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Effect of an Insulation Device in Preventing Hypothermia during Magnetic Resonance Imaging Examinations for Dogs and Cats under General Anesthesia. Animals (Basel) 2021; 11:ani11082378. [PMID: 34438834 PMCID: PMC8388625 DOI: 10.3390/ani11082378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/09/2021] [Accepted: 08/09/2021] [Indexed: 11/21/2022] Open
Abstract
Simple Summary Magnetic resonance imaging examinations require general anesthesia, and it is difficult to prevent a decrease in body temperature because a machine for warming the body cannot be placed in the magnetic resonance imaging room, which must have a low room temperature. In this study, we created a heat insulating device that does not affect magnetic resonance imaging and examined the effectiveness of this device for dogs and cats undergoing magnetic resonance imaging examinations. In the dogs and cats wearing bubble wrap and down cloth blanket, the decrease in body temperature was minimal. The heat insulating device developed in this study protected the animals from the cold air and prevented heat loss from the body surface, minimizing a decrease in body temperature. The results obtained in this study suggest that dogs and cats requiring magnetic resonance imaging can be protected from hypothermia due to general anesthesia without the need for special machinery. Abstract Dogs and cats under general anesthesia may develop hypothermia. When performing a magnetic resonance imaging (MRI) examination, it is not possible to place a magnetic material in the MRI room, and MRI equipment requires a low room temperature. This study investigated the effectiveness of a heat insulating device that prevented hypothermia during MRI examinations in dogs and cats. The animals that underwent MRI examinations under general anesthesia were divided into control groups (no covering) and heat insulating groups (wearing bubble wrap and down cloth blankets), and their body temperatures were measured before and after the MRI examinations. The changes in body temperatures were as follows: control dogs (n = 17), median of −1.0 (from −2.5 to 0.3) °C; heat insulated dogs (n = 7), −0.3 (from −0.8 to 0.2) °C; control cats (n = 14), −1.85 (from −2.7 to −0.6) °C; and heat insulated cats (n = 12), −0.8 (from −1.5 to −0.1) °C. These results revealed that the bubble wrap and down cloth blanket significantly prevented hypothermia and heat loss from the body surface during MRI examinations of dogs and cats.
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Navarro KL, Huss M, Smith JC, Sharp P, Marx JO, Pacharinsak C. Mouse Anesthesia: The Art and Science. ILAR J 2021; 62:238-273. [PMID: 34180990 PMCID: PMC9236661 DOI: 10.1093/ilar/ilab016] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 02/04/2021] [Accepted: 12/01/2020] [Indexed: 12/15/2022] Open
Abstract
There is an art and science to performing mouse anesthesia, which is a significant component to animal research. Frequently, anesthesia is one vital step of many over the course of a research project spanning weeks, months, or beyond. It is critical to perform anesthesia according to the approved research protocol using appropriately handled and administered pharmaceutical-grade compounds whenever possible. Sufficient documentation of the anesthetic event and procedure should also be performed to meet the legal, ethical, and research reproducibility obligations. However, this regulatory and documentation process may lead to the use of a few possibly oversimplified anesthetic protocols used for mouse procedures and anesthesia. Although a frequently used anesthetic protocol may work perfectly for each mouse anesthetized, sometimes unexpected complications will arise, and quick adjustments to the anesthetic depth and support provided will be required. As an old saying goes, anesthesia is 99% boredom and 1% sheer terror. The purpose of this review article is to discuss the science of mouse anesthesia together with the art of applying these anesthetic techniques to provide readers with the knowledge needed for successful anesthetic procedures. The authors include experiences in mouse inhalant and injectable anesthesia, peri-anesthetic monitoring, specific procedures, and treating common complications. This article utilizes key points for easy access of important messages and authors’ recommendation based on the authors’ clinical experiences.
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Affiliation(s)
- Kaela L Navarro
- Department of Comparative Medicine, Stanford University, Stanford, California, USA
| | - Monika Huss
- Department of Comparative Medicine, Stanford University, Stanford, California, USA
| | - Jennifer C Smith
- Bioresources Department, Henry Ford Health System, Detroit, Michigan, USA
| | - Patrick Sharp
- Office of Research and Economic Development, University of California, Merced, California, USA
- Animal Resources Authority, Murdoch, Australia
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia
| | - James O Marx
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Cholawat Pacharinsak
- Corresponding Author: Cholawat Pacharinsak, DVM, PhD, DACVAA, Stanford University, Department of Comparative Medicine, 287 Campus Drive, Stanford, CA 94305-5410, USA. E-mail:
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Klune CB, Robbins HN, Leung VS, Pang DS. Hypothermia During General Anesthesia Interferes with Pain Assessment in Laboratory Rats ( Rattus norvegicus). JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE 2020; 59:719-725. [PMID: 32907696 DOI: 10.30802/aalas-jaalas-20-000018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Accurate pain assessment methods are necessary to ensure animal welfare and reliable data collection in animal research. The Rat Grimace Scale (RGS), a facial expression pain scale, allows effective identification of pain. However, the potential confounds of this method remain mostly unexplored. General anesthesia, which is used in many laboratory procedures, suppresses thermoregulation and results in hypothermia. We investigated the effects of isoflurane-induced hypothermia on RGS scores. Twenty (10 male and 10 female) Sprague-Dawley rats each received 30 min of anesthesia, followed by 30 min of observation after the return of sternal recumbency. Rats were randomized to receive warming with an electric heating pad or no warming during both periods. Unwarmed rats became hypothermic within 15 min after isoflurane exposure began and returned to normothermia within 15 min after returning to sternal recumbency. Warmed rats did not deviate from the normothermic range. The RGS scores of unwarmed rats were significantly higher than baseline levels for 3 h after anesthesia and were higher than those of warmed rats at 5 and 180 min after anesthesia. Hypothermia resulted in a larger proportion of rats crossing a predetermined analgesic intervention threshold. Our findings show that hypothermia induced by isoflurane anesthesia presents a confound to accurate RGS scoring. These results emphasize the importance of maintaining normothermia to avoid inflated pain scores and to obtain accurate pain assessment.
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Affiliation(s)
- Cassandra B Klune
- David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Hayley Nk Robbins
- Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Vivian Sy Leung
- Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Daniel Sj Pang
- Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada; Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, Québec, Canada;,
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Rufiange M, Leung VSY, Simpson K, Pang DSJ. Prewarming Followed by Active Warming is Superior to Passive Warming in Preventing Hypothermia for Short Procedures in Adult Rats (Rattus norvegicus) Under Isoflurane Anesthesia. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE : JAALAS 2020; 59. [PMID: 32513348 PMCID: PMC7338875 DOI: 10.30802/aalas-jaalas-19-000114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 09/16/2019] [Accepted: 12/27/2019] [Indexed: 11/05/2022]
Abstract
General anesthesia is a common procedure in laboratory rats; however, it impairs thermoregulation, rapidly leading to hypothermia as warm core blood is distributed to the cooler periphery. The protective strategy of prewarming before the onset of anesthesia delays hypothermia, but only for a short period. This prospective, randomized, cross-over, experimental study in adult male and female SD rats (n = 8) was designed to compare passive (fleece blanket) and active (temperature controlled heating pad) warming. Initial treatment order was randomized, with a cross-over after a minimum 5 d washout period. Both groups underwent a period of prewarming in a warming box to increase core temperature by 1% (median 0.4 °C). At completion of prewarming, general anesthesia was induced and maintained for 30 min with isoflurane carried in oxygen. Core temperature was monitored for a further 30 min after anesthesia. Active warming resulted in higher core temperatures during anesthesia. During passive warming, hypothermia occurred after approximately 30 min of anesthesia and continued into recovery. In contrast, active warming prevented hypothermia. Prewarming followed by passive warming delayed hypothermia for approximately 30min, but active warming was more effective at maintaining normothermia both during and after general anesthesia.
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Affiliation(s)
- Maxime Rufiange
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC, Canada
- Groupe de Recherche de Pharmacologie Animale du Québec (GREPAQ), Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC, Canada
| | - Vivian SY Leung
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC, Canada
- Groupe de Recherche de Pharmacologie Animale du Québec (GREPAQ), Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC, Canada
| | | | - Daniel SJ Pang
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC, Canada
- Groupe de Recherche de Pharmacologie Animale du Québec (GREPAQ), Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC, Canada
- Department of Veterinary Clinical and Diagnostic Sciences, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
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Affiliation(s)
- Mickey Tivers
- Paragon Veterinary Referrals, Paragon Business Village, Wakefield, UK
| | - Sophie Adamantos
- Paragon Veterinary Referrals, Paragon Business Village, Wakefield, UK
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Rufiange M, Leung VSY, Simpson K, Pang DSJ. Pre-warming before general anesthesia with isoflurane delays the onset of hypothermia in rats. PLoS One 2020; 15:e0219722. [PMID: 32126085 PMCID: PMC7053737 DOI: 10.1371/journal.pone.0219722] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 01/09/2020] [Indexed: 01/09/2023] Open
Abstract
General anesthesia causes hypothermia by impairing normal thermoregulatory mechanisms. When using inhalational anesthetic agents, Redistribution of warm blood from the core to the periphery is the primary mechanism in the development of hypothermia and begins following induction of anesthesia. Raising skin temperature before anesthesia reduces the temperature gradient between core and periphery, decreasing the transfer of heat. This prospective, crossover study (n = 17 adult male and female SD rats) compared three treatment groups: PW1% (pre-warming to increase core temperature 1% over baseline), PW40 (pre-warming to increase core temperature to 40°C) and NW (no warming). The PW1% group was completed first to ensure tolerance of pre-warming. Treatment order was then randomized and alternated after a washout period. Once target temperature was achieved, anesthesia was induced and maintained with isoflurane in oxygen without further external temperature support. Pre-warming was effective at delaying the onset of hypothermia, with a significant difference between PW1% (12.4 minutes) and PW40 (19.3 minutes, p = 0.0044 (95%CI -12 to -2.2), PW40 and NW (7.1 minutes, p < 0.0001 (95%CI 8.1 to 16.0) and PW1% and NW (p = 0.003, 95%CI 1.8 to 8.7). The rate of heat loss in the pre-warmed groups exceed that of the NW group: PW1% versus NW (p = 0.005, 95%CI 0.004 to 0.027), PW40 versus NW (p < 0.0001, 95%CI 0.014 to 0.036) and PW1% versus PW40 (p = 0.07, 95%CI -0.021 to 0.00066). Pre-warming alone confers a protective effect against hypothermia during volatile anesthesia; however, longer duration procedures would require additional heating support.
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Affiliation(s)
- Maxime Rufiange
- Faculty of Veterinary Medicine, Department of Clinical Sciences, Université de Montréal, Saint-Hyacinthe, QC, Canada
- Faculty of Veterinary Medicine, Groupe de Recherche de Pharmacologie Animale du Québec (GREPAQ), Université de Montréal, Saint-Hyacinthe, QC, Canada
| | - Vivian S. Y. Leung
- Faculty of Veterinary Medicine, Department of Clinical Sciences, Université de Montréal, Saint-Hyacinthe, QC, Canada
- Faculty of Veterinary Medicine, Groupe de Recherche de Pharmacologie Animale du Québec (GREPAQ), Université de Montréal, Saint-Hyacinthe, QC, Canada
| | - Keith Simpson
- Vetronic Services Ltd, Abbotskerswell, England, United Kingdom
| | - Daniel S. J. Pang
- Faculty of Veterinary Medicine, Department of Clinical Sciences, Université de Montréal, Saint-Hyacinthe, QC, Canada
- Faculty of Veterinary Medicine, Groupe de Recherche de Pharmacologie Animale du Québec (GREPAQ), Université de Montréal, Saint-Hyacinthe, QC, Canada
- * E-mail:
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Cullen MD, Archer DC, Mair TS. Clinical audit in equine practice, and the International Colic Surgery Audit. EQUINE VET EDUC 2019. [DOI: 10.1111/eve.13134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M. D. Cullen
- School of Veterinary Science Philip Leverhulme Equine Hospital Neston Cheshire UK
| | - D. C. Archer
- School of Veterinary Science Philip Leverhulme Equine Hospital Neston Cheshire UK
| | - T. S. Mair
- Bell Equine Veterinary Clinic Mereworth, Maidstone Kent UK
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Pang DSJ, Rousseau-Blass F, Pang JM. Morbidity and Mortality Conferences: A Mini Review and Illustrated Application in Veterinary Medicine. Front Vet Sci 2018; 5:43. [PMID: 29560359 PMCID: PMC5845710 DOI: 10.3389/fvets.2018.00043] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 02/21/2018] [Indexed: 11/30/2022] Open
Abstract
This mini review presents current knowledge on the role of morbidity and mortality conferences (M&MCs) as a powerful educational tool and driver to improve patient care. Although M&MCs have existed since the early twentieth century, formal evaluation of their impact on education and patient care is relatively recent. Over time, M&MCs have evolved from single discipline discussions with a tendency to focus on individual errors and assign blame, to multidisciplinary, standardized presentations incorporating error analysis techniques, and educational theory. Current evidence shows that M&MCs can provide a valuable educational experience and have the potential to generate measurable improvements in patient care.
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Affiliation(s)
- Daniel S J Pang
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC, Canada
| | - Frédérik Rousseau-Blass
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC, Canada
| | - Jessica M Pang
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC, Canada
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Schuster CJ, Pang DSJ. Forced-air pre-warming prevents peri-anaesthetic hypothermia and shortens recovery in adult rats. Lab Anim 2017; 52:142-151. [PMID: 28599579 DOI: 10.1177/0023677217712539] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
General anaesthesia disrupts thermoregulation in mammals, which can cause hypothermia. Decreases in core body temperature of 1℃ cause significant postoperative complications in humans, and peri-anaesthetic hypothermia in mice increases data variability, which can potentially increase animal use. In rats, the impact of different temperature management strategies on the incidence and severity of hypothermia, and the accuracy of different temperature measurement methods, is unknown. Eighteen adult male and female SD rats were block-randomized to one of three treatment groups: no-warming (NW), limited-warming (LW, heat pad during anaesthesia), and pre-warming (PW, warm air exposure before anaesthesia, followed by heat pad). Anaesthesia (isoflurane) duration was for 40 min. Core body temperature (intra-abdominal telemetric temperature capsule) was recorded during anaesthesia and recovery. During anaesthesia, rectal, skin, and tail temperatures were also recorded. In the PW group, core temperature was maintained during anaesthesia and recovery. By contrast, the NW group was hypothermic (11% temperature decrease) during anaesthesia. The LW group showed a decrease in temperature during recovery. Recovery to sternal recumbency was significantly faster in the PW (125 [70-186] s, P = 0.0003) and the LW (188 [169-420] s, P = 0.04) groups than in the NW group (525 [229-652] s). Rectal temperature underestimated core temperature (bias -0.90℃, 95% limits of agreement -0.1 to 1.9℃). Skin and tail temperatures showed wide 95% limits of agreement, spanning 6 to 15℃, respectively. The novel strategy of PW was effective at maintaining core temperature during and after anaesthesia. Rectal temperature provided an acceptable proxy for core body temperature.
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Affiliation(s)
- C J Schuster
- Department of Veterinary Clinical and Diagnostic Sciences, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
| | - D S J Pang
- Department of Veterinary Clinical and Diagnostic Sciences, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
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Dugdale AHA. “PDSA” - but not as you know it?! J Small Anim Pract 2016; 57:445-6. [DOI: 10.1111/jsap.12544] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 07/14/2016] [Indexed: 11/30/2022]
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