What scores can be used to assess a patient's risk for intraoperative and postoperative anesthesia complications, particularly for an adult patient with potential comorbidities such as cardiovascular disease or diabetes?

Risk Assessment Scores for Perioperative Anesthesia Complications

The Revised Cardiac Risk Index (RCRI) combined with the American Society of Anesthesiologists Physical Status (ASA-PS) classification should be used as the primary risk stratification tools for assessing intraoperative and postoperative anesthesia complications in adult patients with comorbidities. 1, 2

Primary Risk Stratification Tools

Revised Cardiac Risk Index (RCRI)

• The RCRI is the most extensively validated and ACC/AHA-endorsed tool for cardiac risk assessment, comprising six independent predictors: ischemic heart disease, heart failure, cerebrovascular disease, insulin-dependent diabetes, preoperative creatinine >2 mg/dL (>170 mmol/L), and high-risk surgery 3, 1, 2
• Risk stratification by RCRI score: 0-1 points = Low risk (<1% major adverse cardiac events [MACE]), 2 points = Moderate risk, ≥3 points = High risk 1, 4, 2
• Important caveat: RCRI performs poorly in vascular surgery populations; consider alternative tools like the NSQIP calculator for these patients 1, 2

American Society of Anesthesiologists Physical Status (ASA-PS) Classification

• ASA-PS is an independent predictor of both medical complications and mortality across all surgical procedures 1, 5
• Classification: Class I (completely healthy), Class II (mild systemic disease), Class III (severe systemic disease not incapacitating), Class IV (incapacitating disease threatening life), Class V (moribund patient not expected to survive 24 hours) 3
• Odds ratios for complications range from 2.05 to 63.25 and for mortality from 5.77 to 2011.92 as ASA class increases from 2 to 5 5
• ASA-PS combined with surgeon risk estimates achieves discrimination (AUC 0.84) equivalent to complex clinical data-based models 6

Advanced Risk Calculators

NSQIP Surgical Risk Calculator

• The American College of Surgeons NSQIP calculator may offer superior discrimination compared to RCRI, particularly for procedure-specific risk assessment 1, 4, 2
• Uses 21 patient-specific variables and the specific CPT code to calculate percentage risk of MACE, death, and 8 other outcomes 1
• Shows a median delta c-statistic of 0.11 higher than RCRI for predicting myocardial infarction and cardiac arrest 1
• Available as an interactive online tool at surgicalriskcalculator.com 3

NSQIP MICA (Myocardial Infarction or Cardiac Arrest) Model

• Built on data from >200,000 patients across 180 hospitals, validated on separate dataset 3
• Five predictors: type of surgery, functional status, elevated creatinine (>1.5 mg/dL), ASA class, and age 3
• Performed better than Lee index (RCRI) overall, though with some reduction in performance for vascular patients 3

AUB-HAS2 Cardiovascular Risk Index

• Easily calculated tool stratifying patients into low (score 0-1), intermediate (score 2-3), and high risk (score >3) based on 6 clinical elements 4, 2

Complementary Assessment Tools

Functional Capacity Assessment

• Duke Activity Status Index (DASI) should be combined with risk scores for enhanced stratification 1, 4, 2
• Poor functional capacity (inability to achieve 4 METs) indicates increased risk of perioperative adverse cardiovascular events 4, 2
• Functional capacity is a reliable predictor of both perioperative and long-term cardiac events 2

Biomarker-Enhanced Risk Stratification

• For patients with RCRI ≥2, measuring preoperative NT-proBNP and/or troponin enhances risk prediction, with combination providing median delta c-statistic improvement of 0.12 over RCRI alone 1
• B-type natriuretic peptide (BNP) levels provide additional risk stratification beyond standard risk scores 4, 2

Pulmonary Risk Assessment

Procedure-Related Risk Factors

• High-risk procedures for pulmonary complications include: aortic aneurysm repair, thoracic surgery, upper abdominal surgery, neurosurgery, head and neck surgery, and vascular surgery 3
• Prolonged surgery duration (3-4 hours) is an independent predictor with pooled odds ratio of 2.14 3
• General anesthesia carries odds ratio of 1.83 for pulmonary complications compared to regional techniques 3
• Emergency surgery has odds ratio of 2.21 for pulmonary complications 3

Patient-Related Pulmonary Risk Factors

• Impaired sensorium, abnormal chest examination findings, alcohol use, and weight loss modestly increase pulmonary complication risk 3
• Asthma is NOT a risk factor for postoperative pulmonary complications based on good evidence 3
• Obesity shows no significant difference in pulmonary complication rates (6.3% obese vs 7.0% nonobese) 3

Age-Specific Risk Considerations

• Age is a powerful independent predictor: patients 66-85 years have OR 2.67 for delirium, patients >85 years have OR 6.24 for delirium compared to those ≤65 years 1
• Male sex independently increases risk (OR 1.28) compared to female sex 1
• BMI <18.5 substantially increases delirium risk (OR 2.25) 1

Practical Application Algorithm

For Low-Risk Patients (RCRI 0-1, ASA I-II)

• Proceed with standard intraoperative monitoring 4, 2
• Obtain 12-lead ECG only if recent chest pain or ischemic equivalent present 1

For Moderate-Risk Patients (RCRI 2, ASA III)

• Obtain preoperative 12-lead ECG 1
• Consider functional capacity assessment with DASI 1, 4
• Consider biomarker assessment (NT-proBNP/troponin) 1

For High-Risk Patients (RCRI ≥3, ASA IV-V)

• Implement comprehensive cardiac monitoring 4, 2
• Obtain preoperative ECG and assess left ventricular function if heart failure history or dyspnea of unknown origin 1
• Measure NT-proBNP and troponin for enhanced risk stratification 1
• Consider surveillance for myocardial injury after noncardiac surgery (MINS) 4
• For ASA-PS V patients specifically, add SAPS II score (highest sensitivity 77.3%, AUC 0.784) or APACHE II score (AUC 0.681) for additional mortality prediction 7

Critical Pitfalls to Avoid

• Do not rely on RCRI alone for vascular surgery patients—use NSQIP calculator or Gupta score instead 1, 2
• Emergency surgery increases cardiac risk regardless of RCRI score; focus on immediate perioperative optimization rather than extensive testing 1
• Do not order routine spirometry for risk assessment—it does not translate into effective risk prediction for individual patients and is not superior to history and physical examination 3
• No single risk score has been definitively proven superior for all populations; combining multiple tools (RCRI + ASA-PS + functional capacity) provides more comprehensive stratification than any single tool 4, 2