CO<sub>2</sub> induced acute respiratory acidosis and brain tissue                intracellular pH: a <sup>31</sup>P NMR study in swine

Martoft, L.; Stødkilde‐Jørgensen, Hans; Forslid, A.; Pedersen, Henrik D.; Pf, Jørgensen

doi:10.1258/002367703766453092

Cited by 50 publications

(29 citation statements)

References 29 publications

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“…Therefore, the animal in the gas box increases its rate of breathing, which under these circumstances results in the inhalation of an increased amount of CO 2 . It appeared that when blood pH decreases, the pH of the cerebrospinal fluid follows (Martoft et al, 2003), resulting in neuronal inhibition and anaesthesia (Woodburry and Karler, 1960). The normal pH of brain fluid is 7.4 and induction of unconsciousness occurs at a pH of 7.1 (Eisele et al, 1967).…”

Section: Discussionmentioning

confidence: 99%

Castration of piglets under CO2-gas anaesthesia

Gerritzen

Kluivers-Poodt

Reimert

et al. 2008

Animal

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It has become common practice in pig fattening production systems to castrate young boar piglets without the use of anaesthesia. In this study, we examined whether or not CO 2 gas is capable of inducing an acceptable anaesthetic state during which castration can be performed. The first step was to identify the most promising CO 2 /O 2 mixture. Based on the results from this first experiment, a mixture of 70% CO 2 1 30% O 2 was chosen for further investigation as a potential anaesthetic during the castration of young piglets. Thereby, it was established whether the duration and depth of anaesthesia were acceptable for castration where the animal has to be insensible and unconscious. Physiological effects were assessed based on electroencephalogram (EEG) and electrocardiogram (ECG) measurements, blood gas values and behavioural responses. During the induction phase, the only typical behaviour the piglets exhibited when exposed to the 70/30 gas mixture was heavy breathing. All piglets (n 5 25) lost consciousness after approximately 30 s according to the EEG. Heart rate decreased slowly during the induction phase, a serious drop occurred when piglets lost their posture. Immediately after this drop, the heart rate neared zero or showed a very irregular pattern. Shortly after loss of posture, most animals showed a few convulsions. None of the animals showed any reaction to castration in behaviour and/or on the EEG and ECG. On average, the piglets recovered within 59 s, i.e. EEG returned to its pre-induction pattern and piglets were able to regain a standing position. After 120 s, heart rate returned to pre-induction levels. In order to explore the usage range of CO 2 concentration, 24 piglets were exposed to 60% CO 2 1 20% O 2 1 20% N 2 for up to 30 s after loss of consciousness (as registered on EEG), and castrated after removal from the chamber. Sixteen of the 24 animals showed a reaction to the castration on the EEG. To establish the maximum time piglets survive in 70% CO 2 1 30% O 2 , five piglets were placed in this mixture for 3 min. Two of them died. After that, four piglets were placed in this mixture for 2 min after unconsciousness, one died after 2 min. It was concluded from this study that it is possible to anaesthetise piglets with a mixture of 70% CO 2 1 30% O 2, but that there are limits to its safety in terms of CO 2 concentration and duration of exposure. Before implementation for practical use, further research is essential to assess the limits of gas concentration and exposure times.

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Section: Discussionmentioning

confidence: 99%

Castration of piglets under CO2-gas anaesthesia

Gerritzen

Kluivers-Poodt

Reimert

et al. 2008

Animal

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“…In addition to standard biometrics, such as animal age, weight, sex and strain, additional factors that may affect the outcome of MSI analysis should also be recorded, such as the time taken to dissect tissues (and in what order), as well as the type of anesthetic used. For example the permeability of the blood brain barrier is thought to be affected by CO 2 euthanasia (acidosis) [50]. Other pre-mortem factors that can impact heavily on tissue composition include infections, seizures, as well as hypoxia.…”

Section: Collectionmentioning

confidence: 99%

Sample preparation for mass spectrometry imaging: Small mistakes can lead to big consequences

Goodwin

2012

Journal of Proteomics

272

249

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“…Low to moderate concentrations of CO 2 (ranging from 5% to 35%) cause changes in respiration rate (Thomas & Spyer 2000), heart rate and blood pressure (Dripps & Comroe 1947, Kety & Schmidt 1947, Smith & Harrap 1997, as well as HPA axis activity (Barbaccia et al 1996). High concentrations of CO 2 initially cause similar responses and may induce hyperventilation before respiratory and cardiac depression and subsequent failure (Martoft et al 2003). The accumulation of CO 2 also causes acidification of nasal mucosa (Anton et al 1992, AVMA 2001.…”

Section: Physiological Effects/actions Of Comentioning

confidence: 99%

Carbon dioxide for euthanasia: concerns regarding pain and distress, with special reference to mice and rats

et al. 2005

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SummaryCarbon dioxide (CO 2 ) is the most commonly used agent for euthanasia of laboratory rodents, used on an estimated tens of millions of laboratory rodents per year worldwide, yet there is a growing body of evidence indicating that exposure to CO 2 causes more than momentary pain and distress in these and other animals. We reviewed the available literature on the use of CO 2 for euthanasia (as well as anaesthesia) and also informally canvassed laboratory animal personnel for their opinions regarding this topic. Our review addresses key issues such as CO 2 flow rate and final concentration, presence of oxygen, and prefilled chambers (the animal is added to the chamber once a predetermined concentration and flow rate have been reached) versus gradual induction (the animal is put into an empty chamber and the gas agent(s) is gradually introduced at a fixed rate). Internationally, animal research standards specify that any procedure that would cause pain or distress in humans should be assumed to do so in non-human animals as well (Public Health Service 1986, US Department of Agriculture 1997, Organization for Economic Cooperation and Development 2000). European Union guidelines, however, specify a certain threshold of pain or distress, such as 'skilled insertion of a hypodermic needle', as the starting point at which regulation of the use of animals in experimental or other scientific procedures begins (Biotechnology Regulatory Atlas n.d.). There is clear evidence in the human literature that CO 2 exposure is painful and distressful, while the non-human literature is equivocal. However, the fact that a number of studies do conclude that CO 2 causes pain and distress in animals indicates a need for careful reconsideration of its use. Finally, this review offers recommendations for alternatives to the use of CO 2 as a euthanasia agent.Keywords Carbon dioxide; euthanasia; pain; distress; anaesthesia; welfare; rodents Carbon dioxide (CO 2 ) is commonly used for euthanasia and anaesthesia of laboratory rodents, largely because of its ease of use, relative safety, and low cost, as well as its capacity to euthanize large numbers of animals in a short time span (Ambrose et al. 2000). In large institutions and those with significant rodent-breeding programmes, large numbers of rodents are often euthanized in a short time (Kline et al. 1963) and an appropriate gas agent is often the best way to approach such a challenge. However, CO 2 is not physiologically inert and the published evidence on whether or not CO 2 administration causes pain or distress in animals raises questions about its routine use. This paper reviews this published evidence and includes information on the effects of CO 2 in both humans and nonhumans. Methodological details are included when possible in order to provide a clear

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CO₂ induced acute respiratory acidosis and brain tissue intracellular pH: a ³¹P NMR study in swine

Cited by 50 publications

References 29 publications

Castration of piglets under CO2-gas anaesthesia

Castration of piglets under CO2-gas anaesthesia

Sample preparation for mass spectrometry imaging: Small mistakes can lead to big consequences

Carbon dioxide for euthanasia: concerns regarding pain and distress, with special reference to mice and rats

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CO2 induced acute respiratory acidosis and brain tissue intracellular pH: a 31P NMR study in swine

Cited by 50 publications

References 29 publications

Castration of piglets under CO2-gas anaesthesia

Castration of piglets under CO2-gas anaesthesia

Sample preparation for mass spectrometry imaging: Small mistakes can lead to big consequences

Carbon dioxide for euthanasia: concerns regarding pain and distress, with special reference to mice and rats

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Product

Resources

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CO₂ induced acute respiratory acidosis and brain tissue intracellular pH: a ³¹P NMR study in swine