Interstitial Air & Chronic Lung Diseases PDF

### Interstitial Air: - Occurs in individuals who have partial bronchiolar obstruction - Occurs in individuals with a perforating injury (e.g., a fractured rib) - When interstitial air reaches the subcutaneous tissue, marked swelling of the head and neck and crackling crepitation (subcutaneous em...

### Interstitial Air: - Occurs in individuals who have partial bronchiolar obstruction - Occurs in individuals with a perforating injury (e.g., a fractured rib) - When interstitial air reaches the subcutaneous tissue, marked swelling of the head and neck and crackling crepitation (subcutaneous emphysema) can occur over the chest, - Air is resorbed spontaneously after the site of entry seals ### Chronic Obstructive Pulmonary Disease: - **Symptoms:** Dyspnea, cough, wheezing, weight loss, reduced FEV1 with normal or near-normal FVC. - **Presentation of Emphysema:** Barrel-chested, dyspnea, prolonged expiration, hyperinflated lungs, flattened diaphragm. - **Disease Progression:** Dyspnea, hyperventilation, hypoxemia, secondary pulmonary hypertension, right-sided congestive heart failure (cor pulmonale) - **Chronic Bronchitis:** Persistent cough for at least 3 consecutive months in at least 2 consecutive years, common among smokers and urban dwellers. ### Emphysematous Conditions Other Than COPD: - **Compensatory Emphysema:** Dilation of residual alveoli in response to loss of lung substance - **Obstructive Overinflation:** Expansion of lung due to air trapping - **Bullous Emphysema:** Large subpleural blebs or bullae - >1 cm in diameter - **Mediastinal (Interstitial) Emphysema:** Entry of air into the interstitium of the lung. ### Chronic Bronchitis: - **Pathogenesis:** Hypersecretion of mucus, beginning in the large airways, cigarette smoking is the most common cause, air pollutants such as sulfur dioxide and nitrogen dioxide may also contribute. ### Pulmonary Emphysema: - Marked enlargement of air spaces, - Destruction of alveolar septa without fibrosis.