Monitoring respiration: what the clinician needs to know.

A recent large prospective cohort study showed an unexpectedly high in-hospital mortality after major non-cardiac surgery in Europe, as well as a high incidence of postoperative pulmonary complications. The direct effect of postoperative respiratory complications on mortality is still under investigation, for intensive care unit (ICU) and in the perioperative period. Although respiratory monitoring has not been actually proven to affect in-hospital mortality, it plays an important role in patient care, leading to appropriate setting of ventilatory support as well as risk stratification. The aim of this article is to provide an overview of various respiratory monitoring techniques including the role of conventional and most recent methods in the perioperative period and in critically ill patients. The most recent techniques proposed for bedside respiratory monitoring, including lung imaging, are presented and discussed, comparing them to those actually considered as gold standards.