Electrical Activity of the Diaphragm During Reverse Triggering - A Case Report

Reverse triggering is defined as diaphragmatic muscle contraction triggered by mandatory breath of ventilator. Reverse triggering induced double cycling and large tidal volume (VT) in Pressure Control Ventilation (PCV). An 81-year-old male was admitted to the ICU after tricuspid valve plasty. A close observation of graphic monitor showed a deflection of pressure waveform in the middle of mandatory breath. Electric activity of the diaphragm (EAdi) revealed diaphragmatic contraction following mandatory breath. When diaphragmatic contraction started at the end of mandatory breath it induced double-cycling. When it started at the middle of mandatory breath VT increased. As spontaneous breathing increased, reverse triggering disappeared. While the consequences of reverse triggering are under discussion, in our case it led double cycling and large VT, and it might be injurious. We should recognize it is more common than expected.