Formulation of optimization measures
A random selection of 90 patients who underwent gastrointestinal surgery in supine position in November 2017 was selected for the study. The start time of anesthesia induction, the start time and end time of catheterization, the start time and end time of prepare and drape the operative site, and the start time of operation were obtained by the monitoring recording in operating room. We calculate and record the time of every procedure and between 2 adjacent procedures. After discussion by 3 anesthesiologists, 3 surgeons, and 3 operating room nurses, teamwork optimization measures will be established. (The researching flow as show in the Fig 1)