Respiratory Flashcards
Compare ABG of CHF exacerbation vs COPD exacerbation?
CHF: respiratory alkylosis with hypoxia (increased pH, decreased pCO2, and decreased pO2)
COPD: Respiratory acidosis with hypoxia (decreased pH, increased pCO2, and decreased pO2)
How are exudates and transudates distinguished?
Exudate:
Effusion protein/serum protein ratio > 0.5
Effusion lactate dehydrogenase (LDH)/serum LDH ratio > 0.6
Effusion LDH level > two-thirds the upper limit of the laboratory’s reference range of serum LDH
Transudate would be < 0.5, 0.6, and two-thirds upper limit respectively
What vent setting affect PaCO2?
RR and TV
What are the early exam findings in a patient with idiopathic pulmonary fibrosis?
Fine bibasilar crackles in patient with progressive dyspnea
In ARDS, what is the PaO2/FiO2 ratio (P/F)?
P/F ≤300 mm Hg
What is the pH of normal, transudative, and exudative pleural fluid and empyema?
Normal: 7.60
Transudate: 7.4-7.55
Exudate: 7.30-7.45
Empyema: <7.30
How is pulmonary hypertension secondary to LV dysfunction managed?
Loop diuretics and ACE-I, often with beta-blocker and spironolactone
What is the management of pulmonary hypertension due to hypoxemia from chronic lung disease?
Bronchodilators and/or oxygen
What medications are used to treat idiopathic pulmonary hypertension?
Endothelin receptor antagonists (e.g. bosentan), phosphodiesterase-5 inhibitors (e.g. sildenafil), and/or prostanoids (e.g. epoprostenol)
What are two major indicators of poor prognosis in patients with a PE?
Low oxygen saturation and atrial fibrillation
How is PAO2 calculated?
PAO2 = (FiO2 x [Patm - PH20]) - (PaCO2/0.8)
Simplified to 150 - (PaCO2/0.8) at sea level
What is the expected A - a gradient for a patient?
(Patient age)/4 + 4
What is the best diagnostic test for bronchiectasis?
High-resolution CT of the chest - will see bronchial dilation, lack of airway tapering, and bronchial wall thickening
What is the mechanism of an exudative pleural effusion?
Increased capillary or pleural permeability or disruptions to lymphatic outflow
What should you consider in a patient with recurrent pneumonia in the same location of the lung?
Localized airway obstruction (e.g. neoplasm) - get CT
What can cause a “Thickened peritracheal stripe and splayed carina bifurcation” on cxr?
Enlarged L atria (eg mitral stenosis) or an subcarinal mass
What is the cause of a transudative pleural effusion with low glucose?
RA
What are the main causes of ARDS?
Sepsis, gastric aspiration, trauma, low perfusion, pancreatitis
What are the criteria for diagnosis of ARDS?
- ) PaO2/FiO2 < 200 (<300 means acute lung injury)
- ) Bilateral alveolar infiltrates on CXR
- ) PCWP is <18 (means pulmonary edema is non cardiogenic)
What constitutes a positive bronchodilator response?
At least a 12% increase in FEV1 (or FVC) = asthma
What is the best prognostic indicator in COPD?
FEV1
If a patient suddenly develops digital clubbing, what does that indicate?
Underlying malignancy - likely pulmonary (get a cxr)
Finding is called hypertrophic osteoarthropathy
What are the lung findings in silicosis?
Small nodules in the upper lobes with eggshell calcifications
What test should patients with silicosis get annually?
TB test - predisposed to TB
What does a popcorn calcification on cxr indicate?
Hamartoma (benign)
How do gas exchange, lung compliance, and pulmonary arterial pressure change in ARDS?
Gas exchange is impaired (ventilation-perfusion mismatch), lung compliance decreases due to loss of surfactant and an increase in elastic recoil of the edematous lungs, and pulmonary arterial pressure increases due to hypoxic vasoconstriction
Where is the origin of most PEs?
> 90% come from the proximal LE (e.g. iliac, femoral, popliteal) veins
