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86 Cards in this Set
- Front
- Back
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How is hypoxic vasoconstriction adaptive? Maladaptive? |
Adaptive: if there is an area of low perfusion, it will induce hypoxia and thus receive less perfusion
Maladaptive: when it causes pulmonary hypertension |
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Effects of lung volumes on pulmonary vascular resistance |
Extraalveolar vessels: pulled open during inspiration (negative pressure)
Intraalveolar vessels: compressed during inspiration (compressed by inflated alveoli)
Overall: pulmonary vascular resistance increases at either extreme of lung volume |
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Distribution of lung ventilation and perfusion |
Ventilation: Gravity --> more weight at bottom of lung --> alveoli are smaller and thus more compliant --> more ventilation at lung bases.
Perfusion: due to simple gravity (and perhaps also ventilation differences), the base of the lung is more perfused than the apices.
Differences in perfusion are more pronounced than differences in ventilation, so the V/Q ratio is HIGHER at the lung apices, and thus PaO2 is higher in the lung apices.
Note that in the supine position, ventilation and perfusion is more equally distributed. |
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West lung zones |
Zone 1: higher than arterial perfusion; no perfusion
Zone 2: lower than arterial perfusion but higher than venous perfusion. Resistance to flow is determined by the difference between arterial and alveolar pressure.
Zone 3: alveolar pressure is lower than both arterial and venous pressure; resistance to flow is determined by the differences in arterial and venous pressure (this is akin to the normal systemic circulation).
Zone 4: only theoretical |
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Normal physiologic contributors to A-a gradient |
- Bronchial circulation - Coronary circulation (return through Thesbian veins) - Differences in regional distribution of ventilation and perfusion |
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Causes of hypoxia in obese patients |
Obesity-related hypoventilation (normal A-a gradient) |
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Can V/Q mismatch be compensated for with increases in minute ventilation? |
Yes, dead space; not shunt. |
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Normal range for V/Q ratio |
0.8 - 1.0 |
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Quantification of shunt |
1. Mixing equation: Qt = total flow CcO2 = end pulmonary capillary oxygen content CaO2 = arterial oxygen content CvO2 = mixed venous oxygen content
2. Shunt fraction: PBF / SBF = AO-MV / PV-PA MV = PO2 of mixed venous blood
3. Shunt study: see whether oxygenation improves upon administration of O2 (if not --> shunt)
4. Bubble test: 1-3 cycles: intracardiac shunt 3-8 cycles: intrapulmonary shunt |
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Etiologies of diffusion impairment |
1. Shorter transit time of blood through alveoli: - Extreme exercise - Exercise at high altitudes - Exercise with pulmonary fibrosis
2. Increased thickness of alveolar-capillary membrane - Interstitial lung disease - Sarcoidosis
3. Decrease in total area of diffusion - Pneumonectomy - Pulmonary vascular disease - Emphysema |
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Mucus production |
1. Submucosal goblet cells & glands 2. Alveolar fluid production (clara cells and type I pneumocytes) 3. Serum transudate |
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Mucus anti-microbial proteins |
1. Lactoferrin: recognize bacterial surface patterns (neutrophils) 2. Transferrin (like lactoferrin, produced by pneumocytes) 3. Lysozymes 4. Defensins: broad immune function; inactivated by inappropriate salt levels. Alpha-defensins: neutrophils 5. Opsonizers |
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Organization of mucociliary elevator |
Sol layer: bottom layer w/cilia Gel layer: viscous layer that traps particles. This is the layer that is transported up the "elevator." |
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Regulation of ions in the respiratory epithelium and consequences of dysregulation |
- Excessive surface respiratory fluid: epithelial sodium channel absorption is dominant; osmosis from lumen into cells
Dysregulation (COPD, cystic fibrosis, anatomical impairment, etc.) --> dehydration of the airway mucus --> mucus is more adherent to airways |
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Cilia struture |
2 central microtubules and nine pairs of peripheral microtubules - Dyenin arms proejct from each peripheral dublet - Nexin links connet adjacent peripheral microtubules - Radial spokes connect central to peripheral microtubules |
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Phases of cough |
1. Inspiratory: normal deep inspiration and passive lengthening o f expiratory muscles 2. Compressive phase: closure of glottus, contraction of expiratory muscles and diaphgram; isovolumetric and isometric contraction 3. Expiratory phase: glottis opens; expiratory flow at high rates occurs |
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Cellular innate immunity |
1. Alveolar macrophages (ingest particles, clear surfactant) 2. Dendritic cells: lung APCs that migrate to BALT & lymph nodes 3. Epithelial cells: cytokine signaling 4. Neutrophils: recruited to lung parenchyma (not normally there) to mediate: - Phagocytotic killing - Execute neutrophil extracellular trap (externalized proteinases that opsonize target)- Degranulation-related killing |
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Surfactant effect on pulmonary immunology |
Surfactant down-regulates immune cells |
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Name all the pulmonary immune deficiencies (9) |
1. Primary ciliary dyskinesia (Kartenger's syndrome - impaired mucociliary elevator) 2. Acquired squamous metaplasia of the respiratory epithelium (impaired mucociliary elevator) 3. Neuromuscular disease (impaired cough) 4. Cystic fibrosis 5. Pulmonary alveolar proteinosis (defect in alveolar macrophages) 6. Neutropenia 7. Chronic granulomatous disease (impaired phagocytic killing) 8. Defects in adaptive immunity (i.e. HIV) 9. Immunoglobin deficiencies |
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Primary ciliary dyskinesia (Kartangener syndrome): defect & clinical manifestations |
Defect: mutation in radial spokes/dyenin arms --> ciliary immotility
Clinical manifestations: - Embryonic abnormalities (situs inversus, polysplenia, asplenia) - Recurrent respiratory infections later in life - Bronchiectasis - Sperm dysmotility, infertility |
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How does aging impair the immune defenses of the lung? |
- Loss of central microtubule angle --> impaired coordination of ciliary motility - Immune cell deficiencies associated with pure aging |
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Name three factors that would impair cough |
1. Neuromuscular disorder affecting inspiratory muscle force (myasethenia gravis, quadrapelegia, etc.) 2. Neuromusuclar disorder affecting expiratory muscle force (high cervical lesion) 3. Abnormally viscous mucus (i.e. cystic firosis) --> ineffective cough |
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Cystic fibrosis pathology |
Mutation of CFTR protein --> chlorine channel deficiency --> sodium absorption predominants and respiratory epithelium is dehydrated.
Increased viscosity --> inability to clear mucus --> mucus accumulation in plaques and plugs
Increased mucus stasis --> suscpetibility to infection
Recurrent infection --> bronchiectasis, airway obstruction and recurrent sinusitis |
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What infections are typically seen in cystic fibrosis patients? |
S. aureus, Pseudomonas Burkholderia and aspergillosis |
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Signs & symptoms of cystic fibrosis |
1. At birth - Meconium ileus (diagnostic), SBO - Obstructive jaundice - Failure to thrive - Recurrent pneumonias
2. Children - Recurrent pulmonary infections - Pancreatic insufficiency
3. Adults - Chronic bronchitis - Pansinusitis - Hemoptysis |
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Cystic fibrosis treatment |
1. Topical and inhaled antibiotics 2. Aerosolized recombinant DNA for infection control 3. Promote mucus clearance: inhaled saline, etc. 4. Bronchodilators 5. Lung transplantation 6. Gene therapy |
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Defect in pulmonary alveolar proteinosis: defect, clinical presentation and treatment |
Defect: Autoantibodies to GM-CSF --> pulmonary macrophage defect --> accumulation of surfactant --> predisposition to atypical infections (i.e. nocardia)
Clinical presentation: dyspnea, hypoxia and recurrent infections
Treatment: whole lung lavage to remove surfactant |
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Chronic granulomatous disease: defect and clinical consequences |
Defect: mutation in NADPH oxidase --> imparied phagocytic killing
Clinical consequence: recurrent infection, bronchiectasis |
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IgA deficiency: pulmonary consequences |
Recurrent sinusitis and pulmonary infection
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Common variable immunodeficiency: pulmonary conseqeunces |
Recurrent sinopulmonary infections, bronchiectasis and autoimmune disease |
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What are rales? What are rhonchi? |
Rales: crackles
Rhonchi: coarse crackles (like blowing bubbles through milk) |
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Exhalatory vs. inhalatory wheezes |
Exhalatory: intrapulmonary obstruction (i.e. asthma)
Inhalatory: extrapulmonary obstruction (also called stridor) |
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A 12-year old female presents to the ER with an extensive history of asthma. SaO2 = 81%; no wheezes are heard on examination. |
When asthma is very severe, airflow is so limited that wheezing may stop; this is a bad prognostic sign! |
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Signs of consolidation and their significance |
Significance: there is material in the lung that is not air (edema, pneumonia, etc.) - Dullness on percussion - Bronchial breath sounds (consolidation allows for more transmission of intrapulmonary breath sounds to surface) - Whispered pectoriloquy: audible whispering heard through stethoscope - Egophany: E --> A changes over consolidation - Tactile fremitus |
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What does increased tactile fremitus indicate? Decreased tactile fremitus? |
Increased: consolidation Decreased: pleural effusion |
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Etiology of increased resonance to percussion |
Hyperinflation (obstructive disease) |
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Pathophysiology of clubbing |
Pathophysiology: Megakaryocyte escape from lungs
WIth arthropathy: lung cancer, mesothelioma
Without hypertrophic pulmonary osteoarthropathy: chronic pulmonary infections or edema |
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Acral cyanosis |
Not typically secondary to hypoxia |
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In which diseases do you see increased FEV1/FVC ratio? |
Interstitial pulmonary fibrosis: increased traction of airways --> normal or increased FEV1/FVC ratio. |
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Pathophysiology of interstitial pulmonary fibrosis |
1. FIbrosis --> decreased compliance --> increased work of breathing (dysnpea) 2. Decreased compliance --> lower lung volumes (restriction) 3. Thickening of alveolar-capillary membrane --> diffusion abnormalities 4. Pulmonary hypertension due to vessel compression, inflammation and fibrosis |
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Clinical, exam, imaging and laboratory findings of interstitial pulmonary fibrosis |
1. Clinical history: - Insidious onset - Dyspnea - Dry, chronic cough - Cessation of activities, hobbies, etc.
2. Physical exam findings: - Velcro crackles - Clubbing - Cor pulonale if pulmonary hypertension is present
3. Vitals - Hypoxemia - High or nomal PaCO2 due to compensatory hyperventilation and increased diffusion ability of CO2
4. CRX findings: - Can be normal - Diffuse reticulonodular infiltrates - Can exhibit honeycombing if disease progress is severe
5. More definitive diagnosis/establishment of etiology: high resolution CT, lung biopsy |
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Types of interstitial lung disease |
1. Idiopathic pulmonary fibrosis
2. Nonspecific interstitial pneumonitis
3. Pneumoconises (direct toxicity from inorganic insult) - Asbestosis - Silicosis - Coal Miner's Pneumoconisis
4. Pneumonitis: - Hypersensitivity: antigen reaction from organic insults - Radiation - Drug-induced - Collagen-vascular disease
5. Sarcoidosis
6. Other idiopathic interstitial pneumonias - Cryptogenic organizing pneumonia - Acute interstitial pneumonia - Desquamative interstitial pneumonia
7. Random - Langerhan's cell histiocytosis - Granulomatosis with polyangitis (Wegner's) |
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Nonspecific interstitial pneumonitis |
Uniform inflammation lacking fibroblastic foci; better prognosis than interstitial pulmonary fibrosis due to responsiveness to steroids |
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Silicosis: pathology and pathogenesis |
Pathology: silicotic nodules at lung apices and large, lymph nodes with "egg shell calcification"
Pathophysiology: macropahges "try" to phagocytose silica crystals and release mediators (TNF, IL-1, free radicals, etc.)
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Coal Worker’s Pneumoconiosis: pathology |
Coal macules w/centrilobular emphysematous pattern at lung apices |
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Asbesotsis: pathology and clinical presentaiton |
Pathology: asbestos/Ferruginous bodies (dumbbell-shaped macrophage with iron granules); pleural thickening/ and plaques. Primarily affects BASE of lungs.
Clinical presentation - Interstitial fibrosis and small airway disease - Pleural effusions - Malignancies: carcinoma, mesothelioma |
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Hypersensitivity pneumonitis: pathology and clinical presentation |
Pathology: poorly-formed granuolmas with ILD of the UPPER lobes
Clinical manifestations: Chronic: ILD symptoms |
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Radiation Pneumonitis |
Hallmark pattern: well-defined borders
Treatment: acute is responsive to steroids, chronic has a worse prognosis |
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Idiopathic pulmonary fibrosis: Definition and pathology |
Definition: "Diagnosis of exclusion" in interstitial pulmonary disease.
Pathology: usual interstitial pneumonitis - Heterogenous - Fibroblastic foci - Honecyombing of lung parenchyma - Cobblestone appearance of pleura
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Cyptogenic organizing pneumonia: pathology and clinical features |
Pathology: plugs of fibroblasts in alveolar spaces
Clinical features: - Ground glass appearance on CRX - Responsive to steroids |
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Acute interstitial pneumonia |
Hyaline membrane forming disease w/o risk factors of ARDS |
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Desquamative interstitial pneumonia: pathology and clinical features |
Pathology: diffuse interstitial fibrosis with "smoker's macrophages"
Clinical features: - History of smoking - Responsive to steroids |
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Sarcoidosis: clinical presentation, pathology and treatment |
Clinical presentation: - Involvement of virtually all organs - Skin granulomas and irregular pupils observable on physical exam - Hypercalcemia and elevated ACE on labs - CRX: bilateral hilar adenopathy
Pathology: well-formed granulomas
Treatment: corticosteroids |
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Smoking-releated interstitial lung diseases |
1. Langerhan's cell histiocytosis 2. Desquamative interstitial pneumonia |
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Langerhan's cell histiocytosis: pathology |
Star-shaped nodule with eosinophilic granules and "coffee bean" Langerhan's cells
Findings on electron microscopy as well. |
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Granulomatosis with polyangitis: pathology and clinical features |
Pathology: huge lung nodes grossly; granulomatous inflammation with sub-cicumferential destruction of vascular elastin.
Clinical features: - cANCA positive - Associated with upper airway deformities (saddle deformity of the nasal septum, etc.) - Responds to steroids |
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Alpha-1 antitrypsin deficiencies |
Abnormal folding of alpha-1 trypsin protein.
PIMM (wild-type) |
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Presentation of alpha-1 antitrypsin deficiency |
1. Panacinar emphysema, even in the asbence of tobacco smoking. 2. Liver disease |
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Pathogenesis of anti-1 antitrypsin deficiency |
Elastase production by neutrophils is neutralized by alpha-1-trypsin. Deficiency leads to an imbalance of elastase and antiproteinases --> destruction of the alveolar wall. |
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Pathogenesis of emphysema secondary to smoking |
1. Recruitment and activation of alveolar macrophage and neutrophils --> stimulation of elastase release --> alveolar destruction.
2. ROS release --> direct damage, inhibition of alpha-1-trypsin release
3. Release of inflammatory mediators (TNF-alpha, IL-1, etc.)
4. Thermal damage |
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What diseases increase elasticity? Decrease? What is the physiologic consequence of lung elasticity? |
Increase: pulmonary fibrosis
Decrease: emphysema
Physiologic consequence: elasticity allows for traction of the airways and decreases resistance to flow (emphysematous loss of elasticity --> decreased traction --> increased resistance to flow) |
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Compare and contrast the subtypes of emphysema |
Centrilobular: - Etiology: smoking - Macroscopic location: apices (less perfusion --> less alpha-1 trypsin)
Panacinar: - Etiology: alpha-1 antitrypsin deficiency - Microscopic location: acini (uniform) - Macroscopic location: bases (greater perfusion --> more leukocytes --> more elastase release without concomitant increase in alpha-1-trypsin release)
Bullous: - Etiology: Unknown (not exclusive to smokers) - Microscopic location: distal acini - Macroscopic location: subpleural and alogn lobar septa - Unique presentation and pathology: blebs and bulla (>1 cm) that can clinically result in pneumothorax when ruptured. |
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Presentation of obstrutive disease on CRX |
Hyperinflation --> - Increased lucency - Flattened diaphragm - Narrow cardiac sillhouette |
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Pathology of chronic bronchitis |
1. Squamous metaplasia 2. Thickening of basement membrnae 3. Hypertrophy of mucus glands |
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Pathophysiology of chronic bronchitis |
Large airways (trachea & bronchi) - Mucous gland hypertrophy and mucus hypersecretion - Airway inflammation due to inhaled substances and/or infections
Small airways: - Airway obstruction
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Quantification of chronic bronchitis |
Reid index (normal <0.4): measures submucosal : total mucosal ratio |
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COPD phenotypes |
"Pink puffer": - Chronic bronchitic phenotype - Gaunt/thin due to increased work of breathing - PaO2 and PaCO2 are normal - Tachypenic reaction to increased PaCO2
"Blue bloater" - Emphysematous phenotype - Hypoxemic - Blunted tachypenic response to increase PaCO2 due to desensitization of chemoreceptors - Obese, peripheral edema due to R heart failure; sleep apnea is a common comorbidity |
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COPD: historical elements and physical exam |
Historical elements - Dyspnea - Cough + sputum - Frequent respiratory infections
Physical exam: - Rhonchi and wheezing, which may change after ocough - Cyanosis - Prolonged expiration - Distant breath sounds - Cor pulmonale from pulmonary hypertension --> JVD, peripheral edema, etc. |
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Common comorbidities in COPD |
1. Cardiovascular events (ischemia, RV failure, etc.) 2. Nutritional abnormalities/catchexia 3. Sleep apnea 4. Peripheral muscle disease 5. Anxiety & depression |
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Most important principle in COPD treatment |
Manage exacerbations and maintain activity level and exercise tolerance: decreases morbidity/mortality and enhances QOL |
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Classification of asthma |
Type I hypersensitivity: - Atopic (allergic) - Occupational - Bronchopulmonary aspergillosis
2. Intrinsic, idiosyncratic - Aspirin - Viral infection - Exposure to cold -Stress/exercise - Infection |
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Asthma pathophysiology (sans immune cascade) |
1. Airway hyperresponsiveness 2. Goblet cell hyperplasia and mucus hypersecretion 3. Air trapping due to mucus plugs 4. Airway remodeling --> irreversible component to disease |
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Asthma pathophysiology: immune cascade |
1. Acute-phase response - IgE --> mast cell activation - Mast cell degranulation --> release of IL-4, IL-5 Il-13 and neruohumoral cytokines (histamine, leukotrienes and prostaglandins) --> bronchoconstriction, dilation of vascular compartments, leakage of fluid.
2. Late-phase response - IL-5 & I-13: Eosinophil recruitment --> Major basic protein --> bronchoconstriction - IL-4 --> More Th2 differentiation --> propagation of response - Il-4, IL-13 --> more IgE production --> propagation of response |
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Astham histology |
1. Edema 2. Eosinophil infiltration 3. Charcot-Leyden crystlas 4. Curschmann spirals 5. Remodeling (mucus hyperplasia, BM thickening, blood vessel proliferation and fibrosis) |
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Elias research |
1. IL-13 overexpression in transgenic mouse --> clear pathologic role in asthma
2. YKL-40 is a chitinase that mediates Th1 survival and sensitization; it is elevated in a subgroup of asthmatics, and is a good biomaker for both disease severity and fibrotic index in this group |
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Definition, etiology and pathology of bronchiectasis |
Airway dilation, scarring and inflammation.
Etiology: chronic infections (cystic fibrosis, chronic bronchitis, immune deficiencies, etc.)
Pathology: noted above (dilation, fibrosis and inflammation), often with squamous metaplasia |
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How much fluid is NORMALLY in the pleural space? |
10 cc |
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Serous fluid circulation |
Usually regulated by the parietal pleura 1. Absorbed from intercostal space 2. Drained by parietal pleural lymphatics through pleural stomata
Visceral pleura can absorb fluid from the interstitial space in the lung parenchyma. |
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Pleural vasculature |
Parietal pleura: intercostal arteries, systemic venous drainage Visceral pleura: bronchial arteries, pulmonary veinous drainage (shunt) |
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Pleural exudate vs. transudate vs. Empyema |
Transudate: water only (from increased hydrostatic or colloid pressures) Etiologies: - Colloid pressures: nephrotic syndrome, hypoalbuminemia - Hydrostatic pressures: fluid overload, CHF - Hepatic hydrothorax from abdominal ascites (r-sided pleural efusion)
Exudate: increased leakage of protein and fluid DEFINITION: Light's critera Pleural:serum ratio of total protein > 0.5, OR
Empyema: contains organism (note: just because organisms aren't found, doesn't mean an infectious process isn't at play) |
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Algorithm for management of pleural effusion |
1. Sample via ultrasound-guided thoracentesis UNLESS etiology of CHF is crystal-clear
2. Drain if effusion is complicated: - Loculated - Empyema
3. Sterile exudative effusions without diagnosis: biopsy/pleuroscopy (TB and malignancy may be missed in 20% of cases, even w/repeat thoracocentesis)
4. Refractory effusions to drainage: - Pleurodesis/sclerosis procedure - Surgical removal of pleura (messy/complicated) - Tunneled pleural catheter for periodic home drainage |
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Clinical history, physical exam and imaging findings with pleural effusion |
Clinical history: - Dyspnea - Fever (if infectious) - Pleural pain IF pleuritis is present (no pain with pure effusion)
Physical exam: - Dullness to percussion - Decreased tactile fremitus - Decreased heart/breath sounds - Pleural friction rub
CRX: - Meniscus - Layering in left decubitus position
Thoracic CT: loculated vs. free-flowing effusions |
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Besides effusions: name other pleural pathologies |
1. Supleural TB nidis causing pleuritis hypersensitivity reaction 2. S/p cardiac surgery: L-sided effusion; normal finding! 3. Dressler's syndrome: immune reaction 4. Neoplasms: obstructed lymphatics, direct tuor extension or tumor met from exudative fluid leak 5. Hemothorax (Hct > 50% of thoracocentesis yield) 6. Asbesotsis: pleural plaques and mesothelioma |
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Etiology of pneumothorax |
1. Parietal and visceral pleura: trauma/ iatrogenic 2. Visceral pleura: rupture secondary to infectious process/tumor/emphysema/ ventilation |
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Management of pneumothorax |
1. Observation (not for tension pneumothorax) 2. Simple aspiration 3. Placement of thoracostomy tube |
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Definition of tension pneumothorax |
Pneumothorax in which air in the pleural space is under a positive pressure from a one-way valve effect |
