Related Experiment Videos
Relation between nocturnal symptoms and changes in lung function on lying down in asthmatic children
A Greenough1, L Everett, J Pool
1Department of Child Health, King's College School of Medicine and Dentistry, London.
Insights
Nocturnal asthma symptoms in children are not solely caused by lung function changes when lying down. This study found no significant difference in lung function impairment between asthmatic children with and without nighttime symptoms.
Area of Science:
- Pediatric Pulmonology
- Respiratory Physiology
- Asthma Research
Background:
- Nocturnal symptoms are prevalent in young children with asthma.
- The supine posture may exacerbate lung function impairment, potentially causing nighttime asthma.
- Understanding the physiological basis of nocturnal asthma is crucial for effective management.
Purpose of the Study:
- To investigate the impact of the supine posture on lung function in asthmatic children.
- To determine if changes in lung function during supine rest correlate with nocturnal asthma symptoms.
- To identify potential physiological mechanisms underlying nocturnal asthma in pediatric patients.
Main Methods:
- Studied 31 children (20 with asthma, 11 controls), aged 2.8-8.3 years.
- Measured Peak Expiratory Flow (PEF) and Functional Residual Capacity (FRC) in sitting/standing and supine positions.
- Utilized Wright's peak flow meter and helium gas dilution technique for measurements.
Main Results:
- Peak expiratory flow significantly decreased in asthmatic children upon adopting the supine posture.
- No significant difference in PEF decline was observed between asthmatic children with and without nocturnal symptoms.
- Functional residual capacity decreased in the supine position, but this change was significant only in control and non-nocturnal-symptom asthmatic groups.
Conclusions:
- The findings suggest that increased lung function impairment in the supine posture does not fully explain nocturnal asthma symptoms in children.
- Other physiological or non-physiological mechanisms may be responsible for nighttime asthma exacerbations.
- Further research is needed to elucidate the complex factors contributing to nocturnal asthma.
Abstract:
Nocturnal symptoms are common in young asthmatic children. Such symptoms may be caused by increased impairment of lung function when they adopt the supine posture. Thirty one children aged 2.8-8.3 years were studied, of whom 20 had asthma (10 with frequent nocturnal symptoms) and 11 had no respiratory problems (control subjects). Peak expiratory flow (PEF) was measured with a Wright's peak flow meter and functional residual capacity (FRC) by a helium gas dilution technique after 30 minutes of lying supine; the values were compared with FRC measured sitting and PEF standing. Peak flow fell significantly on adoption of the supine posture in the asthmatic children, but there was no difference in this fall between the asthmatic children with and without nocturnal symptoms. FRC also fell on adoption of the supine posture, but the decrease in FRC was significant only in the control children and the asthmatic children without nocturnal symptoms. The failure to find a greater fall in PEF or a greater change in FRC on adoption of the supine posture among asthmatic children with nocturnal symptoms suggests that mechanisms other than increased impairment of lung function are responsible for nocturnal asthma.