9 14 Methods Study design This is a multicentre, prospective observational study of consecutive patients undergoing emergency intraperitoneal surgery that will be carried out by participants during

14-day, consecutive time periods of the individual participant’s choice during a 5-month study period window. Study setting All acute care surgical units worldwide are eligible to enter. Centres must ensure that they Sunitinib c-kit inhibitor can include consecutive patients and provide >95% data completeness (centres with >5% missing data will be excluded from analysis). There is no minimum number of patients per centre, as long as the patient(s) included are consecutive and multiple teams covering differing periods from one institution are encouraged. Patient inclusion and exclusion criteria The inclusion and exclusion criteria are summarised in box 1. Patients of all ages (adult and paediatric) undergoing emergency intraperitoneal surgery during the chosen period are eligible for inclusion. Emergency procedures are defined as unplanned, non-elective operations and include reoperations after previous procedures. Intraperitoneal surgery includes laparoscopic, laparoscopic converted and open cases. This could include gastrointestinal, vascular, urological and gynaecological

surgery. Box 1 Study inclusion and exclusion criteria Inclusion criteria Patients of all ages (adult and paediatric); Consecutive patients during the chosen study period; Undergoing emergency intraperitoneal surgery; Intraperitoneal surgery includes laparoscopic,

laparoscopic converted and open cases. This could include gastrointestinal, vascular, urological and gynaecological surgery; Emergency procedures are defined as unplanned, non-elective operations and include reoperations after previous procedures. Exclusion criteria Elective (planned) or semielective procedures (where the patient is initially admitted as an emergency, then discharged from hospital, and readmitted at later time for surgery); Caesarean sections. Elective (planned) or semielective (where the patient is initially admitted as an emergency, then discharged from hospital, and readmitted at later time for surgery) procedures are excluded, along with caesarean sections. The latter represent a separate operative group, whose priorities and treatment pathways differ from those of other abdominal emergency operations, and they have been studied in detail elsewhere. Outcome Anacetrapib measures The primary outcome measure is the 24 h perioperative mortality rate. This is the number of deaths during operation or within 24 h of conclusion of an operation, divided by the number of operations performed during the same time period.15 The main secondary outcome measure is the 30-day perioperative mortality rate. This is defined as the total number of deaths within 30 days of a surgical operation divided by the total number of emergency abdominal operations performed during the same time period.