The 3 rd and updated edition of this book represents a new and unique scientific reference for the medical community on how to understand rationale and applications of noninvasive mechanical ventilation (NIMV). Its aim is to establish the indications of NIMV in critically ill patients in weaning from invasive MV. Nowadays, there is a growing evidence-based medicine that recommends use of NIMV in patients after extubation or in difficult weaning patients also affected by comorbidities. This book has been conceived with the vision or providing the best resources for everyone working in ICUs even if belonging to different specialties (intensive care, anesthesiology, pneumology, emergency medicine, etc. ). Considering the enormous increase of literature on this topic, authors have selected major key topics related to NIMV, excluding those with low rate of interest, have updated9781398118058