Informational Sheet: The IACUC has provided a set of guidance documents (Policies, Guidelines, and Informational Sheets) for use when planning animal procedures at the University of Iowa. Informational Sheets provide information about frequently asked questions and represents guidance for best practices. Deviation from the recommendation(s) does not require specific justification.
Purpose: The purpose of this document is to educate researchers on effective uses of local analgesics and anesthetics in rodents. When used properly local analgesics and anesthetics can reduce pain and distress in laboratory animals.
- Lidocaine HCl (without epinephrine) 2% (20 mg/ml) or
- Marcaine HCl (Bupivacaine) 0.5% (5 mg/ml)
- Hypodermic needles (25 or 27g, 1/2” or smaller)
- 1 cc syringes
- Sterile multi-use injection vials for dilutions
- Sterile, pyrogen-free water for injection
Formulary: Rats and Mice
|Lidocaine (2%)||Dilute to 0.5%, do not exceed 7mg/kg total dose; Incisional line block||Use Locally before making surgical incision||Faster onset than bupivicaine but short (<1hour) duration of action|
|Bupivicaine (0.5%)||Dilute to .25%, do not exceed 8mg/kg total dose; incisional line block||Use locally before making surgical incision||Slower onset than lidocaine but longer (~4-8 hour) duration of action|
* See dilution directions below
Dilute the 2% (20 mg/ml) Lidocaine 1:4 to get final concentration of 0.5% (5 mg/ml) (for example: take 1 cc of Lidocaine and add 3 cc of Sterile, pyrogen-free water to an amber, sterile, multi-use vial). Transfer solutions aseptically, carefully label vial with drug name, concentration and date of dilution. Discard diluted solutions in 30 days.
Dilute the 0.5% (5 mg/ml) Bupivacaine 1:2 to get final concentration of 0.25% (2.5 mg/kg) (for example: take 1 cc of Bupivacaine and add 1 cc of sterile, pyrogen-free water to an amber, sterile, multi-use vial). Transfer solutions aseptically, carefully label vial with drug name, concentration and date of dilution. Discard diluted solutions in 30 days.
1. Weigh animal(s) to be treated.
2. Determine maximum dose that can be used depending on weight of animal (see next page).
3. Inject local anesthetic into the subcutaneous space (“line block”) below the planned incision line prior to surgery (once the animal is anesthetized, fur clipped and the skin prepped for surgery).
Insert needle fully into the subcutaneous space below the planned incision. Gently pull back syringe plunger to make sure there is no blood in the hub of the needle (avoid intravenous injections).
Begin injecting small volumes of the local anesthetic as the needle is withdrawn.
Complete injection of the local anesthetic under the planned incision site. If incision site is longer, re-insert needle further along the planned incision and repeat with remaining calculated volume of local anesthetic.
|Weight of Mouse||
Maximum Volume Diluted Lidocaine (0.5%) Do not exceed:
|Maximum Volume Diluted Bupivicaine (0.25%) Do not exceed:|
|Weight of Rat||Maximum Volume Diluted Lidocaine (0.5%) Do not exceed:||Maximum Volume Diluted Bupivicaine (0.25%) Do not exceed:|
Local Anesthetics should be used pre-operatively (before the first incision) and can be used in conjunction with opioid analgesics and/or NSAIDs for controlling moderate to severe pain. Intramuscular and intravenous injection of local anesthetics must be avoided. Systemic toxicity (seizures, heart rhythm disturbances and death) results from overdosage or accidental intravenous injection.
Last Reviewed by Committee 2/10/15