ALAT Anesthesia and Analgesia in Laboratory Animals 5 — Questions and Answers
Question 1: Which of the following best describes 'balanced anesthesia' in laboratory animal medicine?
- Using only one drug at the highest safe dose
- Combining multiple agents to achieve analgesia, muscle relaxation, and unconsciousness (Correct answer)
- Alternating between injectable and inhalant agents during a procedure
- Administering anesthesia without monitoring
Correct answer: Combining multiple agents to achieve analgesia, muscle relaxation, and unconsciousness
Balanced anesthesia uses multiple drugs targeting different pathways to reduce individual drug doses and side effects.
Question 2: An IACUC protocol requires refinement of anesthetic procedures. Which of the following changes would be considered a refinement?
- Increasing the number of animals used
- Replacing injectable anesthesia with inhalant anesthesia for shorter procedures (Correct answer)
- Eliminating post-operative analgesics to reduce handling
- Using heavier sedation to avoid monitoring
Correct answer: Replacing injectable anesthesia with inhalant anesthesia for shorter procedures
Switching to inhalant anesthesia for short procedures allows rapid recovery and titration, improving animal welfare.
Question 3: Which drug is commonly used to reverse the sedative and cardiovascular effects of xylazine in laboratory animals?
- Naloxone
- Flumazenil
- Atipamezole (Correct answer)
- Neostigmine
Correct answer: Atipamezole
Atipamezole is a selective alpha-2 adrenoceptor antagonist that effectively reverses xylazine's effects.
Question 4: A guinea pig undergoing surgery under ketamine/xylazine anesthesia begins showing signs of a light anesthetic plane. Which of the following is the SAFEST supplemental agent to administer?
- An additional full dose of ketamine/xylazine
- Isoflurane via mask at 1–2% (Correct answer)
- IV propofol bolus
- IM pentobarbital
Correct answer: Isoflurane via mask at 1–2%
Supplementing injectable anesthesia with low-concentration isoflurane allows titrated depth control with rapid adjustment.
Question 5: Which of the following best describes the purpose of a pre-anesthetic fast in laboratory rabbits?
- To prevent aspiration pneumonia during anesthesia
- To reduce intestinal gas and improve respiration (Correct answer)
- To eliminate the risk of regurgitation
- To ensure the animal is calm before induction
Correct answer: To reduce intestinal gas and improve respiration
Rabbits cannot vomit, so fasting is done to reduce GI gas that can impair diaphragm movement and ventilation, not to prevent aspiration.
Question 6: Which route of analgesic administration is most appropriate for a mouse that is difficult to restrain for injections post-surgery?
- Intravenous injection
- Oral administration via drinking water or gel (Correct answer)
- Intramuscular injection every 4 hours
- Subcutaneous implant changed daily
Correct answer: Oral administration via drinking water or gel
Oral analgesics delivered in drinking water or gel formulations reduce handling stress and are practical for small rodents post-surgery.
Question 7: What is the primary reason that intraperitoneal (IP) injection is commonly used for anesthetic drug delivery in mice and rats?
- It provides the fastest onset of all routes
- It is easy to perform and allows administration of larger volumes (Correct answer)
- It bypasses first-pass hepatic metabolism
- It results in the most predictable drug concentrations
Correct answer: It is easy to perform and allows administration of larger volumes
IP injection is technically simple and accommodates larger drug volumes than IM or IV routes in small rodents.
ALAT Anesthesia and Analgesia in Laboratory Animals 5
Which of the following best describes 'balanced anesthesia' in laboratory animal medicine?