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NIYOM S, MAMA KR, KING M, CONTINO E, FERRIS D, VALDES-MARTINEZ A, FRISBIE DD, MCILWRAITH W, ZUMBRUNNEN J. Influence of changing lateral recumbency and mode of ventilation on the alveolar-arterial oxygen tension gradient and selected laboratory analytes in adult isoflurane anesthetized horses. J Vet Med Sci 2018; 80:1584-1589. [PMID: 30175753 PMCID: PMC6207512 DOI: 10.1292/jvms.18-0032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 08/20/2018] [Indexed: 11/22/2022] Open
Abstract
This study investigated the influence of changing recumbency and mode of ventilation over repeated anesthesias on the alveolar to arterial oxygen tension gradient (PA-aO2) and laboratory analytes in eight horses during a year-long imaging study. Anesthesia was induced with xylazine, diazepam or guaifenesin, and ketamine and maintained with isoflurane. Horses were positioned in right or left lateral recumbency for computed tomography. Ventilation was controlled during 47% of the anesthetics. Blood was sampled from an arterial catheter prior to (30 ± 5 min from connection to anesthetic circuit), within 5 min of changing lateral recumbency, and prior to circuit disconnection (24 ± 6 min after second sample) for measurement of pH, partial pressure of arterial oxygen (PaO2) and partial pressure of arterial carbon dioxide, blood glucose and electrolytes. PA-aO2 was calculated. Data from five anesthetic episodes for each horse were summarized as mean ± standard error and analyzed using a mixed-model ANOVA. t tests were used for pairwise comparisons (P<0.05). PaO2 decreased after turning (198 vs. 347 mmHg), then increased to 291 mmHg prior to disconnection. Correspondingly, PA-aO2 was wider (252 vs.120 mmHg), and improved before disconnection (190 mmHg). Body temperature, ionized-Ca2+ and blood glucose were lower, and Na+ was higher at the last time point. In conclusion, turning anesthetized horses decreases PaO2 and results in a widening PA-aO2 suggesting a cautious approach in animals with pre-existing hypoxemia.
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Affiliation(s)
- Sirirat NIYOM
- Department of Companion Animal Clinical Sciences, Faculty of
Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand
| | - Khursheed R. MAMA
- Department of Clinical Sciences, College of Veterinary
Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523,
U.S.A
| | - Melissa KING
- Department of Clinical Sciences, College of Veterinary
Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523,
U.S.A
| | - Erin CONTINO
- Department of Clinical Sciences, College of Veterinary
Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523,
U.S.A
| | - Dora FERRIS
- Department of Clinical Sciences, College of Veterinary
Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523,
U.S.A
| | - Alex VALDES-MARTINEZ
- Department of Environmental & Radiological Health
Sciences, Colorado State University, Fort Collins, CO 80523, U.S.A
| | - David D. FRISBIE
- Department of Clinical Sciences, College of Veterinary
Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523,
U.S.A
| | - Wayne MCILWRAITH
- Department of Clinical Sciences, College of Veterinary
Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523,
U.S.A
| | - James ZUMBRUNNEN
- Department of Statistics, Colorado State University, Fort
Collins, CO 80523, U.S.A
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Uquillas E, Dart CM, Perkins NR, Dart AJ. Effect of reducing inspired oxygen concentration on oxygenation parameters during general anaesthesia in horses in lateral or dorsal recumbency. Aust Vet J 2017; 96:46-53. [PMID: 29265178 DOI: 10.1111/avj.12662] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Revised: 05/26/2017] [Accepted: 06/22/2017] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To compare the effects of two concentrations of oxygen delivered to the anaesthetic breathing circuit on oxygenation in mechanically ventilated horses anaesthetised with isoflurane and positioned in dorsal or lateral recumbency. METHODS Selected respiratory parameters and blood lactate were measured and oxygenation indices calculated, before and during general anaesthesia, in 24 laterally or dorsally recumbent horses. Horses were randomly assigned to receive 100% or 60% oxygen during anaesthesia. All horses were anaesthetised using the same protocol and intermittent positive pressure ventilation (IPPV) was commenced immediately following anaesthetic induction and endotracheal intubation. Arterial blood gas analysis was performed and oxygenation indices calculated before premedication, immediately after induction, at 10 and 45 min after the commencement of mechanical ventilation, and in recovery. RESULTS During anaesthesia, the arterial partial pressure of oxygen was adequate in all horses, regardless of position of recumbency or the concentration of oxygen provided. At 10 and 45 min after commencing IPPV, the arterial partial pressure of oxygen was lower in horses in dorsal recumbency compared with those in lateral recumbency, irrespective of the concentration of oxygen supplied. Based on oxygenation indices, pulmonary function during general anaesthesia in horses placed in dorsal recumbency was more compromised than in horses in lateral recumbency, irrespective of the concentration of oxygen provided. CONCLUSION During general anaesthesia, using oxygen at a concentration of 60% instead of 100% maintains adequate arterial oxygenation in horses in dorsal or lateral recumbency. However, it will not reduce pulmonary function abnormalities induced by anaesthesia and recumbency.
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Affiliation(s)
- E Uquillas
- Research and Clinical Trials Unit, University Veterinary Teaching Hospital Camden, School of Veterinary Science, University of Sydney, 410 Werombi Road, Camden, New South Wales, 2570, Australia
| | - C M Dart
- Research and Clinical Trials Unit, University Veterinary Teaching Hospital Camden, School of Veterinary Science, University of Sydney, 410 Werombi Road, Camden, New South Wales, 2570, Australia
| | - N R Perkins
- School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia
| | - A J Dart
- Research and Clinical Trials Unit, University Veterinary Teaching Hospital Camden, School of Veterinary Science, University of Sydney, 410 Werombi Road, Camden, New South Wales, 2570, Australia
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Williams DC, Brosnan RJ, Fletcher DJ, Aleman M, Holliday TA, Tharp B, Kass PH, LeCouteur RA, Steffey EP. Qualitative and Quantitative Characteristics of the Electroencephalogram in Normal Horses during Administration of Inhaled Anesthesia. J Vet Intern Med 2015; 30:289-303. [PMID: 26714626 PMCID: PMC4913671 DOI: 10.1111/jvim.13813] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 08/27/2015] [Accepted: 11/17/2015] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND The effects of anesthesia on the equine electroencephalogram (EEG) after administration of various drugs for sedation, induction, and maintenance are known, but not that the effect of inhaled anesthetics alone for EEG recording. OBJECTIVE To determine the effects of isoflurane and halothane, administered as single agents at multiple levels, on the EEG and quantitative EEG (qEEG) of normal horses. ANIMALS Six healthy horses. METHODS Prospective study. Digital EEG with video and quantitative EEG (qEEG) were recorded after the administration of one of the 2 anesthetics, isoflurane or halothane, at 3 alveolar doses (1.2, 1.4 and 1.6 MAC). Segments of EEG during controlled ventilation (CV), spontaneous ventilation (SV), and with peroneal nerve stimulation (ST) at each MAC multiple for each anesthetic were selected, analyzed, and compared. Multiple non-EEG measurements were also recorded. RESULTS Specific raw EEG findings were indicative of changes in the depth of anesthesia. However, there was considerable variability in EEG between horses at identical MAC multiples/conditions and within individual horses over segments of a given epoch. Statistical significance for qEEG variables differed between anesthetics with bispectral index (BIS) CV MAC and 95% spectral edge frequency (SEF95) SV MAC differences in isoflurane only and median frequency (MED) differences in SV MAC with halothane only. CONCLUSIONS AND CLINICAL IMPORTANCE Unprocessed EEG features (background and transients) appear to be beneficial for monitoring the depth of a particular anesthetic, but offer little advantage over the use of changes in mean arterial pressure for this purpose.
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Affiliation(s)
- D C Williams
- William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, CA
| | - R J Brosnan
- Departments of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA
| | - D J Fletcher
- Section of Emergency and Critical Care, Cornell University, Ithaca, NY
| | - M Aleman
- Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA
| | - T A Holliday
- Departments of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA
| | - B Tharp
- Department of Neurology, University of California Davis Medical Center, Sacramento, CA
| | - P H Kass
- Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA
| | - R A LeCouteur
- Departments of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA
| | - E P Steffey
- Departments of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA
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Hubbell JAE, Muir WW. Oxygenation, oxygen delivery and anaesthesia in the horse. Equine Vet J 2014; 47:25-35. [DOI: 10.1111/evj.12258] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 02/26/2014] [Indexed: 11/30/2022]
Affiliation(s)
- J. A. E. Hubbell
- The Department of Veterinary Clinical Sciences; College of Veterinary Medicine; The Ohio State University; Columbus USA
| | - W. W. Muir
- Veterinary Clinical Pharmacology Consulting Services; Columbus Ohio USA
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Sá P, Texeira Neto F, Campagnol D, França R, Moreira M. Efeitos do modo ventilatório sobre variáveis hemogasométricas em equinos submetidos à mudança de decúbito durante a anestesia geral inalatória com halotano. ARQ BRAS MED VET ZOO 2010. [DOI: 10.1590/s0102-09352010000300008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Compararam-se os efeitos da ventilação espontânea (V E) e controlada (V C) em equinos submetidos à mudança de decúbito durante anestesia. Dezesseis animais foram equitativamente divididos em dois grupos: V E e V C. Os procedimentos cirúrgicos foram iniciados com os animais em decúbito lateral esquerdo (DLE) e, após 75 minutos, os animais foram reposicionados em decúbito lateral direito (DLD). Análises hemogasométricas do sangue arterial foram realizadas após 30 e 75 minutos com os animais posicionados em cada decúbito (M1 e M2 no DLE e M3 e M4 no DLD, respectivamente). Durante a V E, observaram-se hipercapnia (PaCO2 >45mmHg), acidose respiratória (pH <7,35), redução significativa da oxigenação sanguínea após 75min da mudança de decúbito (M4: 205,8±124,7mmHg) em relação aos valores de PaO2 observados antes da mudança de posicionamento (M1: 271,8±84,8mmHg). A Vc foi associada a valores de PaCO2 e pH mais próximos da normalidade bem como resultou em valores de PaO2 significativamente maiores (52 a 96% de elevação nos valores médios) que a V E. Conclui-se que a mudança de decúbito, em equinos anestesiados com halotano e mantidos sob V E, resulta em hipercapnia, acidose respiratória e diminuição dos valores de PaO2. A instituição de V C, desde o início da anestesia, previne a acidose respiratória, além de resultar em valores de PaO2 mais próximos do ideal para animais respirando O2 a 100%.
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Affiliation(s)
| | | | | | | | - M. Moreira
- Regimento de Cavalaria Dragões da Independência
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Mansel JC, Clutton RE. The influence of body mass and thoracic dimensions on arterial oxygenation in anaesthetized horses and ponies. Vet Anaesth Analg 2008; 35:392-9. [DOI: 10.1111/j.1467-2995.2008.00400.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Solano AM, Brosnan RJ, Steffey EP. Rate of change of oxygen concentration for a large animal circle anesthetic system. Am J Vet Res 2005; 66:1675-8. [PMID: 16273896 DOI: 10.2460/ajvr.2005.66.1675] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To describe the effects of changes in circuit volume and oxygen inflow rate on inspired oxygen concentration for a large animal circle anesthetic system. STUDY POPULATION A large animal circle anesthetic system, a 10 L/min flowmeter, and 20- and 40-L breathing bags. PROCEDURE Circuit volume was determined by a carbon dioxide dilution technique. Oxygen flow rates of 3, 6, and 10 L/min were delivered to the circuit with the large breathing bag, and a flow rate of 6 L/min was used with the small bag. Gas samples were collected during a 20-minute period. The time constant (tau) and half-time (T1/2) were calculated and compared with measured values. RESULTS Mean +/- SEM volume of the breathing circuit with a 20- and 40-L breathing bag was 32.97 +/- 0.91 L and 49.26 +/- 0.58 L, respectively. The tau from measurements was 11.97, 6.10, and 3.60 minutes at oxygen flow rates of 3, 6, and 10 L/min, respectively, for the large breathing bag and 3.73 minutes at a flow rate of 6 L/min for the small breathing bag. The T1/2 was 8.29, 4.22, and 2.49 minutes at oxygen flow rates of 3, 6, and 10 L/min, respectively, for the large breathing bag and 2.58 minutes for the small breathing bag. CONCLUSIONS AND CLINICAL RELEVANCE This study emphasizes that there are delays in the rate of increase in the inspired oxygen concentration that accompany use of conventional large animal circle anesthetic systems and low rates of inflow for fresh oxygen.
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Affiliation(s)
- Adrian M Solano
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
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Aida H, Steffey EP, Pascoe JR, Yarbrough TB, Takahashi T, Hiraga A, Hobo S, Smith BL, Steffey MA, Jones JH. Use of sevoflurane for anesthetic management of horses during thoracotomy. Am J Vet Res 2000; 61:1430-7. [PMID: 11108193 DOI: 10.2460/ajvr.2000.61.1430] [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
OBJECTIVE To evaluate sevoflurane as an inhalation anesthetic for thoracotomy in horses. ANIMALS 18 horses between 2 and 15 years old. PROCEDURE 4 horses were used to develop surgical techniques and were euthanatized at the end of the procedure. The remaining 14 horses were selected, because they had an episode of bleeding from their lungs during strenuous exercise. General anesthesia was induced with xylazine (1.0 mg/kg of body weight, IV) followed by ketamine (2.0 mg/kg, IV). Anesthesia was maintained with sevoflurane in oxygen delivered via a circle anesthetic breathing circuit. Ventilation was controlled to maintain PaCO2 at approximately 45 mm Hg. Neuromuscular blocking drugs (succinylcholine or atracurium) were administered to eliminate spontaneous breathing efforts and to facilitate surgery. Cardiovascular performance was monitored and supported as indicated. RESULTS 2 of the 14 horses not euthanatized died as a result of ventricular fibrillation. Mean (+/- SD) duration of anesthesia was 304.9 +/- 64.1 minutes for horses that survived and 216.7 +/- 85.5 minutes for horses that were euthanatized or died. Our subjective opinion was that sevoflurane afforded good control of anesthetic depth during induction, maintenance, and recovery. CONCLUSIONS AND CLINICAL RELEVANCE Administration of sevoflurane together with neuromuscular blocking drugs provides stable and easily controllable anesthetic management of horses for elective thoracotomy and cardiac manipulation.
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Affiliation(s)
- H Aida
- Equine Research Institute, Japan Racing Association, Utsunomiya, Tochigi
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Aguilera-Tejero E, Estepa JC, López I, Mayer-Valor R, Rodríguez M. Arterial blood gases and acid-base balance in healthy young and aged horses. Equine Vet J 1998; 30:352-4. [PMID: 9705121 DOI: 10.1111/j.2042-3306.1998.tb04111.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- E Aguilera-Tejero
- Dpto. Patología Clínica Veterinaria, Universidad of Córdoba, Campus Universitario de Rabanales, Spain
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Gasthuys F, de Moor A, Parmentier D. Haemodynamic effects of change in position and respiration mode during a standard halothane anaesthesia in ponies. ZENTRALBLATT FUR VETERINARMEDIZIN. REIHE A 1991; 38:203-11. [PMID: 1907066 DOI: 10.1111/j.1439-0442.1991.tb01003.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The effects of change in position and respiration modes were studied in 5 experimental ponies during a standard halothane anaesthesia. A marked cardiovascular depression (decrease in mean arterial blood pressure, cardiac output, stroke volume and left ventricle work) occurred in recumbent, spontaneously breathing ponies. No significant differences were found between right and left lateral recumbency. The most pronounced cardiovascular depression was observed in the dorsal position. Sternal recumbency appeared to be slightly beneficial (higher systemic blood pressure and arterial oxygenation). Peripheral resistance tended to decrease in the lateral positions (peripheral vasodilatation) but increased slightly in dorsally recumbent ponies. The mean pulmonary artery pressure decreased significantly in the dorsal position. Pulmonary resistance increased slightly in the laterally and the sternally positioned ponies, suggesting a pulmonary vasoconstriction. On the other hand, pulmonary resistance decreased in dorsal recumbency. Arterial oxygenation decreased progressively during anaesthesia but remained always above standing control values. Hypoventilation (increase in arterial carbon dioxide to +/- 60 mm Hg) was observed in all positions. Controlled intermittent positive pressure ventilation (I.P.P.V.) induced a further decrease of all cardiovascular parameters although no significant differences in cardiac indexes were found regarding the spontaneous breathing protocol. In ventilated ponies the greatest cardiovascular depression was again observed in dorsal recumbency. Peripheral resistance increased slightly in the sternally positioned ponies. A gradual time-dependent increase in pulmonary resistance was observed. Apparently, the arterial oxygenation improved slightly in all positions (especially the sternal posture) when I.P.P.V. was applied.
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Affiliation(s)
- F Gasthuys
- Large Animal Surgical Clinic, State University of Gent, Belgium
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Grandy JL, Hodgson DS. Anesthetic considerations for emergency equine abdominal surgery. Vet Clin North Am Equine Pract 1988; 4:63-78. [PMID: 3289697 DOI: 10.1016/s0749-0739(17)30650-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The physiologic changes that take place in horses presented for emergency abdominal surgery and the effects of these changes on the horse's anesthetic management are discussed.
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Affiliation(s)
- J L Grandy
- Department of Clinical Sciences, Colorado State University College of Veterinary Medicine and Biomedical Sciences, Fort Collins
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