What is the most convenient method of inducing anesthesia in small rodents?
Open-Drop or Nose Cone Method of Isoflurane Anesthesia in Mice and Rats Show PURPOSE: This procedure details how to use an isoflurane/propylene glycol mixture to anesthetize rodents. Isoflurane is an inhalant anesthetic designed for use with a precision vaporizer. This method should be reserved for instances where short duration anesthesia is desired or it is impractical to use a precision vaporizer. The open-drop method of isoflurane exposure can be used to anesthetize mice and rats for brief non-surgical procedures. To maintain anesthesia for 5-10 minutes duration, a simple nose cone can be constructed from a syringe with the plunger removed. Note that even when diluted, this method does not allow for more than crude control of the concentration of the anesthetic and therefore the potential for inadvertent overdose with this method is significantly greater than when a precision vaporizer is used. Mice and rats need to be watched very closely and observed during induction to avoid anesthetic overdose and death. APPLICATION: The open-drop and nose cone method of inducing isoflurane anesthesia is an alternative to the use of a precision vaporizer where short duration anesthesia is desired for minor procedures in rodents. Precision vaporizers provide a much safer and more reliable method of inducing isoflurane anesthesia. The open-drop and nose cone procedures are not acceptable for major surgical procedures or procedures requiring greater than 10 minutes of surgical anesthesia or where the use of a precision vaporizer is required to maintain an adequate and safe level of anesthesia. Important Safety Consideration: Because of risks to human health, the use of inhalant anesthetic is not recommended on open bench tops. The following procedures should only be performed in a certified ducted hood, biosafety cabinet or portable ductless hood equipped with a charcoal filter. The Department of Environmental Health and Safety should be consulted regarding appropriate scavenging methods to mitigate human exposure to excess anesthetic agent. PROCEDURES: Materials:
Optional Materials:
Any type of container with a secure lid may be used, provided it is constructed of non-porous material that is sanitizable and allows for constant visualization of the animal. Ensure that the animal does not contact the isoflurane-soaked pad, which can cause skin irritation and potential overdosing since isoflurane is also absorbed through skin. The container should be of sufficient size to comfortably accommodate the animal, but not so large as to require excessive anesthetic. ** Use of isoflurane without propylene glycol dilution is unacceptable, as the vapor pressure of isoflurane will lead to lethal accumulations of anesthetic in the vapor phase.** Open Drop Procedure (For brief procedures): Mice will remain deeply anesthetized for approximately 30 seconds and rats for one minute. This method can be used for retro-orbital blood sampling, tail biopsies and similar rapid procedures. To maintain longer anesthetic times, see Nose Cone Procedure.
Nose Cone Procedure This method can be used with the Open Drop Procedure above to maintain anesthesia for up to 10 minutes duration and is appropriate for minor surgical procedures, such as subcutaneous tumor implantation. Procedures lasting longer than 10 minutes should be performed using a precision vaporizer system.
Important Safety Consideration: Because of risks to human health, the use of inhalant anesthetics is not recommended on open bench tops. The above procedures should only be performed in a certified ducted hood, biosafety cabinet or portable ductless hood equipped with a charcoal filter. The Department of Environmental Health and Safety should be consulted regarding appropriate scavenging methods to mitigate human exposure to excess anesthetic agent. **As a reminder DLAR does not have ducted hoods or charcoal filtered hoods in any animal housing room. This method cannot be used in animal housing rooms. Investigators should contact DLAR for locations of appropriately ducted hoods where this can be safely performed in the vivarium procedure rooms.** Which method of anaesthesia is used for mice & rat?The open-drop method of isoflurane exposure can be used to anesthetize mice and rats for brief non-surgical procedures. To maintain anesthesia for 5-10 minutes duration, a simple nose cone can be constructed from a syringe with the plunger removed.
What is the best agent for induction of anaesthesia?Propofol, etomidate, and ketamine are the intravenous (IV) sedative-hypnotic agents commonly used to induce general anesthesia (table 1), while adjuvant agents (eg, opioids, lidocaine, midazolam, and volatile anesthetics) are often used to supplement the effects of the primary sedative-hypnotic induction agent (table 2 ...
What is the best way to administer anesthesia?Your anesthesiologist usually delivers the anesthesia medications through an intravenous line in your arm. Sometimes you may be given a gas that you breathe from a mask. Children may prefer to go to sleep with a mask. Once you're asleep, the anesthesiologist may insert a tube into your mouth and down your windpipe.
Which physical method of anaesthesia used in animals?Inhalation anesthesia is more common for the large laboratory animals such as dogs, cats, sheep, goats, and monkeys. However, it has gained an increased importance in small laboratory animals like rodents.
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