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da Silva ANE, Dutra GHP, Justo AA, de Araujo GSM, Bressan TF, Carregaro AB. Minimum anesthetic concentration of isoflurane and sevoflurane and cardiorespiratory effects of varying inspired oxygen fractions in Magellanic penguins (Spheniscus magellanicus). Vet Res Commun 2024; 48:1621-1630. [PMID: 38433171 DOI: 10.1007/s11259-024-10336-w] [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: 12/14/2023] [Accepted: 02/19/2024] [Indexed: 03/05/2024]
Abstract
The aim of this study was to determine the minimum anesthetic concentration of isoflurane (MACISO) and sevoflurane (MACSEVO) and evaluate the cardiorespiratory changes induced by varying fractions of inspired oxygen (FiO2) in Magellanic penguins (Spheniscus magellanicus). Twenty adult penguins (3.53 ± 0.44 kg) of undetermined sex were used. Both MACISO (n = 9) and MACSEVO (n = 13) were established using an up-and-down design. Next, twelve mechanically ventilated penguins were maintained at 1 MACISO or 1 MACSEVO (n = 6 per group) with the FiO2 initially set at 1.0. Three FiO2 values (0.6, 0.4 and 0.2) were then held constant during anesthesia for 20 minutes each. Arterial blood samples were collected for gas analysis after the 20-minute period for each FiO2. Mean ± SD MACISO was 1.93 ± 0.10% and MACSEVO was 3.53 ± 0.13%. Other than heart rate at 0.6 FiO2 (86 ± 11 beats/minute in MACISO and 132 ± 37 beats/minute in MACSEVO; p = 0.041), no significant cardiorespiratory differences were detected between groups. In both groups, decreasing the FiO2 produced increased pH values and reduced partial pressures of carbon dioxide and bicarbonate. Partial pressures of oxygen (PaO2) gradually lowered from 1.0 FiO2 through 0.2 FiO2, though hypoxemia (PaO2 < 80 mmHg) occurred only with the latter FiO2. The MACISO and the MACSEVO for the Magellanic penguin fell within the upper range of reported avian MAC estimates. To prevent hypoxemia in healthy, mechanically ventilated, either isoflurane- or sevoflurane-anesthetized Magellanic penguins, a minimum FiO2 of 0.4 should be used.
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Affiliation(s)
- André Nicolai Elias da Silva
- Department of Veterinary Medicine, School of Animal Science and Food Engineering, University of São Paulo, Av. Duque de Caxias Norte, 225, Pirassununga, SP, 13635-900, Brazil
| | - Gustavo Henrique Pereira Dutra
- Department of Veterinary Medicine, School of Animal Science and Food Engineering, University of São Paulo, Av. Duque de Caxias Norte, 225, Pirassununga, SP, 13635-900, Brazil
- Veterinary Unit of the Santos Aquarium, Santos Aquarium, Santos, SP, 11030-600, Brazil
| | - André Augusto Justo
- Department of Veterinary Medicine, School of Animal Science and Food Engineering, University of São Paulo, Av. Duque de Caxias Norte, 225, Pirassununga, SP, 13635-900, Brazil
| | - Giuliano Souza Mendonça de Araujo
- Department of Veterinary Medicine, School of Animal Science and Food Engineering, University of São Paulo, Av. Duque de Caxias Norte, 225, Pirassununga, SP, 13635-900, Brazil
| | - Thais Feres Bressan
- Department of Veterinary Medicine, School of Animal Science and Food Engineering, University of São Paulo, Av. Duque de Caxias Norte, 225, Pirassununga, SP, 13635-900, Brazil
| | - Adriano Bonfim Carregaro
- Department of Veterinary Medicine, School of Animal Science and Food Engineering, University of São Paulo, Av. Duque de Caxias Norte, 225, Pirassununga, SP, 13635-900, Brazil.
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Marchese GA, Calvo Carrasco D, Pascal M. Multimodal analgesic technique in a peacock (
Pavo cristatus
) anaesthetised for orthopaedic surgery. VETERINARY RECORD CASE REPORTS 2022. [DOI: 10.1002/vrc2.469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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3
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Molter C, Escobar A, Schroeder C. Backyard Poultry and Waterfowl Sedation and Anesthesia. Vet Clin North Am Exot Anim Pract 2021; 25:163-180. [PMID: 34823690 DOI: 10.1016/j.cvex.2021.08.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The popularity of backyard poultry (chickens, turkey, guinea fowl) and waterfowl (ducks and geese) is increasing in the United States, and these animals frequently present for veterinary care. Like other birds, these species have unique anatomy that should be clinically considered before anesthesia. A balanced approach to an injectable, inhalational, or combination anesthesia protocol must be taken to ensure a safe outcome for the patient and to achieve the procedural needs. A well-informed clinician may use both sedation and general anesthesia to care for backyard bird patients in practice.
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Affiliation(s)
- Christine Molter
- Animal Health Department, Houston Zoo, Inc., 1513 Cambridge Street, Houston, TX 77030, USA.
| | - André Escobar
- Department of Clinical Sciences, Ross University School of Veterinary Medicine, PO Box 334, Basseterre, St. Kitts, West Indies
| | - Carrie Schroeder
- Department of Surgical Sciences, University of Wisconsin School of Veterinary Medicine, 2015 Linden Drive, Madison, WI 53706, USA
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4
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Yaygingul R. Comparison of the Anesthetic Effects of Isoflurane and Sevoflurane Inhalation on the Cardiovascular System of the Common Buzzard ( Buteo buteo). J Avian Med Surg 2021; 34:237-242. [PMID: 33099976 DOI: 10.1647/1082-6742-34.3.237] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The aim of this study was to compare the effects of isoflurane (ISO) and sevoflurane (SEVO) inhalation anesthesia on the cardiovascular system of the common buzzard (Buteo buteo). Fourteen common buzzards of unknown sex and age, weighing 700-900 g each, were used for the study. The buzzards were randomly divided into an ISO group and a SEVO group, each comprising 7 buzzards. The buzzards were then anesthetized by masked induction with either ISO or SEVO. After induction, all buzzards were intubated with a 2.5-mm-diameter uncuffed endotracheal tube. Anesthesia was maintained with 3% ISO or 4% SEVO in a 3 L/min flow of 100% oxygen. Before induction, immediately after induction, and at intervals of 5, 10, 15, 20, 25, and 30 min after the patients were induced, the heart rate, respiratory rate, and body temperature of the buzzards were recorded. In addition, before and during anesthesia, serum electrolytes (sodium, ionized calcium, and potassium), blood gas measurements (arterial pH, arterial partial pressure of carbon dioxide, arterial partial pressure of oxygen, bicarbonate concentration, and oxyhemoglobin saturation), and hematocrit values were evaluated in the blood samples taken from both the ISO and SEVO groups. A statistically significant decrease in body temperature was observed in both groups. A significant decrease in heart rate was observed in the ISO group. The increases in partial pressure of carbon dioxide and bicarbonate concentration were statistically significant in both groups. The effects of ISO and SEVO anesthesia on the cardiovascular and respiratory system in the buzzards were similar based on the results of this study.
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Affiliation(s)
- Rahime Yaygingul
- Aydin Adnan Menderes University, Veterinary Faculty, Department of Surgery, 09016 Isikli, Aydin, Turkey,
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5
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Filatova TS, Abramochkin DV, Pavlova NS, Pustovit KB, Konovalova OP, Kuzmin VS, Dobrzynski H. Repolarizing potassium currents in working myocardium of Japanese quail: a novel translational model for cardiac electrophysiology. Comp Biochem Physiol A Mol Integr Physiol 2021; 255:110919. [DOI: 10.1016/j.cbpa.2021.110919] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/06/2021] [Accepted: 02/06/2021] [Indexed: 12/14/2022]
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6
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The Determination of the Minimum Anaesthetic Concentration of Halothane in the Rock Dove (Columba livia) Using an Electrical Stimulus. BIRDS 2021. [DOI: 10.3390/birds2010006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
This study aims to determine the minimum anaesthetic concentration (MAC) of halothane in the Rock Dove using electrical stimulus. Seven Rock Doves are anaesthetised with halothane, and the MAC is determined using the bracketing method. An electrical stimulus (two single pulses and two five-second stimuli, all separated by five-second pauses; 30 Hz, 30 V, 7.5 ms) is applied to the legs via subcutaneous electrodes. A maximum of eight periods of electrical stimulation, each with a preceding 15 min stable phase, is applied to each bird. If the non-reflexive movement occurred following stimulation, the end-tidal halothane (Fe’Hal) is increased by 10% before the next stimulus delivery. If no movement occurred, Fe’Hal is decreased by 10%. The MAC is the average of the highest concentration that allowed movement and the lowest that prevented movement. Physiological variables and ventilatory settings are recorded every five minutes. The current delivered is calculated offline. The mean ± SD MAC of halothane is 1.62 ± 0.29%, calculated from five birds. During the entire anaesthesia, all birds had cardiac arrhythmias —with three having sporadic recurrent periods of prolonged ventricular standstill followed by marked sinus tachycardia. The mean recorded voltage and calculated current and resistance are 27.6 ± 2.7 V, 20.3 ± 7.3 mAmp and 1.6 ± 0.9 kΩ, respectively. The advantage of halothane for prolonged anaesthesia in Rock Doves may be limited when noxious stimulation is used, due to the development of severe ventricular arrhythmias.
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Filatova TS, Abramochkin DV, Shiels HA. Warmer, faster, stronger: Ca 2+ cycling in avian myocardium. J Exp Biol 2020; 223:jeb228205. [PMID: 32843363 DOI: 10.1242/jeb.228205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 08/17/2020] [Indexed: 11/20/2022]
Abstract
Birds occupy a unique position in the evolution of cardiac design. Their hearts are capable of cardiac performance on par with, or exceeding that of mammals, and yet the structure of their cardiomyocytes resembles those of reptiles. It has been suggested that birds use intracellular Ca2+ stored within the sarcoplasmic reticulum (SR) to power contractile function, but neither SR Ca2+ content nor the cross-talk between channels underlying Ca2+-induced Ca2+ release (CICR) have been studied in adult birds. Here we used voltage clamp to investigate the Ca2+ storage and refilling capacities of the SR and the degree of trans-sarcolemmal and intracellular Ca2+ channel interplay in freshly isolated atrial and ventricular myocytes from the heart of the Japanese quail (Coturnix japonica). A trans-sarcolemmal Ca2+ current (ICa) was detectable in both quail atrial and ventricular myocytes, and was mediated only by L-type Ca2+ channels. The peak density of ICa was larger in ventricular cells than in atrial cells, and exceeded that reported for mammalian myocardium recorded under similar conditions. Steady-state SR Ca2+ content of quail myocardium was also larger than that reported for mammals, and reached 750.6±128.2 μmol l-1 in atrial cells and 423.3±47.2 μmol l-1 in ventricular cells at 24°C. We observed SR Ca2+-dependent inactivation of ICa in ventricular myocytes, indicating cross-talk between sarcolemmal Ca2+ channels and ryanodine receptors in the SR. However, this phenomenon was not observed in atrial myocytes. Taken together, these findings help to explain the high-efficiency avian myocyte excitation-contraction coupling with regard to their reptilian-like cellular ultrastructure.
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Affiliation(s)
- Tatiana S Filatova
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, Moscow 119234, Russia
- Department of Physiology, Pirogov Russian National Research Medical University, Ostrovityanova str.,1, Moscow 117997, Russia
| | - Denis V Abramochkin
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, Moscow 119234, Russia
- Department of Physiology, Pirogov Russian National Research Medical University, Ostrovityanova str.,1, Moscow 117997, Russia
- Ural Federal University, Mira 19, Ekaterinburg 620002, Russia
- Laboratory of Cardiac Physiology, Institute of Physiology of komi Science Centre of the Ural Branch of the Russian Academy of Sciences, FRC Komi SC UB RAS, Pervomayskaya str., 50, 167982 Syktyvkar, Komi Republic, Russia
| | - Holly A Shiels
- Faculty of Biology, Medicine and Health, Core Technology Facility, 46 Grafton Street, University of Manchester, Manchester M13 9NT, UK
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Hwang J, Kang S, Seok S, Ahmed S, Yeon S. Ophthalmic findings in cinereous vultures (Aegypius monachus). Vet Ophthalmol 2019; 23:314-324. [PMID: 31774216 DOI: 10.1111/vop.12728] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 10/21/2019] [Accepted: 10/30/2019] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The aim of the present study was to provide ophthalmic reference values under normal physiological conditions for Aegypius monachus (cinereous vulture). PROCEDURES Thirty-two eyes of sixteen adult captive cinereous vultures were used for this study. Tear tests and tonometry in conscious and anesthetized states, neuro-ophthalmic tests, measurement of corneal diameter, slit-lamp biomicroscopy, ophthalmoscopy, and funduscopy were performed. RESULTS Schirmer tear test (STT) value was 11.4 ± 2.6 and 11.5 ± 2.8 mm/min in the right (OD) and left eye (OS), respectively. Phenol red thread test (PRT) values were 22.3 ± 2.1 mm/15 s OD and 22.8 ± 3.0 mm/15 s OS. The results showed a strong correlation between STT and PRT in both eyes. Intraocular pressure (IOP) values were 32.8 ± 6.9 mm Hg OD and 31.9 ± 7.1 mm Hg OS with TonoVet and 20.7 ± 4.5 mm Hg OD and 19.5 ± 4.1 mm Hg OS with Tono-Pen. There were significant differences in IOPs between rebound and applanation tonometry in both OD and OS. Tear production and IOP values showed significant reductions with general anesthesia in both tear tests and both tonometry (P < .001). Horizontal corneal diameter (mm) was 15.56 ± 0.96 OD and 15.56 ± 0.96 OS. Vertical diameter (mm) was 14.13 ± 0.96 OD and 14.06 ± 1.06 OS. The horizontal diameter was significantly longer than vertical diameter (P < .001). CONCLUSIONS Ocular morphologic information and normal reference range values for various ophthalmic measurements were obtained in clinically healthy cinereous vultures, which can facilitate accurate diagnosis and better management of ophthalmic diseases in cinereous vultures.
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Affiliation(s)
| | - Seonmi Kang
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research, Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | | | - Sohail Ahmed
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research, Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Seongchan Yeon
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research, Institute for Veterinary Science, Seoul National University, Seoul, Korea
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9
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Altimiras J, Lindgren I, Giraldo-Deck LM, Matthei A, Garitano-Zavala Á. Aerobic performance in tinamous is limited by their small heart. A novel hypothesis in the evolution of avian flight. Sci Rep 2017; 7:15964. [PMID: 29162941 PMCID: PMC5698454 DOI: 10.1038/s41598-017-16297-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 11/09/2017] [Indexed: 12/13/2022] Open
Abstract
Some biomechanical studies from fossil specimens suggest that sustained flapping flight of birds could have appeared in their Mesozoic ancestors. We challenge this idea because a suitable musculoskeletal anatomy is not the only requirement for sustained flapping flight. We propose the “heart to fly” hypothesis that states that sustained flapping flight in modern birds required an enlargement of the heart for the aerobic performance of the flight muscles and test it experimentally by studying tinamous, the living birds with the smallest hearts. The small ventricular size of tinamous reduces cardiac output without limiting perfusion pressures, but when challenged to fly, the heart is unable to support aerobic metabolism (quick exhaustion, larger lactates and post-exercise oxygen consumption and compromised thermoregulation). At the same time, cardiac growth shows a crocodilian-like pattern and is correlated with differential gene expression in MAPK kinases. We integrate this physiological evidence in a new evolutionary scenario in which the ground-up, short and not sustained flapping flight displayed by tinamous represents an intermediate step in the evolution of the aerobic sustained flapping flight of modern birds.
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Affiliation(s)
- Jordi Altimiras
- AVIAN Behavioral Genomics and Physiology, Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden.
| | - Isa Lindgren
- AVIAN Behavioral Genomics and Physiology, Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
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10
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EFFECTS OF TRAMADOL ON THE MINIMUM ANESTHETIC CONCENTRATION OF ISOFLURANE IN WHITE-EYED PARAKEETS (PSITTACARA LEUCOPHTHALMUS). J Zoo Wildl Med 2017; 48:380-387. [DOI: 10.1638/2016-0180r1.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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11
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DiGeronimo PM, da Cunha AF, Pypendop B, Brandão J, Stout R, Rinaldi M, Tully TN. Cardiovascular tolerance of intravenous bupivacaine in broiler chickens (Gallus gallus domesticus) anesthetized with isoflurane. Vet Anaesth Analg 2017; 44:287-294. [PMID: 28342761 DOI: 10.1016/j.vaa.2016.05.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 04/04/2016] [Accepted: 05/07/2016] [Indexed: 12/01/2022]
Abstract
OBJECTIVE To determine the median effective dose (ED50) of intravenous (IV) bupivacaine associated with a 50% probability of causing clinically relevant cardiovascular effects [defined as 30% change in heart rate (HR) or mean arterial pressure (MAP)] in chickens anesthetized with isoflurane. STUDY DESIGN Randomized up-and-down study. ANIMALS A total of 14 Ross-708 broiler chickens (Gallus gallus domesticus) weighing 1.70-2.75 kg. METHODS Anesthesia was induced and maintained with isoflurane. Monitoring included the electrocardiogram and invasive arterial pressures. Chickens were administered bupivacaine IV over 2 minutes using a dose based on the response of the previous animal. Dose was decreased when HR and/or MAP in the previous animal increased or decreased ≥30% after bupivacaine administration, or increased when HR or MAP changed <30%. The ED50 was defined as the dose resulting in ≥30% variation in HR or MAP in 50% of the population studied. RESULTS The IV ED50 of bupivacaine was 1.94 mg kg-1 using Dixon's up-and-down method and 1.96 mg kg-1 by logistic regression. CONCLUSIONS AND CLINICAL RELEVANCE These results suggest that 1.33 and 1.96 mg kg-1 of IV bupivacaine are associated with a respective 1 or 50% probability of a clinically significant change in MAP in isoflurane-anesthetized chickens. Identification of the cardiovascular changes associated with different doses of bupivacaine can be used as the basis for studies of therapeutic applications in the domestic chicken. Further studies are required to determine interspecies variation.
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Affiliation(s)
- Peter M DiGeronimo
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA
| | - Anderson F da Cunha
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA.
| | - Bruno Pypendop
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - João Brandão
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA
| | - Rhett Stout
- Division of Laboratory Animal Medicine, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA
| | - Max Rinaldi
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA
| | - Thomas N Tully
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA
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12
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Seok SH, Jeong DH, Hong IH, Lee HC, Yeon SC. Cardiorespiratory dose-response relationship of isoflurane in Cinereous vulture (Aegypius monachus) during spontaneous ventilation. J Vet Med Sci 2017; 79:160-165. [PMID: 27725351 PMCID: PMC5289254 DOI: 10.1292/jvms.16-0314] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Anesthesia is an inevitably important component of diagnosis and treatments examining the health condition of wild animals. Not only does anesthesia become an
essential tool in minimizing stress of the patients and providing an opportunity to deliver accurate and safe procedures, but it also ensures the safety of the
medical crew members. This study was conducted to investigate the dose-response cardiorespiratory effects of isoflurane during spontaneous ventilation in ten
cinereous vultures. Each bird was administered isoflurane at initial concentration of 1.0, 1.5, 2.0, 2.5 and 3.0 and then an end-tidal isoflurane concentrations
(ETiso) of 1.0% for an equilibration period of 15 min in the given order. At the end of the equilibration period, the direct blood pressure (BP), heart rate
(HR), respiratory rate (RR) and end tidal CO2 partial pressure (PETCO2) were recorded, and blood gas analysis was performed.
Increasing isoflurane concentrations during spontaneous ventilation led to dose-dependent increases in HR and PETCO2, with minimal changes
in RR, decreased arterial BP and respiratory acidosis. Overall, isoflurane for anesthesia of spontaneously breathing cinereous vultures is a suitable choice for
diagnostic or surgical procedures.
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Affiliation(s)
- Seong-Hoon Seok
- Laboratory of Veterinary Surgery and Behavior, College of Veterinary Medicine, Gyeongsang National University, Jinju, Republic of Korea
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Zalucki O, van Swinderen B. What is unconsciousness in a fly or a worm? A review of general anesthesia in different animal models. Conscious Cogn 2016; 44:72-88. [PMID: 27366985 DOI: 10.1016/j.concog.2016.06.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 05/31/2016] [Accepted: 06/20/2016] [Indexed: 12/14/2022]
Abstract
All animals are rendered unresponsive by general anesthetics. In humans, this is observed as a succession of endpoints from memory loss to unconsciousness to immobility. Across animals, anesthesia endpoints such as loss of responsiveness or immobility appear to require significantly different drug concentrations. A closer examination in key model organisms such as the mouse, fly, or the worm, uncovers a trend: more complex behaviors, either requiring several sub-behaviors, or multiple neural circuits working together, are more sensitive to volatile general anesthetics. This trend is also evident when measuring neural correlates of general anesthesia. Here, we review this complexity hypothesis in humans and model organisms, and attempt to reconcile these findings with the more recent view that general anesthetics potentiate endogenous sleep pathways in most animals. Finally, we propose a presynaptic mechanism, and thus an explanation for how these drugs might compromise a succession of brain functions of increasing complexity.
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Affiliation(s)
- Oressia Zalucki
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Bruno van Swinderen
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
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Botman J, Gabriel F, Dugdale AHA, Vandeweerd JM. Anaesthesia with sevoflurane in pigeons: minimal anaesthetic concentration (MAC) determination and investigation of cardiorespiratory variables at 1 MAC. Vet Rec 2016; 178:560. [PMID: 27083873 DOI: 10.1136/vr.103654] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2016] [Indexed: 11/03/2022]
Abstract
The objective of the study was to determine the minimal anaesthetic concentration (MAC) of sevoflurane (SEVO) in pigeons and investigate the effects of 1 MAC SEVO anaesthesia on cardiovascular and respiratory variables compared with the awake state. This is a prospective, experimental study. Animals were seven healthy adult pigeons. After acclimatisation to handling, heart rate (HR), heart rhythm, respiratory rate (fR), end-expired carbon dioxide tension (PE'CO2), inspired CO2 tension, indirect systolic arterial blood pressure (SAP) and cloacal temperature were measured to determine baseline, 'awake' values. Pigeons were then anaesthetised with SEVO and MAC was determined by the 'bracketing' method. The same variables were monitored during a 40 minute period at 1.0 MAC SEVO for each bird. Mean MAC was 3.0±0.6 per cent for SEVO. During maintenance of anaesthesia at 1.0 MAC, SAP decreased significantly (P<0.001) without any significant change in HR. Although PE'CO2 increased significantly (P=0.001) despite an increase in fR, awake PE'CO2 values were unexpectedly low. Sinus arrhythmias were detected in two birds under SEVO anaesthesia. The times to tracheal intubation and to recovery were 2.5±0.7 and 6.4±1.7 minutes, respectively. Recovery was rapid and uneventful in all birds. In conclusion, SEVO is suitable for anaesthesia in pigeons.
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Affiliation(s)
- J Botman
- Department of Veterinary Medicine, University of Namur, Namur, Belgium
| | - F Gabriel
- Department of Veterinary Medicine, University of Namur, Namur, Belgium
| | - A H A Dugdale
- School of Veterinary Science, University of Liverpool, Chester, Wirral, UK
| | - J-M Vandeweerd
- Department of Veterinary Medicine, University of Namur, Namur, Belgium
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15
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Botman J, Dugdale A, Gabriel F, Vandeweerd JM. Cardiorespiratory parameters in the awake pigeon and during anaesthesia with isoflurane. Vet Anaesth Analg 2015; 43:63-71. [PMID: 25929705 DOI: 10.1111/vaa.12262] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 12/04/2014] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To determine baseline cardiovascular and respiratory variables in the awake pigeon, and to assess those variables during anaesthesia at the individual minimal anaesthetic concentration (MAC) of isoflurane during spontaneous breathing. STUDY DESIGN Prospective, experimental trial. ANIMALS Seven healthy adult pigeons weighing a mean ± standard deviation (SD) of 438 ± 38 g. METHODS Heart rate (HR), heart rhythm, respiratory rate (fR), end-expired carbon dioxide tension (Pe'CO2), indirect systolic arterial pressure (SAP) and cloacal temperature (T) were measured in birds in the awake state (after acclimatization to handling). Two weeks later, the pigeons were anaesthetized with isoflurane in order to determine their MAC and evaluate the same cardiovascular and respiratory variables during a further 40 minutes of isoflurane anaesthesia. RESULTS In the awake pigeon, mean ± SD HR, SAP, fR, Pe'CO2 and T were, respectively, 155 ± 28 beats minute(-1), 155 ± 21 mmHg, 34 ± 6 breaths minute(-1), 38 ± 8 mmHg (5.1 ± 1.1 kPa) and 41.8 ± 0.5 °C. Mean isoflurane MAC was 1.8 ± 0.4%. During maintenance of anaesthesia at MAC, although no significant decreases between values obtained in the awake and anaesthetized states emerged in HR or respiratory rate, significant decreases in SAP and cloacal temperature and an increase in Pe'CO2 were observed. No arrhythmia was identified in awake pigeons, whereas second- and third-degree atrioventricular blocks occurred under isoflurane. CONCLUSIONS AND CLINICAL RELEVANCE Isoflurane MAC in pigeons appeared to be higher than in other avian species. Isoflurane anaesthesia in pigeons resulted in hypercapnia, hypotension, mild hypothermia and second- and third-degree atrioventricular blocks.
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Affiliation(s)
- Julie Botman
- Integrated Veterinary Research Unit (IVRU), Namur Research Institute for Life Sciences (NARILIS), Department of Veterinary Medicine, Faculty of Sciences, University of Namur, Namur, Belgium
| | - Alex Dugdale
- Department of Anaesthesiology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, UK
| | - Fabien Gabriel
- Integrated Veterinary Research Unit (IVRU), Namur Research Institute for Life Sciences (NARILIS), Department of Veterinary Medicine, Faculty of Sciences, University of Namur, Namur, Belgium
| | - Jean-Michel Vandeweerd
- Integrated Veterinary Research Unit (IVRU), Namur Research Institute for Life Sciences (NARILIS), Department of Veterinary Medicine, Faculty of Sciences, University of Namur, Namur, Belgium
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Brandão J, da Cunha AF, Pypendop B, Stout R, Nevarez J, Tully TN. Cardiovascular tolerance of intravenous lidocaine in broiler chickens (Gallus gallus domesticus) anesthetized with isoflurane. Vet Anaesth Analg 2014; 42:442-8. [PMID: 25229315 DOI: 10.1111/vaa.12226] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2014] [Accepted: 07/11/2014] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To determine the cardiovascular effects of lidocaine infused intravenously (IV) in broiler chickens. STUDY DESIGN Two phase study: Phase 1, randomized up-and-down study to determine effective dose 50 (ED50) for lidocaine; Phase 2, prospective randomized study to determine the cardiovascular effects of lidocaine. ANIMALS Seventeen Ross-708 broiler chickens (Gallus gallus domesticus) [11 chickens (Phase 1) and 6 chickens (Phase 2)], weighing 2.6-4.3 kg. METHODS After induction of anesthesia with isoflurane and placement of monitoring equipment including invasive blood pressure, chickens were administered lidocaine IV. During Phase 1, using an up-and-down design, each animal received a variable dose selected based on the response of the previous animal. During Phase 2, each animal was administered 6 mg kg(-1) of lidocaine IV over 2 minutes. Clinically irrelevant cardiovascular effects were defined as a relative decrease of heart rate (HR) and mean blood pressure (MAP) <30% subsequent to IV lidocaine administration. The ED50 was defined as the dose rate that would cause clinically irrelevant cardiovascular depression in 50% of the population. RESULTS During Phase 1, using an up-and-down study design (n = 11), the ED50 of lidocaine was determined to be 6.30 mg kg(-1) and 6.22 mg kg(-1) (95% confidence interval, 5.30-7.13 mg kg(-1)), when calculated by Dixon's up-and-down method, and logistic regression, respectively. During Phase 2, following infusion of lidocaine (6 mg kg(-1)), no clinically relevant effects on HR or MAP were detected in any animal. CONCLUSIONS AND CLINICAL RELEVANCE Previous reports state that the dose of lidocaine used in birds should be ≤4 mg kg(-1). In this study, 6 mg kg(-1) of lidocaine injected IV was not associated with adverse cardiovascular effects. These results suggest that the dose of 4 mg kg(-1) can be exceeded, at least in chickens, and opens the possibility of other therapeutic uses for lidocaine in birds.
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Affiliation(s)
- João Brandão
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA
| | - Anderson F da Cunha
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA
| | - Bruno Pypendop
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Rhett Stout
- Department of Laboratory Animal Medicine, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA
| | - Javier Nevarez
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA
| | - Thomas N Tully
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA
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Paré M, Ludders JW, Erb HN. Association of partial pressure of carbon dioxide in expired gas and arterial blood at three different ventilation states in apneic chickens ( Gallus domesticus ) during air sac insufflation anesthesia. Vet Anaesth Analg 2013; 40:245-56. [DOI: 10.1111/vaa.12005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 11/23/2011] [Indexed: 11/28/2022]
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Minimum Anesthetic Concentration and Cardiovascular Dose–Response Relationship of Isoflurane in Cinereous Vultures (Aegypius monachus). J Zoo Wildl Med 2011; 42:499-503. [DOI: 10.1638/2010-0151.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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19
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Cardiorespiratory effects of isoflurane anesthesia in crested caracaras (Caracara plancus). J Zoo Wildl Med 2011; 42:12-7. [PMID: 22946364 DOI: 10.1638/2009-0055.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
To evaluate the cardiorespiratory changes induced by isoflurane (ISO) anesthesia in the crested caracara (Caracara plancus), eight crested caracaras that weighed 1.0 kg (range 0.9-1.1 kg) were the subjects for the study. The birds were anesthetized by face mask with ISO for brachial artery catheterization. After recovery, anesthesia was re-induced and maintained with ISO with spontaneous ventilation. Electrocardiography, direct systolic arterial blood pressure (SAP), diastolic arterial blood pressure (DAP), mean arterial blood pressure (MAP), respiratory rate (RR), end-tidal carbon dioxide (P(ET)CO2), and cloacal temperature (T degrees C) were measured before induction (baseline, under physical restraint) and after 5, 10, 15, 20, 25, 30, 35, and 40 min of ISO anesthesia. Arterial blood samples were collected for blood gas analysis at baseline, 10, 25, and 40 min. No cardiac arrhythmias were observed in the present study. RR, SAP, DAP, MAP, T degrees C and pH decreased from baseline values, whereas arterial partial pressures of oxygen and carbon dioxide, bicarbonate concentration, and P(ET)CO2 were significantly higher than baseline. Apnea was not observed in any bird. ISO anesthesia is suitable for use in healthy members of this species despite the moderate cardiovascular and respiratory depression produced.
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Escobar A, Thiesen R, Vitaliano SN, Belmonte EA, Werther K, Nunes N, Valadão CAA. Some cardiopulmonary effects of sevoflurane in crested caracara (Caracara plancus). Vet Anaesth Analg 2009; 36:436-41. [PMID: 19709047 DOI: 10.1111/j.1467-2995.2009.00481.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVE To evaluate the cardiorespiratory changes induced by sevoflurane (SEV) anesthesia in the crested caracara (Caracara plancus). STUDY DESIGN Prospective experimental trial. ANIMALS Eight crested caracaras (Caracara plancus) weighing 1.0 (0.9-1.1) kg were used for the study. METHODS The birds were anesthetized by face mask with isoflurane for brachial artery catheterization. After recovery, anesthesia was re-induced with 6% SEV via face mask. After induction, a noncuffed endotracheal tube was placed and anesthesia was maintained with SEV (3.5% end-tidal) in oxygen (1 L minute(-1)) using an Ayre's T-piece nonrebreathing circuit, with spontaneous ventilation. Electrocardiography (ECG), direct systolic, diastolic and mean arterial blood pressure (SAP, DAP, and MAP), respiratory rate (f(R)), end-tidal carbon dioxide (Pe'CO(2)), and cloacal temperature (T degrees C) were measured before induction (baseline - under physical restraint) and after 5, 10, 15, 20, 25, 30, 35 and 40 minutes of SEV anesthesia. Arterial blood samples were collected for gas analysis at baseline and then at 10, 25 and 40 minutes. RESULTS No ventricular arrhythmias were observed in the present study. Respiratory rate, SAP, DAP, MAP, T degrees C and pH decreased from pre-induction values, while arterial partial pressures of oxygen and carbon dioxide, bicarbonate concentration, and Pe'CO(2) were significantly higher than baseline. None of the birds were apneic. CONCLUSION AND CLINICAL RELEVANCE Sevoflurane anesthesia is suitable for use in healthy members of this species, despite the moderate cardiovascular and respiratory depression produced.
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Affiliation(s)
- André Escobar
- Department of Veterinary Clinics and Surgery, Faculdade de Ciências Agrárias e Veterinárias, São Paulo State University, Jaboticabal, SP, Brazil.
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Mercado JA, Larsen RS, Wack RF, Pypendop BH. Minimum anesthetic concentration of isoflurane in captive thick-billed parrots (Rhynchopsitta pachyrhyncha). Am J Vet Res 2008; 69:189-94. [DOI: 10.2460/ajvr.69.2.189] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Edling TM, Degernes LA, Flammer K, Horne WA. Capnographic monitoring of anesthetized African grey parrots receiving intermittent positive pressure ventilation. J Am Vet Med Assoc 2001; 219:1714-8. [PMID: 11767920 DOI: 10.2460/javma.2001.219.1714] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine whether end-tidal partial pressure of carbon dioxide (PETCO2) correlated with PaCO2 in isoflurane-anesthetized African grey parrots receiving intermittent positive pressure ventilation (IPPV). DESIGN Prospective study. ANIMALS 14 healthy mature African grey parrots (Psittacus erithacus timnus). PROCEDURE Each bird was anesthetized via mask with isoflurane, intubated, and connected to a pressure-limited intermittent-flow ventilator. Respiratory rate was altered while holding peak inspiratory pressure constant (5 cm H2O) to achieve a PETCO2 in 1 of 3 ranges: < 30 mm Hg, 30 to 40 mm Hg, and > 40 mm Hg. Blood was collected from the superficial ulnar artery of each bird at least once during each of the 3 ranges. Arterial blood samples were collected for blood gas analysis while PETCO2 was recorded simultaneously. RESULTS A strong correlation between PETCO2 and PaCO2 was detected over a wide range of partial pressures, although PETCO2 consistently overestimated PaCO2 by approximately 5 mm Hg. End-tidal partial pressure of CO2 and PaCO2 also correlated well with arterial blood pH, and the acute response of the bicarbonate buffer system to changes in ventilation was similar to that of mammals. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that PETCO2 reliably estimates PaCO2 in isoflurane-anesthetized African grey parrots receiving IPPV and suggest that IPPV combined with capnography is a viable option for anesthetic maintenance in avian anesthesia.
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Affiliation(s)
- T M Edling
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh 27606, USA
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