Establishing Normative Values of Peak Expiratory Flow Rates in the Paediatric Population in Jharkhand

Background The peak expiratory flow rate (PEFR) is the maximum flow rate (expressed as L/s) generated during a forceful exhalation, starting from full inspiration. It is an effort-dependent parameter and reflects large airway flow. It depends on lung recoil, muscular strength of patients, and voluntary effort. The PEFR is a simple and easy way to detect early changes in lung function. The PEFR can be measured by a peak flow meter or a spirometer; however, a spirometer is more accurate than a peak flow meter. The PEFR is known to vary according to age, gender, and anthropometric parameters like height, weight, BMI, ethnicity, and altitude. PEFR values for different populations are needed because they help to determine the variable expiratory flow limitation in asthma. There is no study done to find out the normal PEFR in children in Jharkhand. Hence, this study aimed to establish the reference values of the PEFR of children in Jharkhand. Methodology Three hundred and sixteen healthy children belonging to the age group of 6-18 years attending the OPD of Rajendra Institute of Medical Sciences, Ranchi were studied. All the children were asked to perform spirometry, and the PEFR was recorded. Patient demographic details like age, sex, height, weight, BMI, and ethnicity were documented. These factors were selected to see how the PEFR of children in Jharkhand correlated with them and compare it with the values obtained from similar studies conducted in different parts of India. Results Three hundred and sixteen children were studied, consisting of 194 male participants and 122 female participants. The mean PEFR for male participants was 3.90±1.58L/s and for female participants, it was 4.04±1.49L/s. The correlation coefficient of the PEFR with height was 0.792, that of the PEFR with weight was 0.713 and that of the PEFR with BMI was 0.364. Hence, height is the best predictor of PEFR. The lowest correlation of BMI with PEFR shows that the recent rise in obesity in the paediatric population should not be expected to affect the lung function significantly. Conclusion The mean PEFR of children in Jharkhand is lower than that of children in northern (mean PEFR of male participants =4.41 ± 1.54 L/s, mean PEFR of female participants = 4.17 ± 1.17 L/s) and southern India (mean PEFR of male participants = 4.88±1.29 L/s, mean PEFR of female participants = 4.25±1.29 L/s). Compared to neighbouring states in eastern India, the mean PEFR of children in Jharkhand is lower.