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Necrotic skin ulcerations caused by xylazine in people who inject intravenous drugs. J Eur Acad Dermatol Venereol 2024; 38:e551-e553. [PMID: 38334215 DOI: 10.1111/jdv.19817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 01/19/2024] [Indexed: 02/10/2024]
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Not Carfentanil-A Case of Unexpected Xylazine Detection. J Appl Lab Med 2024; 9:629-634. [PMID: 38300830 DOI: 10.1093/jalm/jfad119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 10/25/2023] [Indexed: 02/03/2024]
Abstract
Historically, xylazine has been utilized in veterinary medicine for decades as an anesthetic and analgesic sedative to facilitate safe handling, diagnostic testing, and surgical procedures in large animals. Currently, xylazine is an emerging threat to human health. It has been detected in the illicit drug supply chain, often as an adulterant. It has been more commonly added to illicit substances, most notably fentanyl, by drugmakers to enhance drug effect. End users are often unaware of its presence. This is alarming given the large number of xylazine-involved overdose deaths while laboratory detections are deficient and reversal agents are absent. Herein, we present the first documented case of xylazine identified via gas chromatography-tandem mass spectrometry at University of California Davis Health despite a peculiarly mild clinical presentation. We hope to increase awareness of this potentially fatal adulterant that is often missed in evaluation and engender further opportunities to study this ongoing issue.
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A confirmed case of xylazine-induced skin ulcers in a person who injects drugs in Miami, Florida, USA. Harm Reduct J 2024; 21:64. [PMID: 38491467 PMCID: PMC10941577 DOI: 10.1186/s12954-024-00978-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Accepted: 03/01/2024] [Indexed: 03/18/2024] Open
Abstract
BACKGROUND Xylazine is an alpha-2 adrenergic receptor agonist that has emerged as a contaminant in the illicit drug supply of fentanyl. Xylazine use may be suspected in naloxone-resistant overdoses and atypical, chronic wounds in people who use drugs (PWUD). This case is unique because it is the first case to our knowledge describing wound care for a xylazine-induced wound with a confirmatory xylazine test strip (XTS) in the setting of a syringe services program (SSP) and in the state of Florida. CASE PRESENTATION A 43-year-old woman with a past medical history of severe opioid use disorder and stimulant use disorder presented to a student-run clinic at a Miami SSP for wound care. She had multiple ulcerations diffusely over her bilateral forearms with surrounding erythema and warmth. Seven weeks later, she presented to clinic again for wound care because her wounds had progressed. At this visit, a XTS was used to confirm the presence of xylazine in her urine. Wound care management and harm reduction strategies employed at both visits were informed by best clinical judgement due to lack of formal guidelines at the time. Wound outcomes are unknown as the patient has not returned to clinic. CONCLUSIONS Many PWUD at highest risk for acute and chronic health consequences of xylazine-adulterated fentanyl do not have access to healthcare outside of low barrier clinics and SSPs due to lack of insurance or mistrust of the traditional healthcare system due to stigma. There is an urgent need for access to XTS for PWUD and clinical practice guidelines for the treatment of xylazine-related wounds in outpatient clinics.
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Xylazine-associated Wounds: Clinical Experience From a Low-barrier Wound Care Clinic in Philadelphia. J Addict Med 2024; 18:9-12. [PMID: 38019592 DOI: 10.1097/adm.0000000000001245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2023]
Abstract
ABSTRACT The veterinary sedative xylazine is spreading in unregulated opioid supplies across North America. Among people who use drugs with repeated exposure to xylazine, a distinct wound type has emerged. Here, we describe these wounds and share our experience treating them in a nurse-led, low-barrier wound care clinic in Philadelphia, PA. We propose a reimagining of wound treatment across settings to better serve people who use drugs, and we advocate for stronger protections against the harms of an increasingly adulterated drug supply. Our perspective from the epicenter of the xylazine crisis can inform the response of communities across the country who are starting to face harms associated with xylazine.
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The Appearance of Xylazine in the United States as a Fentanyl Adulterant. Prim Care Companion CNS Disord 2023; 25:22nr03473. [PMID: 37923548 DOI: 10.4088/pcc.22nr03473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2023] Open
Abstract
Importance: Use of xylazine in the United States as an adulterant for drugs of abuse has increased in recent years, thus it is important for health care providers to understand the basic pharmacology and toxidrome of the drug, as well as management options for patients who have overdosed. Observations: Data obtained from studies between 2006 and 2022 indicate a rapidly increasing incidence of xylazine overdose in the United States, with overdose cases now being seen in 25 states. Hallmark symptoms of xylazine overdose include respiratory depression, bradycardia, hyperglycemia, central nervous system depression, and initial hypertension turning to unstable blood pressure. Xylazine overdose is not reversible with naloxone and requires supportive measures. Conclusions and Relevance: It is important for health care providers to be aware of presenting symptoms in xylazine overdose so that proper care can be provided. Facilities may consider adding xylazine to their routine toxicology report to aid in patient management and better assess the incidence of xylazine use as an adulterant in a given geographic area. Prim Care Companion CNS Disord 2023;25(6):22nr03473. Author affiliations are listed at the end of this article.
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Fentanyl and its derivatives, xylazine, and benzodiazepines: new sources of risk for acute poisonings. EMERGENCIAS : REVISTA DE LA SOCIEDAD ESPANOLA DE MEDICINA DE EMERGENCIAS 2023; 35:400. [PMID: 37801427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 10/08/2023]
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Abstract
RATIONALE Xylazine has emerged in recent years as an adulterant in an increasing number of opioid-positive overdose deaths in the United States. Although its exact role in opioid-induced overdose deaths is largely unknown, xylazine is known to depress vital functions and cause hypotension, bradycardia, hypothermia, and respiratory depression. OBJECTIVES In this study, we examined the brain-specific hypothermic and hypoxic effects of xylazine and its mixtures with fentanyl and heroin in freely moving rats. RESULTS In the temperature experiment, we found that intravenous xylazine at low, human-relevant doses (0.33, 1.0, 3.0 mg/kg) dose-dependently decreases locomotor activity and induces modest but prolonged brain and body hypothermia. In the electrochemical experiment, we found that xylazine at the same doses dose-dependently decreases nucleus accumbens oxygenation. In contrast to relatively weak and prolonged decreases induced by xylazine, intravenous fentanyl (20 μg/kg) and heroin (600 μg/kg) induce stronger biphasic brain oxygen responses, with the initial rapid and strong decrease, resulting from respiratory depression, followed by a slower, more prolonged increase reflecting a post-hypoxic compensatory phase, with fentanyl acting much quicker than heroin. The xylazine-fentanyl mixture eliminated the hyperoxic phase of oxygen response and prolonged brain hypoxia, suggesting xylazine-induced attenuation of the brain's compensatory mechanisms to counteract brain hypoxia. The xylazine-heroin mixture strongly potentiated the initial oxygen decrease, and the pattern lacked the hyperoxic portion of the biphasic oxygen response, suggesting more robust and prolonged brain hypoxia. CONCLUSIONS These findings suggest that xylazine exacerbates the life-threatening effects of opioids, proposing worsened brain hypoxia as the mechanism contributing to xylazine-positive opioid-overdose deaths.
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Characteristics of xylazine-related deaths in West Virginia-Xylazine-related deaths. Am J Addict 2023; 32:309-313. [PMID: 36504413 PMCID: PMC10121736 DOI: 10.1111/ajad.13365] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 11/11/2022] [Accepted: 11/19/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND AND OBJECTIVES The involvement of xylazine, a veterinary drug, in West Virginia (WV) human drug-related deaths was examined. METHODS WV drug deaths from 2019 (when xylazine was first identified) to mid-2021. Characteristics including toxicology findings were compared between xylazine and nonxylazine deaths. RESULTS Of 3292 drug deaths, 117 involved xylazine, and the proportions of deaths with it have increased (1% [2019] to 5% [mid-2021)]. Xylazine decedents had more cointoxicants, with fentanyl (98%) predominant followed by methamphetamine. Xylazine decedents had a significantly greater history of drug or alcohol misuse and hepatic disease. CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE In one of the largest analyses of xylazine-involved deaths in a predominantly rural state, identification of xylazine was increasing with multiple cointoxicants (especially fentanyl), and was present in a few deaths with only one other substance involved. Health professionals should be aware of possible enhanced toxicity from xylazine ingestion especially since naloxone does not reverse xylazine's adverse effects.
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Warning About Xylazine, a Veterinary Sedative Found in Illicit Drugs. JAMA 2022; 328:2296. [PMID: 36538321 DOI: 10.1001/jama.2022.20045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Anaesthesia-Induced Transcriptomic Changes in the Context of Renal Ischemia Uncovered by the Use of a Novel Clamping Device. Int J Mol Sci 2021; 22:ijms22189840. [PMID: 34576005 PMCID: PMC8464990 DOI: 10.3390/ijms22189840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 09/01/2021] [Accepted: 09/02/2021] [Indexed: 11/16/2022] Open
Abstract
Ischemia is a common cause of acute kidney injury worldwide, frequently occurring in patients undergoing cardiac surgery or admitted to the intensive care unit (ICU). Thus, ischemia-reperfusion injury (IRI) remains one of the main experimental models for the study of kidney diseases. However, the classical technique, based on non-traumatic surgical clamps, suffers from several limitations. It does not allow the induction of multiple episodes of acute kidney injury (AKI) in the same animal, which would be relevant from a human perspective. It also requires a deep and long sedation, raising the question of potential anaesthesia-related biases. We designed a vascular occluding device that can be activated remotely in conscious mice. We first assessed the intensity and the reproducibility of the acute kidney injury induced by this new device. We finally investigated the role played by the anaesthesia in the IRI models at the histological, functional and transcriptomic levels. We showed that this technique allows the rapid induction of renal ischemia in a repeatable and reproducible manner, breaking several classical limitations. In addition, we used its unique specificities to highlight the renal protective effect conferred by the anaesthesia, related to the mitigation of the IRI transcriptomic program.
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Anesthetics fragment hippocampal network activity, alter spine dynamics, and affect memory consolidation. PLoS Biol 2021; 19:e3001146. [PMID: 33793545 PMCID: PMC8016109 DOI: 10.1371/journal.pbio.3001146] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 02/15/2021] [Indexed: 02/07/2023] Open
Abstract
General anesthesia is characterized by reversible loss of consciousness accompanied by transient amnesia. Yet, long-term memory impairment is an undesirable side effect. How different types of general anesthetics (GAs) affect the hippocampus, a brain region central to memory formation and consolidation, is poorly understood. Using extracellular recordings, chronic 2-photon imaging, and behavioral analysis, we monitor the effects of isoflurane (Iso), medetomidine/midazolam/fentanyl (MMF), and ketamine/xylazine (Keta/Xyl) on network activity and structural spine dynamics in the hippocampal CA1 area of adult mice. GAs robustly reduced spiking activity, decorrelated cellular ensembles, albeit with distinct activity signatures, and altered spine dynamics. CA1 network activity under all 3 anesthetics was different to natural sleep. Iso anesthesia most closely resembled unperturbed activity during wakefulness and sleep, and network alterations recovered more readily than with Keta/Xyl and MMF. Correspondingly, memory consolidation was impaired after exposure to Keta/Xyl and MMF, but not Iso. Thus, different anesthetics distinctly alter hippocampal network dynamics, synaptic connectivity, and memory consolidation, with implications for GA strategy appraisal in animal research and clinical settings.
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Anesthesia may alter mRNA expression of certain wound healing-associated genes in dermal wound environment of the rats. Mol Biol Rep 2019; 46:2819-2827. [PMID: 30838502 DOI: 10.1007/s11033-019-04728-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 02/27/2019] [Indexed: 11/26/2022]
Abstract
Some anesthetics including ketamine/xylazine and thiopental have been shown to alter the expression of genes related with inflammatory cytokines and chemokines in previous studies unassociated with wound healing, arising the question of whether commonly used anesthetics in wound healing models could interfere with the transcriptional responses of the genes associated with skin wound healing. The gene expression profile in wound biopsies of rats who received widely used anesthetics doses of intraperitoneal ketamine/xylazine (50 mg/kg and 10 mg/kg) or thiopental (50 mg/kg) in comparison with control rats was analyzed by monitoring the expression of genes effective on various phases of wound healing. The expression levels of 84 genes were determined on 3rd, 7th and 14th days of post-wounding using a qPCR array system. Of the genes either up or downregulated fivefolds or more, three (Egf, Col5a1 and Cxcl3) and two (Tgfa and Il2) genes were found to be the most responsive ones to ketamine/xylazine or thiopental anesthesia respectively in a period of 14 days after correction for multiple testing. However, up to 22 and 24 genes for ketamine/xylazine and thiopental were found to be differentially expressed in the same period without correction for multiple-comparisons testing (p < 0.05). In conclusion, our data suggest that ketamine/xylazine and thiopental may alter the transcriptional responses of some genes associated with wound healing in rats. We strongly suggest to consider the possible alteration effect of these anesthetics on gene expression in animal models of dermal wound healing.
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Impact of repeated anesthesia with ketamine and xylazine on the well-being of C57BL/6JRj mice. PLoS One 2018; 13:e0203559. [PMID: 30231081 PMCID: PMC6145541 DOI: 10.1371/journal.pone.0203559] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 08/22/2018] [Indexed: 12/11/2022] Open
Abstract
Within the scope of the 3Rs of Russel and Burch, the number of laboratory animals can be reduced by repeated use of an animal. This strategy only becomes relevant, if the total amount of pain, distress or harm the individual animal experiences does not exceed the severity of a single manipulation. For example, when using imaging techniques, an animal can be examined several times during a study, but it has to be anesthetized each time imaging is performed. The severity of anesthesia is thought to be mild according to the Directive 2010/63/EU. However, the Directive does not differentiate between single and repeated anesthesia, although repeated anesthesia may have a greater impact on well-being. Hence, we compared the impact of single and repeated anesthesia (six times at an interval of three to four days) by injection of ketamine and xylazine (KX) on the well-being of adult female and male C57BL/6JRj mice. After anesthesia, well-being of mice was assessed according to a protocol for systematic assessment of well-being including nesting, the Mouse Grimace Scale (MGS), a test for trait anxiety, home cage activity, and the rotarod test for motor activity, food intake, and body weight, as well as corticosterone (metabolite) analysis. Repeated anesthesia increased the MGS in mice of both sexes and caused short-term effects on well-being of female mice in the immediate post-anesthetic period, indicated by longer lasting effects on trait anxiety-related behavior. However, corticosterone metabolite concentrations suggested that mice habituated to the stress induced by repeated KX administration. Hence, the mildly negative effects on well-being of repeated KX anesthesia do not seem to accumulate over time using the respective regimen. However, further observations for severity classification are warranted in order to more specifically determine the duration of mild distress and trait anxiety.
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Exposure to warmer postoperative temperatures reduces hypothermia caused by anaesthesia and significantly increases the implantation rate of transferred embryos in the mouse. Lab Anim 2016; 38:50-4. [PMID: 14979988 DOI: 10.1258/00236770460734399] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Embryo transfer (ET) is among the key factors determining the overall efficiency of transgenic technology in the mouse. A successful ET depends among other factors on the quality of the transferred embryos, foster mothers and anaesthetic reagents and on the transfer techniques. Anaesthesia-caused deaths and suboptimal ET procedures are factors which reduce the success of transgenic experiments and mouse colony maintenance. Here we compared the effects of two anaesthetic reagents—a ketamine/xylazine combination, and tribromoethanol (Avertin)—on the rates of implantation and development to term of mouse zygotes transferred into the oviducts of CD-1 foster mothers, and evaluated whether hypothermia caused by anaesthetics after the ET operation could be overcome by postoperative incubation of the foster mothers. We established two experimental groups of fosters, one of which was kept at room temperature (RT, 21°C) with the other in an incubator (33°C) overnight after ET. Rates of implantation, resorption and development to normal fetuses were evaluated by sacrificing the foster mothers on the 15th day of their pregnancy. Our results showed that regardless of the anaesthetic reagents used, the rates of implantation and of development to normal fetuses can be significantly improved by exposing the foster mothers to warmer temperatures (33°C) immediately after the ET operation. These results may have important implications in increasing the success rate of ET with micromanipulated embryos.
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Effects of xylazine, romifidine, or detomidine on hematology, biochemistry, and splenic thickness in healthy horses. THE CANADIAN VETERINARY JOURNAL = LA REVUE VETERINAIRE CANADIENNE 2014; 55:334-340. [PMID: 24688132 PMCID: PMC3953931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Alpha-2 agonist-induced changes in packed cell volume (PCV), total solids (TS), selected biochemical parameters, and splenic thickness were investigated in horses. Four healthy mares were treated in a blinded, randomized, cross-over design with a dose of xylazine (0.5 mg/kg), romifidine (0.04 mg/kg), or detomidine (0.01 mg/kg) IV, and detomidine (0.02 mg/kg) IM. Hematology, TS, colloid osmotic pressure (COP), plasma osmolality; glucose, lactate, urea (BUN) and electrolyte concentrations; venous blood pH and ultrasonographic splenic thickness were evaluated at intervals for 300 min. Repeated measures analysis of variance (ANOVA) were performed with P < 0.05. There was a significant change over time in PCV and TS following each treatment (P < 0.001), with median (range) reductions of 20.9% (12.9% to 27.3%) and 5.8% (3.0% to 10.3%), respectively. Red blood cell count, BUN, and COP decreased while osmolality, glucose, Na(+), and splenic thickness increased. Treatments induced clinically significant transient changes in PCV, TS, and other biochemical parameters, which should be considered when assessing horses that received these drugs.
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Anesthetic-induced transient hyperglycemia and insulin resistance do not depend on the sympathoadrenal axis. MINERVA ENDOCRINOL 2013; 38:379-388. [PMID: 24285105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
AIM Glucose homeostasis is maintained under strict physiological control in which the central nervous system is very important. Ketamine/xylazine mixture induces hyperglycemia, although the mechanism involved is unknown. We aimed to study the role of sympathoadrenal axis on glycemia and insulinemia in adult rats. METHODS NInety-day-old male Wistar rats were used. Half of the rats underwent removal of the adrenal gland medullae (adrenodemedullation, ADM). After overnight fasting, all rats were given the intravenous glucose tolerance test (ivGTT), which was performed in six groups: awake, ketamine/xylazine (KX) and thiopental (Thiop) anesthetized intact rats, and the same groups of ADM rats. The intraperitoneal insulin tolerance test (1U/kg BW) was performed in an additional animal group to record the rate constant of plasma glucose disappearance (Kitt). Tissue insulin sensitivity was also evaluated by the homeostasis model assessment (HOMA). RESULTS Ketamine/xylazine increased basal glycemia by 110.6% (P<0.001) in intact rats. In the ADM group, KX rats had a reduction of 36.6% (P<0.05) basal glycemia. Thiop caused a decrease of 70.3% (P<0.05) in basal insulinemia in intact rats. ADM reduced fasting insulin in all groups. Insulin sensitivity was elevated in intact Thiop rats, while insulin resistance was observed in intact KX rats. Both anesthetics induced glucose intolerance during ivGTT in the intact group, but not in ADM rats. Insulin secretion was reduced for both anesthetics in intact and ADM rats. CONCLUSION Sympathoadrenal axis activity is not involved with the hyperglycemia induced by thiopental or ketamine/xylazine.
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Antiemetic efficacy of promethazine on xylazine-induced emesis in cats. THE CANADIAN VETERINARY JOURNAL = LA REVUE VETERINAIRE CANADIENNE 2012; 53:193-195. [PMID: 22851784 PMCID: PMC3258836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The prophylactic antiemetic effect of 3 dosages of promethazine injected into cats 1 h before administration of xylazine was compared with that of a saline solution. Prior treatment with 2 and 4 mg/kg of promethazine significantly reduced the frequency of emetic episodes. Promethazine may be used as a prophylactic antiemetic in cats treated with xylazine.
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Gait analysis using 3D accelerometry in horses sedated with xylazine. Vet J 2011; 193:212-6. [PMID: 22082509 DOI: 10.1016/j.tvjl.2011.10.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Revised: 09/30/2011] [Accepted: 10/14/2011] [Indexed: 11/17/2022]
Abstract
The aim of the present study was to verify the efficacy and sensitivity of an accelerometric device in detecting and quantifying the degree of movement alteration produced in horses sedated with xylazine. Horses (n=6) were randomly administered either xylazine or a control by intravenous injection, with at least 1 week between each treatment. A triaxial accelerometric device was used for the accelerometric gait assessment 15 min before (baseline) and 5, 15, 30, 45, 60, 75, 90, 105 and 120 min after each treatment. Eight different accelerometric parameters were calculated, including speed, stride frequency, stride length, regularity, dorsoventral power, propulsion power, mediolateral power and total power, with the force of acceleration and the dorsoventral, mediolateral and craniocaudal (propulsive) parts of the power then calculated. Administration of xylazine decreased many of the parameters investigated, with significant differences for speed, stride frequency, dorsoventral power, propulsion power and total power at 5, 15, 30 and 45 min after injection. There were no significant differences in stride length values at any time point. Decreases in regularity values were evident with significant differences at every time point from 5 to 120 min following xylazine injection. Force values were also significantly reduced from 5 to 30 min after treatment and a redistribution of the total power was observed 5 min after injection as the mediolateral power increased significantly, while the dorsoventral power decreased. Accelerometry offers a practical, accurate, easy to use, portable and low cost method of objectively monitoring gait abnormalities at the walk in horses after sedation with xylazine.
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Tiletamine-zolazepam and xylazine is a potent cardiodepressive combination: a case report. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE : JAALAS 2007; 46:63-64. [PMID: 17994676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Intramuscular injection of tiletamine-zolazepam and xylazine is commonly used as a preanesthetic for veterinary surgical procedures and for short-term restraint. However, this combination can have marked cardiodepressive and hypothermic effects that persist for hours to days. Here we present a case report of these effects in a swine heart failure model.
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Anti-emetic effect of oculo-acupuncture on dogs with xylazine induced vomiting. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2007; 35:447-53. [PMID: 17597503 DOI: 10.1142/s0192415x07004965] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The present study was conducted in order to clarify the anti-emetic effect of oculo-acupuncture (OA) on dogs with xylazine-induced vomiting, and also to compare the anti-emetic effect of OA and body acupuncture (AP). Twelve dogs induced to vomit by xylazine were selected from total 29 mongrel dogs in preliminary experiment and were used as subjects in this study. This study was comprised of two experiments. In experiment 1, the anti-emetic effects of OA on dogs were examined in the stomach/spleen region (experimental group I), the zhongjiao region (experimental group II), and the stomach/spleen region plus the zhongjiao region (experimental group III) using 12 dogs induced to vomit for one week interval repeatedly. On the other hand, needle acupuncture (AP) (BL20 + BL21, experimental group A) and OA (stomach/spleen and zhong jiao regions) combined with needle AP (BL20 + BL21) (experimental group B) were examined using 6 vomiting dogs, for one week interval repeatedly in experiment 2. As a result, the vomiting rates of experimental group I (50%, p < 0.05), experimental group II (58.3%) and experimental group III (41.6%, p < 0.01) were lower than that of control (100%), respectively in experiment 1. The vomiting rates of both experimental group A (50%, p < 0.05) and experimental group B (50%, p < 0.05) were lower than that of control (100%) in experiment 2. The starting vomiting time in experimental groups was similar to that of the control groups in experiment 1 and 2. This study demonstrated that OA had anti-emetic effects on dogs with xylazine-induced vomiting and OA in the stomach/spleen region plus the zhongjiao region was the most effective in anti-emesis among the experimental groups. In addition, body AP and OA combined with body AP had a similar anti-emetic effect on dogs with xylazine-induced vomiting.
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Impact of sedation method on the diagnosis of hip and elbow dysplasia in Swedish dogs. Prev Vet Med 2007; 78:196-209. [PMID: 17112612 DOI: 10.1016/j.prevetmed.2006.10.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2005] [Revised: 09/24/2006] [Accepted: 10/07/2006] [Indexed: 10/23/2022]
Abstract
Our objective was to investigate the effect of sedation method on the screening result for hip and elbow dysplasia. The study was based on a questionnaire survey of routines for hip and elbow screening at Swedish veterinary clinics and results of hip and elbow status, for eight breeds (Bernese Mountain Dog, Boxer, German Shepherd Dog, Golden Retriever, Labrador Retriever, Newfoundland, Rottweiler, and Saint Bernard) recorded by the Swedish Kennel Club. In total 5877 and 5406 dogs examined for hip and elbow dysplasia, respectively, from January 2002 through March 2003 were included. We used logistic regression to examine whether the type of chemical restraint used for sedation affected the screening result for hip and elbow dysplasia. In addition to sedation method, the effects of veterinary clinic, sex, breed, and age at screening were studied. The type of chemical restraint used for sedation affected the screening result for hip but not for elbow dysplasia. Acepromazine gave less than half the odds of hip dysplasia compared with medetomidine and butorphanol (the most common method), medetomidine alone or xylazine. Females had about 25% higher odds for developing hip dysplasia whereas males had almost 40% higher odds for developing elbow dysplasia. Saint Bernard, Newfoundland and German Shepherd Dog had the highest odds of developing hip dysplasia, whereas Rottweiler and Labrador Retriever had the lowest odds. Boxer had the lowest risk for elbow dysplasia, followed by Labrador Retriever. Saint Bernard and Rottweiler had the highest odds of elbow dysplasia. Increasing age increased the odds of both hip and elbow dysplasia, by about 2.5% per month. Following the results in this study, recording of the type of chemical restraint used for sedation during hip screening has now become mandatory in Sweden. This makes it possible to account for the effect of sedation method in a model for prediction of breeding values for hip dysplasia.
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Parametric evaluation of methotrimeprazine-midazolam-ketamine and methotrimeprazine-midazolam-ketamine-xylazine combination in dogs. Acta Cir Bras 2006; 21:304-9. [PMID: 16981033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2006] [Accepted: 06/13/2006] [Indexed: 05/11/2023] Open
Abstract
PURPOSE To evaluate the parameters of dogs anesthetized by different dissociative drugs protocols through continuous intravenous infusion. METHODS Thirty healthy dogs of both sexes were assigned randomly to three groups (G1, G2, and G3). G1 was administered with methotrimeprazine as a pre-anesthetic medication, intravenously midazolam-ketamine as bolus for induction and midazolam-ketamine by continuous intravenous infusion for a 60 minute-period of maintenance. G2: the same as for G1. plus an increase in the midazolam dose during maintenance. G3: the same treatment as for G2, plus the addition of xylazine during maintenance. Immediately after induction the anesthetic maintenance started, and measures were taken 15 minutes after pre-medication, at 10 minutes intervals, during maintenance (M0 to M7). RESULTS Bradycardia, atrioventricular blockage, bradypnea and hypoxemia were shown in G3. G1 and G2 showed a slight hypotension only. CONCLUSION There were some advantages by using the continuous intravenous via: no parameters oscillation and reduction in the anesthetic recovery period. The increase in midazolam dose brought about little parametric variations which were greater when xylazine was used, with a consequent hypoxemia, bradyarrhytmia, and decrease in respiratory frequency and minute volume.
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The analgesic effects of intrathecal xylazine and detomidine in sheep and their antagonism with systemic atipamezole. Vet Anaesth Analg 2005; 32:297-307. [PMID: 16135211 DOI: 10.1111/j.1467-2995.2005.00214.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To evaluate the analgesic and adverse side effects of intrathecal (IT) xylazine (XYL) and detomidine (DET) and the subsequent effects of two doses of intravenous (IV) atipamezole (ATI). STUDY DESIGN Prospective, randomized, cross-over. ANIMALS Five adult healthy female sheep with mean body mass of 55 +/- 2.3 kg. Material and methods Each sheep underwent four treatments: 1) 50 microg kg(-1) XYL IT and 5 microg kg(-1) ATI IV, 2) 50 microg kg(-1) XYL IT and 2.5 microg kg(-1) ATI IV, 3) 10 microg kg(-1) DET IT and 5 microg kg(-1) ATI IV, 4) 10 microg kg(-1) DET IT and 2.5 microg kg(-1) ATI IV. Pain threshold (TH) was tested by applying pulsed and stepwise incremental direct current to the skin overlying the pastern. The current at the point of foot lift was recorded as the TH. Heart rate (HR), mean arterial pressure, arterial oxygen (PO(2)) and carbon dioxide (PCO(2)) tensions were monitored. Outcomes were derived as differences between baseline assessment and measurements after treatment. Two-way anova was used to analyse drug effects, treatment differences between groups were examined with an F-test or Wilcoxon's rank sum test in case of non-parametric data distribution. p was set at 0.05. RESULTS Both drugs increased the pain TH, caused small increases in PCO(2), and small decreases in HR, the latter was only significant for XYL recipients. Xylazine produced a significantly higher TH, more rapidly and for longer than DET. Atipamezole only significantly affected PaCO(2) in the XYL group 2. The pain TH was not affected in either group after IV ATI. CONCLUSIONS At the doses used, IT XYL, and to a lesser extent DET, induced pastern analgesia. Atipamezole 5 microg kg(-1) IV antagonized some side effects without affecting analgesia. CLINICAL RELEVANCE Intrathecal XYL may be useful as an analgesic in sheep. Its safety is increased because IV ATI antagonizes side effects, but not analgesia.
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Ischemic brain damage after ketamine and xylazine treatment in a young laboratory monkey (Macaca fascicularis). CONTEMPORARY TOPICS IN LABORATORY ANIMAL SCIENCE 2005; 44:19-24. [PMID: 16138776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
After a 4-year-old female laboratory cynomolgus monkey manifested neurological abnormalities, including tetanic spasm, after intramuscular injection of 20 mg/kg ketamine, we administered 2 mg/kg xylazine in an attempt to control the seizure. However, the animal continued to display opisthotonus, nystagmus, and symptomatic epilepsia. Analysis of blood chemistry revealed a dramatically increased creatine phosphokinase level. Abnormal histopathological findings included acute neuronal necrosis or glial reaction or both in the cerebral cortex, nucleus lentiformis, hippocampus, cerebellar cortex and nucleus, and medulla oblongata; severe myocardial hemorrhagic necrosis; and hepatic subcapsular hematoma. Although the mechanism of this neuronal damage has not been clarified, it may be attributable to an ischemic condition in the brain, probably due to temporal cardiac arrest or hemorrhagic change in the liver and heart, with subsequent decreased blood pressure, after ketamine and/or xylazine treatment. Because both drugs often are used as general anesthetics in veterinary medicine, attention should be paid to this rare case with neural damage.
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EFFICACY OF IMMOBILIZING FREE-RANGING ELK WITH TELAZOL® AND XYLAZINE HYDROCHLORIDE USING TRANSMITTER-EQUIPPED DARTS. J Wildl Dis 2005; 41:395-400. [PMID: 16107675 DOI: 10.7589/0090-3558-41.2.395] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
From January 1999 to April 2002, 14 free-ranging elk were darted with a mixture of Telazol reconstituted with xylazine hydrochloride (HCl) in a forested habitat in southwestern Oklahoma and north-central Arkansas. Elk were darted from ground blinds, tree stands, or a vehicle at distances of 14-46 m and were recovered 37-274 m from the dart site. Elk were located using radiotelemetry with 3-cc disposable Pneu-dart transmitter darts. Mean+/-SD dose of Telazol and xylazine HCl was 590+/-192 mg/ml and 276+/-153 mg/ml, respectively, and mean time to standing after injection of reversal agent was 27 min (range: 1-65 min). The combination of Telazol and xylazine HCl successfully immobilized free-ranging elk, and transmitter-equipped darts permitted successful location of sedated elk by two people in areas of dense forest cover. The dose required to sedate elk appeared to vary depending on physiology and behavior, but no drug-induced mortality occurred despite the wide variance in the doses administered. We recommend 500 mg Telazol reconstituted with 300 mg xylazine HCl as an initial dose for a >or=200 kg elk. If needed to achieve full sedation, up to 3 additional ml of the mixture may be administered without adverse effects.
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Levels of glutathione peroxidase, lipoperoxidase and some biochemical and haematological parameters in gazelles anaesthetised with a tiletamin–zolazepam–xylazine combination. Vet J 2005; 169:126-8. [PMID: 15683777 DOI: 10.1016/j.tvjl.2004.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2004] [Indexed: 10/26/2022]
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Effect of intratesticular injection of xylazine/ketamine combination on canine castration. J Vet Sci 2004; 5:151-5. [PMID: 15192343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023] Open
Abstract
This study was performed to compare the effect of intratesticular (IT) injection of xylazine/ketamine combination for canine castration with those of intramuscular (IM) or intravenous (IV) injection. Xylazine and ketamine was administered simultaneously via intratesticularly (IT group), intramuscularly (IM group) or intravenously (IV group) at doses of 2 and 10 mg/kg, respectively. Pain response at the time of injection, mean induction time, mean arousal time, mean walking time and cardiopulmonary function during anesthesia were monitored after the xylazine and ketamine administration. In IV and IM groups, heart rates were significantly decreased 30 and 45 min after xylazine and ketamine administration, respectively (p < 0.05). Respiratory rates were significantly decreased in the IV group (p < 0.05). In the IT group, there was no significant changes in heart and respiratory rates. The occurrence of cardiac arrhythmias was less severe in IT group compared with those in IM and IV groups. The route of administration did not affect rectal temperature. Mean induction time was significantly (p < 0.05) longer in IT group than in IM and IV groups. On the contrary, mean arousal time and mean walking time were shortened in IT group. Clinical signs related to pain response at the time of injection and vomiting were less observed in IT group than in IM group, and head shaking was less shown in IT group than in IM and IV groups during recovery period. These results indicated that intratesticular injection of xylazine/ketamine for castration has several advantages such as less inhibition of cardiopulmonary function and fast recovery from anesthesia without severe complications, and would be an effective anesthetic method for castration in small animal practice.
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Comparison of the depressive effects of four anesthetic regimens on ventilatory and cardiovascular variables in the guinea pig. Comp Med 2004; 54:77-85. [PMID: 15027622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
BACKGROUND AND PURPOSE Guinea pigs are one of the most difficult rodents to anesthetize safely, and as a consequence, there is a paucity of reports regarding the effects of anesthesia on their cardiorespiratory variables. We used long-term indwelling cannulas for studying the guinea pig in the conscious state, and subsequently investigated the effects of four types of injectable anesthetic regimens on cardiorespiratory variables. METHODS Using barometric plethysmography (conscious: long-term cannulated, n = 11; no cannulation, n = 28) or trachea-out plethysmography (anesthetized: n = 7 for each of the four groups), we recorded ventilatory, cardiovascular, metabolic, and arterial gas variables during air breathing and in response to 10 min of hypoxia (8% O2) and 10 min of hypercapnia (8% CO2). The four anesthetic regimens tested were: Saffan (infused at 9.75 mg/kg of body weight/h, i.v.); ketamine/xylazine (14.6/3.7 mg/kg/h, i.v.); pentobarbitone (8.3 mg/kg/h, i.v.) plus Innovar Vet (0.15 mg/kg every 1 to 1.5 h, s.c.); or pentobarbitone alone (22 mg/kg/h, i.v.). RESULTS The least depressive anesthetic with regard to ventilation (VE) was ketamine/xylazine. Air breathing was depressed by only 17% (cf approx 50 to 60% for all other regimes), and the VE responses to hypoxia and hypercapnia were attenuated the least. All anesthetics equally depressed mean arterial blood pressure (from 70 mmHg to 56 mmHg) and ketamine/xylazine was the only anesthetic to reduce heart rate (from 260 beats/min to 198 beats/min). CONCLUSION Although all anesthetics induce cardiorespiratory depression to some extent, the use of ketamine/ xylazine is recommended for future use in respiratory studies of the guinea pig where anesthesia cannot be avoided.
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Clinical observations during induction and recovery of xylazine-midazolam- propofol anesthesia in horses. J Vet Med Sci 2003; 65:805-8. [PMID: 12939509 DOI: 10.1292/jvms.65.805] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To evaluate clinical usefulness of xylazine (1.0 mg/kg)-midazolam (20 microg/kg)-propofol (3.0 mg/kg) anesthesia in horses, 6 adult Thoroughbred horses were examined. The quality of induction varied from poor to excellent and 5 out of 6 horses presented myotonus in the front half of the body. However, paddling immediately after induction observed in other reports of equine propofol anesthesia was not observed. Recovery time was 35.3 +/- 9.3 min and the quality of recovery was calm and smooth in all horses. Respiration rate decreased after induction and hypoxemia was observed during lateral recumbency. Heart rate also decreased after induction, however mean arterial blood pressure was maintained above approximately 100 mmHg.
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Abstract
The effect of surgery on phagocytic activity of blood leukocytes and mitogen-induced blastogenesis of lymphocytes was studied in fourteen dogs. Simple ovariohysterectomy with anaesthesia induced by ketamine and xylazine or by ketamine, xylazine and halothane caused a short nonsignificant depression of phagocytic activity that persisted for four hours after surgery. Ingestion capacity of leukocytes decreased significantly immediately after surgery. Mitogen-induced blastogenesis of lymphocytes was depressed significantly in the first 48 hours and despite partial recovery this parameter did not reach the value of the control groups until the end of observation (7 days). A more conspicuous decrease of blastogenic response of blood lymphocytes to mitogens was found after the use of ketamine and xylazine in a dose maintaining anaesthesia. Anaesthesia with ketamine and xylazine in the lower dose and maintained with halothane resulted in a later improvement of the blastogenic response of lymphocytes.
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Abstract
A case of suspected drug-impaired driving involving self-administration of xylazine (Xyla-Ject), a veterinary tranquilizing agent, and paroxetine is presented. Qualitative and quantitative analysis of xylazine and paroxetine were performed by gas chromatography with a flame-ionization detector (GC-FID) and gas chromatography/mass spectrometry (GC/MS). Whole blood xylazine and paroxetine concentrations were 0.57 and 0.02 microg/ml, respectively.
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Abstract
Twelve captive wild-caught adult arctic foxes (Alopex lagopus) were anesthetized a total of 24 times for an equal number of surgical procedures involving implantation of heart rate (HR) and core body temperature transmitters (Tb) between October 1995 and April 1997. Xylazine-ketamine and medetomidine-ketamine anesthesia was used, resulting in an unacceptably high death rate. One out of four foxes anesthetized with xylazine-ketamine died, whereas two of nine foxes anesthetized with medetomidine-ketamine died out of a total of 20 surgical procedures. Durations of the surgeries for implantation of Tb transmitters and HR transmitters were 73 +/- 7 min and 95 +/- 13 min, respectively.
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Effects of propofol as an anaesthetic agent in adult lions (Panthera leo): a comparison with two established protocols. Res Vet Sci 2002; 72:137-40. [PMID: 12027594 DOI: 10.1053/rvsc.2001.0535] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The aims of this study were to evaluate the effects of a ketamine/propofol anaesthetic protocol in lions (Panthera leo), and to compare it to two commonly used anaesthetic protocols. Seventeen adult lions were anaesthetised using three different protocols. Group XK (n=6) was anaesthetised with intramuscular (i.m.) injections of xylazine and ketamine. Group KD (n=5) was anaesthetised with an i.m. injection of ketamine, followed by an intravenous (i.v.) injection of ketamine and diazepam. Group KP (n=6) was anaesthetised with an i.m. injection of ketamine followed by an i.v. injection of propofol. There was a significant difference in heart rate (P<0.0002), which was lowest in group XK and highest in KD. Jaw tone was significantly lower in Group XK (P<0.05). No undesirable effects were noted following injection of the propofol. Propofol was a suitable and safe drug for maintenance of anaesthesia in adult lions.
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Early effects of tribromoethanol, ketamine/xylazine, pentobarbitol, and isoflurane anesthesia on hepatic and lymphoid tissue in ICR mice. Comp Med 2002; 52:63-7. [PMID: 11900415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
We investigated the effects of various anesthetic agents on hepatic and splenic injury in mice. Three and six hours after intraperitoneal injection of TBE, intramuscular injection of ketamine/xylazine combination (K/X), intraperitoneal injection of pentobarbital (PB), and inhalation of isoflurane (IF), or intraperitoneal and intramuscular injection of control saline, mice were exsanguinated and serum was obtained for measurement of hepatic aspartate transaminase (AST), alanine transaminase (ALT) and gamma-glutamyltransferase (GGT). The spleen and liver also were obtained, and sections were examined by use of routine light microscopy for pathologic changes and for apoptosis, as determined by use of the in situ terminal deoxynucleotidyl transferase-mediated dUPT nick-end-labeling (TUNEL) histochemical analysis. Three hours after TBE or K/X administration, AST activity increased three- to fourfold above that in untreated and saline-injected control animals, and remained high at six hours. Administration of PB did not effect AST activity at three hours, but there was a significant increase at six hours. Activity of ALT was non-significantly increased three hours after TBE and K/X, but not PB administration. Administration of IF had no effect on hepatic enzyme activities, and GGT was not increased after administration of any of the agents. Markedly increased apoptosis was observed in splenic follicles and in hepatic Kupffer and endothelial cells at three hours after TBE and K/X administration, but apoptosis decreased to control levels by six hours. Increased apoptosis was not observed after IF administration. Administration of TBE and K/X causes injury to lymphocytes and to hepatic Kupffer and endothelial cells within three hours, and PB administration induces changes within six hours. Thus, use of these anesthetic agents should be avoided when experiments are being designed to test short-term effects of an experimental intervention on the spleen and possibly on all lymphoid tissues. In addition, they also should be avoided in experiments testing effects on hepatic tissue.
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Treatment of hypoxemia during xylazine-tiletamine-zolazepam immobilization of wapiti. THE CANADIAN VETERINARY JOURNAL = LA REVUE VETERINAIRE CANADIENNE 2001; 42:861-4. [PMID: 11708204 PMCID: PMC1476651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Hypoxemia is a commonly observed complication during the chemical immobilization of wild ruminants. If severe and left untreated, it can predispose animals to arrhythmias, organ failure, and capture myopathy. The following prospective study was designed to measure the degree of hypoxemia in wapiti that were immobilized with a combination of xylazine and tiletamine-zolazepam and to assess the response to nasal oxygen therapy. Pulse oximetry and arterial blood gas analysis were used to assess the degree of hypoxemia prior to nasal insufflation of oxygen and to demonstrate any beneficial effects of this intervention. All wapiti exhibited mild to marked hypoxemia (PaO2 = 43 +/- 11.8 mmHg) prior to treatment and showed marked improvement after 5 minutes of nasal insufflation of oxygen at 10 L/min (PaO2 = 207 +/- 60 mmHg). This inexpensive, noninvasive technique has great benefit in treating clinical hypoxemia under field conditions, and we recommend that nasal insufflation of oxygen be implemented during xylazine-tiletamine-zolazepam-induced immobilization of wapiti and other wild ruminants.
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Abstract
OBJECTIVE To determine antiemetic efficacy of prophylactic administration of dexamethasone and its influence on sedation in cats sedated with xylazine hydrochloride. ANIMALS 6 healthy adult cats (3 males and 3 females). PROCEDURE The prophylactic antiemetic effect of 4 doses of dexamethasone (1, 2, 4, and 8 mg/kg of body weight, IM) or saline (0.9% NaCl) solution (0.066 ml/kg, IM) administered 1 hour before administration of xylazine (0.66 mg/kg, IM) was evaluated. Cats initially were given saline treatment (day 0) and were given sequentially increasing doses of xylazine on days 7, 14, 21, and 28. After xylazine injection, all cats were observed for 30 minutes to allow assessment of frequency of emesis and time until onset of the first emetic episode. The influence of dexamethasone on xylazine-induced sedation in these cats also was evaluated. RESULTS Prior treatment with 4 or 8 mg/kg of dexamethasone significantly reduced the frequency of emetic episodes and also significantly prolonged the time until onset of the first emetic episode after xylazine injection. Time until onset of the first emetic episode also was significantly prolonged for dexamethasone at a dose of 2 mg/kg. Time until onset of sedation after administration of xylazine was not altered by administration of dexamethasone. CONCLUSIONS AND CLINICAL RELEVANCE Dexamethasone (4 or 8 mg/kg, IM) significantly decreased the frequency of emetic episodes induced by xylazine without compromising sedative effects in cats. Dexamethasone may be used prophylactically as an antiemetic in cats treated with xylazine.
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Abstract
A 6.5-year-old male rhesus macaque (Macaca mulatta) was presented with acute paraplegia following a surgical procedure. During surgery, he experienced an acute hypotensive episode that required 3 hours of supportive therapy before hemodynamic stability was restored. Paraplegia remained unchanged until euthanasia 72 hours later. At necropsy, spinal cord segments T10-S3 had acute, massive panmedullary necrosis, which involved most of the central and middle spinal cord, sparing the peripheral white matter. Additional lesions included arterial border zone necrosis of the brain, centrilobular hepatic necrosis, and proximal renal tubular necrosis. The histologic findings of central spinal cord necrosis with a preserved rim of white matter is consistent with severely decreased flow in the anterior spinal artery. Such lesions can result from episodes of generalized hypoperfusion. Possible factors contributing to the hypotensive episode in this case included the addition of xylazine to ketamine and atropine in the preanesthetic medication, positioning during anesthesia, and decreased blood pressure during surgery.
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Comparative cardiopulmonary effects of carfentanil-xylazine and medetomidine-ketamine used for immobilization of mule deer and mule deer/white-tailed deer hybrids. CANADIAN JOURNAL OF VETERINARY RESEARCH = REVUE CANADIENNE DE RECHERCHE VETERINAIRE 2000; 64:64-8. [PMID: 10680659 PMCID: PMC1189583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Three mule deer and 4 mule deer/white-tailed deer hybrids were immobilized in a crossover study with carfentanil (10 microg/kg) + xylazine (0.3 mg/kg) (CX), and medetomidine (100 microg/kg) + ketamine (2.5 mg/kg) (MK). The deer were maintained in left lateral recumbency for 1 h with each combination. Deer were immobilized with MK in 230+/-68 s (mean +/- SD) and with CX in 282+/-83 seconds. Systolic, mean and diastolic arterial pressure were significantly higher with MK. Heart rate, PaO2, PaCO2, pH, and base excess were not significantly different between treatments. Base excess and pH increased significantly over time with both treatments. Both treatments produced hypoventilation (PaCO2 > 50 mm Hg) and hypoxemia (PaO2 < 60 mm Hg). PaO2 increased significantly over time with CX. Body temperature was significantly (P<0.05) higher with CX compared to MK. Ventricular premature contractions, atrial premature contractions, and a junctional escape rhythm were noted during CX immobilization. No arrhythmias were noted during MK immobilization. Quality of immobilization was superior with MK, with no observed movement present for the 60 min of immobilization. Movement of the head and limbs occurred in 4 animals immobilized with CX. The major complication observed with both of these treatments was hypoxemia, and supplemental inspired oxygen is recommended during immobilization. Hyperthermia can further complicate immobilization with CX, reinforcing the need for supplemental oxygen.
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Self-mutilation in rabbits following intramuscular ketamine-xylazine-acepromazine injections. THE CANADIAN VETERINARY JOURNAL = LA REVUE VETERINAIRE CANADIENNE 1999; 40:581-2. [PMID: 12001340 PMCID: PMC1539777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Following hind leg intramuscular injections of ketamine, xylazine, and acepromazine, 4 of 6 rabbits exhibited self-mutilation of the digits. At necropsy, the affected sciatic nerve appeared enlarged. Lymphohistiocytic perineural inflammation and fibrosis were observed, together with nerve degeneration. Neuronal regeneration as the reason for self-mutilation is discussed.
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Alpha-2 receptor agonists and a species-specific mechanism of hypoxaemia. Anaesthesia 1999; 54:607-8. [PMID: 10404184 DOI: 10.1046/j.1365-2044.1999.96794l.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Cardiovascular pathology possibly associated with ketamine/xylazine anesthesia in Dutch belted rabbits. LABORATORY ANIMAL SCIENCE 1999; 49:153-60. [PMID: 10331545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
BACKGROUND AND PURPOSE After myocardial necrosis and fibrosis was observed in five rabbits which had been anesthetized a variable number of times, the potential relationship of these lesions and anesthesia was evaluated in 35 other rabbits. METHODS Anesthesia was induced by intramuscular administration of ketamine and xylazine followed by infusion of lactated Ringer's solution also containing ketamine and xylazine. Group A rabbits (n = 9) were subjected to multiple anesthesias and were evaluated by echocardiography, thoracic radiography, electrocardiography, determination of serum coronavirus titer, vitamin E concentration, and complete necropsy. Prior to a single acute procedure followed by necropsy, group B rabbits (n = 11) were evaluated by echocardiography only. Group C rabbits (n = 10) had never been anesthetized and were necropsied after euthanasia. Group D rabbits (n = 5) had intermediate anesthesia exposure history and were evaluated by echocardiography only. Myocardial fibrosis was scored semi-quantitatively on a scale of 0 to 4. RESULTS Canine coronavirus test results were negative; hypovitaminosis E was evident, and fibrosis scores were significantly increased in group A, compared with group B or group C, rabbits. CONCLUSION Etiologic differentials included alpha2-agonist-mediated coronary vasoconstriction with associated myocardial hypoperfusion, hypovitaminosis E and free radical injury, and other anesthetic-induced physiologic trespass.
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Histopathologic alterations induced in the lungs of sheep by use of alpha2-adrenergic receptor agonists. Am J Vet Res 1999; 60:154-61. [PMID: 10048544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
OBJECTIVE To study effects of central- and peripheral-acting alpha2-adrenergic receptor agonists on lung parenchyma, platelets, and pulmonary intravascular macrophages (PIM) of sheep. ANIMALS 12 healthy mature female sheep. PROCEDURE Group-1 (control, n = 2) sheep received 5 ml of physiologic saline solution IV and were euthanatized 3 minutes later. Sheep of group 2 (n = 8) received xylazine (150 microg/kg of body weight, IV), then 2 sheep each were euthanatized 3, 10, or 60 minutes, or 12 hours later. Sheep (n = 2) of group 3 were given ST-91 (30 microg/kg, IV), then were euthanatized 3 minutes later. Immediately after euthanasia, the lungs were fixed intratracheally and tissue was obtained for light and electron microscopy after 1 hour. RESULTS Pulmonary parenchymal damage or morphologic alterations in PIM and platelets were not evident in control sheep. Three minutes after xylazine administration, morphologic changes in PIM were appreciable. After 10 minutes, extensive damage to the capillary endothelium and alveolar type-I cells, intra-alveolar hemorrhage, and interstitial and alveolar edema were evident. Most PIM had complete internalization of the surface coat. Similar changes were seen 60 minutes after xylazine administration; however, by 12 hours, morphologic features of PIM and lung parenchyma were almost completely restored. Evidence of PIM activation, obvious damage to capillary endothelium, and extensive pulmonary edema also were evident 3 minutes after ST-91 administration. CONCLUSIONS XYLAZINE induces severe pulmonary parenchymal damage when administered at clinical sedative doses in sheep; morphologic changes in PIM within 3 minutes after administration of these drugs are substantial; and platelet aggregation is not apparent.
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Relative efficiency of succinylcholine, xylazine, and carfentanil/xylazine mixtures to immobilize free-ranging moose. J Wildl Dis 1999; 35:38-48. [PMID: 10073344 DOI: 10.7589/0090-3558-35.1.38] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We compared the efficiency of succinylcholine chloride, xylazine hydrochloride and carfentanil/xylazine mixtures in immobilizing 364 free-ranging moose (Alces alces) between 1987 and 1997 in Québec (Canada). With succinylcholine chloride (0.070, 0.062, 0.051 mg/kg of estimated body weight for calves, juveniles and adults), 63% of the 252 immobilization attempts led to complete immobilization and marking, whereas 7% of the darted animals died of respiratory paralysis during handling. The moose took an average of 13 min to lay down after darting (down time). Injection of xylazine (3.67-4.22 mg/kg) permitted sedation (the animal laid down but got up again when approached) or complete immobilization in 78% of the 40 darted adult moose, the mean down time being 8.7 min. No mortality was noted with this drug but 58% of the marked animals were only sedated. The use of RX821002A (0.058 mg/kg) as an antagonist, permitted a mean recovery time of 2.8 min after intravenous injection. With the carfentanil/xylazine mixtures (0.0071 and 0.181 mg/kg), 96% of the immobilization trials (n = 72) led to complete (88%) or partial (8%) immobilization, but 6% of the moose died several days after capture. The mean down time was 6.6 min, and injection of naltrexone (0.709 mg/kg) antagonized the effect of the immobilizing agent within 3.7 min. The respiratory rate was higher (P < 0.05) among moose immobilized with xylazine (35/min) than among those immobilized with carfentanil/xylazine mixtures (19/min) but this variation could be related to a longer pursuit time (z = 3.60; P < 0.01) and higher stress levels during handling. Rectal temperature also was higher with xylazine but the difference was small (39.7 vs. 39.3, P = 0.03) and did not differ significantly between the sexes (P > 0.05). Considering loss of materials and helicopter flight time due to non-successful marking trials, carfentanil/xylazine mixtures were the least expensive ($333 Cdn/animal).
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Abstract
Tribromoethanol is widely used as an anaesthetic agent for embryo-transfer surgery for the generation of transgenic mice. Potential side effects such as local irritation, fibrous adhesions in the abdominal cavity, and mortalities of unknown cause have been reported. Mice of three different strains (CD-1, OF-1, NMRI) received intraperitoneal injections of pentobarbiturate (60 mg/kg, 0.4%), tribromoethanol (240 mg/kg, 1.2%), tribromoethanol (450 mg/kg, 2.5%), ketamine/xylazine (120 mg/kg, 1.2%/16 mg/kg, 0.16%) or saline (NaCl, 0.9%). After 24 h the animals were sacrificed and blinded histopathological examination of abdominal organs was performed by light microscopy. Tribromoethanol caused focal to diffuse necrosis primarily of subperitoneal muscle fibres of the abdominal wall, and, occasionally, necrotic changes on the surface of abdominal organs. These changes were associated with acute peritoneal inflammation and fibrinous serositis of the abdominal organs. The severity of the findings increased with the concentration of tribromoethanol. The use of ketamine/xylazine yielded a comparable success rate in embryo transfer without undesirable side effects. Further use of tribromoethanol is not recommended.
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Epidural analgesia in addax (Addax nasomaculatus). J Zoo Wildl Med 1998; 29:285-7. [PMID: 9809599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
Epidural analgesia was used 22 times in three female addax (Addax nasomaculatus). The addax were physically restrained in a drop-floor chute and sedated with acepromazine (0.14-0.34 mg/kg). Epidural analgesia was induced with 2% lidocaine (0.17-0.38 mg/kg) via a 20-ga 1-inch needle placed at the sacrococcygeal intervertebral space or the first intercoccygeal intervertebral space. Adequate analgesia was attained to allow manipulation of the reproductive tract and transvaginal ultrasound-guided oocyte collection.
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Hemodynamic response to anesthesia in pregnant and nonpregnant ICR mice. LABORATORY ANIMAL SCIENCE 1998; 48:357-63. [PMID: 10090043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Mean arterial blood pressure (BP) and heart rate (HR) during and after recovery from anesthesia in pregnant and nonpregnant ICR mice were evaluated. Mice were evaluated during mechanical ventilation, from 15 to 60 min after induction of anesthesia. The anesthetic protocols were pentobarbital (80 mg/kg, given intraperitoneally [i.p.]); two low doses of ketamine and xylazine (90 mg/kg, 7.5 mg/kg, respectively, i.p., with a second dose given 20 min after the initial dose); and a single high dose of ketamine and xylazine (150 mg/kg, 12.5 mg/kg, respectively, i.p.). The BP was measured in the right carotid artery, using a fluid-filled catheter connected to a chamber containing a solid-state pressure transducer. Mechanical ventilation was performed via tracheotomy, using a normalized minute ventilation of 3.5 ml*min-1*g-1 for nonpregnant mice and 3.0 ml*min-1*g-1 for pregnant mice. Mean BP was lower and HR was higher in pregnant than in nonpregnant mice for each anesthetic protocol. Pentobarbital induced significantly greater tachycardia and hypotension than did the other protocols. The average BP and HR were similar between two low doses and a single high dose of ketamine and xylazine. During spontaneous breathing from 30 to 180 min after recovery from anesthesia by use of a single low dose, ketamine and xylazine induced similar HR profiles, but mean BP in pregnant mice recovered earlier than did that in nonpregnant mice. These results suggest that ketamine and xylazine induced adequate anesthesia for superficial surgical procedures in pregnant and nonpregnant mice while inducing small changes in HR and BP, and pregnancy resulted in a different hemodynamic reaction in response to ketamine and xylazine. These data will be useful for the design and interpretation of physiologic protocols using pregnant and nonpregnant genetically targeted mice.
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Impairment of gas exchange due to alveolar oedema during xylazine sedation in sheep; absence of a free radical mediated inflammatory mechanism. Res Vet Sci 1998; 65:71-5. [PMID: 9769076 DOI: 10.1016/s0034-5288(98)90030-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We studied the mechanism of impairment of gas exchange following sedation with the alpha2 adrenoreceptor agonist, xylazine, in Suffolk cross-bred sheep spontaneously breathing room air. Xylazine caused a significant fall in PaO2 from a mean (pre-xylazine) of 97.9 mm Hg (6.7 mm Hg SEM) to a mean of 38.1 mm Hg (3.2 mm Hg SEM) one minute after injection with a transient increase in PaCO2 from a mean (pre-xylazine) of 32.6 mm Hg (1.9 mm Hg SEM) to a mean of 40.2 mm Hg (3.0 mm Hg SEM). There was no significant fall in mean arterial pressure or in white cell count. There was no significant change in a number of indices of free radical release which included ascorbyl radical, plasma antioxidant potential and alpha-tert-butyl phenyl nitrone (PBN) spin adduct measured simultaneously in both arterial and venous blood. In all sheep given xylazine there was no histological evidence of platelet emboli but lung histopathology showed evidence of pulmonary oedema and intense microvascular congestion with red cells extravasated into alveoli. No such histological changes were seen in the lungs of normal sheep. The impaired gas exchange during sedation with xylazine in sheep is caused, not by an oxidant mediated inflammatory mechanism or by platelet emboli, but by intense alveolar oedema which is probably due to pulmonary venospasm.
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Abstract
We immobilized 21 pygmy spotted skunks (Spilogale pygmaea), in the tropical deciduous forest at the Chamela Biological Station (Mexico) from October 1994 to May 1997, with a mixture of ketamine (KH) and xylazine (XH). Skunks were immobilized with a mean (+/- SD) dosage of 15.7 +/- 8.3 mg/kg KH and 8.1 +/- 4.3 mg/kg XH. Mean induction and recovery time (n = 21) were 1.7 +/- 1.6 and 34.2 +/- 12.2 min, respectively. One individual was immobilized with XH, induction time was 1 min, and recovery time was 45 min. Foaming salivation was observed in this animal. No other adverse effects were observed for the other animals in this sample.
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