A multicentre, international evaluation of emergency abdominal surgery to establish surgical outcomes and identify common, modifiable best practice processes.

Background: With over 200 million surgical operations per year worldwide and with nearly every acute hospital providing surgical services, outcomes from emergency general surgery represent internationally important healthcare markers. Best practice and modifiable processes that are relevant to good patient outcomes around the world require validation using patient-level data.

Aim: The primary aim of this study is to identify internationally relevant, modifiable surgical practices (in terms of modifiable equipment and clinical management) associated with best care. These factors will include use of imaging, supplementary oxygen, pulse oximetry, critical care, and safety checklists.

Method: This is a multicentre, international, prospective cohort study. Any hospital in the world performing acute surgery will be eligible to enter. Any patient undergoing emergency surgery with an incision entering the peritoneal cavity is eligible. Routine, anonymised clinical data on consecutive patients will be collected over a two week period in each surgical centre, with up to 30 days follow-up data collected. The primary outcome is 24-hour post-operative mortality rate. Secondary outcomes include 30-day inpatient post-operative mortality rate, and 30-day serious complication rate. Participating centres will also be asked to complete a survey that will collect data on hospital structural and resource characteristics.

Data will be entered and stored securely via the University of Edinburgh's REDCap system. This pragmatic protocol (which will delivered across many low-resource settings) does not allow for independent verification of data entry. Data collection norms are laid out in the protocol, where data definitions are also clearly provided. Sample size is not relevant to this exploratory audit. Centres will only be included where there is at least 95% data completeness.

Potential explanatory variables that will be explored in subsequent analysis include country Human Developmental Index, and resource differences.

Centre Inclusion Criteria:

• Any acute surgical unit worldwide is eligible to enter
• All participating centres will be required to register their details, complete an online training module, and complete a pilot audit prior to commencing.
• Centres must ensure that they can include consecutive patients and provide at least 95% data completeness.
• There is no minimum number of patients per centre, as long as the patient(s) included are consecutive.

Inclusion Criteria:

• All sequential patients undergoing emergency intra-peritoneal surgery during the chosen 2-week period should be included.
• Emergency (unplanned, non-elective, same admission) procedures only. This includes patients undergoing an emergency re-operation after a previous procedure on the same in-patient stay.
• Laparoscopic, laparoscopic converted and open cases can be included.
• Any age patient (adult and paediatric) can be included.

Exclusion Criteria:

• Elective (planned) or semi-elective (where patient initially admitted as an emergency, then discharged from hospital, and re-admitted at later time for surgery) procedures.
• Caesarean section. These patients represent a separate operative group, with different priorities and treatment pathways. They have been studied in detailed elsewhere, and their frequency would skew the results of this study.

The study population will be recruited from all acute surgical units worldwide which provide an emergency surgery service.