Mouse and Rat Anesthesia and Analgesia

Abstract

Anesthesia and analgesia play pivotal roles in ethically and humanely using animal models in research, especially concerning mice and rats. These rodent species, extensively utilized in scientific investigations due to their genetic resemblance to humans, serve as invaluable tools for studying diseases and testing treatments. Proper anesthesia and analgesia not only prioritize animal welfare but also heighten experimental validity by minimizing stress-induced physiological responses. Recent years have seen remarkable advancements in anesthesia for mice and rats. The focus has shifted away from the 'one size fits all' toward tailoring anesthesia protocols, considering factors like age, strain, and the nature of the experimental procedure. The use of inhalation agents such as isoflurane and sevoflurane is often preferred due to their rapid induction and recovery characteristics, allowing precise control over anesthesia depth. However, refinements in injectable anesthetic agents also provide researchers the flexibility to select suitable agents based on study requirements. Additionally, progress in analgesic techniques has led to effective pain management strategies for these rodents. Common analgesics such as nonsteroidal anti-inflammatory drugs (NSAIDs), opioids, and local anesthetics are administered to alleviate pain and discomfort. However, standard practice also involves continuous monitoring of animals' behavior and physiological parameters, ensuring timely adjustments in analgesic regimens for optimal pain relief without compromising experimental outcomes. By integrating tailored anesthesia and analgesia protocols into the experimental design, researchers uphold high animal welfare standards while obtaining reliable scientific data. This contributes significantly to advancing medical knowledge and therapeutic interventions with reproducible results. Published 2024. This article is a U.S. Government work and is in the public domain in the USA. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Injectable anesthesia for mouse and rat Basic Protocol 2: Inhalant anesthesia using isoflurane for mouse and rat Basic Protocol 3: Analgesia for mice and rats.

Keywords: analgesia; anesthesia; mouse; rat; surgery.

Fig1:

Isoflurane vaporizer (A) safely administers inhalant anesthesia for rodents, suitable for lab research or veterinary purposes, needs a supply of compressed oxygen to deliver isoflurane. The SomnoSuite^® (B), designed specifically for mice and rats, operates as a low-flow anesthesia delivery system. Unlike standard vaporizers, the SomnoSuite^® features a precise syringe pump and integrated digital vaporizer, utilizing either room air or compressed gas to administer anesthesia at low rates tailored to the animal’s size. Using less anesthesia benefits the animals during procedures and significantly lowers the risk of waste anesthesia gas exposure for lab personnel. Additionally, the SomnoFlo^® serves as a compact, standalone vaporizer. It also operates using either room air or compressed gas and connects the anesthetic bottle directly to the SomnoFlo^® without requiring a syringe pump (https://www.kentscientific.com/products/somnoflo).

Fig1:

Isoflurane vaporizer (A) safely administers inhalant anesthesia for rodents, suitable for lab research or veterinary purposes, needs a supply of compressed oxygen to deliver isoflurane. The SomnoSuite^® (B), designed specifically for mice and rats, operates as a low-flow anesthesia delivery system. Unlike standard vaporizers, the SomnoSuite^® features a precise syringe pump and integrated digital vaporizer, utilizing either room air or compressed gas to administer anesthesia at low rates tailored to the animal’s size. Using less anesthesia benefits the animals during procedures and significantly lowers the risk of waste anesthesia gas exposure for lab personnel. Additionally, the SomnoFlo^® serves as a compact, standalone vaporizer. It also operates using either room air or compressed gas and connects the anesthetic bottle directly to the SomnoFlo^® without requiring a syringe pump (https://www.kentscientific.com/products/somnoflo).

Fig2:

During the induction preparations, it’s crucial to prepare and test the rodent anesthetic workstation components: oxygen tank (A) or oxygen central supply (B), isoflurane vaporizer with O2 flow meter and isoflurane level indicator (C) in the vaporizer, induction chamber (see figure 3B), activated charcoal canister (D), heat support devices, and connections in the anesthetic circuit. Additionally, it is advisable to use an isoflurane bottle pouring adaptor (E) to minimize spills when filling the isoflurane.

Fig2:

During the induction preparations, it’s crucial to prepare and test the rodent anesthetic workstation components: oxygen tank (A) or oxygen central supply (B), isoflurane vaporizer with O2 flow meter and isoflurane level indicator (C) in the vaporizer, induction chamber (see figure 3B), activated charcoal canister (D), heat support devices, and connections in the anesthetic circuit. Additionally, it is advisable to use an isoflurane bottle pouring adaptor (E) to minimize spills when filling the isoflurane.

Fig2:

During the induction preparations, it’s crucial to prepare and test the rodent anesthetic workstation components: oxygen tank (A) or oxygen central supply (B), isoflurane vaporizer with O2 flow meter and isoflurane level indicator (C) in the vaporizer, induction chamber (see figure 3B), activated charcoal canister (D), heat support devices, and connections in the anesthetic circuit. Additionally, it is advisable to use an isoflurane bottle pouring adaptor (E) to minimize spills when filling the isoflurane.

Fig2:

During the induction preparations, it’s crucial to prepare and test the rodent anesthetic workstation components: oxygen tank (A) or oxygen central supply (B), isoflurane vaporizer with O2 flow meter and isoflurane level indicator (C) in the vaporizer, induction chamber (see figure 3B), activated charcoal canister (D), heat support devices, and connections in the anesthetic circuit. Additionally, it is advisable to use an isoflurane bottle pouring adaptor (E) to minimize spills when filling the isoflurane.

Fig2:

During the induction preparations, it’s crucial to prepare and test the rodent anesthetic workstation components: oxygen tank (A) or oxygen central supply (B), isoflurane vaporizer with O2 flow meter and isoflurane level indicator (C) in the vaporizer, induction chamber (see figure 3B), activated charcoal canister (D), heat support devices, and connections in the anesthetic circuit. Additionally, it is advisable to use an isoflurane bottle pouring adaptor (E) to minimize spills when filling the isoflurane.

Fig3:

Active scavenging systems for rodents (A) can be employed using a canister and an induction chamber (B). The induction chamber facilitates the intake of room air and waste gases into a waste gas collection system. Another commonly employed active scavenging technique for anesthesia in laboratory rodents is the snorkel apparatus which is place above, or to the side of, the induction chamber area (C).

Fig3:

Active scavenging systems for rodents (A) can be employed using a canister and an induction chamber (B). The induction chamber facilitates the intake of room air and waste gases into a waste gas collection system. Another commonly employed active scavenging technique for anesthesia in laboratory rodents is the snorkel apparatus which is place above, or to the side of, the induction chamber area (C).

Fig3:

Active scavenging systems for rodents (A) can be employed using a canister and an induction chamber (B). The induction chamber facilitates the intake of room air and waste gases into a waste gas collection system. Another commonly employed active scavenging technique for anesthesia in laboratory rodents is the snorkel apparatus which is place above, or to the side of, the induction chamber area (C).

Fig4:

The anatomical face mask (or nose cones) design enables the anesthesia masks (A) to accommodate mice and rats of various sizes, providing surgeons access to the rodents’ eyes and head while effectively sealing the nose and mouth. Additionally, commercially available coaxial masks offer an alternative design. The stereotaxic gas anesthesia mask (B) is affixed to the stereotaxic frame, equipped with two tubes linked to a fresh gas supply (O2 and Isoflurane) and a scavenging system. These masks are compatible with active scavenging systems.

Fig4:

The anatomical face mask (or nose cones) design enables the anesthesia masks (A) to accommodate mice and rats of various sizes, providing surgeons access to the rodents’ eyes and head while effectively sealing the nose and mouth. Additionally, commercially available coaxial masks offer an alternative design. The stereotaxic gas anesthesia mask (B) is affixed to the stereotaxic frame, equipped with two tubes linked to a fresh gas supply (O2 and Isoflurane) and a scavenging system. These masks are compatible with active scavenging systems.

Fig5:

The rodent stereotaxic anesthesia system (A) comprises key components, including an oxygen supply, isoflurane vaporizer, induction chamber, active scavenging system, heat support device, stereotaxic frame, stereotaxic face mask, injection control panel, and microscope. Meanwhile, the SomnoSuite^® anesthetic system (B) includes a digital vaporizer, induction chamber, face mask (or nosecone), and an activated charcoal canister, operating without an oxygen supply.

Fig5:

The rodent stereotaxic anesthesia system (A) comprises key components, including an oxygen supply, isoflurane vaporizer, induction chamber, active scavenging system, heat support device, stereotaxic frame, stereotaxic face mask, injection control panel, and microscope. Meanwhile, the SomnoSuite^® anesthetic system (B) includes a digital vaporizer, induction chamber, face mask (or nosecone), and an activated charcoal canister, operating without an oxygen supply.