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Pharm 1 - Inhalant Anesthetics

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dslemeraldcity's version from 2016-03-25 06:34

Basics

Question Answer
What drugs do you need to use in combination w/ inhalant anesthetics?None, they are complete anesthetics (relax mm, analgesia, anesthesia)
Where are inhalant anesthetics metabolized?In the LUNGS
How do inhalant anesthetics cause anesthesia?Disrupt the transfer of ions (disrupt conduction of nervous signals)
How safe are inhalant anesthetics?Low margin of safety, but machines allow us to control this well
Which inhalant anesthetics can cause a seizure?Enflurane, Sevoflurane (SEizurEN)
How would you describe the molecules of inhalant anesthetics?Small & lipid soluble
Would you use inhalant anesthetics w/ head trauma?NO, they ↑ IC pressure*
Which inhalant anesthetics can help treat seizures?Iso, Des, Sevo (Sevo can also cause...weird) (ISO DESpise SEizures)
Which drug most commonly causes malignant hyperthermia?Halothane
How (which) do inhalant anesthetics affect pigs?Halothane can cause malignant hyperthermia in pigs, avoid
What is the basic path of inhalant anesthetics?Lung → Blood → Brain → Blood → Lung
Concentration of _________ governs effects in brainArterial blood conc.
What is the route into the body? Out?Lungs for both
What is the partition coefficient?Ratio of the concentration of the agent in 2 phases at equilibrium. 2 kinds we use: blood:gas & oil:gas
What does the blood:gas partition coefficient determine?The RATE (speed) (think of speed of blood flowing)
What does the oil:gas partition coefficient determine?The POTENCY of the drug
Name the 7 drugs in order from slowest to fastest (putting animal to sleep? recover rate? same scale as B:G? so confused)Ether, Halothane, Enflurane, Isoflurane, Sevoflurane, Nitrous oxide, Desflurane
What drug is the best for heart & the worst for lungs?Desflurane (my heart is Desperate for you, but my lungs just can't breath)
Mnemonic to the order of drugs slowest to fastest?Every Halloween Everyone Is Scared N' Disguised
Which drugs are the heart-friendliest ones?Isoflurane & Desflurane (Iso des-parate for your heart)
If you have a ↑ blood:gas ratio, what does that mean for speed?SLOW.
If B:G ratio is ↑, what does it mean for solubility? Speed?↑ BG means ↑ solubility means ↓ speed (↑ solubility means it dissolve in the blood well, so it converts back into a gas slower)
If you have a ↓ blood:gas ratio, what does that mean for speed?Fast (↓ solubility means it doesn't dissolve in the blood well, so it converts back into a gas quicker)
If you have a ↑ oil:gas ratio, what does this mean for potency?↑ potency
If you have a ↓ oil:gas ratio, what does this mean for potency?↓ potency
If you have ↑ O:G, what does this mean for MAC? Potency?↑ O:G = ↓ MAC = ↑ potency
Ex: if the MAC of Desflurane is 6xs higher than Halothane, what does this mean for potency?Desflurane is less potent MAC- Minimal Alveolar Concentration
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Respiratory

Question Answer
How do inhalant anesthetics affect alveolar ventilation? What does this do to the partial pressure of CO2?They ↓ alveolar ventilation (which is a direct relation to the dose) which ↑ the partial pressure of CO2
What does a MAC of 1 mean?It means successful anesthesia in 50% pts
What do we use the MAC to measure?Effectiveness
What does an ↑ in concentration do to the MAC?↑ conc = ↑ mac (if you have to increase conc of the drug, then that means that the minimal alveolar conc of drug needs to be increased as well)
What does MAC stand for?Minimum alveolar concentration
What would you say the MAC tells you?Effective concentration where it's effective in 50% of the animals
What does ↑ MAC do to the compensating responses?↑ MAC = ↓ compensating responses
How do inhalant anesthetics affect the bronchi?Bronchodilation
Which inhalant anesthetic causes laryngeal spasm (making it hard to intubate)?Desflurane ("DESent" let you intubate) (Also remember Injectable Anesthetic Barbiturates cause this as well)
If you ↑ the mac, what happens to the breathing rate?↑ mac, ↓ of breathing (give more gas, breathe less)
Which inhalant anesthetic is the most resp. depressive (rate)Desflurane (("DESparate for air")?)
Which inhalant anesthetic causes the highest partial pressure of CO2? What is this related to?Desflurane, bc it causes the more resp. rate depression (aka ↓ alveolar ventilation)
What is the "minute volume"Amount of air inhaled & exhaled in a minute
↑ MAC does what to the minute volume?Decreases it....Desflurane is the most severe example of this
Which inhalant anesthetic causes the highest partial pressure of CO2? The 1 w/ the least affect?Most = Desflurane. Least = Isoflurane
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Cardiovascular

Question Answer
If you ↑ the inhalant anesthetic dose, what happens to the CO? Contractility? Stroke volume?They would all decrease?
How come there are such pronounced CV affects w/ inhalant anesthetics?They alter the Ca++ homeostasis
How do inhalant anesthetics affect the cerebral blood flow?↑ cerebral blood flow (↑ IC pressure--- no good for head trauma)
Where do inhalant anesthetics ↑ blood flow? Dec?↑ cerebrum, ↓ liver & kidney
What is automaticity of the myocardium? How do inhalant anesthetics affect it?Automaticity = body tries to compensate depressive effects of the inhalant anesthetics. However, although it is INCREASED! it cannot overwhelm the drug effects
Which inhalant anesthetic causes the steepest decrease in CO?Halothane (Hal was lazy, had bad output)
What do inhalant anesthetics do to blood pressure? Resistance?↓ BP & resistance
Which inhalant anesthetics can cause an ↑ in heart rate?Halothane & Desflurane (esp if the MAC is over 1.5) (my heart races, desparate for you, im in hal)
Which inhalant anesthetic causes a decrease in splanchnic blood flow?Halothane (I can think Halothane makes pigs hot to touch bc drew blood away from organs)
What is the decrease in blood pressure dependent on?Dose
Which drugs preserve CO?Isoflurane & Desflurane (Iso Desparately love your heart)
Which drug causes the steepest drop in blood pressure?Desflurane (Des Drop)
Which drug causes the most severe drop in CO?Halothane
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Liver & Kidney, Muscles

Question Answer
Which drug will cause hepatocellular injury? Why?Halothane, bc it has hepatotoxic metabolites
How do inhalant anesthetics affect hepatic circulation?Decreases it
How do inhalant anesthetics affect renal blood flow? GFR?↓ them
Do inhalant anesthetics provide muscle relaxation?Yes, some mm relax
Which drug most commonly causes malignant hyperthermia (a myopathy)? How does this happen?Halothane, loss of control of Ca++ = muscle rigidity = ↑ metabolism = heat
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