Reference value of peak cough flow in Thai subjects aged 20-90 years

Abstract

Cough is a defense mechanism that protects the airways from aspiration and clears secretions. Ineffective cough is risk to respiratory complications. Cough capacity can evaluated by peak cough flow (PCF) which measurement is noninvasive method, a simple and convenient. However, reference value of PCF in Thai population has not been investigated. Therefore, the aimed of the present study was to assess reference valve of PCF in Thais and to determine the relationship between PCF and age in Thai people. A total 386 participants (male 123 and female 236) between 20-90 years old (mean 52.31 ± 14.87 years). PCF was investigated by using Mini Wright peak flow meter. Results showed that the PCF values ranged between 200 - 700 L/min. The PCF values were significantly higher in male than in female (421.30 ± 99.16 และ 325.93 ± 68.75 L/min.; p<0.001, respectively) and age was negatively correlation with PCF (r= -0.331, p<0.001). In conclusion, the values for subjects regarding PCF were between 200 - 700 L/min. The PCF was inversely proportional to age. Therefore, people who had PCF value less than the reference value was indicated to reduce cough capacity and is a risk of infection in the respiratory tract easily.

Key words: Cough, cough peak flow, maximal respiratory pressure, physical therapy