Related Experiment Video
Updated: Jul 11, 2026

Method to Obtain Pattern of Breathing in Senescent Mice through Unrestrained Barometric Plethysmography
Published on: April 28, 2020
Correlates of peak expiratory flow lability in elderly persons
P L Enright1, R L McClelland, A S Buist
1College of Public Health, University of Arizona, Tuscon, AZ 85724, USA. lungguy@aol.com
Peak expiratory flow (PEF) lability is common in the elderly, especially those with asthma. Home monitoring of PEF lability proves successful and can identify abnormal respiratory function in older adults.
Area of Science:
- Gerontology
- Pulmonology
- Respiratory Medicine
Background:
- Peak expiratory flow (PEF) lability, a measure of respiratory variability, is not well-characterized in the elderly population.
- Understanding factors influencing PEF lability is crucial for diagnosing and managing respiratory conditions in older adults.
Purpose of the Study:
- To identify correlates of peak expiratory flow (PEF) lability in individuals aged 65 years and older.
- To establish normal ranges and predictors of abnormal PEF lability in the elderly.
Main Methods:
- A community-based sample of 4,581 elderly participants from the Cardiovascular Health Study were assessed.
- A subset of 1,836 participants underwent home-based twice-daily PEF monitoring for two weeks.
- PEF lability was calculated using the formula: (highest daily PEF - lowest daily PEF) / mean daily PEF.
Main Results:
- Home PEF measurements were accurate compared to spirometry.
- Mean PEF lability was higher in individuals with current asthma (18%) versus healthy non-smokers (12%).
- Abnormally high PEF lability (>29%) was observed in 26% of asthmatics and 14% of others. Independent predictors included race, smoking history, airway obstruction, daytime sleepiness, and respiratory symptoms.
Conclusions:
- Home monitoring of PEF lability is feasible and successful in the elderly.
- PEF lability of 30% or greater is considered abnormal in the elderly and is associated with asthma.
Related Concept Videos
Respiratory Volumes
Tidal Volume (TV) Tidal volume (TV) is the air inhaled or exhaled in a...
Assessment of Ventilation II: Respiratory Depth and Rhythm
Respiratory depth measures the volume of air inhaled or exhaled during a breath. It can vary from shallow to deep and typically remains consistent when a person is at rest or asleep. Occasionally, individuals will automatically inhale deeply, known as sighing, which inflates the lungs with more air than normal breathing.
To assess respiratory depth, observe the degree of chest excursion or movement:
Factors Affecting Pulmonary Ventilation
Alveolar Surface Tension
The alveolar fluid lines the luminal surface of the alveoli and exerts a force called surface tension. This force is caused by the polar water molecules in the liquid being more strongly attracted to each...
Physical Assessment of the Respiratory Tract II: Inspection
Chest Configuration
The chest configuration can...
Chronic Obstructive Pulmonary Disease-IV: Assessement and Diagnostic Studies
Medical History
Pulmonary Function Tests
Pulmonary Function Tests are crucial diagnostic tools for assessing respiratory function, particularly in patients with chronic respiratory disorders. They comprehensively evaluate lung volumes, ventilatory function, breathing mechanics, diffusion, and gas exchange. These tests help diagnose pulmonary diseases and play a significant role in monitoring disease progression, evaluating disability, and assessing response to therapy.
PFTs involve using a spirometer, a...

