Airway-centred disease characterized by decreased expiratory air flow

Def: reduced ‣

Characteristic Spirometry for Obstructive Conditions

VS Interpretation: Normal Curve

VS Restrictive PFT

• Scoop appearance: (1) more gradual effort-independent decline, (2) reduced peak flow

  

• if absolute TLC is obtained via Body Plethysmography : (3) increase RV, (4) increased TLC → left shift

  

  • Increase in RV > increase in TLC → thus, VC is either normal or low

    

• Reduced expiratory airflows

  • Reduced FEV1/EVC
  • Reduced peak flow

Pathogenesis

Dynamic Airway collapse → Air trapping

• Increased Lung Compliance (loss of elastic recoiling → driving force)
• increased airway resistance (smaller diameter of the airway)
  • mucus
  • bronchospasm
  • extrinsic compression

Air trapping → symptoms

• Lung is full so you can’t take any more breath in

  

Severity

ATS/ERS - Severity for lung diseases

GOLD Classification