Related Experiment Video
Updated: Jul 16, 2026
05:31
Noninvasive Sampling of Mucosal Lining Fluid for the Quantification of In Vivo Upper Airway Immune-mediator Levels
Published on: August 7, 2017
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
Summary
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.
Related Concept Videos
01:19Factors Affecting Pulmonary Ventilation
Besides the pressure difference between the external environment and the lungs, the airflow rate and ease of pulmonary ventilation are also influenced by three other factors: surface tension of the fluid in the alveoli, compliance of the lungs, and airway resistance.
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...
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...
01:29Asthma-I: Introduction
Asthma is a chronic respiratory ailment that requires careful management due to its varying symptoms and influencing factors. It is characterized by airway inflammation, bronchial hyperresponsiveness, and reversible airflow obstruction, leading to symptoms like wheezing, shortness of breath, chest tightness, and coughing. The symptom frequency and intensity may vary considerably over time. It is also linked to immune system responses to allergens and irritants, highlighting the complex...
01:24Asthma-III: Symptoms and Complications
Asthma, a common chronic respiratory condition, is classified considering the frequency and severity of symptoms alongside lung function impairment. Understanding this classification is essential for appropriate treatment and management. Here's a detailed look at the classification of asthma and its clinical features and complications:
Classification of Asthma
Classification of Asthma
01:30Asthma-IV: Diagnostic and Management
The diagnosis and management of asthma are comprehensive, encompassing clinical assessments, lung function tests, and pharmacological interventions. Here's an overview:
Clinical Assessment for Asthma:
This is the first step in diagnosing and managing asthma. It includes:
Clinical Assessment for Asthma:
This is the first step in diagnosing and managing asthma. It includes:
01:28Asthma I: Introduction
Asthma is a chronic inflammatory disorder of the airways characterized by variable airflow obstruction and heightened bronchial responsiveness to a wide range of triggers. The underlying inflammation leads to airway swelling, mucus hypersecretion, and smooth muscle constriction, all of which narrow the airway lumen and impede airflow. Clinically, asthma presents with recurrent episodes of wheezing, shortness of breath, chest tightness, and coughing, symptoms that typically vary in intensity and...
01:13Asthma III: Clinical Manifestations
Asthma presents with a characteristic pattern of episodic respiratory symptoms that reflect underlying airway inflammation, bronchoconstriction, and mucus hypersecretion. Although severity varies among individuals, certain clinical manifestations are considered hallmarks of the disorder and often guide diagnosis and assessment.Respiratory SymptomsA persistent cough is one of the most common early features of asthma. It is frequently dry and tends to worsen at night or in the early morning,...