RESUMEN
BACKGROUND: Upper airway obstruction may cause pulmonary hypertension in childhood. In this study we aimed to identify a possible correlation of systolic pulmonary arterial pressure (SPAP), using Doppler echocardiography, with nasal patency (NP), as measured by rhinomanometry, in mouth-breathing (MB) children with allergic rhinitis (AR) and adenotonsillar hypertrophy (ATH). METHODS: In this cross-sectional study we evaluated 183 patients, from 2 to 12 years of age, at an MB referral clinic in Brazil, from December 2013 to 2017. We allocated patients to 4 etiology groups: group 1, 60 MBs with ATH; group 2, 47 MBs with AR; group 3, 43 MBs with both ATH and AR; and group 4, 33 nasal breathing control subjects. The ratio of total nasal inspiratory flow (assessed by active anterior rhinomanometry) and expected inspiratory flow adjusted for height determined the percent NP (%NP). RESULTS: The median %NP was higher in controls than in the MB groups (controls, 114% [79-147%]; ATH: 65% [5-116%]; AR: 57% [23-144%]; ATH and AR: 64% [3-120%]; p < 0.001). Median SPAP was higher in the MB groups than in controls (SPAP: ATH, 26.0 [20.0-35.0] mmHg; AR, 26.0 [22.0-32.0] mmHg; ATH and AR, 26.30 [20.0-34.0] mmHg; control, 22.0 [16.0-30.0] mmHg; p < 0.001). SPAP showed a negative association with %NP (Spearman's rho = -0.24; p < 0.001). CONCLUSION: Reduced nasal airflow in MB children showed a correlation with higher levels of systolic pulmonary arterial pressure. The AR and ATH groups were similar in nasal obstruction severity and systolic pulmonary arterial pressure level distribution.