Clinical risk scores to guide perioperative management

Abstract

Perioperative morbidity is associated with reduced long term survival. Comorbid disease, cardiovascular illness, and functional capacity can predispose patients to adverse surgical outcomes. Accurate risk stratification would facilitate informed patient consent and identify those individuals who may benefit from specific perioperative interventions. The ideal clinical risk scoring system would be objective, accurate, economical, simple to perform, based entirely on information available preoperatively, and suitable for patients undergoing both elective and emergency surgery. The POSSUM (Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity) scoring systems are the most widely validated perioperative risk predictors currently utilised; however, their inclusion of intra- and postoperative variables precludes validation for preoperative risk prediction. The Charlson Index has the advantage of consisting exclusively of preoperative variables; however, its validity varies in different patient cohorts. Risk models predicting cardiac morbidity have been extensively studied, despite the relatively uncommon occurrence of postoperative cardiac events. Probably the most widely used cardiac risk score is the Lee Revised Cardiac Risk Index, although it has limited validity in some patient populations and for non-cardiac outcomes. Bespoke clinical scoring systems responding to dynamic changes in population characteristics over time, such as those developed by the American College of Surgeons National Surgical Quality Improvement Program, are more precise, but require considerable resources to implement. The combination of objective clinical variables with information from novel techniques such as cardiopulmonary exercise testing and biomarker assays, may improve the predictive precision of clinical risk scores used to guide perioperative management.

The obesity paradox in the surgical population

“…Furthermore, recognition and optimization of other, non-cardiac, chronic ailment conditions prior to surgery can also be beneficial, both in the perioperative stage as well as for the long-term. 13 Although several preoperative risk-scoring systems exist, 14 BMI has not been included, since it was not considered as an independent (preoperative) risk factor or predictor for postoperative and long-term outcomes.…”

Clinical review: Can we predict which patients are at risk of complications following surgery?

“…These systems can be classified as those estimating population risk or individual risk [18,19]. Scores predicting individual risk can be general, organ specific, or procedure specific.…”

Surgical Risk Preoperative Assessment System (SURPAS)

“…We argue that for a risk calculator to be accepted into widespread use, it must: (1) be easy to use; (2) be broadly encompassing of many different types of surgery and surgical complications; (3) provide reliable and meaningful risk estimates; (4) be based on readily available preoperative data; (5) be available to the public; and (6) be updated periodically. To achieve these goals, the tool must be based on a broadly representative sample of the current surgical population, encompassing most major surgical procedures.…”

“…[1][2][3][4][5] However, formal risk assessment tools are not routinely used for preoperative assessment, education, and optimization of the surgical patient. 6,7 Estimation of patient risk is typically based on a combination of widely accepted or previously reported values, and subjective assessment of individual patient comorbidities by providers.…”