TY  - CHAP
M1  - Book, Section
TI  - Chronic Obstructive Pulmonary Disease
A1  - Kasper, Dennis L.
A1  - Fauci, Anthony S.
A1  - Hauser, Stephen L.
A1  - Longo, Dan L.
A1  - Jameson, J. Larry
A1  - Loscalzo, Joseph
PY  - 2016
T2  - Harrison's Manual of Medicine, 19e
AB  - Chronic  obstructive  pulmonary  disease  (COPD)  is  a  disease  state  characterized  by  chronic  airflow  obstruction;  thus,  pulmonary  function  testing  is  central  to  its  diagnosis.  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  131-1):  ≥80%  is  stage  I,  50–80%  is  stage  II,  30–50%  is  stage  III,  and  <30%  is  stage  IV.  Cigarette  smoking  is  the  major  environmental  risk  factor  for  COPD.  The  risk  of  COPD  increases  with  cigarette  smoking  intensity,  which  is  typically  quantified  as  pack-years.  (One  pack  of  cigarettes  smoked  per  day  for  1  year  equals  1  pack-year.)  Individuals  with  airway  hyperresponsiveness  and  certain  occupational  exposures  (e.g.,  coal  mining,  gold  mining,  and  cotton  textiles)  are  likely  also  at  increased  risk  for  COPD.  In  countries  in  which  biomass  combustion  with  poor  ventilation  is  used  for  cooking,  an  increased  risk  of  COPD  among  women  has  been  reported.  COPD  is  a  progressive  disorder;  however,  the  rate  of  loss  of  lung  function  often  slows  markedly  if  smoking  cessation  occurs.  In  normal  individuals,  FEV1  reaches  a  lifetime  peak  at  around  age  25  years,  enters  a  plateau  phase,  and  subsequently  declines  gradually  and  progressively.  Subjects  can  develop  COPD  by  having  reduced  maximally  attained  lung  function,  shortened  plateau  phase,  or  accelerated  decline  in  lung  function.  
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/19
UR  - accessmedicine.mhmedical.com/content.aspx?aid=1128786404
ER  -