ALAT Anesthesia and Analgesia in Laboratory Animals 4 — Questions and Answers
Question 1: Which of the following is the most reliable indicator of adequate anesthetic depth in a mouse?
- Loss of righting reflex
- Loss of pedal withdrawal reflex (Correct answer)
- Slow respiratory rate
- Absence of whisker movement
Correct answer: Loss of pedal withdrawal reflex
Loss of the pedal withdrawal reflex (toe pinch) indicates surgical anesthetic depth in mice.
Question 2: What is the primary advantage of using a syringe pump for continuous rate infusion (CRI) of analgesics in laboratory animals?
- It eliminates the need for monitoring
- It provides steady plasma drug concentrations (Correct answer)
- It reduces drug cost significantly
- It allows oral administration
Correct answer: It provides steady plasma drug concentrations
CRI via syringe pump maintains consistent plasma drug levels, avoiding peaks and troughs associated with bolus dosing.
Question 3: A rabbit under isoflurane anesthesia develops apnea. What is the FIRST action the technician should take?
- Administer atropine IV
- Reduce the isoflurane concentration (Correct answer)
- Begin manual positive-pressure ventilation
- Inject doxapram to stimulate breathing
Correct answer: Reduce the isoflurane concentration
Reducing isoflurane concentration addresses the likely cause (overdose) while maintaining anesthesia.
Question 4: Which opioid is most commonly used for post-operative analgesia in rodents due to its long duration of action?
- Fentanyl
- Morphine
- Buprenorphine (Correct answer)
- Tramadol
Correct answer: Buprenorphine
Buprenorphine provides 6–12 hours of analgesia in rodents, making it the most practical choice for post-operative pain management.
Question 5: Which anesthetic agent used in laboratory animals is classified as a Schedule III controlled substance in the United States?
- Ketamine (Correct answer)
- Xylazine
- Isoflurane
- Propofol
Correct answer: Ketamine
Ketamine is a DEA Schedule III controlled substance, requiring specific record-keeping and storage requirements.
Question 6: What physiological change is most commonly observed in laboratory animals during hypothermia induced by anesthesia?
- Increased heart rate
- Prolonged anesthetic recovery (Correct answer)
- Elevated blood pressure
- Increased oxygen consumption
Correct answer: Prolonged anesthetic recovery
Hypothermia slows drug metabolism, leading to prolonged recovery from anesthesia in laboratory animals.
Question 7: When using a non-rebreathing circuit for a rat weighing 350 g under isoflurane anesthesia, what is the minimum recommended fresh gas flow rate?
- 50 mL/min
- 200 mL/min
- 500 mL/min (Correct answer)
- 1000 mL/min
Correct answer: 500 mL/min
Non-rebreathing circuits require at least 500 mL/min (often 0.5–1 L/min) in small rodents to prevent CO2 rebreathing.
ALAT Anesthesia and Analgesia in Laboratory Animals 4
Which of the following is the most reliable indicator of adequate anesthetic depth in a mouse?