RT Book, Section
A1 Jameson, J. Larry
A1 Fauci, Anthony S.
A1 Kasper, Dennis L.
A1 Hauser, Stephen L.
A1 Longo, Dan L.
A1 Loscalzo, Joseph
SR Print(0)
ID 1167067242
T1 Chronic Obstructive Pulmonary Disease
T2 Harrison's Manual of Medicine, 20e
YR 2020
FD 2020
PB McGraw-Hill Education
PP New York, NY
SN 9781260455342
LK accessmedicine.mhmedical.com/content.aspx?aid=1167067242
RD 2023/05/29
AB Chronic  obstructive  pulmonary  disease  (COPD)  is  a  syndrome  characterized  by  chronic  airflow  obstruction.  COPD  includes  emphysema  (lung  parenchymal  destruction),  chronic  bronchitis  (chronic  cough  and  phlegm  production),  and  small  airway  disease  (fibrosis  and  destruction  of  small  airways)  in  varying  combinations  in  different  pts.  The  presence  of  airflow  obstruction  is  determined  by  a  reduced  ratio  of  the  forced  expiratory  volume  in  1  s  (FEV1)  to  the  forced  vital  capacity  (FVC).  Among  individuals  with  a  reduced  FEV1/FVC  ratio,  the  severity  of  airflow  obstruction  is  determined  by  the  level  of  reduction  in  FEV1  (Table  133-1):  ≥80%  is  stage  I,  50–80%  is  stage  II,  30–50%  is  stage  III,  and  <30%  is  stage  IV.  Pts  who  do  not  meet  these  classic  thresholds  for  airflow  obstruction  may  have  emphysema,  chronic  bronchitis,  and  respiratory  symptoms  suggestive  of  COPD.