Normal values and evaluation of forced end-expiratory flow.

Area of Science:

• Pulmonary Medicine
• Respiratory Physiology
• Diagnostic Spirometry

Background:

• Spirometry is crucial for assessing lung function.
• Identifying sensitive markers for early detection of obstructive lung diseases is essential.
• Existing measures like forced mid-expiratory flow (FEF25-75%) have limitations in early disease detection.

Purpose of the Study:

• To evaluate the utility of forced end-expiratory flow (FEF75-85%) as a novel spirometric measurement for detecting early obstructive pulmonary disease.
• To compare the performance of FEF75-85% with FEF25-75% in relation to age, height, smoking status, and disease presence.

Main Methods:

• Conducted spirometry on 803 healthy adults to establish prediction formulas for FEF75-85%.
• Compared FEF75-85% and FEF25-75% in smokers vs. non-smokers and in patients with peripheral airway disease.
• Assessed the diagnostic value of FEF75-85% using predicted values and standard error of estimate.

Main Results:

• FEF75-85% demonstrated a negative correlation with age and a positive correlation with height.
• FEF75-85% significantly differentiated smokers from non-smokers, unlike FEF25-75%.
• In patients with peripheral airway disease, FEF75-85% was markedly reduced compared to predicted values, showing greater sensitivity than FEF25-75%.

Conclusions:

• FEF75-85% is a sensitive spirometric parameter for detecting early obstructive pulmonary disease.
• This measurement shows greater diagnostic value in identifying smokers and patients with airway obstruction compared to FEF25-75%.
• FEF75-85% is proposed as a simple and effective ventilatory test for screening populations for early lung disease.