Effect of body positions on peak expiratory flow rates in adult asthmatics

Background: The National Institute of Health asthma guidelines recommend assessing PEF during hospitalization including improvement to a PEF of >70% of the predicted value before discharge. The Global Initiative for asthma recommends monitoring of PEF in hospitalized patients. Current guidelines for correct PEF maneuver include standing, but it has been observed that many respiratory therapists and patients use supine position. Aim: To determine which one of the 3 different positions i.e. standing, lying back at 450 angle on pillows and sitting up slumped forward 100 with legs extended generates higher peak expiratory pressure and can be used as optimal position for generating peak expiratory flow in asthmatics. Materials and methods: A cross sectional study was performed in 20 asthmatic subjects aged 18-50 years in whom correct instructions for PEF technique were given according to guidelines of National Institute of Health. The steps were repeated 3 times in each position and the best of 3 attempts in each of the 3 positions were used for analysis. Level of significance kept at 5%. Results: Mean and SD of lying back at 450 was 254.5±29.28, sitting up with slumped forward 100 was 281±28.26 and that of standing was 302.5±27.88. Statistically significant result was found using nonparametric test i.e. Friedman test where χ2=40 and p=0.0001. Conclusion: There is significant difference between PEFR values in standing, sitting with slump forward 100 and lying back 450 position. Standing position is the best option for adult asthmatics to measure their PEF values as it generated maximum PEF.