Free VTNE Veterinary Anesthesia Questions and Answers — Questions and Answers
Question 1: An anesthetized patient's end-tidal CO2 (ETCO2) begins to rise and the inspiratory CO2 is also noted to be above zero. Which of the following is the most likely cause?
- Hypothermia
- Exhausted soda lime (Correct answer)
- Decreased cardiac output
- Anesthetic overdose
Correct answer: Exhausted soda lime
Exhausted soda lime in a rebreathing circuit can no longer absorb expired carbon dioxide. This leads to rebreathing of CO2, causing a rise in both inspiratory and end-tidal CO2 levels (hypercapnia).
Question 2: Which of the following drugs is an alpha-2 adrenergic agonist that provides sedation, analgesia, and muscle relaxation but can also cause significant cardiovascular side effects such as bradycardia and initial hypertension?
- Atropine
- Propofol
- Dexmedetomidine (Correct answer)
- Ketamine
Correct answer: Dexmedetomidine
Dexmedetomidine is a potent alpha-2 adrenergic agonist commonly used in veterinary medicine. Its primary effects are sedation, analgesia, and muscle relaxation. However, it is known to cause profound cardiovascular effects, including an initial hypertension followed by a decrease in blood pressure, and a significant, centrally-mediated bradycardia.
Question 3: A 5-year-old healthy beagle is undergoing a routine dental cleaning under general anesthesia with isoflurane. The veterinary technician notes the patient's heart rate has dropped to 50 bpm. Which of the following drugs would be the most appropriate to administer to treat this bradycardia?
- Glycopyrrolate (Correct answer)
- Diazepam
- Hydromorphone
- Acepromazine
Correct answer: Glycopyrrolate
Glycopyrrolate is an anticholinergic drug used to treat or prevent bradycardia by blocking the effects of the parasympathetic nervous system on the heart. It has a slower onset but longer duration than atropine, making it suitable for this scenario. Diazepam is a benzodiazepine for sedation/anxiety, hydromorphone is an opioid for pain, and acepromazine is a tranquilizer that can cause vasodilation, none of which directly treat bradycardia.
Question 4: The Minimum Alveolar Concentration (MAC) of an inhalant anesthetic agent refers to the:
- concentration required to maintain a surgical plane of anesthesia in all patients.
- lowest concentration of anesthetic in the alveoli that prevents movement in 50% of patients in response to a noxious stimulus. (Correct answer)
- maximum safe concentration that can be delivered by the vaporizer.
- percentage of the anesthetic agent that is metabolized by the liver.
Correct answer: lowest concentration of anesthetic in the alveoli that prevents movement in 50% of patients in response to a noxious stimulus.
MAC is a standard measure of the potency of an inhalant anesthetic. A lower MAC indicates a more potent anesthetic, meaning less of the agent is required to achieve a given anesthetic depth. It is specifically defined as the concentration at which 50% of subjects do not respond to a painful (noxious) stimulus.
Question 5: During anesthesia, which of the following monitoring parameters provides the most direct and earliest indication of inadequate ventilation?
- Pulse oximetry
- Electrocardiogram (ECG)
- Blood pressure
- Capnography (Correct answer)
Correct answer: Capnography
Capnography measures the end-tidal CO2 (ETCO2), which directly reflects the adequacy of a patient's ventilation. An increasing ETCO2 is an early sign of hypoventilation. While pulse oximetry measures oxygenation, a patient can be hypoventilating and still maintain normal oxygen saturation, especially if on supplemental oxygen. ECG and blood pressure monitor cardiovascular status, not ventilation directly.
Question 6: A common and potentially life-threatening complication during the immediate post-anesthetic recovery period for dogs and cats is:
- Hyperglycemia
- Hypertension
- Hypothermia (Correct answer)
- Polyuria
Correct answer: Hypothermia
Hypothermia is one of the most common complications during anesthesia and recovery. Anesthetic drugs depress the thermoregulatory center in the brain, and patients lose body heat to the environment. Severe hypothermia can lead to prolonged recovery, cardiac arrhythmias, and impaired drug metabolism.
