Assessing the Correlation between the Results of Single Breath Counting and Peak Expiratory Flow Rate in Evaluation of pulmonary function among Patients Presenting to the Emergency Department with Acute Asthma Attack

Asthma is a chronic disease usually characterized by periodic wheezing, coughs, and shortness ofbreath as a result of hyper responsiveness and inflammation of the airway. The purpose of this study was to assessthe correlation between the results of single breath counting and peak expiratory flow rate methods in evaluation ofpulmonary function among patients presenting to the emergency department with acute asthma attack.

This cross-sectional study was performed on 33 patients with complaint of acute asthma attack before and after theinitial treatment, peak flowmetry, and Single Breath Counting (SBC) were performed. A checklist including age, sex,respiratory rate, blood oxygen saturation, asthma severity, SBC, and Peak Expiratory Flow Rate (PEFR) was filled outbefore and after treatment. Statistical analysis was performed to evaluate the relationship between data using SPSSv.26.

33 patients, including 13 women and 20 men with the mean age of 32.39±10.58 years were studied.Statistical analysis showed a significant direct linear relationship between SBC and PEFR before and after treatment,percentage of oxygen saturation changes, and between percentage of SBC changes with PEFR (r = 0.933, r = 0.915,and r = 0.892, respectively) and a significant inverse linear relationship was observed between PEFR and SBC withasthma severity (P <0.05). There was no significant inverse linear relationship between SBC and the percentage ofchanges in respiratory rate (r = -0.279, P> 0.05).

The results can indicate the competency of SBC toreplace PEFR in evaluation of pulmonary function in adult patients presenting to the emergency department withacute asthma attack.