Single Breath Counting in the Assessment of Pulmonary Function

Abstract

Study objectives: To assess the correlation of single breath counting (SBC) and peak expiratory flow rate (PEFR) to forced expiratory volume in the first second (FEV 1 Design: Prospective comparison of pulmonary function measurements. Setting: University hospital pulmonary function test (PFT) laboratory. Type of participants: Consenting patients scheduled to have PFTs May 1, 1992, through November 1, 1992. Interventions: SBC was measured by asking patients to take a deep breath and count as far as possible in their normal speaking voice without taking another breath. Counting was timed to a metronome set at 2 counts per second. A hand-held peak flowmeter was then used to measure PEFR. Standard PFTs then were performed. Measurements and main results: Twenty-two patients were enrolled. The correlation of SBC to FEV 1 ( r=.68) was slightly better than of PEFR to FEV 1 ( r=.63). SBC was also found to correlate well with PEFR ( r=.68). Conclusion: SBC is a reasonable alternative to PEFR. Further investigation in an emergency department setting is warranted. [Bartfield JM, Ushkow BS, Rosen JM, Dylong K: Single breath counting in the assessment of pulmonary function. Ann Emerg Med August 1994;24:256-259.]