Peak flow meter and digital spirometer: A comparative study of peak expiratory flow rate values

Abstract

Background: Peak expiratory flow rate (PEFR) is one of the important and widely used lung function tests as it is very easy, reliable, and reproducible. PEFR is very sensitive and accurate index of airway obstruction and the strength of respiratory muscles. Many factors are known to affect its value such as age, sex, height, and body surface area, the normal range for males and females is 450–550 L/min and 320–470 L/min, respectively. PEFR can be determined using both peak flow meter and digital spirometer. Peak flow meter is a simple inexpensive handheld device; hence, it is relatively easy to measure PEFR by peak flow meter. The digital spirometers measure PEFR along with various other lung function parameters. It has been recorded in the previous studies that the PEFR values given by various peak flow meters and spirometer varies, in laboratory calibration tests, the error has been shown up to 26%. The present comparative study is undertaken to determine whether the PEFR values derived from peak flow meter and spirometer has any significant difference or not. Aims and Objectives: The objective of the study was to determine and compare the PEFR values using peak flow meter and digital spirometer. Materials and Methods: The study comprises 200 healthy male medical students in the age group of 18–25 years, conducted in the Department of Physiology, Bidar Institute of Medical Sciences, after obtaining ethical clearance from the Institutional Ethical Committee. The subjects will be instructed about the procedure for recording PEFR. All the subjects will be made acquainted with peak flow meter and spirometer before actual recording. PEFR will be recorded in sitting position. Three readings will be taken and the best among these will be taken as final value. Results: The mean PEFR measured by peak flow meter and spirometer was 338.7 ± 122.45 L/min and 299.6 ± 121.63 L/min, respectively. PEFR value is significantly greater when measured by peak flow meter than by spirometer (P < 0.05). Conclusion: Even though the values measured by both instruments vary, still the peak flow meters can still be advised for measuring PEFR in healthy individuals and daily monitoring of symptoms in asthma and chronic obstructive pulmonary disease patients as these are not very expensive, and procedure can be easily performed by all and repeated tests give almost same results.