Inhalational Agents Study Guide UPDATED
ACTUAL Exam Questions and
CORRECT Answers
What factors affect the uptake of inhaled anesthetics? - CORRECT ANSWER - solubility,
cardiac output, arterial to venous partial pressure difference, and ventilation/perfusion mismatch
Uptake= [solubilityxCOx(PAxPV)]/barometric pressure
What physical characteristic of inhaled anesthetics predicts potency? - CORRECT
ANSWER - MAC. Potency=lipid solubility=OG P/C
What are the B/G partition coefficients, the vapor pressure, and lipid solubility's of the inhaled
anesthetics - CORRECT ANSWER - Isoflurane: 1.4, 240, 91
Sevoflurane: .65, 160, 47
Desflurane: .45, 669, 19
Nitrous Oxide: .47, 39,000, 1.4
What factors determine the speed of induction of inhalation anesthesia? - CORRECT
ANSWER - MAC, alveolar minute ventilation, high inspired concentration, low blood
solubility
also high gas flow, small circuit, less machine absorption
The brain partial pressure is equal to ___________. - CORRECT ANSWER - alveolar partial
pressure
What affects the brain's partial pressure of inhaled agents? - CORRECT ANSWER - Uptake,
ventilation, concentration, and second gas effect
, MAC mirrors brain partial pressure
Define Fi, FA, and FA/FI? - CORRECT ANSWER - Fi is the inspired gas concentration and is
affected by fresh gas flow rate, breathing system volume, and absorption of machine
FA is the alveolar concentration and is determined by uptake, ventilation, concentration, and
second gas effect
FA/Fi is the ratio of alveolar concentration to inspired concentration. Equilibrium value is 1
What is the blood:gas partition coefficient? - CORRECT ANSWER - A ratio of the
concentration of the anesthetic in the blood phase to the gas phase when equilibrium occurs
How does the solubility of an inhaled agent affect the rate of rise on the FA/FI curve? -
CORRECT ANSWER - The lower the solubility, the greater the rate of rise, the quicker to
equilibrium
Which factors affect the transfer of inhaled agents for the anesthesia machine to the brain? -
CORRECT ANSWER - Inspired partial pressure, alveolar ventilation, characteristics of
anesthetic breathing machine, blood-gas partition coefficient, cardiac output, alveolar to venous
partial pressure difference, brain-blood partition coefficient, cerebral blood flow, and arterial to
venous partial pressure difference
What are the 4 basic tissue groups that affect the uptake of anesthetic gases? Which group
achieves the most rapid equilibrium of anesthetic agents? - CORRECT ANSWER - Vessel-
rich
Muscle
Fat
Vessel-poor
Vessel-rich receives 75% of the CO (besides alveolar)
ACTUAL Exam Questions and
CORRECT Answers
What factors affect the uptake of inhaled anesthetics? - CORRECT ANSWER - solubility,
cardiac output, arterial to venous partial pressure difference, and ventilation/perfusion mismatch
Uptake= [solubilityxCOx(PAxPV)]/barometric pressure
What physical characteristic of inhaled anesthetics predicts potency? - CORRECT
ANSWER - MAC. Potency=lipid solubility=OG P/C
What are the B/G partition coefficients, the vapor pressure, and lipid solubility's of the inhaled
anesthetics - CORRECT ANSWER - Isoflurane: 1.4, 240, 91
Sevoflurane: .65, 160, 47
Desflurane: .45, 669, 19
Nitrous Oxide: .47, 39,000, 1.4
What factors determine the speed of induction of inhalation anesthesia? - CORRECT
ANSWER - MAC, alveolar minute ventilation, high inspired concentration, low blood
solubility
also high gas flow, small circuit, less machine absorption
The brain partial pressure is equal to ___________. - CORRECT ANSWER - alveolar partial
pressure
What affects the brain's partial pressure of inhaled agents? - CORRECT ANSWER - Uptake,
ventilation, concentration, and second gas effect
, MAC mirrors brain partial pressure
Define Fi, FA, and FA/FI? - CORRECT ANSWER - Fi is the inspired gas concentration and is
affected by fresh gas flow rate, breathing system volume, and absorption of machine
FA is the alveolar concentration and is determined by uptake, ventilation, concentration, and
second gas effect
FA/Fi is the ratio of alveolar concentration to inspired concentration. Equilibrium value is 1
What is the blood:gas partition coefficient? - CORRECT ANSWER - A ratio of the
concentration of the anesthetic in the blood phase to the gas phase when equilibrium occurs
How does the solubility of an inhaled agent affect the rate of rise on the FA/FI curve? -
CORRECT ANSWER - The lower the solubility, the greater the rate of rise, the quicker to
equilibrium
Which factors affect the transfer of inhaled agents for the anesthesia machine to the brain? -
CORRECT ANSWER - Inspired partial pressure, alveolar ventilation, characteristics of
anesthetic breathing machine, blood-gas partition coefficient, cardiac output, alveolar to venous
partial pressure difference, brain-blood partition coefficient, cerebral blood flow, and arterial to
venous partial pressure difference
What are the 4 basic tissue groups that affect the uptake of anesthetic gases? Which group
achieves the most rapid equilibrium of anesthetic agents? - CORRECT ANSWER - Vessel-
rich
Muscle
Fat
Vessel-poor
Vessel-rich receives 75% of the CO (besides alveolar)
