To further examine current intubation practice among critically ill patients who are in need of endotracheal intubation, the investigators plan to perform a prospective cross-sectional study of adult critically ill patients who needed endotracheal intubation at participating sites between August 1st, 2015 to August 1st, 2016. The investigators aim to describe the current intubation practice among the participating sites with a description of complications that may have surfaced during the peri-intubation period and to isolate predictive factors of these complications.