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210 Cards in this Set
- Front
- Back
Which muscle relaxant is excreted the most renally?
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Pancuronium
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What is the hallmark of propofol infusion syndrome? |
Metabolic acidosis + Cardiac dysfunction + rhabdomyolysis + other stuff |
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How is atracurium metabolized and excreted?
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Hoffman degradation and ester hydrolysis by nonspecific esterases
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How is vecuronium metabolized? (% urine, liber, bile)
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15% urine, 25% liver, 60% bile
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How is rocuronium metabolized? (% urine, liber, bile)
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10% urine, 20% liver, 70% bile
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Endocrine side effect of etomidate?
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Blocks 11-beta-hydroxylase activity (adrenal suppression)
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What receptors does labetalol block?
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beta-1, beta-2, and alpha-1
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How does ondansetron work?
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5-HT3 receptor antagonist
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At what receptors does metoclopramide work? (3)
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D2 antagonist, 5HT-4 AGonist, weak 5HT-3 blocker
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How does droperidol work?
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D2 antagonist
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Myasthenia gravis: how does it affect SCh?
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More resistant
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Why are patient's with myasthenia gravis more resistant to SCh?
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SCh needs to activate an absolute number of receptors to work; less receptors available in MG
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Myasthenia gravis: how does it affect ND-NMBA? |
Need less ND-NMBA |
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Why are patient's with myasthenia gravis more sensitive to ND-NMBA? |
Fewer receptors needed to be blocked by the ND-NMBA's to achieve good blockade |
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What is myasthenic syndrome?
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Lambert-Eaton Syndrome: antibodies against pre-synaptic Ca channels
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How does Huntington's chorea affect sensitivty to SCh?
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More sensitive
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Why are patient's with Huntington's chorea more sensitive to SCh?
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Decreased pseudocholinesterases
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SCh sensitivity in myasthenic syndrome (LES)?
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Increased sensitivity (easier to block NMJ acitivity with less presynaptic calcium channels)
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What else (other than muscle weakness) should you watch out for in myasthenic syndrome?
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Autonomic dysfunction (orthostatic hypotension) and gastroparesis
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ND-NMBA sensitivity in myasthenic syndrome (LES)?
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Increased sensitivity (easier to block NMJ acitivity with less presynaptic calcium channels)
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Which anesthestic's sedation mimics sleep?
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Dexmedetomidine
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Which drug is water-soluble in its bottle, but lipid soluble in blood?
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Midazolam
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Max dose of epinephrine for local injection?
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5 mcg/kg
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What is the concentration of 1:100,000 epinephrine?
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1 gram per 100,000 mL = 1,000,000 mcg / 100,000 mL = 10 mcg/mL
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What is the concentration of 1:200,000 epinephrine?
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1 gram per 200,000 mL = 1,000,000 mcg / 200,000 mL = 5 mcg/mL
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Why should you avoid beta-blockers in asthma?
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Can precipitate bronchoconstriction (beta-2 agonist = albuterol)
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How do anticholinergics affect LES tone?
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Decreased (more relaxation = more vomiting risk)
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How do inhalational agents affect LES tone?
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Decreased (more relaxation = more vomiting risk)
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How does propofol affect LES tone (at normal doses)?
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No effect
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How do opioids affect LES tone?
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Decreased (more relaxation = more vomiting risk) except with propofol
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How do NMBA's affect LES tone?
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Increase!
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Which anticholinesterase can cross the BBB?
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Physostigmine (tertiary compound, unlike other quartenary compounds)
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Which IV anesthestic blocks NMDA activity? |
Ketamine |
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Which opioid agonist has anticholinergic properties as well?
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Meperidine
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How does ketamine affect ICP? Why?
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Increased ICP; potent cerebral vasodilator
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Ketamine stereoisomers? Which is more potent?
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Sold as a racemic mixture; S-enantiomer is more potent
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How does ketamine affect respiration?
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No effect
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Ketamine metabolite potency?
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Norketamine; 20% potency
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What are the indirect sympathetomimetic drugs? (4)
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Ephedrine, amphetamines, mephentermine, metaraminol
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Which sympathetomimetic drug is a beta-1 AND beta-2 agonist?
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isoproterenol
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Which sympathetomimetic drug is a beta-1 agonist only?
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dobutamine
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Which sympathetomimetic drug is an alpha-1 agonist only? (2)
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phenylephrine (and methoxamine)
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What receptors does epinephrine act on?
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beta-1 and beta-2 > alpha
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What receptors does norepinephrine act on?
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alpha > beta-1; NO beta-2
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What is the difference in receptor activity between epi and norepi?
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Alpha: norepi > epi; Beta-1: similar; Beta-2: epi only (no norepi activity)
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Why does methylnaltrexone only work peripherally?
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Cannot cross BBB due to it's structure
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How do -navir drugs affect anesthetics?
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Block CYP3A4 > decreased midazolam metabolism (increased sensitivity to midazolam)
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What receptor does Substance P act on? |
Neurokinin-1 (NK1) receptor |
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What are the effects of neurokinin-1 antagonists (apepitant)?
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Anxiolysis, antidepressant, antiemetic, but NO analgesia (weird because Substance P assoc. w/ pain)
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Patient is being treated for MG: how does this affect SCh activity?
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MG treatment = anticholinesterase > blocks pseudocholinesterase > prolonged SCh activity
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1 twitch (TOF) = ? % height reduction of single twitch?
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90
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Which NMBA's cause histamine release?
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SCh and atracurium
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Which NMBA's stimulate autonomic ganglia and cardiac mACh receptors?
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SCh (because it is similar to ACh)
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How does rocuronium affect cardiovascular function?
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Weakly blocks cardiac mACh receptors
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Which NMBA's block mACh receptors on the heart?
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rocuronium (weakly) and pancuronium (moderately)
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What are the two pathways for norepinephrine metabolism?
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MAOI (intracellular) and COMT (liver)
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How is the action of norepinephrine terminated, by what %? (two pathways)
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80% repuptake (some MAOI degradation) and 20% circulation (COMT degradation in liver)
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What should you give with ketamine to decrease emergence delirium?
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Midazolam 5 mins before induction
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How does metoclopramide affect LES?
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Increases LES tone, stimulates motility (overall, less vomiting potential)
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How much does SCh increase [K] by?
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0.5 mEq/L
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How does calcium affect ND-NMBA activity?
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Decreases it (more Ca to cause NMJ activity)
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How do aminoglycosides affect ND-NMBA activity?
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Enhance
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How do local anesthestics affect ND-NMBA acitivity?
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Enhance
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How do volatile anesthestics affect ND-NMBA activity?
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Enhance
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How does magnesium affect ND-NMBA activity?
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Enhance
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What two main anesthesia drugs can interact with MAOI's?
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Ephedrine and meperidine
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SCh and MS?
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Avoid; MS can cause muscle weakness and hyperkalemia with SCh
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SCh and Guillan-Barre?
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Avoid; GBS causes paralysis and SCh can cause hyperkalemia
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SCh and MG: how is potassium release affected?
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More SCh is needed in SCh, K release remains the same as normal
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Which antibiotics do NOT affect NMBA?
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erythromycin (macrolide), cephalosporins, tetracyclines, penicillins
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Which antibiotics potentiate NMBA?
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aminoglycosides, clindamycin, and fluoroquinolones
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How does neomycin help in hepatic encephalopathy?
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Kills ammonia-producing gut bacteria
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How does flumazenil help in hepatic encephalopathy?
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GABA receptors are activated in HE, flumazenil blocks them
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Normal duration of SCh block? (mins)
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5-10
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Normal dibucaine number? (%)
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80
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Incidence of heterozygous atypical pseudocholinesterase?
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1/500
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Heterozygous atypical pseudocholinesterase: dibucaine number? (%)
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60
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Heterozygous atypical pseudocholinesterase: block duration? (mins)
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20
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Homozygous atypical pseudocholinesterase: dibucaine number? (%)
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30
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Homozygous atypical pseudocholinesterase: block duration? (mins)
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>60
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Homozygous atypical pseudocholinesterase: incidence?
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1/3200
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What isotype of pseudocholinesterase causes SHORTER SCh duration?
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C5
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Days to peak effect of SCh hyperkalemia in burns, trauma, stroke, etc.?
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10-50
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Duration of effect (months) of SCh hyperkalemia in burns, trauma, stroke, etc.?
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6 months
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Main side-effect of flumazenil?
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Nausea/vomiting
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What is the pharmacodynamic limitation of ketorolac?
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Dose-ceiling effect with regard to analgesia (>10mg)
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Ketorolac is contraindicated with what medications? |
probenecid (decreased ketorolac clearance), and pentoxifylline (PDE inhibitor, used for claudication) |
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Do not give what induction agents with AIP?
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Barbituates and etomidate
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Do not give what pain meds with AIP?
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Ketorolac and pentazocine (partial KOP agonist, complete MOP antagonist)
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Why is codeine less effective with SSRIs? (what specific enzymes)
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SSRI inhibits CYP2D6 activity, which normally converts inactive codeine to active morphine
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What are oxycodone and hydrocodone converted to in the body?
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Oxymorphone and hydromorphone (Dilaudid)
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Intra-arterial injection of etomidate: what should you do?
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Observe; no adverse intra-arterial effects
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Why does fentanyl have faster onset than morphine?
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Higher lipid solubility
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Which opioid reaches steady state fastest after infusion is started?
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Remifentail (1hr)
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Patient received bleomycin in the past: anesthestic considerations?
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Keep FiO2 at lowest possible because of lifelong risk of testicular cancer w/ bleomycin, esp w/ high FiO2
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Advantage of rocuronium over other ND-NMBAs?
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Rapid onset: 1.5-3 minutes (vs 3-7 mins)
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Onset of rocuronium after RSI dose?
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1-1.5 minutes
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How does acute hyperkalemia affect SCh?
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Hyperkalemia > hyperpolarization > Harder for SCh to depolarize > resistance
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How does acute hyperkalemia affect ND-NMBA?
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Hyperkalemia > hyperpolarization > Harder for muscle to depolarize > more sensitive to ND-NMBA
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What surgeries have increased risk of recall?
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cardiac, endoscopic airway, C-section and trauma
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At what % of receptor blockade can reversal be achieved?
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<50%
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What are the two tests to check is muscle strength is back?
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100Hz tetanus and 5-second head lift
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Which dopamine blocker can treat WPW?
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Droperidol
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Why is verapamil dangerous in WPW?
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Blocks nodal conduction > more accessory pathway conduction
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Treatment of HD stable WPW?
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vagal, IV adenosine, Class 1 or 2 antiarrhythmics; avoid nodal blockers
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Half-life of pseudocholinesterase?
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12 hours
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How much decrease in pseudocholinesterase (e.g. liver failure) to prolong SCh? (%)
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75
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Potency of steroids? (hydrocortisone, prednisone, methylpred, beta, dexa)?
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Hydro: 1, pred: 4, methylpred: 5, dex/beta: 25
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What is recovery index?
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Time to spontaneous recovery of twitch height from 25% to 75%
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Which NMBA's recovery index is not affected by age?
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Atracurium and cistracurium (because metabolism only dependent on pH and temp)
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SCh has what effect on HR? Why?
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Stimulates nicotinic receptors of NONDOMINANT autonomic system (PNS dominant in adults)
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SCh has what effect on HR in children after first dose? Why?
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Bradycardia; Kids = SNS dominant, so SCh stimulates non-dominant (PNS) leading to bradycardia
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SCh has what effect on HR in adults after first dose? Why?
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Tachycardia; Adults = PNS dominant, so SCh stimulates non-dominant (SNS) leading to tachycardia
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SCh has what effect on HR after 2nd dose? Why? |
Bradycardia! Usually, 2nd dose after DL, SCh stimulates cardiac muscarinic receptors |
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SCh induced bradycardia in children: mechanism? (2) |
Stimulation of nodal mACh-R by SCh and stimulation on nACh-R of nondominant PNS |
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Which anesthesia drugs are metabolized by non-specific esterases? (3)
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Esmolol (RBC esterase), Remifentanil, and Atracurium (cistra = Hoffman ONLY)
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SCh is contraindicated in children: why?
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Undiagnosed myopathies/dystrophies can lead to fatal hyperkalemia
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NMBA's of different duration are given in serial: the block will behave like which? (1st/2nd)
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Duration will be closer to whatever the first drug is because it occupies most of the receptor sites
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How can you decrease emergence delirium with sevo?
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Pretreat with fentanyl, ketamine, nalbuphine, clonidine, Precedex
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What is the side effect of etomidate that patient's complain about the most?
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PONV
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Pancuronium: cardiovascular side effects? Mechanism?
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increase CO, BP, HR. 1. vagolytic 2. norepi reuptake inhibitor 3. norepi release
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Side effect of IV dantrolene for MH?
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Muscle weakness (most common), nausea, diarrhea, blurry vision
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Side effects of oral dantrolene for UMN lesions?
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Rarely, hepatitis and pleural effusions
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Metformin: why discontinue it 48 hours before surgery?
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Risk of acidosis ONLY in patients with poor renal or hepatic function
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How long does naltrexone (oral agent, sometimes used for alcoholism) last?
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24 hours
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Why is buprenorphine hard to reverse with naloxone?
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Extremely high affinity for MOP (33x morphine) even though it's a partial agonist; relatively resistant to naloxone
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Anesthetic with highest incidence of PONV?
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Etomidate (vs. Propofol, midazolam might be protective)
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Which vasodilator only acts on pulmonary arteries?
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Nitric oxide
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Which vessels does nitroglycerin IV primarily dilate?
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Veins > arteries
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Which vessels does nitroprusside primarily dilate?
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All vessels (veins, systemic arteries, pulmonary arteries)
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Which vasodilators only act on systemic arteries? (2)
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Hydralazine and nicardipine
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What vessels does PGE1 dilate? |
pulmonary arterial and systemic arterial >> veins |
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Which vasodilators are the best venodilators? (2)
|
Nitroglycerin and nitroprusside
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Which vasodilators act on pulmonary arteries?
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Nitric oxide, nitroprusside, and PGE1
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Action at the NMJ is terminated by what mechanism?
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Diffusion away from NMJ (not metabolism or elimination)
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Dexmedetomidine: MOA? |
highly selective alpha-2 agonist (1:1,600 a1:a2) |
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Dexmedetomidine: onset and peak?
|
rapid <5 minutes onset, 15 minutes to peak
|
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Dexmedetomidine: cardiovascular effects?
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Decrease in HR (can be profound) and CO; BP initially rises (peripheral alpha stimulation), then levels off, then drops (15% in an hour)
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Why does BP initially rise then fall with dexmedetomidine? |
Initial rise due to peripheral alpha-2 stimulation, eventually (1 hr) BP falls due to central alpha-2 overriding |
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What is fospropofol?
|
Prodrug of propofol (no hyperlipidemia, burning, or infection risk!)
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Effects of pre-op H2-blockers on anesthetics?
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P450 inhibition = longer diazepam, lidocaine duration
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Anesthetics with least reported allergic reactions? (2) |
ketamine and benzodiazepines |
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Alfentanil: potency (compared to fentanyl)
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Lower (<25%)
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Alfentanil: duration (compared to fentanyl)
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Much shorter
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Alfentanil: onset (compared to fentanyl) |
Fastest opioid |
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Alfentanil: metabolism
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96% cleared by liver in 1h (no renal dependence)
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Hyperkalemia with SCh after burns: onset?
|
48h
|
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Hyperkalemia with SCh after burns: peak
|
7-10 days
|
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Clonidine dose for post-op shivering?
|
75 mcg IV
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Patient gets still chest after induction: cause and treatment?
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Cause = opioids; Treatment = NMBA
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Which induction agent causes the least respiratory depression?
|
Ketamine (2 mg/kg induction = 30-60s onset)
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NMS possible treatment agents? (2)
|
Dantrolene and dopamine agonists (bromocriptine, amantadine)
|
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How does cyanide toxicity work?
|
Binds Fe and inhibits cytochrome oxidase, inhibiting oxidative phosphorylation (cellular respiration)
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Why is there no cyanosis in CN toxicity?
|
Oxygen is not used up because CN blocks cytochrome oxidase from binding oxygen
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Treatment for CN toxicity?
|
Sodium thiosulfate (converts CN to thiocyanate); nitrites - generate metHb which binds CN
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How does cyclophosphamide treatment affect anesthetic drugs?
|
Can decrease plasma cholinesterase
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Lidocaine max dose for local anesthesia?
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5 mg/kg or 300 mg
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Lidocaine + epi max dose for local anesthesia?
|
7 mg/kg or 500 mg
|
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Sugammadex dosing: emergency?
|
16 mg/kg
|
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Sugammadex: normal dosing?
|
Deep (TOF = 0; PTC > 1) = 4 mg/kg; Moderate (TOF 2-4): 2 mg/kg
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Sugammadex: contraindications?
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Avoid in renal failure, not harmful but makes redosing NMBA tricky; kids < 18
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What drugs can sugammadex bind and interfere with? (2)
|
Progesterone (OCP) and Toremifene (SERM for cancer)
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How does chlorpromazine work?
|
D2 antagonist
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How does chlorpromazine affect NMBA?
|
No effect
|
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Milrinone: MOA?
|
PDE3 inhibitor > higher cAMP levels > positive inotrope + vasodilator
|
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Milrinone: interaction with beta-blockers?
|
None (both increase cAMP via separate pathyways)
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TCA: anesthetic considerations? mechanism?
|
TCA's decrease norepi reuptake: can exaggerate ephedrine's effects
|
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Ephedrine effect in TCA user?
|
More pronounced because of higher norepi levels
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MAC requirements in TCA users?
|
Higher MAC because of higher norepi and other neurotransmitters
|
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Tirofiban: MOA?
|
Blocks GpIIb/IIIa (platelet receptor) interaction with vWF and fibrinogen
|
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Clopidogrel: MOA?
|
Blocks ADP from binding P12Y2 receptor
|
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What does P12Y2 activation by ADP do?
|
Conformational change in GpIIb/IIIa to bind ADP/fibrogen
|
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What drugs inhibit GpIIb/IIIa?
|
abciximab, eptifibatide, tirofiban
|
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How do heparin, LMWH and fondaparinux work?
|
Potentiate antithrombin III activity which inactivate factor Xa
|
|
What anesthetics are metabolized by non-specific esterases?
|
Remifentanil, esmolol, atracurium
|
|
Which IV drugs burn with injection?
|
Etomidate, Propofol and benzos that aren't midazolam (lorazepam and diazepam)
|
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Irreversible alpha-blocker?
|
Phenoxybenzamine
|
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Which drugs should you avoid in cardiac tamponade?
|
Negative inotropes (e.g. beta-blockers)
|
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Why does dantrolene cause diuresis?
|
Formulated with mannitol
|
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IV anesthetic that Adrenal suppression
|
Etomidate
|
|
IV anesthetic that Thrombosis, phlebitis, specific antagonist available
|
Lorazepam
|
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IV anesthetic that Pain on injection, severe hypotension in elderly
|
Propofol
|
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IV anesthetic that Increases ICP
|
Ketamine
|
|
IV anesthetic can cause lactic acidosis with prolonged use |
Propofol |
|
Which opioid is most likely to cause opioid-induced hyperalgesia? |
Remifentanil |
|
Opioids that demonstrates ceiling effect with regard to respiratory depression
|
Mixed agonist-antagonist drugs, such as butorphanol, nalbuphine, and pentazocine
|
|
Mixed agonist-antagonist drugs - butorphanol, nalbuphine, and pentazocine: MOA
|
partial KOP agonist, complete MOP antagonist
|
|
Opioid that causes antagonism of NMDA receptors
|
Methadone
|
|
Opioid that is also a norepinephrine reuptake inhibitor (NRI)
|
Tramadol and Tapentadol
|
|
Tramadol: MOA - inhibits? (6)
|
NMDA-R, serotonin and norepi reuptake, 5-HT2C-R, nACh, M1 and M3 mACh-R
|
|
Tramadol: MOA - agonist? (2)
|
partial μ-opioid, TRPV1-receptor
|
|
Yohimbe: MOA?
|
alpha-2 antagonist
|
|
Phase I block: fade?
|
Nope
|
|
Which block stage has posttetanic facilitation
|
Nondepolarizing and Phase II block
|
|
Effect on MAC: Amphetamines?
|
Acute: increased MAC; chronic: decreased MAC
|
|
Effect on MAC: alpha-2 agonists (clonidine)
|
Decrease
|
|
Effect on MAC: hyperthyroidism
|
No effect
|
|
Effect on MAC: Alcohol
|
Acute: decrease MAC; chronic: increased MAC
|
|
Effect on MAC: Lidocaine
|
Decrease
|
|
Effect on MAC: lithium
|
Decrease (lower catecholamine levels)
|
|
Effect on MAC: opioids
|
Decrease
|
|
Effect on MAC: duration of anesthesia
|
No effect
|
|
Effect on MAC: gender
|
No effect
|
|
Effect on MAC: Pregnancy
|
Decrease (sedative effects of progesterone)
|
|
Effect on MAC: severe hypoxia
|
Decrease
|
|
Which anticholinergics can cause CNS effects?
|
Tertiary: scopolamine and atropine
|
|
Least effective anticholinergic for decreased oral secretions?
|
Atropine
|
|
Effect of anti-ACh on LES tone?
|
Decrease
|
|
Which anticholinergic doesn't cross the BBB?
|
Glycopyrrolate
|
|
Which anticholinergics can cause mydriasis and cycloplegia?
|
Scopolamine (careful with rubbing eyes after patch) > atropine
|