Pharm I Final Exam

Question 1

Oil:gas partition coefficients 🧐

Answer 1

When a high-volume primary gas (first gas) like nitrous oxide enhances the uptake of a concurrently administered secondary gas (second gas) like oxygen or volatile anesthetics. This occurs due to increased tracheal inflow and higher concentration of the second gas in a reduced lung volume from the first gas uptake

Question 2

Oil:gas partition coefficients 🧐

Answer 2

Indicates how an inhaled anesthetic distributes between oil and gas phases at equilibrium. Can estimate MAC using the formula: MAC = 150 / Oil:Gas Partition Coefficient. The constant 150 represents the average product of oil:gas solubility and MAC for various anesthetic

Question 3

Second-gas effect 🤔

Answer 3

When a high-volume primary gas (first gas) like nitrous oxide enhances the uptake of a concurrently administered secondary gas (second gas) like oxygen or volatile anesthetics. This occurs due to increased tracheal inflow and higher concentration of the second gas in a reduced lung volume from the first gas uptake

Question 4

Blood:gas partition coefficients 🤓

Answer 4

Reflects how an inhaled anesthetic distributes between blood and alveolar gas at equilibrium. A lower coefficient means less soluble in blood and faster equilibration of Pa and PA. Traditionally categorize anesthetics as soluble, intermediately soluble, or poorly soluble based on this value

Question 5

Tissue:blood partition coefficients 🧑🏻‍🔬

Answer 5

Determines uptake of anesthetic into tissues and equilibration time with Pa. Equilibration time estimated using time constants based on amount dissolved in tissue over tissue blood flow. Fat has high capacity but low flow, extending equilibration time.

Question 6

MAC 🥼

Answer 6

Minimum alveolar concentration, the concentration preventing movement in 50% of patients in response to a noxious stimulus. Standardized measure of potency. MAC-awake is about half of MAC

Question 7

Halothane 💊

Answer 7

Introduced in 1956, issues with enhancing arrhythmogenic effects of epinephrine.

Question 8

Desflurane and sevoflurane 🔬

Answer 8

Totally fluorinated ethers allowing rapid induction, precise control, and quick recovery regardless of duration. Popularity from market demands like ambulatory surgery rather than significant pharmacological improvements

Question 9

Fresh gas flow rates 💵

Answer 9

Lower rates can reduce costs of new inhaled anesthetics. Less soluble anesthetics like desflurane are ideal for low flows.

Question 10

Nitrous oxide 🎈

Answer 10

Characteristics include low potency, poor solubility, commonly used with opioids/volatiles, rapid achievement of alveolar/brain partial pressures.

Question 11

Halothane properties 🧪

Answer 11

Clear nonflammable liquid, sweet odor vapor. Intermediate solubility and potency. Stored in amber bottles with thymol

Question 12

Isoflurane properties 👩‍🔬

Answer 12

Clear nonflammable liquid, pungent ethereal odor. Intermediate solubility and potency. Extreme physical stability with no detectable deterioration over 5 years

Question 13

Desflurane composition 🧬

Answer 13

Fluorinated methyl ethyl ether. Differs from isoflurane by substituting fluorine for chlorine. Requires specialized heated/pressurized vaporizers due to high vapor pressure.

Question 14

CO poisoning detection 🚨

Answer 14

Pulse oximetry can’t differentiate COHb from O2Hb. Warning signs include erroneous gas analyzer readings and trifluoromethane causing false enflurane readings. CO-oximetry can directly measure COHb.

Question 15

Desflurane properties 🧪

Answer 15

Low blood:gas partition coefficient 0.42 and MAC 6.6%, allowing rapid achievement and offset of