Pulmonary function test

폐기능 검사(Pulmonary function test, PFT)

TLC=IC(inspiratory capacity)+FRC(funtional residual capacity)=VC+RV=ERV+TV(tidal volume)+IRV+RV
Restrictive pattern: FVC<80%, FVC가 작을수록 심함, TLC, VC, RV 모두 감소
- parenchymal restrictive pattern: RV 감소
  - 질환: IPF, sarcoidosis
- extraparenchymal restrictive pattern with limitation in inspiration and expiration: RV 증가
  - 질환: Neuromuscular disease, chest wall 이상
Obstructive pattern: FEV1/FVC<70%, FEV1이 작을수록 심함
- 질환: 천식, COPD, 기관지 확장증, Bronchiolitis
- Extrathoracic obstruction은 흡기시, Intrathoracic obstruction은 호기시 장애