DVM Anesthesia and Surgical Principles 5 — Questions and Answers
Question 1: Which technique is preferred to prevent regurgitation and aspiration in brachycephalic dogs during anesthetic induction?
- Pre-oxygenation followed by rapid sequence induction and immediate intubation (Correct answer)
- Mask induction with isoflurane for 5 minutes before intubation
- Administration of metoclopramide 2 hours before induction only
- Prolonged sedation with acepromazine before induction
Correct answer: Pre-oxygenation followed by rapid sequence induction and immediate intubation
Rapid sequence induction with pre-oxygenation minimizes the time the airway is unprotected, reducing aspiration risk in brachycephalic dogs prone to regurgitation.
Question 2: In small animal surgery, the correct classification of a surgical wound in which the GI tract was entered electively without contamination is:
- Clean
- Clean-contaminated (Correct answer)
- Contaminated
- Dirty
Correct answer: Clean-contaminated
A clean-contaminated wound is one where a hollow viscus (GI, respiratory, urogenital) is entered under controlled conditions without significant spillage.
Question 3: A cat undergoing anesthesia has a SpO2 of 92% on room air pre-induction. This corresponds to an approximate PaO2 of:
- 80 mmHg
- 65 mmHg (Correct answer)
- 45 mmHg
- 100 mmHg
Correct answer: 65 mmHg
Based on the oxyhemoglobin dissociation curve, SpO2 of 92% corresponds to a PaO2 of approximately 65 mmHg, indicating mild hypoxemia.
Question 4: Which of the following is the mechanism by which succinylcholine causes neuromuscular blockade?
- Competitive antagonism of acetylcholine at the nicotinic receptor
- Persistent depolarization of the motor end plate, preventing repolarization (Correct answer)
- Inhibition of acetylcholinesterase at the neuromuscular junction
- Blockade of presynaptic voltage-gated calcium channels
Correct answer: Persistent depolarization of the motor end plate, preventing repolarization
Succinylcholine mimics acetylcholine but resists hydrolysis, causing sustained end-plate depolarization that renders the muscle unresponsive to further stimulation.
Question 5: Wound closure by second intention (healing by granulation) is most appropriate for which of the following scenarios in a dog?
- A clean laceration over the thorax less than 6 hours old
- A heavily contaminated degloving injury of the distal limb (Correct answer)
- An elective flank incision after splenectomy
- A fresh bite wound on the neck with moderate tissue loss
Correct answer: A heavily contaminated degloving injury of the distal limb
Heavily contaminated wounds with significant tissue loss are best managed by open wound care and second-intention healing to avoid sealing infection under a primary closure.
Question 6: A sheep undergoes anesthesia for 90 minutes in dorsal recumbency. At recovery, it is ataxic and reluctant to rise. The most likely complication is:
- Hypoglycemia from prolonged fasting
- Bloat and regurgitation during anesthesia (Correct answer)
- Post-anesthetic myopathy of the forelimbs from compression
- Laryngospasm during extubation
Correct answer: Bloat and regurgitation during anesthesia
Ruminants in dorsal recumbency rapidly accumulate gas in the rumen because eructation is impossible, leading to bloat that can impair ventilation and cardiovascular function.
Question 7: Which nerve block, performed at the infraorbital foramen, provides analgesia for maxillary dental procedures in dogs?
- Mental nerve block
- Infraorbital nerve block (Correct answer)
- Inferior alveolar nerve block
- Maxillary nerve block at the pterygomaxillary fissure
Correct answer: Infraorbital nerve block
Blocking the infraorbital nerve at the foramen desensitizes the ipsilateral upper premolars, canine, incisors, and adjacent soft tissues for maxillary dental procedures.
DVM Anesthesia and Surgical Principles 5
Which technique is preferred to prevent regurgitation and aspiration in brachycephalic dogs during anesthetic induction?