A Study of Postural Variation in Peak Expiratory Flow Rates in Healthy Adult Female Subjects in South India

Abstract

Background: Peak expiratory flow rate (PEFR) reflects the strength and condition of respiratory muscles and the degree of airflow limitation in large airways. PEFR shows postural variation that follows a specific pattern in asthmatics and healthy individuals has been identified. Adequate data are not available for the postural variation in normal individuals, who are students in professional courses, and had a sedentary lifestyle. Lung volumes in normal subjects were significantly higher in a standing position. Others have reported that in healthy subjects spirometric indices were higher in the standing in comparison with the sitting position whereas other studies have reported no differences 
between spirometric values obtained in lying, sitting, and standing positions. Hence, this study is undertaken to study the postural variation in PEFR in healthy adult female subjects in South India.

Methods: PEFR was recorded in 50 adult healthy female students aged 18–23 years and studying in professional courses (MBBS, BDS, Nursing, and MSc). Mini wright’s peak flow meter was used to measure the PEFR. Three readings were taken PEFR in standing and lying posture. Best of three recordings is taken as the final value.

Results: PEFR is decreased in lying posture compared to standing posture in subjects studied, and the quantum of difference was noted.

Conclusion: In postural changes, PEFR measurements significantly differ based on whether the measurements are taken in the standing or in the lying posture in healthy participants. The effect of posture may be of importance in recording PEFR and changing to a better posture may be especially useful for those patients with weak expiration.