ALAT Anesthesia and Analgesia in Laboratory Animals 1 — Questions and Answers
Question 1: Which of the following is the most commonly used injectable anesthetic combination in laboratory rodents?
- Ketamine/xylazine (Correct answer)
- Propofol/midazolam
- Thiopental/atropine
- Fentanyl/droperidol
Correct answer: Ketamine/xylazine
Ketamine/xylazine is the most widely used injectable anesthetic combination in laboratory rodents due to its effectiveness, ease of administration, and availability of a partial reversal agent (atipamezole for xylazine).
Question 2: What is the primary purpose of a pre-anesthetic evaluation in laboratory animals?
- To determine the exact mg/kg dose required
- To assess health status and identify potential anesthetic risks (Correct answer)
- To select the appropriate recovery cage size
- To document the animal's weight for billing purposes
Correct answer: To assess health status and identify potential anesthetic risks
Pre-anesthetic evaluation assesses the animal's overall health status to identify conditions that may increase anesthetic risk and guide appropriate agent selection and dosing.
Question 3: Which monitoring parameter most directly reflects cardiovascular function during anesthesia?
- Rectal temperature
- Respiratory rate and tidal volume
- Heart rate and pulse quality (Correct answer)
- Mucous membrane color alone
Correct answer: Heart rate and pulse quality
Heart rate and pulse quality directly reflect cardiac output and peripheral perfusion, making them essential cardiovascular monitoring parameters during anesthesia.
Question 4: What is the appropriate first response if an anesthetized animal's respiratory rate drops significantly below normal?
- Increase the anesthetic concentration
- Administer a reversal agent if available and provide ventilatory support (Correct answer)
- Wait 10 minutes to determine if it self-corrects
- Immediately euthanize the animal per protocol
Correct answer: Administer a reversal agent if available and provide ventilatory support
A significantly decreased respiratory rate indicates excessive anesthetic depth or respiratory compromise requiring immediate ventilatory support and reversal agents if applicable.
Question 5: Which route of administration is most commonly used to induce inhalant anesthesia in small laboratory rodents?
- Intravenous injection via tail vein
- Subcutaneous injection
- Induction chamber followed by nose cone maintenance (Correct answer)
- Intramuscular injection into the hindlimb
Correct answer: Induction chamber followed by nose cone maintenance
Induction chambers allow safe delivery of inhalant anesthetics to small rodents who cannot easily be masked initially; a nose cone is then used for maintenance.
Question 6: What does the term 'balanced anesthesia' mean in laboratory animal medicine?
- Using equal volumes of two injectable anesthetic agents
- Maintaining equal anesthetic depth throughout all four limbs
- Using a combination of agents to achieve anesthesia while minimizing each drug's side effects (Correct answer)
- Balancing the anesthesia machine gas flow meter at zero
Correct answer: Using a combination of agents to achieve anesthesia while minimizing each drug's side effects
Balanced anesthesia uses multiple drugs at lower individual doses to achieve the desired anesthetic effect with fewer cumulative side effects than high doses of any single agent.
Question 7: Which reflex test is used to confirm adequate surgical anesthetic depth in a rodent?
- Corneal reflex
- Righting reflex
- Pedal withdrawal reflex (toe pinch) (Correct answer)
- Swallowing reflex
Correct answer: Pedal withdrawal reflex (toe pinch)
Loss of the pedal withdrawal reflex (absence of limb retraction upon firm toe pinch) confirms adequate surgical anesthetic depth in rodents.
ALAT Anesthesia and Analgesia in Laboratory Animals 1
Which of the following is the most commonly used injectable anesthetic combination in laboratory rodents?