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Peak flow variation in childhood asthma: a three-year analysis

J E Gern1, P A Eggleston, K C Schuberth

  • 1Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD.

The Journal of Allergy and Clinical Immunology
|April 1, 1994
PubMed

Insights

Peak expiratory flow (PEF) variation may not accurately reflect individual asthma control. However, mean diurnal variation (MDV) can be a useful indicator of asthma severity in group studies.

Area of Science:

  • Pediatric Pulmonology
  • Allergy and Immunology
  • Respiratory Medicine

Background:

  • Peak expiratory flow (PEF) variation is proposed as an indicator for asthma severity and bronchial hyperreactivity.
  • Assessing PEF variation's utility in tightly controlled allergic asthma requires further investigation.

Purpose of the Study:

  • To examine the relationship between PEF variation, methacholine reactivity, symptom scores, and medication needs in children with allergic asthma.
  • To determine if PEF variation is a reliable indicator of asthma severity and bronchial hyperreactivity.

Main Methods:

  • Studied 74 children with allergic asthma, measuring PEF variation (mean diurnal variation - MDV), methacholine reactivity, symptom scores, and medication requirements.
  • Longitudinal analysis of 33 children over 36 months to track changes in MDV and other asthma variables.

Main Results:

  • Statistically significant correlations were found between MDV and methacholine reactivity (r=0.43) and symptom scores (r=0.28).
  • Visit-to-visit changes in MDV did not consistently reflect changes in other asthma metrics.
  • Group MDV decreased over time, particularly in those with higher initial MDV, coinciding with reduced medication needs and methacholine reactivity.

Conclusions:

  • Children with moderately severe, tightly controlled asthma may exhibit normal PEF variation.
  • The correlation between PEF variation and asthma variables is too weak for individual patient treatment decisions.
  • Mean diurnal variation (MDV) shows potential as a useful indicator of asthma severity in group research.

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