Limiting the Tidal Volumes in ARDS with Modern Ventilators

Recently, Wing and colleagues [19] showed that modern ventilators have an increasing number of optional settings that can change the size of the delivered tidal volume. These settings may increase the delivered tidal volume and disrupt a low tidal volume strategy. Recognizing how each setting within a mode affects the type of breath delivered is critical when caring for ventilator-dependent patients. The AVEA has two options in volume A/C: demand breaths and V-sync. When activated, these options allow the patient to exceed the set tidal volume. When using the Evita XL, the option Auto-Flow can be turned on or off, and when this option is on, the tidal volume may vary. The PB 840 does not have any additional options that affect volume delivery, and it maintains the set tidal volume regardless of patient effort. The SERVO-i’s demand valve allows additional flow if the patient’s inspiratory flow rate exceeds the set flow rate, increasing the delivered tidal volume; this option can be turned off with the latest software upgrade. The continuous monitoring of the low tidal volumes during the ARDS ventlatory support must be implemented in our ICUs in order to guarantee that a protective ventilation is continuously offered to our ARDS patients.