Persisting airflow limitation in asthmatics receiving routine self-adjusted medication

Area of Science:

• Pulmonology
• Respiratory Medicine
• Asthma Research

Background:

• Asthma management involves patient-adjusted medication for symptom control.
• Assessing airflow limitation is crucial for understanding asthma severity and progression.

Purpose of the Study:

• To investigate the prevalence and characteristics of Persistent Airflow Limitation (PAL) in moderate asthma.
• To evaluate the utility of peak expiratory flow (PEF) in identifying PAL compared to spirometry.
• To explore the relationship between PAL and patient factors like age and asthma duration.

Main Methods:

• Sixty-two moderate asthma patients self-adjusted medication and recorded daily PEF for 8 months.
• Spirometry and PEF measurements were taken monthly, with and without bronchodilator administration.
• Persistent Airflow Limitation (PAL) was defined as consistently low measurements (below predicted minus 2 SD), assessed using both FEV1 and PEF.

Main Results:

• PAL was identified in 7/62 patients using FEV1 and in 27/62 patients using PEF.
• PAL prevalence was significantly associated with older patient age and longer asthma duration (p < 0.02).
• Home-recorded PEF correlated well with in-clinic flow-volume curves, and lower expiratory flows at 50% and 25% of FVC were observed in patients with PAL.

Conclusions:

• Peak expiratory flow (PEF) is a valuable tool for identifying Persistent Airflow Limitation (PAL) in moderate asthma, potentially indicating more severe small airways dysfunction.
• PAL is more prevalent when assessed by PEF than FEV1 in this cohort.
• Age and duration of asthma are significant factors associated with the presence of PAL.