Electromyography of the diaphragm in infants: Where technique becomes practice

The studies presented in this thesis investigated the use of transcutaneous electromyography of the diaphragm (dEMG) in (preterm) infants and children. The underlying objective was to improve current cardiorespiratory monitoring and possibly implement this technique as an aid in the titration of respiratory support in critically-ill children admitted to the neonatal (NICU) or pediatric intensive care unit (PICU). With dEMG the electrical activity of the diaphragm is measured, using skin electrodes. As the diaphragm is the main respiratory muscle, monitoring its function throughout ICU admission could provide relevant information on the patient’s respiratory condition.
The thesis investigated the methodology of dEMG, its potential use for patient monitoring in the delivery room and its use as a clinical tool in the ICU to monitor work of breathing, investigate weaning of respiratory support and assess patient-ventilator interaction. The methodological studies show that while interpreting the measurements, the positioning of the electrodes and analysis of the recordings should be considered, as these factors impact signal strength. The clinical studies show dEMG is a feasible technique in both the NICU- and the acute setting (in the delivery room). In both settings the effect of respiratory support on the activity of the diaphragm has been investigated. In the NICU, the correlation between diaphragm activity and work of breathing has been assessed. Lastly, dEMG has shown to be useful to investigate the interaction between the patient and the ventilator during non-invasive respiratory support, showing high levels of patient-ventilator asynchrony.
All studies support further research to implement dEMG as a continuous monitoring tool for respiratory effort in the NICU and PICU. In the not too distant future dEMG might be useful to monitor work of breathing and improving synchronization of respiratory support with spontaneous breathing in these critically-ill infants.