A. Normal

1. Cannot normally hear expiration
2. Sounds do not travel through air-filled (normal) lungs
3. If lungs are congested, with consolidations, atelectasis, etc. then may hear sounds

B. Wheezes

1. Constricted airways
2. They are usually expiratory and most commonly heard in asthma
3. May be present in pulmonary edema conditions
   1. Particularly with severe Congestive Heart Failure (CHF), called "cardiac asthma"
   2. Also in non-cardiogenic pulmonary edema (less commonly)

C. Crackles (Rales)

1. Opening of closed airways (eg. CHF, fibrosis, atelectasis)
2. "Dry" vs "wet" crackles may help distinguish fluid vs fibrosis
3. Early, wet crackles - usually due to fluid accumation
4. Mid/late, usually dry crackles - usually due to fibrosis (smaller airways)
5. Fibrosis most common in interstital disease

D. Rhonchi

1. Sonorous sounds, deep, in large airways
2. Sounds like slurping up last parts of a milkshake)
3. Generally found in conditions with inflamed bronchi, severe pneumonia, COPD, asthma
4. Usually associated with sputum production

E. Bronchial (tubular sounds)

1. Expiratory/inspiratory sounds
2. Usually associated with consolidation, collapse

F. Other Sounds

1. Stridor (Whistle)
   1. High pitched, noisy respiration, like wind blowing
   2. Sign of upper respiratory obstruction, especially in larynx or trachea (eg. anaphylaxis)
   3. May be caused by acute or chronic tracheal narrowing
2. Squeaks
   1. High pitched sound, usually on inspiration
   2. Characteristic of bronchiolitis obliterans
3. Honks: rhonchus lower airway sounds, fairly deep

1. Total lung space: 3L per lung (5-6L total)
2. Alveolar area: 100 square meters
3. Tidal Volume: 500ml per breath, respirations at15/minute --> 7.5L/min
   1. Dead Space: 150ml per breath
   2. Alveolar Ventilation: 350ml per breath (VTID-VD)
4. Oxygen Absorbed: 20ml per breath
5. CO2 Released: 17ml per breath
6. Maximal air uptake/minute: ~5L/min during exercise (higher in runners, etc)
7. Normal Heart Pump volume: 5-6L/min
8. Resultant Normal Ventilation Perfusion Ratio (V/Q) ~1

B. Arterial Blood Values

1. Normal PAO2 alveolar: 104mm Hg
2. Normal PaO2 arteriolar: 70-90mm Hg
3. Normal O2 saturation: 97% arterial
4. Normal O2 dissolved in blood: 19ml/100ml. blood

C. Basic Spirometry Values

1. FEV1 (measures airway patency): normal 80% of predicted
2. FVC (measures capacity): normal 80% of predicted (~3-5 liters)
3. DLCO (diffusing capacity): normal 90-100% of predicted
4. FEV1/FEC (assesses obstruction): normal >75% of predicted