---
title: Preoperative Risk Assessment
description: A comprehensive clinical reference on evaluating and mitigating patient risk factors prior to surgery.
keywords: [preoperative, risk assessment, RCRI, NSQIP, ASA, perioperative]
category: clinical
---

## Introduction

Preoperative risk assessment is a critical component of perioperative care, enabling clinicians to identify and address modifiable risk factors, optimize medical conditions, and guide shared decision-making with patients. A thorough preoperative evaluation considers the patient's comorbidities, functional status, medication regimen, and surgical factors to estimate the risk of postoperative complications and mortality. By implementing appropriate risk mitigation strategies, providers can enhance patient safety and improve surgical outcomes.

## Cardiac Risk Assessment

The Revised Cardiac Risk Index (RCRI) is a widely used tool for predicting the risk of major adverse cardiac events (MACE) in patients undergoing non-cardiac surgery. The RCRI assigns 1 point each for the presence of high-risk surgery, history of ischemic heart disease, history of heart failure, history of cerebrovascular disease, insulin-dependent diabetes, and preoperative serum creatinine >2.0 mg/dL. Patients are stratified as low-risk (0-1 points), intermediate-risk (2 points), or high-risk (≥3 points), with corresponding MACE rates of 0.4%, 3.0%, and 9.1%, respectively.

For patients at elevated cardiac risk, further evaluation with non-invasive cardiac stress testing or coronary angiography may be warranted to detect and manage underlying coronary artery disease. Pharmacologic risk reduction with perioperative beta-blockers or statins should be considered, balancing the potential benefits and risks. The American College of Cardiology/American Heart Association (ACC/AHA) guidelines provide detailed recommendations for perioperative cardiac management.

## Pulmonary Risk Assessment

Patients with underlying pulmonary disease, such as chronic obstructive pulmonary disease (COPD) or obstructive sleep apnea, are at increased risk of postoperative pulmonary complications (PPCs), including respiratory failure, pneumonia, and atelectasis. The GOLD criteria define COPD as a post-bronchodilator FEV1/FVC ratio <0.70, with severity staged based on the degree of airflow limitation.

The ARISCAT (Assess Respiratory Risk in Surgical Patients in Catalonia) score is a validated tool that incorporates patient factors (age, preoperative SpO2, respiratory infection within the past month) and surgical factors (site and duration) to estimate the risk of PPCs. Patients are categorized as low-risk (ARISCAT score <26), intermediate-risk (26-44), or high-risk (≥45), with corresponding PPC rates of 2.9%, 13.3%, and 38.9%, respectively.

Preoperative optimization of pulmonary function with bronchodilators, corticosteroids, and airway clearance techniques, as well as postoperative respiratory physiotherapy, can help mitigate the risk of PPCs. In high-risk patients, consideration should be given to minimally invasive surgical approaches or postponing elective procedures until the patient's pulmonary status is optimized.

## Renal Risk Assessment

Patients with chronic kidney disease (CKD) are at increased risk of postoperative acute kidney injury (AKI), which is associated with higher morbidity and mortality. The Kidney Disease: Improving Global Outcomes (KDIGO) guidelines define AKI as an increase in serum creatinine by ≥0.3 mg/dL within 48 hours or ≥1.5 times baseline within 7 days.

The Acute Kidney Injury Network (AKIN) and KDIGO staging systems can be used to assess the severity of AKI, with higher stages indicating worse prognosis. Risk factors for postoperative AKI include advanced age, diabetes, hypertension, heart failure, anemia, and exposure to nephrotoxic medications or contrast dye.

Preoperative optimization of volume status, avoidance of nephrotoxins, and careful perioperative hemodynamic management are crucial strategies to mitigate the risk of AKI. In high-risk patients, consideration should be given to alternative surgical approaches, delaying elective procedures, or initiating renal replacement therapy in the perioperative period.

## Frailty Assessment

Frailty is a state of increased vulnerability to stressors, resulting from age-related declines in physiological reserves and multi-system dysregulation. Frail patients are at higher risk of postoperative complications, prolonged hospital stay, and mortality.

The Clinical Frailty Scale (CFS) is a simple, 9-point assessment tool that categorizes patients as very fit (CFS 1-2), well (CFS 3-4), vulnerable (CFS 5), mildly frail (CFS 6), moderately frail (CFS 7), severely frail (CFS 8), or very severely frail (CFS 9). Patients with a CFS ≥5 are considered frail and may benefit from targeted interventions, such as prehabilitation, geriatric consultation, and postoperative transitional care.

The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) Surgical Risk Calculator is another tool that incorporates frailty assessment to predict the risk of postoperative complications and mortality. By identifying frail patients, clinicians can optimize their medical conditions, engage in shared decision-making, and implement appropriate perioperative care strategies.

## Multidisciplinary Approach

Effective preoperative risk assessment requires a multidisciplinary approach, involving collaboration between surgeons, anesthesiologists, internists, geriatricians, and other healthcare providers. This team-based approach ensures a comprehensive evaluation of the patient's comorbidities, functional status, and perioperative risks, enabling the development of a personalized care plan.

The American Society of Anesthesiologists (ASA) Physical Status Classification System is a widely used tool that provides a standardized assessment of a patient's overall health status, ranging from ASA I (healthy patient) to ASA VI (brain-dead patient). This classification, along with the specific risk factors identified, can guide the intensity of preoperative optimization, intraoperative management, and postoperative monitoring.

By implementing a structured preoperative risk assessment and utilizing validated risk stratification tools, clinicians can make informed decisions, optimize patient care, and improve surgical outcomes. Ongoing research and the development of novel risk assessment models will continue to enhance the precision and utility of preoperative risk evaluation.