Fig. 1
From: Time-based capnography detects ineffective triggering in mechanically ventilated children
Representative example of ineffective triggering visible in the time-based capnogram. Recording of ventilator flow (V′), airway pressure (Paw), oesophageal pressure (Poes) and end-tidal CO2 versus time tracings. The interrupted red line marks an ineffective patient effort. Ineffective triggering visible as a negative deflection in the time-based capnogram can only occur when gas flow that does not contain CO2 passes through the sensor. As a consequence, detecting ineffective triggering cannot be done using the time-based capnogram when there is a concomitant flow < 0 L/min. When flow during this effort is becoming > 0 L/min, a negative deflection in the Paw and Poes tracings with a concomitant negative deflection in the time-based capnogram can be seen