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Avelino JA, Walsh CA, Wharton KN, Ekanayake D, Ekanayake-Alper D. A Comparison of Three Anesthetic Drug Combinations for Use in Inducing Surgical Anesthesia in Female Guinea Pigs ( Cavia porcellus). JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE : JAALAS 2024; 63:182-189. [PMID: 38182132 PMCID: PMC11022950 DOI: 10.30802/aalas-jaalas-23-000064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 10/09/2023] [Accepted: 12/08/2023] [Indexed: 01/07/2024]
Abstract
Guinea pigs are often used in translational research, but providing them with safe and effective anesthesia is a challenge. Common methods like inhalant anesthesia and injectable ketamine/xylazine induce surgical anesthesia but can negatively affect cardiovascular, respiratory, and thermoregulatory systems and complicate the interpretation of research outcomes. Several alternative anesthetic regimens have been investigated, but none have consistently achieved a surgical plane of anesthesia. Therefore, identifying an anesthetic regimen that achieves a stable state of the surgical plane of anesthesia while preserving cardiorespiratory function would be a valuable contribution. To address this issue, we compared the efficacy of 3 anesthetic combinations in female Dunkin-Hartley guinea pigs: 1) alfaxalone, dexmedetomidine, and fentanyl (ADF); 2) alfaxalone, midazolam, and fentanyl (AMF); and 3) alfaxalone, midazolam, fentanyl, and isoflurane (AMFIso). We monitored anesthetic depth, heart rate, oxygenation, respiratory rate, respiratory effort, blood pressure, and body temperature every 15 min from injection to recovery. We also recorded the time to loss of righting reflex, duration of anesthesia, and time to achieve a surgical plane. The results showed no statistically significant differences in induction and recovery times among the groups. In the AMFIso group, 100% of the animals achieved a surgical plane of anesthesia, whereas only 10% of the animals in the AMF group reached that level. None of the animals in ADF group reached a surgical plane of anesthesia. Respiratory rate was significantly lower in the AMFIso as compared with the ADF group (P < 0.001) but was not different between the AMF and ADF groups. Temperature was significantly lower in the AMFIso group as compared with both the ADF and AMF groups (P < 0.001). In conclusion, both combinations of solely injectable anesthetics assessed in this study can be used for short, nonpainful procedures without significant cardiorespiratory depression. However, for mildly to moderately painful surgical procedures, the addition of an inhalant anesthetic like isoflurane is necessary for female guinea pigs.
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Key Words
- adf, alfaxalone, dexmedetomidine, and fentanyl
- amf, alfaxalone, midazolam, and fentanyl
- amfiso, alfaxalone, midazolam, fentanyl, and isoflurane
- bpm, breaths per minute
- gp, guinea pig
- hr, heart rate
- kx, ketamine and xylazine
- lorr, loss of righting reflex
- map, mean arterial pressure
- rr, respiratory rate
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Affiliation(s)
- Janelle A Avelino
- Department of Comparative Medicine, Yale School of Medicine, New Haven, Connecticut
| | - Courtney A Walsh
- Department of Comparative Medicine, Yale School of Medicine, New Haven, Connecticut
| | | | - Dinesh Ekanayake
- Department of Mathematics and Philosophy, Western Illinois University, Macomb, Illinois
| | - Dil Ekanayake-Alper
- Department of Comparative Medicine, Yale School of Medicine, New Haven, Connecticut;,
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Gasparik-Küls N, Larenza MP, Rocchi A. Use of a propofol infusion for anaesthetic maintenance in Guinea pigs (Cavia porcellus): a retrospective case series. Vet Anaesth Analg 2023; 50:498-501. [PMID: 37690880 DOI: 10.1016/j.vaa.2023.06.005] [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: 05/11/2022] [Revised: 06/26/2023] [Accepted: 06/28/2023] [Indexed: 09/12/2023]
Abstract
OBJECTIVE To retrospectively evaluate the feasibility of a propofol infusion for anaesthetic maintenance in guinea pigs. STUDY DESIGN Retrospective case series. ANIMALS Client-owned guinea pigs undergoing general anaesthesia. METHODS Anaesthetic records of guinea pigs anaesthetized between March 2015 and March 2018 were reviewed. Animals administered a propofol infusion for > 20 minutes were identified and evaluated. Procedure performed, pre-anaesthetic medication, preoperative and intraoperative respiratory rate (fR) and heart rates (HRs), total amount of propofol administered, total anaesthesia and recovery times were extracted from the records and analysed using descriptive statistics and Pearson correlation tests. Data are reported as mean (range). RESULTS Records of 14 animals meeting the criteria were identified. Following drug combinations were administered for premedication: butorphanol 0.43 (0.3-0.5) mg kg-1, medetomidine 0.1 (0.05-0.2) mg kg-1 and midazolam 1 (0.5-2) mg kg-1 (n = 3); methadone 0.33 (0.25-0.5) mg kg-1, medetomidine 0.07 (0.01-0.1) mg kg-1 and midazolam 0.66 (0.5-1) mg kg-1 (n = 3); butorphanol 0.5 mg kg-1, medetomidine 0.05 mg kg-1 and ketamine 5 mg kg-1 (n = 2); buprenorphine 0.01 mg kg-1, medetomidine 0.07 (0.04-1) mg kg-1 and ketamine 4 (3-5) mg kg-1 (n = 3); butorphanol 0.5 mg kg-1, alfaxalone 1 mg kg-1 and midazolam 0.5 mg kg-1 (n = 1); and methadone 0.38 (0.25-0.5) mg kg-1, medetomidine 0.08 (0.06-1) mg kg-1 with midazolam 0.75 (0.5-1) mg kg-1 (n = 2). Preoperative and intraoperative HRs were 240 (160-300) and 170 (140-200) beats minute-1, respectively. Preoperative and intraoperative fR were 63 (50-86) and 37 (18-80) breaths minute-1, respectively. The propofol infusion rate was 0.45 (0.17-0.80) mg kg-1 minute-1. Total anaesthesia and recovery times were 60 (25-145) and 17 (8-60) minutes, respectively. A slight correlation was found between total propofol dose infused and recovery time (r = 0.58). CONCLUSION AND CLINICAL RELEVANCE Propofol infusions may be a useful alternative to inhalant anaesthetics.
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Affiliation(s)
- Nina Gasparik-Küls
- Department of Anesthesiology and Perioperative Care, Veterinary University of Vienna, Vienna, Austria.
| | - Maria Paula Larenza
- Anaesthesia Section, School of Veterinary Science, Massey University, University Avenue, Palmerston North 4472, New Zealand
| | - Attilio Rocchi
- Department of Anesthesiology and Perioperative Care, Veterinary University of Vienna, Vienna, Austria
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BARTAKOVA A, NOVAKOVA M, STRACINA T. Anesthetized guinea pig as a model for drug testing. Physiol Res 2022; 71:S211-S218. [PMID: 36647909 PMCID: PMC9906665 DOI: 10.33549/physiolres.934994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Based on the World Health Organization statistics, cardiovascular diseases represent the major cause of death worldwide. Although a wide range of treatment approaches and pharmaceuticals is available, the therapy is often not effective enough and therefore health risks for the patient persist. Thus, it is still essential to test new drug candidates for the treatment of various pathophysiological conditions related to cardiovascular system. In vivo models represent indispensable part of preclinical testing of such substances. Anesthetized guinea pig as a whole-body model allows to evaluate complex reactions of cardiovascular system to tested substance. Moreover, action potential of guinea pig cardiomyocyte is quite comparable to that of human. Hence, the results from this model are then quite well translatable to clinical medicine. Aim of this paper was to summarize the methodology of this model, including its advantages and/or limitations and risks, based on the effects of two substances with adrenergic activity on the ECG parameters. The model of anesthetized guinea pig proved to be valuable and suitable for testing of drugs with cardiovascular effects.
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Affiliation(s)
- Anna BARTAKOVA
- Department of Physiology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Marie NOVAKOVA
- Department of Physiology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Tibor STRACINA
- Department of Physiology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
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Comparison of two injectable anaesthetic protocols in Egyptian fruit bats (Rousettus aegyptiacus) undergoing gonadectomy. Sci Rep 2022; 12:15962. [PMID: 36153361 PMCID: PMC9509369 DOI: 10.1038/s41598-022-20408-z] [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: 03/31/2022] [Accepted: 09/13/2022] [Indexed: 11/10/2022] Open
Abstract
Egyptian fruit bats have gained increasing interest being a natural reservoir for emerging zoonotic viruses. Anaesthesia is often required to allow safe handling of bats. We aimed to compare the sedative and cardiopulmonary effects of two balanced anaesthetic protocols in bats undergoing gonadectomy. Group DK (n = 10) received intramuscular dexmedetomidine (40 µg/kg) and ketamine (7 mg/kg), whereas group DBM (n = 10) received intramuscular dexmedetomidine (40 µg/kg), butorphanol (0.3 mg/kg) and midazolam (0.3 mg/kg). Induction time and cardiopulmonary parameters were recorded. If anaesthetic plan was inadequate, isoflurane was titrated-to-effect. At the end of surgery venous blood gas analysis was performed and atipamezole or atipamezole-flumazenil was administered for timed and scored recovery. In DBM group heart rate and peripheral oxygen saturation were significantly higher (p = 0.001; p = 0.003 respectively), while respiratory rate was significantly lower (p = 0.001). All bats required isoflurane supplementation with no significant differences between groups. Induction and recovery times showed no significant differences. In group DK a better recovery was scored (p = 0.034). Sodium and chloride were significantly higher in DBM group (p = 0.001; p = 0.002 respectively). Both anaesthetic protocols were comparable and can be recommended for minor procedures in bats.
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Tracheobronchial-esophageal reflex initiates esophageal hypersensitivity and aggravates cough hyperreactivity in guinea pigs with esophageal acid infusion. Respir Physiol Neurobiol 2022; 301:103890. [PMID: 35358761 DOI: 10.1016/j.resp.2022.103890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 03/13/2022] [Accepted: 03/17/2022] [Indexed: 11/24/2022]
Abstract
Esophageal-tracheobronchial reflex is considered the main mechanism underlying cough due to gastroesophageal reflux, and is associated with esophageal hypersensitivity. We hypothesized that tracheobronchial-esophageal reflex may also exist, and may be related to esophageal hypersensitivity. To test this hypothesis, conscious and ether-anesthetized guinea pigs were subjected to repetitive capsaicin inhalation to establish models of cough (conscious) and cough-free (anesthetized) airway injury, respectively, followed by esophageal acid infusion. Recurrent capsaicin inhalation induced similar cough hyperreactivity to inhaled capsaicin after esophageal acid infusion in guinea pigs with cough and guinea pigs with cough-free airway injury during recurrent capsaicin inhalation. Cough hyperreactivity, along with overexpression of transient receptor potential vanilloid 1 (TRPV1) receptors in esophageal mucosa and in nerve fibers of tracheal mucosa of guinea pigs were blocked by pretreatment with esophageal infusion of capsazepine, but not atropine. Thus, recurrent airway nociceptive stimuli induce esophageal hyperreactivity via a tracheobronchial-esophageal reflex mediated by vagal C afferents expressing TRPV1, and enhance cough due to reflux.
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Sarvi J, Eshar D. Clinical experience using a combination of dexmedetomidine, ketamine, midazolam and hydromorphone for general anaesthesia in two winter white dwarf hamsters (
Phodopus sungorus
) undergoing surgical facial procedures. VETERINARY RECORD CASE REPORTS 2022. [DOI: 10.1002/vrc2.376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jasmine Sarvi
- Department of Clinical Sciences Kansas State University College of Veterinary Medicine Manhattan Kansas USA
| | - David Eshar
- Department of Clinical Sciences Kansas State University College of Veterinary Medicine Manhattan Kansas USA
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Jahreis I, Bascuñana P, Ross TL, Bankstahl JP, Bankstahl M. Choice of anesthesia and data analysis method strongly increases sensitivity of 18F-FDG PET imaging during experimental epileptogenesis. PLoS One 2021; 16:e0260482. [PMID: 34818362 PMCID: PMC8612569 DOI: 10.1371/journal.pone.0260482] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 11/09/2021] [Indexed: 11/24/2022] Open
Abstract
Purpose Alterations in brain glucose metabolism detected by 2-deoxy-2-[18F]-fluoro-D-glucose (18F-FDG) positron emission tomography (PET) may serve as an early predictive biomarker and treatment target for epileptogenesis. Here, we aimed to investigate changes in cerebral glucose metabolism before induction of epileptogenesis, during epileptogenesis as well as during chronic epilepsy. As anesthesia is usually unavoidable for preclinical PET imaging and influences the distribution of the radiotracer, four different protocols were compared. Procedures We investigated 18F-FDG uptake phase in conscious rats followed by a static scan as well as dynamic scans under continuous isoflurane, medetomidine-midazolam-fentanyl (MMF), or propofol anesthesia. Furthermore, we applied different analysis approaches: atlas-based regional analysis, statistical parametric mapping, and kinetic analysis. Results At baseline and compared to uptake in conscious rats, isoflurane and propofol anesthesia resulted in decreased cortical 18F-FDG uptake while MMF anesthesia led to a globally decreased tracer uptake. During epileptogenesis, MMF anesthesia was clearly best distinctive for visualization of prominently increased glucometabolism in epilepsy-related brain areas. Kinetic modeling further increased sensitivity, particularly for continuous isoflurane anesthesia. During chronic epilepsy, hypometabolism affecting more or less the whole brain was detectable with all protocols. Conclusion This study reveals evaluation of anesthesia protocols for preclinical 18F-FDG PET imaging as a critical step in the study design. Together with an appropriate data analysis workflow, the chosen anesthesia protocol may uncover otherwise concealed disease-associated regional glucometabolic changes.
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Affiliation(s)
- Ina Jahreis
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine, Hannover, Germany
| | - Pablo Bascuñana
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Tobias L. Ross
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Jens P. Bankstahl
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
- * E-mail:
| | - Marion Bankstahl
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine, Hannover, Germany
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Sixtus RP, Gray C, Berry MJ, Dyson RM. Nitrous oxide improves cardiovascular, respiratory, and thermal stability during prolonged isoflurane anesthesia in juvenile guinea pigs. Pharmacol Res Perspect 2021; 9:e00713. [PMID: 33543602 PMCID: PMC7862177 DOI: 10.1002/prp2.713] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 12/11/2020] [Accepted: 12/13/2020] [Indexed: 12/26/2022] Open
Abstract
Anesthesia is frequently used to facilitate physiological monitoring during interventional animal studies. However, its use may induce cardiovascular (central and peripheral), respiratory, and thermoregulatory depression, confounding results in anesthetized animals. Despite the wide utility of guinea pigs as a translational platform, anesthetic protocols remain unstandardized for extended physiological studies in this species. Therefore, optimizing an anesthetic protocol that balances stable anesthesia with intact cardiorespiratory and metabolic function is crucial. To achieve this, 12 age and sex-matched juvenile Dunkin Hartley guinea pigs underwent extended anesthesia (≤150 min) with either (a) isoflurane (ISO: 1.5%), or (b) isoflurane + N2 O (ISO+ N2 O: 0.8% +70%), in this randomized cross-over designed study. Cardiovascular (HR, SBP, peripheral microvascular blood flow), respiratory (respiratory rate, SpO2 ), and thermal (Tre and Tsk ) measures were recorded continuously throughout anesthesia. Blood gas measures pre- and post- anesthesia were performed. Incorporation of 70% N2 O allowed for significant reductions in isoflurane (to 0.8%) while maintaining an effective anesthetic depth for prolonged noninvasive physiological examination in guinea pigs. ISO+N2 O maintained heart rate, peripheral blood flow, respiratory rate, and thermoregulatory function at levels closest to those of conscious animals, especially in females; however, it did not fully rescue anesthesia-induced hypotension. These results suggest that for studies requiring prolonged physiological examination (≤150 min) in guinea pigs, 0.8% isoflurane with a 70% N2 O adjuvant provides adequate anesthesia, while minimizing associated cardiorespiratory depression. The preservation of cardiorespiratory status is most marked throughout the first hour of anesthesia.
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Affiliation(s)
- Ryan P. Sixtus
- Department of Paediatrics and Child HealthUniversity of OtagoWellingtonNew Zealand
- Centre for Translational PhysiologyUniversity of OtagoWellingtonNew Zealand
| | - Clint Gray
- Department of Paediatrics and Child HealthUniversity of OtagoWellingtonNew Zealand
- Centre for Translational PhysiologyUniversity of OtagoWellingtonNew Zealand
| | - Mary J. Berry
- Department of Paediatrics and Child HealthUniversity of OtagoWellingtonNew Zealand
- Centre for Translational PhysiologyUniversity of OtagoWellingtonNew Zealand
| | - Rebecca M. Dyson
- Department of Paediatrics and Child HealthUniversity of OtagoWellingtonNew Zealand
- Centre for Translational PhysiologyUniversity of OtagoWellingtonNew Zealand
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Williams AT, Muller CR, Eaker AM, Belcher DA, Bolden-Rush C, Palmer AF, Cabrales P. Polymerized Hemoglobin With Increased Molecular Size Reduces Toxicity in Healthy Guinea Pigs. ACS APPLIED BIO MATERIALS 2020; 3:2976-2985. [DOI: 10.1021/acsabm.0c00039] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexander T. Williams
- Department of Bioengineering, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Cynthia R. Muller
- Department of Bioengineering, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Allyn M. Eaker
- Department of Bioengineering, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Donald A. Belcher
- Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, United States
| | - Crystal Bolden-Rush
- Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, United States
| | - Andre F. Palmer
- Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, United States
| | - Pedro Cabrales
- Department of Bioengineering, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
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Doerning CM, Bradley MP, Lester PA, Nowland MH. Effects of subcutaneous alfaxalone alone and in combination with dexmedetomidine and buprenorphine in guinea pigs (Cavia porcellus). Vet Anaesth Analg 2018; 45:658-666. [PMID: 30064914 DOI: 10.1016/j.vaa.2018.06.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 06/08/2018] [Accepted: 06/16/2018] [Indexed: 01/15/2023]
Abstract
OBJECTIVE To characterize alfaxalone administered subcutaneously (SC) in guinea pigs, both alone and in combination with dexmedetomidine and buprenorphine. STUDY DESIGN Prospective, blinded, crossover study. ANIMALS A total of 15 healthy female guinea pigs weighing 400-600 g. METHODS Alfaxalone (10, 20 and 40 mg kg-1) was administered SC to three guinea pigs as a pilot dose-finding study. Alfaxalone (20 mg kg-1; A20) was selected for comparison against combination protocols of alfaxalone (15 and 20 mg kg-1) with dexmedetomidine (0.25 mg kg-1) and buprenorphine (0.05 mg kg-1; A15DB, A20DB). Each protocol was randomly administered to 12 guinea pigs separated by ≥7 days. Time and quality of induction and recovery, heart rate, respiratory rate, peripheral hemoglobin oxygen saturation, rectal temperature, pedal withdrawal reflex and adverse effects were recorded. RESULTS The median time to induction for A20, A15DB and A20DB was 6.8-8.0 minutes with no significant difference between treatments. Mean duration of recumbency for A20 was 73.6 ± 19.6 minutes. Recumbency duration for A15DB and A20DB extended to 90 minutes, at which time dexmedetomidine was antagonized using atipamezole (0.025 mg kg-1 SC). Physiological variables were within normal limits with the exception of one animal that died 45 minutes following treatment with A20DB. Pedal withdrawal reflex remained intact with all treatments. Minor side effects such as twitching or bruxism occurred sporadically with treatment A20 but not with A15DB and A20DB. CONCLUSIONS AND CLINICAL RELEVANCE SC alfaxalone produced uncomplicated sedation that may be recommended for nonpainful procedures that do not require complete immobility. The addition of dexmedetomidine and buprenorphine increased the duration of sedation and immobility, but did not result in general anesthesia. This combination sedation protocol may be useful for nonpainful procedures requiring extended immobility.
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Affiliation(s)
- Carolyn M Doerning
- Unit for Laboratory Animal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Michael P Bradley
- Unit for Laboratory Animal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Patrick A Lester
- Unit for Laboratory Animal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Megan H Nowland
- Unit for Laboratory Animal Medicine, University of Michigan, Ann Arbor, MI, USA.
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Tuval A, Las L, Shilo-Benjamini Y. Evaluation of injectable anaesthesia with five medetomidine-midazolam based combinations in Egyptian fruit bats (Rousettus aegyptiacus). Lab Anim 2018; 52:515-525. [DOI: 10.1177/0023677218756456] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Egyptian fruit bats are increasingly used as model animals in neuroscience research. Our aim was to characterize suitable injectable anaesthesia for this species, possibly replacing inhalant anaesthesia, thus minimizing occupational health hazards. Eight bats were randomly assigned by a crossover design for subcutaneously administered combinations of medetomidine-midazolam with: saline (MM-Sal), ketamine (MM-Ket), fentanyl (MM-Fen), morphine (MM-Mor), or butorphanol (MM-But). The anaesthetic depth and vital signs were monitored at baseline and every 10 min until bats recovered. If after 180 min the bats did not recover, atipamezole was administered. Mean induction times were 7–11.5 min with all combinations. Twitching during induction was common. All combinations produced anaesthesia, with significantly decreased heart rate (from 400 to 200 bpm) and respiratory rate (from 120–140 to 36–65 rpm). Arrhythmia and irregular breathing patterns occurred. MM-Fen, MM-Mor, and MM-But depressed respiration significantly more than MM-Sal. Time to first movement with MM-Ket and MM-But lasted significantly longer than with MM-Sal. Recovery time was significantly shorter in the MM-Sal (88 min) in comparison to all other treatments, and it was significantly longer in the MM-But (159 min), with atipamezole administered to four of the eight bats. In conclusion, all five anaesthetic protocols are suitable for Egyptian fruit bats; MM-Ket produces long anaesthesia and minimal respiratory depression, but cannot be antagonized completely. MM-Fen, MM-Mor, and MM-But depress respiration, but are known to produce good analgesia, and can be fully antagonized. Administration of atipamezole following the use of MM-But in Egyptian fruit bats is recommended.
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Affiliation(s)
- Avishag Tuval
- Department of Veterinary Resources, Weizmann Institute of Science, Israel
- Department of Neurobiology, Weizmann Institute of Science, Israel
| | - Liora Las
- Department of Neurobiology, Weizmann Institute of Science, Israel
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