Pack-Years of Smoking

Pack-Years of Smoking
www.practicingclinicians.com
• To calculate smoking pack-years:
– Divide the number of cigarettes smoked per day
by 20 (the number of cigarettes in a pack)
– Then multiply by the number of years smoked
(70 cigarettes/day ÷ 20 cigarettes/pack) X 10 years = 35 pack-years
(35 cigarettes/day ÷ 20 cigarettes/pack) X 20 years = 35 pack-years
(20 cigarettes/day ÷ 20 cigarettes/pack) X 35 years = 35 pack-years
1
Smoking Exposure and
Decline in Lung Function
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FEV1 (% of predicted)
85
80
Sustained Quitters
75
Intermittent Quitters
70
Continuous Smokers
65
60
0
1
2
3
4
5
6
7
Year
2
Anthonisen NR, et al. Am J Respir Crit Care Med. 2002;166(5):675-679.
8
9
10
11
Characteristics That Help
Distinguish COPD From Asthma
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Feature
Onset
Family history
Medical or social
history
Patients report
symptoms as...
Airflow obstruction
3
COPD
Asthma
Often in midlife
Often in childhood
Variable
Often
Smoking
(often ≥20 pack-years)
Atopy
(ie, allergy and/or eczema)
Most notable during
exercise
Most notable at night or
early morning
“Mostly bad days”
“Mostly good days”
May be some reversibility
with bronchodilation
Largely reversible
with bronchodilation
Briggs DD Jr, et al. J Respir Dis. 2000;21(9A):S1-S21. Doherty DE. Am J Med.
2004;117(12A):11S-23S.
Clinicians Fail to Distinguish COPD
From Other Respiratory Diseases
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Episodic
Variable
Asthma
Allergy
Rhinitis
Eczema
(atopy)
Cough
Dyspnea
Chest Tightness
Wheezing
Heavy
sputum
production
COPD
Shared Symptoms
4
Chronic
Progressive
Key Indicators of COPD
www.practicingclinicians.com
• Chronic cough
– Present intermittently or every day
– Often present throughout the day;
seldom only nocturnal
• Chronic sputum production
– Any pattern chronic sputum
production may indicate COPD
• Dyspnea that is:
– Progressive (worsens over time)
– Persistent (present every day)
– Worse with exercise
– Worse during respiratory infections
5
“Normal” Test Results in the
Early Stages of COPD
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Changes Can Be Seen Earlier in Spirometry
Than in Many Other Respiratory Parameters
Spirometry
Symptoms
Arterial blood gas
Chest X-ray
Normal
Borderline
Mild
Cough, sputum
Normal
Normal
Time
6
Moderate
Exertional
dyspnea
Severe
Resting
dyspnea
Hypoxemia
Hyperinflation
Volume-Time Curve
Normal
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FVC
Exhaled Volume (L)
5
4
FEV1
3
2
1
1
2
3
4
Time (seconds)
7
FVC = forced vital capacity.
5
6
Robert’s Attempted Tracing 1
(Cough and Early Stop)
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Exhaled Volume (L)
5
4
3
2
1
1
2
3
4
Time (seconds)
8
5
6
GOLD Diagnosis and Staging of COPD:
Postbronchodilator Spirometry Values
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Postbronchodilator Values
FEV1/FVC
FEV1
(postbronchodilator
% of predicted)
I: Mild
<.70
≥80%
II: Moderate
<.70
≥50%, <80%
III: Severe
<.70
≥30%, <50%
IV: Very severe
<.70
<30%a
GOLD Stage
aOr
9
<50% plus chronic respiratory failure.
GOLD Executive Committee. Global Strategy for the Diagnosis, Management, and
Prevention of Chronic Obstructive Pulmonary Disease. Gold web site.
http://www.goldcopd.org. Updated 2008.
Bronchodilator Reversibility Testing
Helps Differentiate COPD From Asthma
www.practicingclinicians.com
Acceptable spirogram
Yes
Obstructive defect
Is FVC low?
Yes
Is FVC low?
Yes
No
Is FEV1/FVC ratio low?
Restrictive
defect
No
Pure obstruction
Mixed obstructive/
restrictive defect
or hyperinflation
Further testing
10
Near-total reversal with
use of β-agonist?
Yes
No
Asthma
COPD
Further
testing
Petty TL. Spirometry made simple. National Lung Health Education Program web site.
http://www.nlhep.org/resources/SpirometryMadeSimple.htm. Published January 1999.
No
Normal
Robert’s Spirometry Results
www.practicingclinicians.com
Exhaled Volume (L)
5
Normal
4
FV
C
3
FEV1
2
1
Measure
FEV1
Predicted
% Predicted
2.1 L
3.4 L
61%
FVC
3.2 L
FEV1/FVC
1
2
3
4
Time (seconds)
11
5
6
Value
.65
Spirometry-Based Diagnosis Dictates How
to Implement Evidence-Based Therapy
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GOLD Stage
I
Mild
II
Moderate
III
Severe
IV
Very Severe
Active reduction of risk factors: influenza vaccine.
Add short-acting bronchodilators when needed
Add regular Rx with 1 long-acting
bronchodilator. Add rehabilitation
Add inhaled corticosteroids
if repeated exacerbations
Long-acting bronchodilators and corticosteroids
are also used for asthma
but in the reverse order.
GOLD Executive Committee. Global Strategy for the Diagnosis, Management, and
Prevention of Chronic Obstructive Pulmonary Disease. Gold web site.
12 http://www.goldcopd.org. Updated 2008.
Consider O2
and surgery
Questionnaire to Differentiate
Asthma and COPD
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Questionnaire Score
• Symptoms compiled
Patients (%)
40
30
20
10
0
<3
3-5
6-8
COPD
13
Beeh KM, et al. Respir Med. 2004;98(7):591-597.
9-11
Asthma
≥12
from chart review to
create quantitative
questionnaire
• Scores based on
• Age of symptom
onset
• Smoking history
• Atopy status
• Cough quality
• High scores associated
with COPD, lower with
asthma
Donna’s Spirometry Results
www.practicingclinicians.com
Exhaled Volume (L)
5
Normal
4
FV
C
3
FEV1
2
1
Measure
FEV1
Predicted
% Predicted
2.0 L
3.7 L
54%
FVC
3.4 L
FEV1/FVC
1
2
3
4
Time (seconds)
14
5
6
Value
.58
All Smoking Cessation Pharmacotherapies
Have Significant Benefit
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Pharmacotherapy
Odds Ratio (95% CI)
Bupropion
2.12 (1.76-2.56)
Nicotine gum
1.65 (1.37-2.01)
Nicotine inhaler
2.18 (1.38-3.45)
Nicotine nasal spray
2.37 (1.57-3.60)
Nicotine patch
1.88 (1.60-2.22)
Nicotine tablet
2.06 (1.47-2.87)
Varenicline
2.55 (1.99-3.24)
Favors
placebo
Favors
treatment
0.2
1.0
7.0
Odds Ratio (95% CI)
Cl = confidence interval.
15 Eisenberg MJ, et al. CMAJ. 2008;179(2):135-144.
Explaining “Lung Age” to Patients
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Susceptible smoker
Never smoked or not susceptible to smoke
Disability
Death
Lung Function FEV1
(% of value at age 25)
100
75
50
Age 52 with equivalent
FEV1 of a 75-year-old
25
0
25
50
Age (years)
16 Parkes G, et al. BMJ. 2008;336(7644):598-600.
75