ACUTE EFFECTS OF POSITIVE PRESSURE ON AUTONOMIC MODULATION AND BRONCHIAL HYPER RESPONSIVENESS IN ASTHMATIC CHILDREN AND ADOLESCENTS

Costa D.¹, David M.C.², Carvalho-Mello M.², Dantas Gomes E.L.²

¹Nove de Julho University, Post Graduation Science Rehabilitation, São Paulo, Brazil, ²Nove de Julho University, São Paulo, Brazil

Background: Asthma is a chronic disease that presents an inflammatory process that coexists with a hyper responsiveness and an abnormality in autonomic balance. The treatment has been improved and in recent years the use of non-invasive ventilation (NIV) with positive pressure, which is a non-pharmacological treatment, has shown improvement in crisis and responsiveness, thereby minimizing the symptoms of the disease. The hypothesis of this study is that the NIV application after an exercise-induced bronchial provocation test (EIB) can improve sharply the autonomic balance, assessed by heart rate variability (HRV).

Purpose: Evaluate the autonomic modulation and clinical responses during testing of EIB and when applying positive pressure after testing.

Methods: cross-sectional study that was evaluating the HRV at rest, during testing of EIB (stable phase), in rest after 10 ´ of the EIB and during NIV with bilevel pressure with IPAP12 cmH2O and EPAP 8 cmH2O. Anthropometric evaluation was performed, the inflammation and lung function, and the clinical control by questionnaire ACQ6.

Results: were evaluated 55 asthmatic children with an average age of 10 ± 3.3 years, which were split in response to bronchial provocation test as responders group (RG) (n = 39) average FeNO 49.9±29.9 and not responders group (NRG) (n = 16) with FeNO average 48.3 ± 22.4 ppb. As the severity of the EIB: 18 (46.15%) showed reduced Fev1 between 10 and 24% classified as mild; 16 (41.02%) showed reduced between 25 and 49%, classified as moderate and, 5 (12.8%) classified as severe. There was significant difference between the RG and NRG in FVC% (RG = 93.3 ± 4.5/NRG = 100.8 ± 1.02) and clinical control by ACQ6 [RG = 1.16 (0.33 -2.0) partially controlled and NRG = 0.58 (0.2 -1.3) controlled]. As for the autonomic variables was found a significant difference in both time domain (TD), and in the frequency domain (FD) of the HRV, indicating an inhibition of the parasympathetic nervous system during testing of BIE that did not return to baseline levels after 10 minutes only after the use of the NIV in both groups, but the parasympathetic inhibition during bronchial provocation test in RG was higher than in the NRG.

Conclusion(s): It is concluded that the RG presents worse clinical control and forced vital capacity that the NRG, in addition to a less effective autonomic regulation. In both groups the NIV assisted in return of autonomic activity basal levels after bronchial provocation test by exercise, confirming our hypothesis that the NIV can improve sharply the autonomic balance in asthmatic children/adolescents.

Implications: Improve autonomic balance should be a concern in the treatment of asthma since it is part of the pathogenesis and control of the disease. The NIV may contribute to this non-pharmacological balance outpatient level.

Funding acknowledgements: CNPq, CAPES and FAPESP

Topic: Paediatrics

Ethics approval: Nove de Julho University Board, (1487225/2016)

All authors, affiliations and abstracts have been published as submitted.