The image (Fig. 1) shows a registry of the electrical activity of the diaphragm using a neurally adjusted ventilatory assist (NAVA) esophageal catheter in a patient being ventilated in pressure control mode. The figure at the bottom superimposes two registries: pressure-time (yellow tracing) and electrical activity-time (grey tracing).

Figure 1

(0.44MB).

All inspirations are mandatory (yellow arrows). However, during each mandatory inspiration, the patient experiences spontaneous inspiration reflected by an increase in electrical activity of the diaphragm (grey arrows). This event coincides in time with a series of negative inflections in the pressure registry (white asterisks).

The registry corresponds to a patient with acute respiratory distress syndrome who suffers reverse triggering.