Reference Value of Nasal Peak Inspiratory Flow Rate in Indian Children: A Cross-sectional Study

Abstract

Introduction: Peak Nasal Inspiratory Flow (PNIF) measurement is a basic, convenient, easy to use and low cost method of determining the nasal airway patency. However, normative data for paediatric population is scarce and not available for Indian children aged 6 to 12 years. Aim: To establish reference value of PNIF in Indian children aged 6 to 12 years of age. Materials and Methods: A descriptive cross-sectional study was conducted between July 2012 and June 2013 in the Himalayan range of east Sikkim district and Sub-Himalayan Terai region of Darjeeling district of West Bengal. Total 1001 children aged 6 to 12 years were selected from 16 schools by simple random sampling. Of these 1001 children, 784 children were enrolled in the study after taking into account inclusion and exclusion criteria. Repeated PNIF measurements were taken from these 784 children. Mean PNIF value was calculated. The effect of age and height on PNIF was studied. The mean and standard deviation of Peak Inhalation Flow Rate (PIFR) are calculated and compared across groups using a one-way ANOVA test. Regression analysis was done to establish an equation of predicting PNIF level based on height for normal children. The analysis was carried out using Statistical Package for Social Sciences (SPSS) version 16 statistical software. An alpha level of 5% was chosen, which means that any p-value less than 0.05 was considered significant. Results: Mean value of PNIF age group; 6-7 years-53.36 L/min, >7-8 years-56.79 L/min, >8-9 years-63.91 L/min, >9-10 years- 69.45 L/min, >10-11years- 80.71 L/min, >11-12 years-85.69 L/ min. PNIF increases with age and height. A simple formula has also been established to calculate mean PNIF at a given height. PNIF or PIFR (L/min)=-52.716+0.945×height in cm. Conclusion: PNIF measurements are possible in children aged six years and older. Age and height also affect PNIF.