We undertook a clinical study approved by the local Research Ethics Committee1 of 200 patients in a postoperative ward of the Cancer Centre, Oxford University Hospitals NHS Trust, Oxford, U.K. Patients were discharged to the ward following upper-gastrointestinal (GI) cancer surgery. This group of patients was selected for our study because of the high incidence (up to 20%) of postsurgical complications, whereby patients can deteriorate physiologically, resulting in adverse outcomes such as readmission to the intensive care unit (ICU) or death. Readmission to the ICU is prolonged and the mortality rate of such patients is high. These adverse events may occur when the physiological condition of the patient is not recognized or acted upon early
