The electronic nose as a diagnostic tool in the discrimination of COPD and controls

1. COPD patients

2. A minimum of ten patients 40-75 years with moderate to severe COPD:

• Smoking 10 cigarettes/day, > 10 pack years or

• Non-smoking (> 10 pack years, > 12 months)

• Matching GOLD severity step 2:

o Presence of symptoms of

 Shortness of breath typically developing on exertion

 Occasional occurrence of cough and sputum production

o Postbronchodilator 50% < FEV1 < 80% predicted

o Postbronchodilator FEV1/FVC < 0.70

• Matching GOLD severity step 3:

o Presence of symptoms of

 Greater shortness of breath

 Reduced exercise capacity

 Fatigue and

 Repeated exacerbations that affect quality of life

o Postbronchodilator 30% < FEV1 < 50%

o Postbronchodilator FEV1/FVC < 0.70



Controls

A minimum of ten asymptomatic age-matched > 40 years controls:

• Non-smoking (< 5 pack-years, > 12 months) and

• Smoking (> 10 pack-years, >10 cigarettes/day) and

• Ex-smoking (> 10 pack years, > 12 months)

• A negative history on lung diseases

• A negative history on any other acute or chronic illness

• Prebronchodilator FEV1 > 80% predicted

• FEV1/FVC > 0.70

• Absence of bronchial hyperresponsiveness demonstrated by PC20 > 4 mg/ml

• Negative skin prick test or RAST to common environmental allergens

• Absence of symptoms of

o Shortness of breath

o Chest pains

o Cough

o Sputum production

o Reduced exercise capacity

o Fatigue



Asthma

A minimum of ten asthmatic patients > 18 years:

• Non-smoking (< 5 pack-years, > 12 months) and

• A negative history on other lung diseases than asthma

• A negative history on any other acute or chronic illness than asthma

• Prebronchodilator FEV1 > 50% predicted

• Presence of bronchial hyperresponsiveness demonstrated by PC20 < 8 mg/ml

• Positive skin prick test or RAST to one or more common environmental allergens

• Chronic use of inhaled corticosteroids

Two or more of the following:

• Severe cardiovascular disease, history or present

• Myocardial infarction

• Coronary bypass surgery

• CVA

• Pulmonary embolism and deep venous thrombosis

• Heart failure

• Diabetes mellitus (documented in the past)

• Hypercholesterolaemia (documented in the past)

• Systemic inflammatory disease

• Cancer diagnosed and treated within 5 years, or known incomplete remission if earlier

• Any active inflammation



One or more of the following:

• The use of oxygen.

• For COPD-patients: GOLD-stadium I or IV.

• For controls: Reversibility in FEV1 by 400 ug of inhaled salbutamol > 12 % pred. (7)

• For asthma patients: the use of oral corticosteroids

• History of other pulmonary diseases or abnormalities eg tuberculosis, bronchiectasis, asthma, lung cancer, sarcoidosis

• Presence or recent history (4 weeks) of paradontitis

• History of upper or lower respiratory infection in the past 4 weeks.

• For patients: Exacerbation in the past 8 weeks

The definition of an exacerbation of COPD will follow the criteria by Anthonisen et al (6). This includes two or more of the following symptoms: worsening dyspnoea, increased sputum purulence, increased sputum volume, or one of these plus one of: upper respiratory tract infection during the past 5 days, fever without other cause, increased wheeze, increased cough or increased heart or respiratory rate by more than 20%.

• The presence of right-sided heart failure as indicated by physical examination.

• Inhalation medication < 12 hours (short-acting bronchodilation) or < 24 hours (long-acting) or < 3 hours inhaled corticosteroids

• Antihistamines, theofylline, and antibiotic use in the past 2 days

• Eating (including chewing gum), drinking, smoking, brushing teeth < 3 hours before measurements

• Bad technique in previous lung function tests

• Lack of comprehension of the study and measurements

• Pregnancy

• Hyper- or hypothyroid function or use of Levothyroxine

• Renal insufficiency