In-hospital mortality prediction by American Society of Anesthesiology and POSSUM score in patients with cancer undergoing abdominal surgery

Abstract

Introduction: Preoperative evaluation and risk stratification is essential to perioperative planning. There are multiple risk scores applied to predict different outcomes. However, specific populations as patients with cancer may have specific risk factors, so it is needed to evaluate if global risk scoresas ASA and POSSUM or P POSSUM are able to assist the surgical team. Objective: To retrospectively assess the value of the ASA classification (American Society of Anesthesiology), POSSUM (Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity), and Porthsmouth POSSUM in prediction of hospital mortality in patients with cancer undergoing abdominal surgery. Methods: Three hundred and thirteen patients who under-went three hundred and nineteen oncologic abdominal surgeries were evaluated using ASA, POSSUM and Porthsmouth-POSSUM in relation to hospital mortality. The variables observed were: age, gender, ASA classification, pul- monary diseases, cardiovascular diseases, preoperative sys-tolic arterial pressure and cardiac rate, Glasgow scale, urea, potassium, sodium, hemoglobin, white cell count, number of simultaneous surgical procedures, observed blood losses, peritoneal contamination, oncological disease and dissemination, elective, emergent or urgent surgery, intensive care support and hospital mortality. Results: The overall hospital mortality rate was 5.59%. These results showed that POSSUM over predicted in-hospital deaths when compared to American Society of Anesthesiologists classification (relative risk, 0.55; P=.07) and Porths- mouth POSSUM (relative risk, 0,43; P=.0007) didn’t equally correspond to ASA predicted perioperative mortality. All evaluated scores didn’t equally predict observed mortality as the standardized mortality rate was 2.25 for ASA classification, 0.4 for POSSUM and 0.8 for P-POSSUM. Conclusion: The ASA classification, POSSUM and P POSSUM scores were not useful in predicting perioperative mortality for patients with cancer submitted to abdominal surgeries. It is needed to evaluate specific populations to adjust the existing perioperative prediction scores to serve as objective methods to assist the surgical team in classifying patients into risk groups with different probabilities of perioperative complications. ASA classification is based mainly on subjective clinical judgments and probably POSUUM and P-POSSUM need to have the equations balanced to specific populations.