Pulmonary function test

Pulmonary function test → assessment of lung function

Used for - dDx restrictive vs. obstructive diseases

• Restrictive disease (idiopathic p fibrosis, sarcoid)

• Obstructive (asthma, COPD)

• Preop and Post tx to ✓ effectiveness

PFT represents

• Patency Airways - Large and Small Airways

• Parenchyma - Alveoli/interstitium

• Pulmonary Vasculature

• Bellows/Pump Mechanism

  • Diaphragm

  • Chest Wall

• Neural Control of Ventilation

dDx

• Obstructive Lung Disease

  • COPD (chronic bronchitis ← → emphysema)

  • Asthma

  • Bronchiectasis

  • Cystic fibrosis

• Restrictive Lung Disease

  • Interstitial lung disease (e.g. pulmonary fibrosis, sarcoidosis)

  • Chest wall pathology (e.g. kyphosis, scoliosis)

  • Obesity

  • Neuromuscular disease (e.g. ALS, muscular dystrophy)

• Pulmonary Vascular Disease

  • Primary pulmonary hypertension

  • Chronic thromboembolic disease

Types of PFTs

• Standard PFTs

  • Spirometry - (including flow-volume loop) - measure of airflow - dx obstruction

  • Lung Volumes - dx restrictive

  • Diffusing Capacity of Carbon Monoxide (DLco) → dx pulmonary vascular pathology

• Specialized PFTs

  • Arterial Blood Gas

  • Exercise Oximetry

  • 6 Minute Walk Test

  • Peak Flow

  • Maximum Inspiratory and

  • Expiratory Pressures A