Zhongguo quanke yixue (Nov 2022)
Association of Nasal Obstruction with Pulmonary Function and Airway Resistance during Tidal Breathing in Infants with Wheezing
Abstract
Background Measurement of lung function during tidal breathing is an important method in the diagnosis, management and severity assessment for infants with respiratory diseases. Nasal obstruction is a common comorbidity of respiratory tract infections, and severe nasal obstructionmay affect the results of pulmonary function test. Objective To assess the association of nasal obstruction with pulmonary function and airway resistance during tidal breathing, and to evaluate the effect of normal saline nasal drops on relieving nasal congestion and improving pulmonary function in infants with wheezing. Methods A total of 55 children with wheezing were included, including wheezing with nasal congestion in 25 cases and wheezing without nasal congestion in 30 cases. Fifty-five infants with wheezing as the chief symptom who were treated in the First Affiliated Hospital of Guangzhou Medical University were retrospectively selected from June 2015 to May 2016. They received the measurement of pulmonary function during tidal breathing, respiratory resistance using the respiratory resistance tester with single-breath method and body plethysmography. Nasal obstruction was assessed, and those with three points were excluded, the remaining infants with 0 and 1-2 points were assigned to wheezing without nasal obstruction group (n=30), wheezing with nasal obstruction group (n=25), respectively. Baseline lung functions were compared between wheezing with nasal obstruction group before nasal obstruction treatment and without nasal obstruction group. And pulmonary functions of wheezing with nasal obstruction group were compared before and after nasal obstruction treatment. Results Wheezing infants with nasal obstruction had higher specific effective airway resistance (sReff) and effective airway resistance (Reff) than those without (P<0.05). The ratio of the proportion of time to reach peak tidal expiratory flow to total expiratory time (TPTEF/TE) 〔 (24.58±6.15) % vs. (21.12±4.16) %〕and the ratio of the volume until peak expiratory flow to the total expiratory volume (VPEF/VE) 〔 (26.38±5.19) % vs. (22.98±3.75) %〕 improved significantly in wheezing infants with nasal obstruction after nasal obstruction was relieved by treatment compared to the baseline (P<0.05). The respiratory resistance (RrsSO), sReff and Reff decreased significantly in wheezing infants with nasal obstruction after nasal obstruction was relieved compared to the baseline (P<0.05) . Conclusion Nasal obstruction could increase the airway resistance (sReff and Reff) in wheezing infants. Pre-test nasal secretion clearance is one criterion in quality control of pulmonary function tests. Nasal obstruction caused by secretions could be effectively relieved by liquefying the secretions with a few drops of normal saline. The tidal breathing parameters (TPTEF/TE and VPEF/VE ratios) and airway resistance parameters (RrsSO, sReff and Reff) were improved after nasal obstruction was relieved.
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