Influence of Inspiratory Pause on Ventilatory Efficiency in Robotic Surgery. A Prospective Paired Study.

In the researchers' words

The investigators aim to determine if the modification of the end inspiratory pause (EIP) during mechanical ventilation adds benefit when applied to patients undergoing robotic surgery and who are ventilated under an individualized open lung approach (iOLA) strategy. The EIP is an adjustable parameter of volume controlled ventilation modes usually set as a percentage of the total inspiratory time. It represents the phase comprised between the moment in which the volume programmed in the ventilator has already been administered (which marks the end of the inspiratory flow), and the opening of the expiratory valve (which marks the beginning of expiration). The investigators will study whether modifications of the EIP produce variations in the "quantity" of the lung that participates in gas exchange (respiratory volume). To do so, the investigators will sequentially apply different EIP to participants (paired study). The investigators´ hypothesis is that increasing the EIP up to a level, may diminish the lung volume that does not participate in breathing (the physiological dead space- VDphys), thereby increasing the respiratory volume. To note: the VDphys includes the "conduction" volume, that represented by trachea, bronchi, et cetera, which is in charge of driving the "air" towards the respiratory zones, and the alveolar dead space (those zones of the respiratory volume that…