Feasibility and reproducibility of pulmonary function tests in preschoolers

Abstract

Relevance: Preschoolers present particularities that reinforce the importance of assessing their pulmonary function; however few studies have focused on pulmonary function tests in this population.

Purpose: To assess the feasibility of assessing breathing pattern through inductive respiratory plethysmography, spirometry and peak cough flow (PCF) in healthy preschoolers, as well as the test-retest reproducibility of these tests.

Methods: It was assessed the breathing pattern (tidal volume-Vt; respiratory frequency-f, inspiratory time -Ti, inspiratory duty cycle-Ti/Ttot, mean respiratory flow-Vt/Ti and rib cage motion-%RC), spirometry (forced vital capacity-FVC, forced expiratory volume in 0.5 second-FEV_0.5 and FEV_0.5/FVC) and PCF of 38 healthy children aged 4.8±0.6 years. To evaluate the test-retest reproducibility, 10 children (according to sample size calculation) were reassessed after three weeks. The study was approved by Ethics Committee. Feasibility was defined as the rate of success achieved by the children. Test-retest reproducibility was evaluated by paired t-test, considering significant p<0.05, and Intraclass Correlation Coefficient (ICC).

Results: The results showed a rate of successes of 100% for breathing pattern, 84% for spirometry and 90% for PCF. Regarding the reproducibility, there were no significant differences between the variables of any test and it were observed the following ICC values: Vt=0.74, f=0.87, Ti=0.88; Ti/Ttot=0.95, Vt/Ti=0.68,%RC=0.66, FVC=0.92, FEV_0.5=0.81, FEV_0.5/FVC=0.75, PCF=0.85.

Conclusions: These results suggest high rate of success in performing the pulmonary function tests and good test-retest reproducibility in healthy preschoolers.