Application of Peak Nasal Inspiratory Flow reference values in the treatment of allergic rhinitis.

OBJECTIVE: To assess the applicability of the Peak Nasal Inspiratory Flow (PNIF) curves in follow-up of children in the treatment of allergic rhinitis. METHODS: Prospective study of 40 patients with AR, grouped in corticosteroid spray versus physiological saline solution use. Follow up for 10 weeks through clinical score and PNIF percentages in relation to the reference curves, with was-out at week 8. Statistical assessment of the effect of treatment on variation of PNIF and clinical score was calculated by ANOVA model and Multiple Comparison of Means Test - Least Significant Difference. RESULTS: There was a statistically significant influence of the group, time and interaction between time and group on PNIF percentages. Throughout follow up, patients from the treatment group had mean PNIF percentages significantly higher than the placebo group. Clinical score results also demonstrated a statistically significant influence between the groups, time and interaction between time and group. CONCLUSION: Increase in PNIF percentage values observed in children treated with intranasal corticosteroids revealed the applicability of PNIF curves in their follow up.

Reference values for peak nasal inspiratory flow in children and adolescents in Brazil.

STATEMENT OF THE PROBLEM: Allergic rhinitis is a global public health issue. Peak nasal inspiratory flow (PNIF) can help in the assessment of patients with allergic rhinitis. However, reference values in the literature for PNIF in school children and adolescents are limited. THE AIM OF THIS STUDY was to identify reference values of PNIF among children and adolescents. METHODS: We conducted a cross-sectional study to identify reference values of PNIF among healthy school children and adolescents aged from eight to fifteen years old, selected from 14 randomly selected public schools. Participants performed measurements of PNIF using the In-check-inspiratory flow meter (Clement Clarke, Harlow, England). PNIF values were correlated to gender, age, height, weight and body mass index. RESULTS: A total of 526 subjects participated in the study. The final linear regression model for PNIF allowed obtaining the following equation for subjects aged from eight to 15 years old: PNIF (l/m) = height (centimeters) x 0.7 + 11.2, for boys and PNIF (l/m) = height (centimeters) x 0.7, for girls. CONCLUSION: the equations of the final regression model resulted in a simple formula to obtain reference values of PNIF for subjects aged from 8 to 15 years old.

Correlations between pulse oximetry and peak expiratory flow in acute asthma.

Few studies are available concerning correlations between pulse oximetry and peak expiratory flow in children and adolescents with acute asthma. Although the Global Initiative for Asthma states that measurements of lung function and oximetry are critical for the assessment of patients, it is not clear if both methods should necessarily be included in their evaluation. Since there is a significant difference in cost between pulse oximetry equipment and peak expiratory flow devices, we determined whether clinical findings and peak expiratory flow measurements are sufficient to determine the severity of acute asthma. The present prospective observational study was carried out to determine if there is correlation between pulse oximetry and peak expiratory flow determination in 196 patients with acute asthma aged 4 to 15 years diagnosed according to the Global Initiative for Asthma criteria. Patients experiencing their first or second wheezing episode, with fever, related acute or chronic diseases, and unable to perform the peak expiratory flow maneuver were excluded. Measurements of peak expiratory flow and pulse oximetry were performed at admission and after 15 min of each inhaled salbutamol cycle. Correlations obtained by linear regression using the Pearson correlation coefficients (r) were 0.41 (P < 0.0001), 0.53 (P < 0.0001), 0.51 (P < 0.0001), and 0.61 (P < 0.0001) at admission and after the first, second and third cycles of salbutamol, respectively. These correlations showed that one measure cannot substitute the other (Pearson's coefficient <0.7), probably because they evaluate different aspects in the airways, suggesting that peak expiratory flow should not be used alone in the assessment of acute asthma in children and adolescents.