Pathology - respiratory Flashcards
Bacterial rhinosinusitis superimposed on viral URI
S. pneumo
H. flu
Morazella catarrhalis
Keisselbach plexus vs. posterior segment of nostril
Benign vs. life-threatening hemorrhages (which come from sphenopalatine artery, a branch of the maxillary artery)
Origin of DVTs
proximal deep veins of lower extremitiy
dorsiflexion of foot = calf pain
use heparin for short term ppx and tx, then warfarin/rivaroxaban for long term tx
Pathophysiology of pulmonary emboli
V/Q mismatch –> hypoxemia –> respiratory alkalosis
Lines of Zahn - interdigitating lines of pink (platelets/fibrin) and red (RBCs) found only in thrombi formed BEFORE death (indicates a pre-mortem thrombus)
6 types of emboli in PE
Fat, Air, Thrombus, Bacteria, Amniotic fluid, Tumor (FATBAT)
fat - long bone injury
amniotic fluid - seen w/ DIC
air - ascending divers
PFTs in obstructive lung disease
decr. FEV1/FVC ratio***
decr. FEV1 (airways close prematurely at high lung volumes)
Hyperplasia of mucus-secreting glands in bronchi
Chronic bronchitis (b = blue bloater)
Reid index = thickness of bronchial wall, >50%
cough: 3 mos/yr, for >2 yrs
Enlargement of air spaces, decr. recoil, decr. diffusion capacity for CO, destruction of alveolar walls
Emphysema (p = pink puffer)
incr. elastase activity = loss of elastic fibers
exhalation through pursed lips = incr. airway pressure, prevent airway collapse
Two main aspects of asthma
Bronchial hyperresponsiveness –> bronchoconstriction
Smooth muscle hypertrophy
Look for mucus plugging, pulsus paradoxus, decr. I:E ratio
Chronic necrotizing infection of bronchi
Bronchiectasis
Permanently dilated airways, purulent sputum, recurrent infections, hemoptysis
PFTs in restrictive lung disease
normal FEV1/FVC ratio
decr. FVC
Etiologies of restrictive lung disease
- ) poor breathing mechanics (normal A-a gradient)
2. ) interstitial lung disease (decr. diffusion capacity, incr. A-a gradient)
Hypersensitvity pneumonitis
Type III/IV rxn
Cor pulmonale, Caplan syndrome (RA + intrapulmonary nodules)
signs of pneumoconioses
Supradiaphragmatic and pleural plaques
Asbestosis
incr. risk of cancer (bronchogenic carcinoma > mesothelioma)
absestos bodies = golden-brown rods that look like dumbbells, found in sputum
Macrophages laden with carbon, inflammation and fibrosis
Coal workers’ pneumoconiosis
Upper lobes affected
anthracosis - similar, but found in urban people with pollution
Mechanism of silicosis
Macrophages respond to silica and release fibrogenic factors, leading to fibrosis. Eggshell calcification of hilar lymph nodes
Affects upper lung lobes
Silica may disrupt phagolysosomes and impair macrophages, incr. susceptibility to TB! also, incr. risk of bronchogenic carcinoma
Therapeutic O2 in neonatal RDS complications
- ) retinopathy
- ) intraventricular hemorrhage
- ) bronchopulmonary dysplasia
Risk factors for neonatal RDS
Prematuriy, maternal diabetes, C-section delivery
Lecithin:sphingomyelin ratio <1.5
Persistently low O2 levels can lead to risk of PDA
Damage mediators in ARDS
- ) neutrophils
- ) activation of coagulation cascade
- ) oxygen-derived free radicals
lead to diffuse alveolar damage, leading to incr. alveolar capillary permeability, then protein-rich leakage into alveoli and pulmonary edema
Vascular changes in pulmonary hypertension
Arteriosclerosis
Medial hypertrophy
Intimal fibrosis of pulmonary arteries
Causes of pulmonary artery hypertension
***hereditary: BMPR2 gene, normally inhibits vascular smooth muscle proliferation
Increased fremitus
consolidation!
lobar pneumonia, pulmonary edema
Hyperresonant breath sounds
Pneumothorax
TGs in pleural fluid
Lymphatic pleural edema (chylothorax)
thoracic duct injury from trauma or malignancy
Atypical pneumonias
Viruses, mycoplasma, legionella, chlamydia
diffuse patchy inflammation localized to interstitial areas at alveolar walls
Two causes of lung abscess
Aspiration of oropharyngeal contents
Bronchial aspiration
Face/arm edema, JVD, swollen collateral veins on chest, shortness of breath, coughing
SVC syndrome, sometimes seen with Pancoast tumor
Medical emergency, can lead to headaches, dizziness, rupture of aneurysm/intracranial arteries (incr. ICP)
Lung cancer complications
SPHERE: SVC syndrome, Pancoast tumor, Horner, Endocrine, Recurrent laryngeal nerve compression, Effusions
Two centrally located lung cancers
Squamous cell
Small cell
Three main neoplastic syndromes with small cell lung cancer
ACTH - Cushing syndrome
SIADH
Abs against pre-synaptic Ca channels - Lambert-Eaton
Look for neuroendocrine cells - Kulchitsky cells
Lung cancer assoc. w/ clubbing, glandular pattern on histology
Adenocarcinoma
activating mutations: KRAS, EGFR, ALK
Lung cancer w/ cavitation, cigarettes, hypercalcemia (PTHrP)
squamous cell carcinoma
hilar mass arising from bronchus
look for keratin pearls and intercellular bridges
Highly anaplastic undifferentiated lung cancer
Large cell carcinoma
pleomorphic giant cells, can secrete b-hCG
Phases of lobar pneumonia
congestion –> red hepatization –> gray hepatization –> resolution
Progression of tuberculous infection
Granulomatous with caseous necrosis
Caseous: T-cell mediated delayed hypersensitivity (Th1 stimulation of macs and CD8 T cells)
