This book aims to give a comprehensive overview of the current challenges and solution posed to the health care professionals who need to use mechanical ventilation to treat their patients.Mechanical ventilation is a cornerstone of the treatment of critically ill patients, as also dramatically underlined aby the recent COVID-19 pandemic. The topic is not simple to approach, since it requires integration of multiple data which, in turn, result from complex interplays between patient's condition and ventilatory settings. While technological development empowered advanced monitoring and decision support, these also increase the burden of data on the practitioners. Furthermore, considering that sometimes mechanical ventilation is seen under two, apparently opposite, approaches, "physiology vs. Protocols", the book aims to reconcile these two aspects. And this has been done by each author following the above trajectory in their chapters.