Handbook of Laboratory Animal Anesthesia and Pain Management

Rodents

Cholawat Pacharinsak, Jennifer C. Smith, Cholawat Pacharinsak, Jennifer C. Smith

• Publisher: CRC Press
• Year: 2017
• eBook ISBN: 9781315356594
• Edition: 1
• Topic: Medicine
• Subtopic: Medical Theory, Practice & Reference

Rodents are the most commonly used species in biomedical research. Individuals conducting rodent research are often responsible to ensure that all areas of anesthesia and analgesia are performed humanely. Anesthetic agent selection, anesthetic monitoring, and postoperative pain assessment and management are essential to the institutional animal care and use program and contribute significantly to the 3Rs by reducing pain and/or distress and refining various procedures.

The Handbook of Laboratory Animal Anesthesia and Pain Management: Rodents is the first book to capture multiple advances in this important area that greatly impacts various experimental methodologies. Richly illustrated in full color, the book serves as a quick reference source for investigators, veterinarians, technicians, and other animal caretakers charged with the care and use of rodents in a research setting. The unique format of this book also makes it extremely valuable to IACUC members, institutional officials, and occupational health and safety professionals.

Key features:

• Presents practical information in easily accessible 'bullet point' format
• Covers anesthetic machine and related equipment, anesthetic management and monitoring, anesthesia and analgesia pharmacology, euthanasia, and record keeping
• Written by well-recognized experts in the laboratory animal community
• Provides extensive references to direct the reader to sources for further study of alternative techniques and their procedures
• Concludes with a thorough chapter on Regulatory Management of Rodent Anesthesia which has global application

1

terms and definitions

Travis Seymour

•  Acute pain: Pain associated with tissue damage that resolves once the tissue heals

•  Allodynia: Pain resulting from nonnoxious stimuli

•  Anesthesia: Loss of sensation to the whole or any part of the body

•  Chronic pain : Persistent pain that lasts significantly longer than the anticipated resolution time

•  General anesthesia: Unconsciousness due to drug-induced, reversible depression of the central nervous system

•  Hyperalgesia: Heightened pain intensity from noxious stimuli that normally cause pain

•  Neuroleptanalgesia: A combination of opioids and sedatives/tranquilizers that work synergistically; provides effective analgesia and sedation while decreasing the dosing requirements of both types of drugs

•  Neuropathic pain: Pain resulting from injury/damage of the peripheral or central nervous system

•  Nociception: Transmission of nociceptive information to higher CNS regions

•  Nociceptors : Receptors associated with mainly afferent neurons that detect noxious stimuli

•  Noxious stimuli: Stimuli causing tissue injury or damage (categorized as mechanical, thermal, chemical, or electrical stimuli)

•  Pain: An unpleasant sensation with an emotional component, usually associated with actual or potential tissue damage

•  Sedation: Depression of consciousness

•  Surgical anesthesia: The plane of anesthesia characterized by unconsciousness, muscle relaxation, and analgesia appropriate for a surgical procedure

•  Tranquilization: A behavioral change whereby the patient is relaxed yet cognizant of its surroundings

bibliography

Pacharinsak, C. and P. Sharp. 2013. Anesthesia in nonhuman primates. In Pocket Handbook of Nonhuman Primate Clinical Medicine, ed. A. Courtney, 1–32. Boca Raton, FL: CRC Press.

Tranquilli, W. J. and K. A. Grimm. 2015. Introduction: Use, definitions, history, concepts, classification, and considerations for anesthesia and analgesia. In Veterinary Anesthesia and Analgesia, the Fifth Edition of Lumb and Jones, eds K. A. Grimm, L. A. Lamont, W. J. Tranquilli, S. A. Greens, and S. A. Robertson. 5th edition, 23–85. Ames, IA: Wiley.

2

understanding anesthetic-related equipment

Daniel Pang

contents

2.1 carrier gas supply

2.1.1 Carrier Gas

2.1.2 Pipeline Oxygen

2.1.3 E Cylinders

2.1.4 Pressure Regulator

2.2 gas safety

2.3 the anesthetic machine

2.4 flowmeters

2.4.1 Safety

2.5 anesthetic vaporizers

2.6 O₂ flush valve

2.7 carbon dioxide (CO₂) absorber

2.8 breathing systems

2.8.1 Classification

2.8.1.1 Non-rebreathing systems

2.8.1.2 Rebreathing systems: Circle system

2.8.1.3 Open systems

2.9 reservoir bags

2.10 waste anesthetic gas

2.11 atmospheric pollution and occupational exposure

2.11.1 Atmospheric Pollution

2.11.2 Occupational Exposure

2.12 anesthesia machine check out procedure

2.12.1 High-Pressure System

2.12.2 Low-Pressure System

2.12.3 Breathing System

bibliography

Modern anesthetic equipment is reliable when regularly maintained and used appropriately. The provision of general anesthesia to laboratory species is often associated with additional constraints specific to the research setting, including animal positioning and access and drug and equipment restrictions. As a result, the associated anesthetic risk may be increased, emphasizing the role of the anesthetist in providing a successful outcome while safeguarding welfare.

2.1 carrier gas supply

2.1.1 Carrier Gas

The carrier gas, typically oxygen, is the gas used to carry an inhalational anesthetic agent to the animal. It may be supplied by connecting an anesthetic machine to a pipeline source or directly to a cylinder.

2.1.2 Pipeline Oxygen

Pipeline oxygen is common in larger units/clinics where it is more convenient to have large, less portable oxygen sources housed together in a secure, remote storage room, from which supplied gas is piped to a large number of suites. The form of oxygen source depends on workplace requirements, ranging from a bank of J cylinders to liquid oxygen containers (Figure 2.1a,b).

• Pipeline oxygen is transported at a pressure of approximately 50–60 psi (345–410 kPa) to the anesthetic machine (Figure 2.2a).

• The final pressure reduction occurs at the flowmeter (see below).

• Oxygen is stored at 1900 psi in both J and E cylinders (Figure 2.2b).

Fig. 2.1 (a) Control unit for two banks of oxygen cylinders. Using dual banks allows for one bank to be replaced with full cylinders while providing a continuous supply of gas from the second bank. The switch from one bank to the other may be manual (as in this example) or automatically controlled. In either case, messages indicating a depletion in gas supply and switching of banks may be sent to a central unit in an area observed by personnel. (b) Liquid oxygen containers used to supply a large veterinary referral hospital.

• J cylinders, containing approximately 6800 L of oxygen when full, are approximately 5 feet in height and may be used to supply pipeline oxygen or can be housed in a laboratory for local use (Figure 2.2c).

2.1.3 E Cylinders

E cylinders are fitted directly to anesthetic machines and contain approximately 660 L of oxygen when full. In the United States, oxygen cylinders are usually colored green, and in Canada, green with white shoulders.

Fig. 2.2 (a) Pressure gauge showing an oxygen pipeline pressure of 59 psi at the point of connection to the anesthetic machine. (b) Pressure gauge showing an oxygen E cylinder pressure of 1900 psi, indicating a full cylinder (approximately 660 L). (c) Oxygen cylinders. Two J cylinders are in the background, with storage caps in place over valves. Notice color markings of green body with white shoulders. Both cylinders are secured to the wall with a strap and bracket. In the foreground are E cylinders stored in dollies. Notice the inconsistent color markings of the E cylinders: steel cylinders have green body with white shoulders, aluminum cylinder has silver body with white shoulders. Cylinder contents should be confirmed by reading the label (visible on E cylinders).

• To calculate the volume of oxygen remaining in an E cylinder: 0.34 × cylinder pressure (psig); for example, for a half-full c...

Table of contents

• Cover
• Half Title
• Series Page
• Title Page
• Copyright Page
• Dedication
• Table of Contents
• preface
• acknowledgments
• editors
• contributors
• 1 terms and definitions
• 2 understanding anesthetic-related equipment
• 3 anesthetic pharmacology and research-related anesthetic considerations
• 4 management of anesthesia
• 5 anesthesia monitoring
• 6 special techniques and species
• 7 pain management
• 8 euthanasia
• 9 regulatory management of rodent anesthesia
• index