1. Complicated pleural effusion: 
- pH < 7.2
- LDH > 1000
- Glucose < 60
- Gross pus visible
- Loculations (may need VATS to break it up for adequate drainage)
- Gram stain or cultures of fluid +
- Need to be drained
2. Tactile fremitus: 
- Feeling vibration on the chest when the patient is vocalizes low frequency sounds (toy boat, blue balloons)
- Increased with consolidated lung (solid/liquid is better at transmitting vibrations than aerated lung)
- Decreased with pleural effusions- decreased transmission/increased space between lung and body wall.
3. Tuberculous pleural effusion
- Exudative (ie. pleural/plasma LDH > 0.6, pleural/plasma protein > 0.5)
- Predominantly lymphocytic in nature (although can be neutrophilic in first 2 weeks)
- Subacute course of illness (weeks to months)
- Fluid cx positive in 1/3 of cases
- Diagnose with pleural biopsy and fluid cx (combo will be positive in 2/3 of cases)
4. Chylothorax
- Most commonly due to malignancy, but can also be caused by trauma, TB, chronic mediastinal infections, sarcoid, radiation fibrosis, lymphangioleiomyomatosis (proliferation of smooth muscle cells in bronchioles, alveolar septa, vessels, lymphatics throughout lung)
- Will see high pleural fluid triglycerides (>110, if its less than 50 it's probably not chylothorax) and low pleural fluid cholesterol
- Usually milky, but can be serous or serosanguinous in someone who is chronically malnourished and has low fat intake.
5. Pathogenesis of respiratory failure in asthma: 
- Narrowed airway diameter (airway edema, bronchospasm, collapse) lead to prolonged expiratory phase. Breathing fast leads to incomplete expiration, leading to air retention. This causes flattening of the diaphragm, reducing its function, forcing reliance on accessory airway muscles which are less efficient (i.e. more lactate/CO2 generated and O2 required per unit work)
- Significant air trapping can lead to ruptured blebs (pneumothorax) or decreased venous return (hypotension)
- Signs of impending respiratory failure: PCO2 that is normal or high, tachypnea > 30, tachycardia >120.
6. Asthma control 
- Steroid burst for asthma: 0.5mg/kg of prednisone for 5 to 7 days.
- Inhaled steroids are, as far we we know, safe during pregnancy (budesonide is the best studied), and certainly less dangerous than poorly controlled asthma.
- Other drugs that are also probably safe in pregnancy: theophylline, LABAs, cromolyn
- Start with low to moderate dose inhaled steroid; when that fails, adding LABA is better than doubling the steroid dose.
- Third line drugs: leukotriene-modifying drugs (although montelukast is first-line for allergic type asthma) and theophylline
- Inhaled anticholinergics have an unclear role in asthma (although they are beneficial in COPD)
7. COPD exacerbation treatment
- Mainstay: oxygen, albuterol, systemic steroids
- Addition of antibiotics has been shown to speed up resolution (and reduce hospital stay and mortality) in moderate to severe COPD exacerbations or people who are on ventilators. Either ceftriaxone + azithro or levoquine. Amoxicillin no longer first line given resistance in H.flu and moraxella.
- Theophylline not recommended for acute symptom management as it adds no benefit over standard treatment and has significant side effects (n/v/heartburn/palpitations/arrhythmias). Also methylxanthines have significant drug interactions.
- Inhaled steroid adds no benefit when someone is already on systemic steroids.
8. Home O2 for COPD
- Has been shown to improve survival (vs inhaled steroids/LABA which improve symptoms and decrease hospitalizations but have not been shown to increase survival)
- Indication: Sats <88% on RA or PO2 <55
- Indication: Sats <89 or PO2 <59 if there is concomitant sequelae of COPD: R heart failure, pulmonary HTN, hematocrit > 56
9. COPD management
- GOLD score: grading based on FEV1: >80 is GOLD I, 50-80 is GOLD II, 30-50 is GOLD III, <30 is GOLD IV. FEV1<50 + severe chronic symptoms also makes you GOLD IV. In all cases, FEV1/FVC must be <70%
- First line is PRN short acting bronchodialtor (either albuterol or ipratropium/atrovent). If that fails, you add long acting bronchodilator, either LABA or long acting anticholinergic (tiotropium/spiriva). If that fails, you add inhaled steroids.
- Lung reduction surgery benefits those with upper lung disease and limited exercise tolerance after pulmonary rehab. Ideal candidate: FEV1 20-35% predicted, DLCO > 20% predicted, hyperinflation, limited comorbidities
- Indication for transplant: hypercapnea pCO2>5,  FEV1<20; either homogenous disease on high-res CT or DLCO<20, unlikely to survive after lung reduction surgery
- In patients <45 who have bibasilar emphysematous disease, r/o a1-antitrypsin
10. COPD and supplemental oxygen
- You want to give oxygen for hypoxic COPD exacerbation, however, O2 supplementation can exacerbate hypercapnea (both by worsening VQ mismatch from blunting of the hypoxic vasoconstriction reaction and from decreasing respiratory drive)
- Titrate oxygen to keep sats > 90 or PaO2 > 60-70.
- Indication for NPPV: tachypnea > 25, pH < 7.5, pCO2 > 45