respiratory Flashcards
Caplan syndrome
RA and pneumoconioes with intrapulmonary nodules
Asbetosis
Affects lower lobes; ferruginous bodies (golden-brown fusiform rods resembling dumbbells) in alveolar sputum; “ivory white” calcified pleural plaques; high risk of lung cancer (bronchogenic carcinoma > mesothelioma)
berylliosis
Beryllium in aerospace and manufacturing industry; affects upper lobes; granulomatous on histolgy and thus, on occasion, responsive to steroids
Coal workers’ pneumoconiosis
Affects upper lobes; black lung disease 2/2 prolonged coal dust exposure; perilymphatic accumulation of coast dust-laden macrophages
Silicosis
Foundaries, sandblasting, mines; upper lobes; macrophages respond to silica and release fibrogenic factors, silica also disrupt phagolysosomes and impair macrophages which increase susceptibility to TB; birefringent silica particles surrounded by fibrous tissue and “eggshell” calcification of hilar lymph nodes; increase risk of bronchogenic carcinoma
Neonatal respiratory distress syndrome: diagnostic test, complications, treatment complications, treatment
Licithin:spingomyelin ratio <1.5 in amniotic fluid; persistently low O2 tension leads to risk of PDA; other complications include metabolic acidosis, necrotizing enterocolitis;therapeutic supplemental oxygen can result in retinopathy of prematurity, intraventricular hemorrhage, bronchopulmonary dysplasia; maternal steroids before birth, artificial surfactant for infant
Small cell carcinoma
Central; neoplasm of neuroendocrine Kulchitsky cells small dark blue cells; chromogranin A positive; amplification of myc oncogenes common; rx with chemo
Adenocarcinoma
Peripheral; most common lung cancer overall and most common among non-smokers; activiating mutations of KRAS, EGFR, ALK; associated with hypertrophic osteoarthropathy (and clubbing); histo: glandular pattern on histology, stains mucin positive;
Bronchioloalveolar subtype of adenocarcinoma
Grows along alveolar septa, apparent “thickening” of alveolar walls; CXR shows hazy infiltrates similar to pneumonia
Squamous cell carcinoma
Central: cavitation, cigarattes, hyperCalcemia 2/2 PTHrP; histo: keratin pearls and intracellular bridges
Large cell carcinoma
Peripheral; highly anaplastic undifferentiated tumor; poor prognosis; histo: pleomorphic giant cells, can secrete beta-hCG
Bronchial carcinoid tumor
Systems due to mass effective, occasionally carcinoid syndrome; histo: nests of neuroendocrine cells chromogranin A positive
TB drugs MOA: rifampin
inhibits bacterial DNA-dependent RNA polymerase, inhibiting transcription
Total airway resistance breakdown
UR tract (nasal passages, mouth, pharynx, larynx) account for half; in LR tract, first 10 out of 21 generations of bronchi contribute most with 2-5 being the highest; in contrast, airways <2 mm in diameters like bronchiolescontribute less to total airway frictional resistance
TB drugs MOA: isoniazid
inhibits mycolic acid (long branched-chain fatty acids in the outer peptidoglycan cell wall) and other mycobacterial virulence factors (sulfatides, wax D, cord factor)) synthesis
Lamellar bodies of type II pneumocytes function
Store and release pulmonary surfactant into fluid layer of the inner surface of alveloi and reduce surface tension; deficiency of this can lead to patchy alveolar atelectasis
Pathogenesis of centriacinar emphysema
Chronic, heavy smoking injures bronchioles, activates alveloar macrophages that attract PMN and macrophages to come and release proteases that degrade extracellular cellular matrix; the resultant protease-antiprotease imbalance leads to acinar wall destruction and irreversible airspace dilatation distal to the terminal bronchioles
Phrenic nerve referred pain MOA
Irritation of the mediastinal or diaphragmatic parietal pleura will cause sharp, inspirational pain in C3-C5 distribution (base of the neck and over shoulder)
Lung abscess 3 MOA
- oropharyngeal, with anaerobic oral flora, a.w. LOC, dysphagia; 2. complication of bacterial pneumonia, more common with immunosuppression, old age, chronic lung disease; 3. septicemia/infectious endocarditis, more common agents being Staph and Strep
Sarcoidosis pw
Erythema nodosum, arthrlagias, hilar LN, elevated serum ACE, liver involvement with scattered noncaseating granulomas
Mycobacterial resistance to isoniazid
Non-expression of the catalase-peroxidase enzyme or through genetic modification of the isoniazid binding site on the mycolic acid synthesis enzyme
TB med MOA: ethambutol
Inhibit synthesis of the mycobacterial cell wall; resistence develops when mycobacteria increases production of arabinosyl transferase
TB med MOA: streptomycin
Aminoglycoside antibiotic that inhbitis mycobacterial protein synthesis by disabling ribosomal 30S subunit and disrupt translation
TB med MOA: pyranizamide
Converted to active form by mycobacterial enzyme pyrazinamidase, and after lowers the environmental pH in susceptible strains