determination of physiologic dead spaceTaco, Paco, Peco, Paco
Vd= Vt×(PaCO2-PECO2)/ PaCO2 respiratoryUWorld Jul 9, 2020, 10:36 PM HirotoShishido
ABG change in pregnancy↑progesterone
→ stimulate the hypothalamus to increase respiration drive primarily via ↑tidal volume (hormone induced laxity of the intercostal muscles allows for enlargement of the throracic cavity) + a slight ↑RR
→ ☆chronic hyperventilation
hypersensitivity pneumonitis vs IPF(idiopathic pulmonary fibrosis)affected patients by IPF are usually older(>50yo)
HP is associated with (poorly formed) noncaseating granulomas but IPF is not respiratoryUWorld Jul 5, 2020, 5:39 AM HirotoShishido
radiation-induced lung injuryacute(1-3months)
impaired gas exchange due to exudative alveolitis → ☆hyaline membrane formation, pneumocyte sloughing(slúː)
chronic(6-12months)
radiation fibrosis(dense fibrous bands) results in decreased lung volume and dilated bronchi and bronchioles(ie traction bronchiectasis)
(predisposition to chronic infections) respiratoryradiologyUWorld Jul 5, 2020, 5:34 AM HirotoShishido
relative high lympholyte count in BAL (bronchoalveolar lavage)(normally, 85% alveolar macrophage, 10% lymphocytes, small percentages of neutrophils and eosinophils)
☆hypersensitivity pneumonitis (eg >20%, often >50%), sarcoidosis, lymphoma, chronic fungi or mycobacterial infection respiratorymicrobiologyUWorld Jul 5, 2020, 5:02 AM HirotoShishido
trachial deviationdeviate toward the affected side
→ atelectasis (alveolar collapse)
cavitary tuberculosis (TB) vs lung abscessTB→ usually due to reactivated (not primary) mycobacterial infection,
common in the ☆upper portions of the lung,
☆do not have air-fluid levels
the most common presenting symptoms of Pancoast tumor・☆shoulder pain radiating toward the axilla and scapula (involvement of the lower brachial plexus)
types of pneumoniaLobar pneumonia
☆S pneumoniae most frequently, also Legionella, Klebsiella
Intra-alveolar exudate consolidation
(Can involve the entire lobe or the whole lung)
Bronchopneumonia
S pneumoniae, S aureus, H influenzae, Klebsiella
Acute inflammatory infiltrates from bronchioles into adjacent alveoli
(usually the lower lobes or right middle lobe)
cryptogenic organizing pneumoniaFormerly known as bronchiolitis obliterans organizing pneumonia (BOOP). Noninfectious pneumonia characterized by inflammation of bronchioles and surrounding structure.
Secondary → caused by chronic inflammatory diseases (eg, RA) or medication side effects (eg, amiodarone).
⊝ sputum and blood cultures, often responds to steroids but not to antibiotics.
☆patchy fibrosis with fibroblastic plugs in the alveolar sacs and ducts, often extending into ajacent alveoli in a butterfly pattern respiratoryUWorld Jun 28, 2020, 12:37 AM HirotoShishido
Picturecarbon-laden macrophages
→ coal worker's pneumoconicosis
known as black lung diseas
increased risk of Caplan syndrome= rheumatoid pneumoconicosis respiratoryUWorld Jun 26, 2020, 1:08 AM HirotoShishido
work of breathingIn patients with restrictive lung disease, the WOB is minimized when the tidal volume is low. Therefore, to compensate for low lung volumes, ☆rapid, shallow breathing is favored (as in this patient).
In contrast, in patients who have obstructive lung disease, the WOB is minimized with lower respiratory rates and higher tidal volumes (ie, relatively slow, deep breathing) (due to faster airflow with increased turbulence) respiratoryUWorld Jun 24, 2020, 12:33 AM HirotoShishido
the 2nd leading cause of lung cancer after cigarrete smoke☆radon
Byproduct of uranium decay, accumulates in basements pathologyrespiratoryfree120 Jun 19, 2020, 5:36 AM HirotoShishido
cerebral autoregulationless sensitive to the arterial partial pressure of oxygen(hypoxic vasodilation) than than to carbon dioxide(hypercapnic vasodilation)
a rapid increase in CBF is not triggered until the PaO2 level drops below 50 mmHg
decreased cerebral rerfusion→ neurologic sequelae, including ☆generalized weakness, blurred vision, presyncope neurologyrespiratoryUWorld Jun 15, 2020, 4:12 AM HirotoShishido
what condition cause hypoxic erythrocytosisSaO2<92% (PaO2<65%) can cause secondary polycythemia
(classified as absolute polycythemia= ☆increase in true RBC mass (51Cr-tagged red blood cell infusion)) hematologyrespiratoryUWorld Jun 14, 2020, 7:25 AM HirotoShishido
histopathologic findings of idiopathic pulmonary fibrosis(IPF)• Patchy areas of chronic interstitial inflammation(lymphocyte infiltration) and ☆interstitial fibrosis intermixed with normal lung
• Early lesions consist of fibroblastic foci that become increasingly collagenous with time
• Honeycomb pattern with fibrotic walls and cystic spaces lined by bronchiolar epithelium
• Fibrosis most prominent in the ☆subpleural and perilobular regions respiratoryUWorld May 30, 2020, 11:48 PM HirotoShishido
