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1. The primary goal of preoperative pulmonary function testing is not to detect lung disease but to quantitate its severity.
2. Chest radiography is a valuable indicator for severe disease, especially in patients with lung hyperinflation.
3. The FEV₁ , which is customarily used as an index of airway obstruction, provides a better perspective of the degree of obstruction when it is expressed as a percentage of FVC (i.e., FEV₁ /FVC).
4. Patients with abnormally low FEV₁ values are likely to experience severe hypercapnia if allowed to breathe spontaneously under general anesthesia.
5. MVV, the most comprehensive test of ventilatory function, is significantly affected by airway obstruction. It is also affected by lung and chest wall elasticity, respiratory muscle strength, coordination, and motivation.
6. The maximum flow rates achievable during pulmonary function testing maneuvers depend on three factors, all of which are related to lung volume: effort or driving pressure, elastic recoil pressure of the lung, and flow resistance of the airways.
7. The upper (extrathoracic) airway, because of the surrounding soft tissue, collapses during inspiration and expands during expiration. The intrathoracic airway responds to pleural pressure changes and therefore expands during inspiration and collapses during expiration.
8. The DDI is equal to PEFR × PaO₂ /1000. ^[20] Patients with pulmonary dyspnea typically have lower PEFR values and a lower DDI than cardiac patients with dyspnea.
9. Evaluation of patients for thoracic surgery is aimed at deciding whether removal of a lung can be tolerated without causing pulmonary insufficiency or severe disability.
10. Ability to climb three flights of stairs without stopping is associated with decreased morbidity and mortality after lung resection.