International Journal of Advanced Research and Review www.ijarr.in ANAESTHESIA IN LABORATORY ANIMALS (original) (raw)
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Anaesthesia in Laboratory Animals
2022
Anaesthesia and analgesia are imperative components in laboratory animal science and these should be incorporated as essential components in all laboratory animal training programmes. It prevents unnecessary pain induced by various experimental procedures(Flecknell, 1993). The uncontrolled or unattended pain can create stress in an animal which creates release of uncontrolled substances. Finally it can lead to a series of unwanted changes in its body. Ultimately, this will influence the experimental outcome. Because of these reasons, the rational use of anaesthesia and analgesia is an ethical and a scientific requirement(Mcintyre, 1971). Anaesthesia is a state of unconsciousness and the component of anaesthesia is analgesia (pain relief), amnesia (loss of memory) and immobilization. The drug used to achieve anaesthesia usually has varying effects in each of these areas. Some drug may be used individually to achieve all three effects. Others have only analgesic or sedative properties(Whelan & Flecknell, 1992).
Protocol for Anesthesia Animal Model in Biomedical Study
Bioscientia Medicina : Journal of Biomedicine and Translational Research
Recognition of pain depends upon intact pathways from pain receptors to thethalamus and cerebral cortex, as well as functional cerebral cortex and subcorticalstructures. Thus any means that renders the cerebral cortex nonfunctional, suchas hypoxia or drug depression, prevents pain. When this happens, stimuli thatevoke motor nerve reflexes that may be painful to the conscious animal are notpainful in the unconscious animal. Equally painful stimuli administered toanimals chemically paralyzed by curare or succinylcholine will not evoke a motorreflex simply because of paralysis, but will cause pain because of the consciousstate. Hence, it is possible that unconscious animals may feel no pain but respondto certain stimuli, and paralyzed animals may feel pain but cannot respond.
Retrospective review of anesthetic and analgesic regimens used in animal research proposals
ALTEX, 2019
animal research, it has been difficult to assess the extent to which experimental procedures were refined in practice. Structured literature reviews of research that involved the use of laboratory animals have provided some insights. Animal research involving surgical procedures carried out on pigs, sheep, dogs, and non-human primates (Coulter et al., 2009), rabbits (Coulter et al., 2011) and rodents (Coulter et al., 2009; Richardson and Flecknell, 2005), published in peer-reviewed journals, has been analyzed with regard to analgesic and anesthetic administration. Stokes and colleagues (2009) focused on studies conducted during two time periods (2000-2001 and 2005-2006) to assess changes in the administration of analgesics and anesthetics to laboratory mice and rats undergoing surgical procedures. The study showed a trend towards improvement such as safer anesthetic regimens used in the later period examined, but this and an earlier review assessing analgesic use in rodents (Richardson and Flecknell, 2005) found that there was still significant scope for refinement, especially with respect to perioperative care. Richardson and Flecknell (2005) not only screened
Innovative refinements to anaesthesia techniques can deliver pain research without pain
wwwsoc.nii.ac.jp
Research into analgesia has traditionally not been possible without subjecting animals to pain. The practice of inflicting pain in some animals in order to relieve pain in others leads to an obvious ethical dilemma. Over the last 15 years we have developed and refined a novel approach to anaesthesia that allows the cerebral cortex of an anaesthetised animal to respond to noxious stimuli in a similar manner to that of a conscious animal experiencing pain. Under these conditions, changes in specific electroencephalographic variables seen in response to noxious stimulation and their attenuation by different methods of analgesia have allowed various analgesic strategies to be directly compared with each other. Our approach has enabled analgesia research to be undertaken for the first time without subjecting animals to pain. We have studied pain and analgesia in this way in cattle, deer, sheep, horses, rats, dogs and wallabies. This paper will outline our new approach to analgesia research and discuss the advantages of this novel technique over more traditional approaches. We will draw on examples of applied analgesia research from several species of mammals in which our techniques have been applied.
Mouse Anesthesia: The Art and Science
ILAR Journal, 2021
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 ...
Four methods for general anaesthesia in the rabbit: a comparative study
Laboratory Animals, 1988
The efficacy and safety of pentobarbitone, ketamine/xylazine, fentanyl/fluanisone/diazepam, and halothane/nitrous oxide anaesthesia were compared in 4 groups of six New Zealand White rabbits. Heart and respiratory rates, body temperature, reflexes, blood pressure and blood gases were measured. Pentobarbitone appeared to be unsuitable for anaesthesia in rabbits, as 5 of the 6 rabbits to whom it was administered, required artificial respiration or died. The combinations of ketamine/xylazine and fentanyl-fluanisone/diazepam both produced unpredictable levels of anaesthesia together with a substantial decline in arterial blood pressure and PO2. Despite a severe drop in blood pressure (up to 37.5%), anaesthesia with halothane and nitrous oxide was found to be superior to the other anaesthetic agents.
Animal pain and nociception studies have greatly contributed to our understanding of acute and chronic pain processing and thereby contributed to the reduction of suffering of patients in pain. In classic analgesiometric tests in conscious animals, animal suffering is inevitable as pain behaviour is the primary outcome. Therefore, the feasibility of refining analgesiometric tests by anaesthesia is reviewed. The influence on analgesiometric tests of different anaesthetics is described. Other objective primary outcome measures than pain behaviour, including quantification of neural activation with c-fos and functional MRI (fMRI), are suggested to reduce animal discomfort for pain testing. In conclusion, reflex analgesiometric tests may be refined by choosing the right anaesthetics and alternative outcome measures such as c-fos or fMRI. Complex, higher order pain behaviour testing still requires conscious animals and can currently not be refined by the use of anaesthetics.
Handbook of Small Animal Regional Anesthesia and Analgesia Techniques
2016
The use of regional anesthesia as a component of perioperative pain management has gained acceptance and popularity in small animal practice over the past few decades. Reasons for this include the fact that many of the regional blocks are straightforward to perform, requiring moderate technical skill given familiarity with patient anatomy; they can be conducted relatively safely given an understanding of local anesthetic drug pharmacology, complications and side effects; and they contribute to the two major tenets of treating pain: preemptive and multimodal analgesia. Providing pre-emptive analgesia by performing regional anesthesia prior to surgery leads to a drastic reduction in intraoperative nociceptive (pain) stimulation. This results in a decrease in anesthetic maintenance drug as well as intra-and postoperative analgesic requirements, thereby decreasing the incidence of drug side effects during surgery, and improving postoperative patient comfort as well as duration of pain relief. Some techniques can be continued postoperatively to assist in managing pain after particularly painful surgeries once the patient has recovered from anesthesia, e.g. instilling local anesthetic into a chest tube after thoracotomy, or injecting local anesthetic into an epidural or spinal catheter after pelvic limb or abdominal surgery. The experience of pain, a sensory process involving the nociceptive pathway, is complex, and involves several steps. Noxious stimuli involving mechanical, chemical or thermal injury to tissue are fi rst transduced into electrical stimuli by peripheral nociceptors (pain receptors). These electrical impulses are then transmitted to the spinal cord, where they are modulated by neurons in the dorsal horn of the gray matter of the spinal cord. Here, impulse intensity can be increased (amplifi ed) or decreased (suppressed). Finally, the nociceptive signals are projected via lateral nerve fi bers to the brain where they are perceived. Whereas most analgesic drugs either decrease the amount of excitatory neurotransmitters, or increase the level of inhibitory neurotransmitters released in the nociceptive pathway, drugs used to provide regional anesthesia block sodium channels in neurons. This completely prevents sensory neurons from transmitting noxious stimuli from the periphery to the brain and spinal cord, or from the spinal cord to the brain in the case of epidural or spinal analgesia, thus providing effective pain relief for the duration of the block. Using regional anesthetic techniques in conjunction with other analgesic drugs that act in different ways on the nociceptive fi bers (e.g. with opioids, alpha-2 agonists, ketamine) results in multimodal analgesia, contributing to an overall decrease in excitatory neurotransmission within electrode (ECG pad). D, Negative lead (cathode). E, Syringe, injection port, and tubing. Reproduced with permission from The Ohio State University.
The assessment of depth of anaesthesia in animals and man
Laboratory Animals, 1992
The assessment of the depth of anaesthesia in man has received much attention in recent years, following a number of reports of people being aware during surgery. A range of different measures have been suggested for determining the adequacy of anaesthesia in man, but such a critical assessment is rarely applied to laboratory animals. This article describes the methods used to assess anaesthetic depth in both man and animals, and compares the relative states of knowledge about anaesthetic depth in animals and man.