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
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 HirotoShishido
relative high lympholyte count in BAL (bronchoalveolar lavage)(normally, 85% alveolar macrophage, 10% lymphocytes, small percentages of neutrophils and eosinophils)
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 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 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
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 HirotoShishido
