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Related Flashcards
Cards In This Set
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What causes low pulse ox but not hypoxemia?
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Carboxyhemoglobinemia, methemoglobinemia, sulfhemoglobinemia,
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What is methemoglobinemia? What is pulse ox in it? What causes it?
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Oxidation of Fe 2+ to Fe 3+; pulse ox is always 85% because ferric hgb does not bind O2 well and equally absorbs hi and low freq pulse ox readings, so get about 85%; note blood is darkdapsone (50% reported cases),
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How does a pulse oximeter work?
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Sends out two wavelengths (660 and 940 mm) and measures ratio of the absorption at those two wavelengths; uses empirical data of ratios to calculate oxygen saturation (oxidized hgb/ oxidized hgb + reduced hgb)
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What is prevalence of asthma? COPD?
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5%10%
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W hat are phases of asthma?
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Early phase (15-30 minutes after exposure to allergen or other irritant, lasts 2 hours
late phase 3-8 hours after initial insult, 24 hoursa |
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Name 3 causes of wheezing that are associated with eosinophilia?
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Eosinophilic pneumonia (fever, wt loss, wheezing, peripheral infiltratesABPA wheezing, fleeting infiltrates, sobChurg-Strauss
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What is immune response in asthma?
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Th2 helper cells activate IL4 -> IgE and IL-5
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How can you use outpatient peak flow?
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Baseline = best measurement during stable 2 week periodThen < 20% decline is mild, 20-50% is moderate, > 50 severe
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Define COPD severity
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All COPD FEV1/FVC < 70%mild: FEV1 > 80% predictedmod: FEV1 50-80% predicatedsevere FEV1 30-50%very severe: FEV1 < 30% or 30-50% with respiratory failure
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What is a + methacholine test?
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See above
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What are three indications for LTRA?
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Exercise-induced astham, aspirin-sensitive asthma, and viral asthma
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What is reactive airways dysfunction syndrome?
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Exposure to irritant once or chronically (chlorine, bleach, ammonia) which can lead to months or years of symptoms
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In patients with worsening or unreponsive chronic asthma, what empiric therapy should be tried?
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PPI for possiblity of GERD-induced symptoms
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What is indication for allergy referral?
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> minimal med management
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What can lead to false positive methacholine challenge?
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Smoking, COPD, rhinitis, URI
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