Exploring the usefulness of surface electromyography to evaluate the effect of PEEP on respiratory muscle activity during spontaneous ventilation

Mechanical ventilation is a life-sustaining treatment that is used when gas exchange or ventilation processes are compromised. When the airways resistance of patient increases, the time span of the expiratory phase is insufficient to exhale all the inspired volume. In order to maintain oxygenation and to reduce the workload of respiratory muscles, it is common to apply an extrinsic positive end-expiratory pressure (PEEP) that counterbalances the increased airways resistance. Several studies have demonstrated the usefulness of surface electromyography (sEMG) to quantify the work of breathing (WOB), particularly in patients with obstructive diseases. This paper explores the usefulness of sEMG of diaphragm and sternomastoid muscles to evaluate the effect of incremental PEEP in a group of ten healthy male volunteers (23.5 ± 2.5 years, 73.1 ± 12.1 kg, 173.8 ± 5.55 cm height), noninvasively ventilated for 20 minutes. The extrinsic PEEP was applied from 0 to 5 cmH₂O in steps of 1 cmH₂O at 30 seconds each. The exploratory study provided different breathing patterns changes on response to incremental PEEP that could be related to the state of their ventilatory mechanics which suggest that sEMG is an interesting tool to identify the patient dynamic response to changes in PEEP.