The early prediction of mortality in acute cholecystitis: Temperature, Neutrophils and Multiple organ failure (TNM) score.

Acute Cholecystitis (AC) accounts for a significant proportion of patients presenting to the Emergency Department with abdominal pain. We suggest grading the severity of AC with a simple system: TNM, an acronym borrowed by cancer staging where T indicated Temperature, N neutrophils and M Multiple organ failure. This retrospective-prospective observational study evaluates the predictive value of TNM score on mortality of patients with AC. TNM was developed in a training cohort of 178 patients with AC who underwent cholecystectomy from February 2005 to December 2012 (retrospectives data). To verify the prognostic value of TNM score, we prospectively recruited 172 patients who were consecutively included and treated from January 2013 to July 2020 as the validation cohort. After defining the categories T, N and M, patients were grouped in stages. The variables analyzed were age, sex, American Society of Anesthesiologists (ASA) score, blood transfusion, temperature, neutrophils count, preoperative organ failure, immune-compromised status, stage. In the training cohort TNM staging was: none patient at stage 0; 6 patients at stage I; 71 patients at stage II; 71 patients at stage III; 30 patients at stage IV. Death occurred in 51 patients. ASA score, neutrophils count, preoperative organ failure, stage III-IV emerged as statistically significant different prognostic factors. ASA score (III-IV) and stage (III-IV) were significant independent predictors of post-operative mortality in multivariate analysis. Comparable results were observed in the validation cohort. TNM classification is very easy to use; it helps to define the mortality risk and it is useful to objectively compare patients with AC.