FA 1 Flashcards
pulsus paradoxus - seen in
- cardiac teponade 2. asthma 3. obstructive sleep apnea
4. pericarditis 5. croup
asthma - histology
- smooth muscle hypertrophy
- Curschmann spirals: shed epithelium forms whorled mucus plugs
- Charcot - Leyden crystals: eosinophilic, hexagonal, double-pointed, needle-like crystal from breakdown of eosinophils in sputum
asthma drugs
- β2 agonists (albuterol, salmeterol, formoterol)
- corticosteroids (fluticasone, budesonide)
- Muscarinic antagonists (ipratropium)
- Antileukotrienes (montelukast, zafirlukast, zileuton)
- omalizumab
- Methylxanthines (theophylline)
- Metacholine
role of corticosteroids (fluticosine, budesonide) in asthma therpay
asthma - albuterol used in
- 1st line therapy for chronic asthma
- during acute exacerbation
asthma - ipratropium vs tiotropium according to action
tiotropium is long acting
montelukast, zafirukast mechanism of action
block leukotriene receptor (CysLT1)
Zileuton mechanism of action / SE
5-lipoxygenase pathway inhibitor. Block conversion of arachnoid acid to leukotrienes
- hepatotoxic
adenosine receptor antagonists
- theophylline
2. caffeine
theophylline adverse effects
- cardiotoxicity
- neurotoxicity
narrow therapeutic index
think asthma as a diagnosis when
- Recurrent episodes of wheezing
- Cough at night
- Coughing or wheezing after exercise
- Cough, wheezing, chest tightness after exposure to allergens or pollutants
- Colds “go down to the chest” or take longer than 10 days
inspiratory reserve volume (IRV)
air that can still be breathed in after normal inspiration (3.3L)
Expiratory reserve volume (ERV)
air that can be breathed out after normal expiration (1L)
Inspiratory capacity (IC)
inspiratory reserve volume (IRV) + tidal volume (TV)
3.8L
Vital capacity (VC)
Maximum volume of gas that can be expired after a maximal inspiration (4.8L)
inspiratory reserve volume (IRV) + tidal volume (TV) + Expiratory reserve volume (ERV)
Functional residual capacity (FRC)
Volume of gas in lungs after normal expiration (2.2L) Residual volume (RV) + Expiratory reserve volume (ERV)
minute ventilation (Ve)
total volume of gas that entering lungs per minute
Ve = tidal volume x respiratory rate
Alveolar ventilation (Va)
volume of gas per unit time that REACHES ALVEOLI
Va = (tidal volume - physiological dead space) x respiratory rate
situations that alter FEV1/FVC
decreased: obstructive lung disease
increased: restrictive lung disease
IRV is used during
exercise
Lung volumes that cannot be measured by spirometry
- residual volume
- Total lung capacity
- Functional residual capacity
Causes of increased Vital capacity
acromegaly
physiologic dead space equation
tidal volume (Vt) x (arterial PCO2- expired PCO2)/ arterial PCO2
physiologic dead space definition
anatomic dead space of conducting airways plus alveolar dead space
Volume of inspired air that does not take part in gas exchange
alveolar dead space distribution
apex of healthy lung is largest contributor of dead space
Physiologic dead space (per breath) normal
150 ml/breath
pathologic dead space
when part of the respiratory zone becomes unable to perform gas exchange (ventilated but not perfused)
Lung cancer - complication
mnemonic: SPHERE + dysphagia + phrenic nerve paresis - heart or pericardial invasion +pleural invasion
1. Superior vena cava syndrome 2. Pancoast tumor
3. Horner syndrome 4. Endocrine (paraneoplastic)
5. Recurrent laryngeal nerve compression (hoarseness)
6. Effusions (pleural or pericardial)
Lung cancer - risk factors
- smoking 2. secondhand smoking 3. radon 4. asbestos 5. family history 6. Asbestosis 7. Silicosis
- Coal
primary lung cancer - types (small or non small?) / location
- small cell (oat cell) carcinoma - central
- adenocarcinoma (non-small) - peripheral
- Squamous cell carcinoma (non-small) - central
- Large cell carcinoma (non-small) - peripheral
- Bronchial carcinoid tumor (non-small) - central or peripheral
lung small cell (oat cell) carcinoma may cause/produce
- Cushing syndrome (ACTH) 2. SIADH
- antibodies against presynapitc Ca2+ channels (Lambert-Eaton myasthenic syndrome)
- or neurons (paraneoplastic myelitis/encephalitis, sabacute cerebellar degeneration)
lung small cell (oat cell) carcinoma - gene amplification
MYC
lung small cell (oat cell) carcinoma - histology
- neoplasm of neuroendocrine Kulchitsky cells (small dark blue cells)
- chromogranin A positive
- undifferentiated (very aggressive)
- Neuron specific enolase positive
lung squamous cell carcinoma - may cause/produce
- cavitation
2. hypercalcemia (produce PTHrP)
lung squamous cell carcinoma - CXR
Hillar mass arising from bronchus b
bronchial carcinoid tumor - histology
nests of neuroendocrine cells
chromogranin A positive
chromogranin A positive lung tumors
- bronchial carcinoid tumor
2. lung small cell (oat cell) carcinoma
bronchial carcinoid tumor - presentation/symptoms
- symptoms due to mass effect
2. carcinoid syndrome (flashing, diarrhea, wheezing)
lung Large cell carcinoma - treatment / it can secrete …
- less responsive to chemotherapy
- remove surgically
- β-hCG
MC primary lung cancer
MC lung cancer in non smokers
adenocarcinoma
lung adenocarcinoma activating mutations / paraneoplastic
- KRAS 2. EGFR 3. ALK
- hypertrophic osteorarthropathy (clubbing)
adenocarcinoma in siitu
bronchioarveolar subtype (hazy infiltrates similar pneumonia)
bronchioarveolar subtype - smoking
Bronchial carcinoid tumor - smoking
both no relationship
mesothelioma - risk factors
asbestosis
smoking is not a risk factor
mesothelioma - histology / RF
- psammoma bodies
- calretinin and cytokeratin (+) in almost all mesotheliomas, ((-) in most carcinomas)
- RF: ASBESTOSIS (not smoking)
pancoast tumor (superior sulcus tumor) may cause
Compression of locoregional structures:
- Horner syndrome
- Superior vena cava syndrome
- hoarseness
- sensorimotor deficits
superior vena cava syndrome - medical emergency because
it can raise intracranial pressure (if obstruction is severe)
–> headaches, dizziness, increased risk of aneurysm/rupture of intracranial arteries
Lung Ca - MC symptom
Lung Ca - single most common area of metastasis
- cough (75%)
- brain
primary spontaneous pneumothorax is due to
rupture of apical blebs or cysts in tall, thin, young males
secondary spontaneous pneumothorax is due to
- diseased lung (bullae in emphysema, infections)
2. mechanical ventilation with use of high pressures (barotrauma)
thrombi pulmonary emboli - histology
lines of Zahn: interdigitating areas of pink (platelets, fibrin) and red (RBCs) found only in thrombi formed before death
lobar pneumonia - typical organisms
- S pneumonia
- Legionella
- Klebsiella
Bronchopneumonia - typical organisms
- S. pneumonia
- S. aureus
- H. influenza
- Klebsiella
interstitial (atypical) pneumonia - typical organisms
- Viruses (influenza, CMV, RSV, adenovirus)
- Mycoplasma
- Legionella
- Chlamydia
organism that causes BOTH Lobar and Bronchopneumonia
Klebsiella
S. pneumonia
bronchopneumonia - distribution
patchy distribution involving >= 1 lobe