Assessment of Asthma in Children Using Electromyography

Autor: P. Keijzer, B. Thio, F. de Jongh, J. Driessen
Rok vydání: 2019
Předmět:
Zdroj: D30. ASTHMA: WHAT’S NEW IN ASSESSMENT AND TREATMENT?.
DOI: 10.1164/ajrccm-conference.2019.199.1_meetingabstracts.a6106
Popis: Rationale - Asthma is one of the most common chronic diseases in childhood, occurring in up to 10% of all children. Exercise induced bronchoconstriction (EIB) is indicative of uncontrolled asthma and can be assessed by means of an exercise challenge test (ECT). These tests however draw heavily on healthcare resources and require demanding repetitive forced breathing manoeuvres of children. In this study the electric activity of the respiratory muscles was measured as a tool to assess EIB. Methods - Children suspected of exercise induced respiratory symptoms performed an ECT wearing a portable EMG amplifier (Dipha-16, Demcon Macawi respiratory systems, Enschede, the Netherlands). EIB was defined as a fall in FEV1 of greater than 13%. Electrodes were placed bilaterally at the diaphragm and accessory breathing (intercostal-, sternocleidomastoid- and trapezoid) muscles. A single reference electrode was placed at the sternum. Children were asked to sit still for 30 seconds after each spirometry measurement to obtain EMG measurements. Data was pre-processed and analyzed in Matlab. Results - 20 Out of 43 children were diagnosed with EIB. Peak amplitude measured at the diaphragm increased significantly more in children with EIB than in children without EIB; 4.85uV (1.82 - 7.84), compared to 0.20uV (-0.10 - 0.54); (P < 0.001) at the point of maximal bronchoconstriction. Increases in EMG peak heights at the diaphragm can accurately distinguish between EIB and non-EIB (Sensitivity 95%, Specificity 91%, AUC 0.973). Increase in activity at the diaphragm is related to the decrease in pulmonary function (Pearson's R = 0:77; R2 = 0.58; P < 0.001). Accessory breathing muscles were often not measurable at baseline, therefore accurate assessment of the changes in activity in response to exercise could not be attained. Conclusion - These results imply that EMG measurements of the diaphragm can be used to accurately distinguish between EIB and non-EIB in children. Larger increases in peak amplitude suggest an increased work of breathing as is expected in children with EIB. Moreover, we found a relation between the decrease in pulmonary function and the increase of EMG peak activity. This technique provides opportunities to non-obtrusively measure bronchoconstriction when spirometry is not feasible or available and may be applied in the clinical setting, such as emergency medicine or in hospital- or home monitoring
Databáze: OpenAIRE