ASSESSMENT OF THE MECHANICAL POWER TRANSMITTED TO THE PATIENTS WITH MECHANICAL VENTILATION IN INTENSIVE CARE UNITS "MECHANICAL POWER DAY"

Introduction and justification:

Over the last few years the investigators have witnessed an important technological developement in the field of mechanical ventilation. Along with the technological advances, the better understanding of the respiratory physiopathology has shown that mechanical ventilation "per se" can lead to deleterious effects.

In this context, the search for those variables which are responsible for the developing of ventilator-induced lung injury (VILI) has become an important goal in this field. In fact, the investigators are witnessing the nearly exponential increase in the publication of studies that have tried to associate the different parameters that intervene in mechanical ventilation with the injury to the lung structure.

Recently the new concept of "mechanical power" has been proposed. It refers to the amount of energy per minute that is transferred to the lung by the ventilator. The generation of this form of energy would include both parameters that were previously proposed to be possible causes for lung damage and new parameters that had not been taken into account until now, such as the flow rate or the respiratory rate, without forgetting the individual characteristics of each ventilated subject.

12J/min has been stablished experimentally as the energy threshold from where changes in the lung that can lead to VILI begin to appear. Nevertheless, the true issue would be to get to know the best way to normalize the mechanical power value. However, it seems reasonable to think that the values of energy originating VILI in experimental animal models and in humans are different.