Patients in VCV did not trigger the ventilator based on the absence of spontaneous respiratory rate as assessed by continuous observation of the ventilator tracings during the procedure.
Vaschetto et al. [19] compared a systematic approach based on daily screening of meaningful physiologic and clinical variables followed by SBT with direct disconnection from the ventilator based on the sole physician's judgment in reducing the rate of reconnection to the ventilator within 48 h; however, the trial was prematurely interrupted due to a high rate of reconnections.
FRC was calculated using an automated procedure available on the ventilator based on the nitrogen washout method with a FiO2 step change of 0.1, as previously described by Olegard et al. [ 13].
Based on the different mechanisms producing ventilator induced lung injury (for example, lung over-distension, concentration of mechanical forces, propagation of liquid-gas interfaces, cyclic recruitment of small airways and alveoli, associated biotrauma) and the variability of disease in humans, each patient will require an individualized form of "protective" ventilation.
This method is based on the ability of modern ventilators to set the inspiratory pressure very accurately and independently from the expiratory pressure.
Sinderby et al. [16] developed an automated, objective and standardized neural index to quantify patient ventilator interaction (NeuroSync) based on the measurements of EAdi and ventilator pressure waveforms.
Each institution defined its own start date based on the availability of electronically captured ventilator data.
Based on the Campbell diagram, the patient and ventilator WOB were estimated on a breath-by-breath basis.
Additionally, one certified respiratory therapist covered a maximum of six ventilated patients and took care of the patient from the respiratory point of view which included maintenance of the airway, cuff pressure measurement and maintenance and ventilator adjustment based on the patient requirement.
There was a strong linear correlation between total WOB calculated by the ventilator and total WOB based on the Campbell diagram (r 2 = 0.93, p < 0.001, Fig. 4).
