P-POSSUM for Outcomes After Abdominal Surgery (PPOSSUM-ABD)

Postoperative complications remain an important cause of morbidity, prolonged hospital stay, intensive care use, and mortality after abdominal surgery. Risk prediction before and after surgery may help clinicians identify high-risk patients, guide perioperative planning, and improve postoperative monitoring. The Portsmouth Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity, known as P-POSSUM, combines physiological and operative variables to estimate the risk of postoperative morbidity and mortality. However, the performance of P-POSSUM may differ across populations, surgical settings, and healthcare systems.

Frailty is increasingly recognized as an important predictor of adverse postoperative outcomes, particularly in older surgical patients. Frailty reflects reduced physiological reserve and increased vulnerability to acute stressors such as emergency surgery, infection, bleeding, and postoperative critical illness. In this study, frailty will be assessed using routinely available clinical information. For retrospective data, frailty-related status will be evaluated using available medical records and a modified frailty index when sufficient data are available. For prospectively enrolled patients, frailty will be assessed based on baseline functional status before the acute surgical illness, using a standardized clinical frailty assessment when feasible.

This study is designed as an ambispective observational cohort study conducted at the Center for Anesthesia and Surgical Intensive Care, Bach Mai Hospital, Vietnam. The study includes retrospective data from patients undergoing abdominal surgery from January 2025 and prospective data collection through May 2026. Eligible adult patients undergoing abdominal surgery will be included according to predefined selection criteria. The investigators will not assign any intervention or modify treatment decisions. Perioperative management, surgical care, anesthesia, postoperative monitoring, and intensive care treatment will be provided according to routine clinical practice.

For each eligible patient, demographic characteristics, comorbidities, physiological variables, operative severity variables, frailty-related variables, perioperative laboratory results, anesthesia and surgical information, postoperative complications, and treatment outcomes will be collected. The P-POSSUM score will be calculated using the predefined physiological and operative scoring components. Study outcomes will be obtained from hospital medical records, anesthesia records, surgical records, intensive care charts, laboratory data, and discharge documentation.

The primary objective is to evaluate the prognostic performance of P-POSSUM for postoperative complications after abdominal surgery. Secondary objectives include evaluating the performance of P-POSSUM for postoperative mortality and other treatment outcomes, assessing calibration and discrimination of the score, and exploring whether the addition of frailty-related variables and routinely available perioperative data improves risk prediction compared with P-POSSUM alone.