An evaluation of peak expiratory flow monitoring: a comparison of sitting versus standing measurements.

Introduction: Current guidelines for the diagnosis and management of asthma suggest that patients perform peak expiratory flow (PEF) measurements while standing; however, recent literature suggests this may not be necessary. The purpose of this study was to determine the impact of patient position on PEF measurements. Methods: A randomized observational analysis of PEF measurements for 211 patients in sitting and standing positions was performed. The highest PEF measurement from tests performed with correct technique in both the sitting and standing position was compared. Results: Overall, PEF measurements did not significantly differ between the sitting and standing positions (506 ± 2 L/min versus 508 ± 2 L/min; P = .45). No differences were seen between mean PEF measurements in the sitting or standing positions for either women or men, nor were there significant differences between mean PEF values for the sitting and standing positions in participants who reported a history of asthma. Conclusions: PEF measurements do not significantly differ based on sitting or standing measurements among healthy participants. Based on the results of this study it may not be necessary for the patient to stand while performing PEF measurements. Further study among patients with asthma is warranted.