Fig. 6
Pressure escalation effects (autoPEEP). Comparison of altered I:E ratios during VCV with three different ETT sizes during insertion of a 16 Fr bronchoscope followed by suction at −765 cm H2O (−75 kPa) with flowtrigger (F/5). Presentation of tracings as in Fig. 2, with initial PPEAK MA 20 cm H2O and PEEP MA 5 cm H2O in all examples. Note that pressures drop to negative values when suctioning is performed with I:E ratio 1:1 and remain unchanged when the ratio is further inversed. Increased end-expiratory pressure (autoPEEP) develops during bronchoscope insertion as a result of progressive air trapping with high resistance and inverse I:E ratio