9
|
Hopster K, Driessen B. Pharmacology of the Equine Foot: Medical Pain Management for Laminitis. Vet Clin North Am Equine Pract 2021; 37:549-561. [PMID: 34674911 DOI: 10.1016/j.cveq.2021.08.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
One of the biggest challenges in managing laminitis in horses remains the control of pain. The best analgesic approach is a multimodal approach, including nonsteroidal anti-inflammatory drugs, opioids, and/or constant rate infusions of α-2 agonists, ketamine, and lidocaine. Recent literature indicates that amitriptyline and soluble epoxide hydrolase inhibitor might be beneficial. Clinically oriented studies will be needed if they have a place in laminitis pain management. The systemic pain control can be combined with local techniques such as long-acting local anesthetics or epidural catheterization that allows for administration of potent analgesic therapy with a lower risk of negative side effects.
Collapse
Affiliation(s)
- Klaus Hopster
- Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, 382 West Street Road, Kennett Square, PA 19348, USA.
| | - Bernd Driessen
- Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, 382 West Street Road, Kennett Square, PA 19348, USA
| |
Collapse
|
10
|
Hector RC, Rezende ML, Nelson BB, Monnet E. Cardiopulmonary function and intestinal blood flow in anaesthetised, experimentally endotoxaemic horses given a constant rate infusion of dexmedetomidine. Equine Vet J 2021; 54:820-828. [PMID: 34528277 DOI: 10.1111/evj.13513] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 06/16/2021] [Accepted: 09/03/2021] [Indexed: 12/16/2022]
Abstract
BACKGROUND Endotoxaemia causes untoward inflammatory-mediated effects that might be attenuated by dexmedetomidine. OBJECTIVES To evaluate the effects of a dexmedetomidine intravenous (IV) infusion on systemic and intestinal haemodynamics and arterial blood gas values in sevoflurane-anaesthetised horses administered Escherichia coli O55:B5 lipopolysaccharides (LPS). STUDY DESIGN Randomised controlled in vivo experiment. METHODS A total of 13 horses weighing 456 ± 86 kg (mean ± standard deviation) and aged 13.9 ± 9.0 years donated for euthanasia underwent ventral midline celiotomy using sevoflurane anaesthesia. Baseline physiological variables were recorded after a 90-minute equilibration period. All horses were given 0.1 mcg/kg bwt LPS IV. Horses were randomly assigned to no further treatment (group LPS; seven horses) or IV administration of dexmedetomidine (loading dose 1.75 mcg/kg bwt followed by 1.75 mcg/kg bwt/h; group LPS-Dex; six horses) with concurrent target sevoflurane dose reduction of 50%. Cardiac index (CI; thermodilution), intestinal blood flow, arterial blood parameters and plasma dexmedetomidine concentration measurements were recorded every 30 minutes until euthanasia at 390 minutes. Data were compared between and within groups to baseline using a mixed model analysis (significance P < .05). RESULTS In LPS-Dex horses, intestinal blood flow and CI were transiently decreased after the dexmedetomidine loading dose, but no significant differences were found compared with baseline during the infusion. Sevoflurane dose was reliably reduced by approximately 40%. Significant differences were identified in creatinine (115 umol/L LPS-Dex; 195 umol/L LPS), bicarbonate (29.7 mmol/L LPS-Dex; 23 mmol/L LPS) and base excess (2.0 mmol/L LPS-Dex; -5.3 mmol/L LPS). Dexmedetomidine plasma concentrations were highest after the loading dose and stable during infusion dosing. MAIN LIMITATIONS Experimental conditions are not reflective of clinical colic management. CONCLUSIONS A dexmedetomidine infusion with sevoflurane dose reduction attenuated some deleterious changes in anaesthetised horses administered LPS without sustained negative cardiovascular effects and may be beneficial during colic surgery.
Collapse
Affiliation(s)
- Rachel C Hector
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Marlis L Rezende
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Brad B Nelson
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Eric Monnet
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| |
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|