DVM Anesthesia and Surgical Principles 3 — Questions and Answers
Question 1: Which reversal agent is used to antagonize the sedative and cardiovascular effects of medetomidine in dogs?
- Flumazenil
- Naloxone
- Atipamezole (Correct answer)
- Neostigmine
Correct answer: Atipamezole
Atipamezole is a selective alpha-2 adrenergic antagonist used to reverse medetomidine and dexmedetomidine sedation and bradycardia.
Question 2: During equine anesthesia, post-anesthetic myopathy most commonly affects muscles that are:
- Actively contracting during surgery
- In the non-dependent position
- Compressed and hypoperfused in the dependent position (Correct answer)
- Denervated by regional blocks
Correct answer: Compressed and hypoperfused in the dependent position
Post-anesthetic myopathy results from ischemia in dependent muscles subjected to prolonged compression and hypoperfusion during recumbency.
Question 3: Which of the following is the correct surgical approach for ovariohysterectomy in a cat performed by the 'hook' technique?
- Flank approach through the external abdominal oblique
- Ventral midline through the linea alba (Correct answer)
- Paramedian approach lateral to the linea alba
- Inguinal approach through the inguinal ring
Correct answer: Ventral midline through the linea alba
The standard feline OHE uses a ventral midline incision through the linea alba, allowing access to both ovaries and the uterine body.
Question 4: Neostigmine is used to reverse neuromuscular blockade. Its mechanism involves:
- Direct stimulation of nicotinic receptors
- Competitive antagonism of non-depolarizing agents
- Inhibition of acetylcholinesterase, increasing synaptic acetylcholine (Correct answer)
- Blocking depolarizing agents at the neuromuscular junction
Correct answer: Inhibition of acetylcholinesterase, increasing synaptic acetylcholine
Neostigmine inhibits acetylcholinesterase, allowing acetylcholine to accumulate and competitively overcome non-depolarizing neuromuscular blocking agents.
Question 5: A 10-kg dog undergoing anesthesia has an ETCO2 of 55 mmHg. The appropriate intervention is:
- Increase inspired oxygen concentration
- Administer sodium bicarbonate IV
- Increase respiratory rate or tidal volume (Correct answer)
- Administer doxapram
Correct answer: Increase respiratory rate or tidal volume
Elevated ETCO2 (hypercapnia) indicates hypoventilation; increasing minute ventilation by raising rate or tidal volume will lower CO2 elimination.
Question 6: Which suture pattern provides the greatest tensile strength for closure of a contaminated abdominal wound in a dog?
- Simple continuous
- Ford interlocking
- Interrupted cruciate (far-near-near-far)
- Simple interrupted (Correct answer)
Correct answer: Simple interrupted
Simple interrupted sutures are preferred in contaminated wounds because failure of one suture does not compromise the entire closure.
Question 7: Perioperative hypothermia in small animals is most effectively prevented by:
- Increasing inhalant concentration
- Administering warm IV fluids and using forced-air warming blankets (Correct answer)
- Preoperative atropine to increase metabolic rate
- Reducing anesthesia duration by 10%
Correct answer: Administering warm IV fluids and using forced-air warming blankets
Active external warming with forced-air blankets combined with warm IV fluids addresses both conductive and convective heat loss, the primary causes of perioperative hypothermia.
DVM Anesthesia and Surgical Principles 3
Which reversal agent is used to antagonize the sedative and cardiovascular effects of medetomidine in dogs?