The British Thoracic Society (BTS) published criteria for grading the severity of chronic obstructive pulmonary disease (COPD).
Parameters:
(1) clinical state
(2) spirometric measurements
|
Cough
|
Breathlessness
|
Abnormal Signs
|
Severity
|
|
smoker's cough
|
none or minimal
|
none
|
mild
|
|
cough with or without sputum production
|
present on exertion
|
some, variable wheezing
|
moderate
|
|
prominent
|
with mild exertion
|
present
|
severe
|
where:
• Abnormal clinical signs include wheezing, cyanosis, peripheral edema, polycythemia, lung overinflation ("barrel chest").
|
FEV1 as percent of expected
|
Arterial Blood Gas
|
Severity
|
|
60 - 79%
|
no hypoxemia
|
mild
|
|
40 - 59%
|
variable hypoxemia but not hypercapnic
|
moderate
|
|
< 40%
|
hypoxemia with or without hypercapnia
|
severe
|
