What are the key components of preoperative (pre-op) risk assessment?

Key Components of Preoperative Risk Assessment

The most effective preoperative risk assessment focuses on cardiovascular risk, functional capacity, and patient-specific risk factors to reduce perioperative morbidity and mortality.

Cardiovascular Risk Assessment

• Perform cardiovascular risk assessment for all patients undergoing high-risk surgery and those undergoing intermediate-risk surgery with additional risk factors 1
• Identify active cardiac conditions requiring evaluation before surgery (unstable coronary syndromes, decompensated heart failure, significant arrhythmias, severe valvular disease) 1
• Assess functional capacity using metabolic equivalents (METs) - patients with good functional capacity (≥4 METs or ability to climb ≥2 flights of stairs) can generally proceed to surgery without further cardiac testing 1, 2
• Obtain ECG for patients with signs or symptoms of cardiovascular disease and those undergoing high-risk procedures with additional risk factors (coronary heart disease, structural heart disease, heart failure, cerebrovascular disease, diabetes, renal impairment) 1, 2
• Consider vital signs assessment (blood pressure and heart rate) and cardiac physical examination as part of standard preoperative evaluation 1

Laboratory Testing

• Reserve laboratory testing for specific indications rather than routine screening 1, 2
• Obtain complete blood count (CBC) for patients at risk of anemia or when significant perioperative blood loss is anticipated 1, 2
• Perform electrolyte and creatinine testing for patients at risk of electrolyte abnormalities or renal impairment (those taking diuretics, ACE inhibitors, ARBs, NSAIDs, digoxin) 1, 2
• Consider glucose testing for patients at high risk of undiagnosed diabetes; A1C testing only if results would change perioperative management 1, 2
• Reserve coagulation testing for patients with history of bleeding, medical conditions predisposing to coagulopathy (liver disease), or those taking anticoagulants 1, 2
• Obtain urinalysis only for patients undergoing urologic procedures or implantation of foreign material 1, 2

Pulmonary Risk Assessment

• Reserve chest radiography for patients with new or unstable cardiopulmonary signs or symptoms 1, 2
• Consider pulmonary function testing only for patients with unexplained dyspnea or poor functional status when results would change perioperative management 1, 3
• Assess smoking history and consider smoking cessation at least 4-8 weeks before surgery to reduce respiratory complications 1
• Evaluate for obstructive sleep apnea, which increases risk of postoperative complications 3

Additional Risk Factors

• Assess age as a risk factor - older age (pooled MD=4.94 years) is associated with increased risk of postoperative delirium 1
• Evaluate ASA physical status - ASA physical status >2 (pooled OR=2.27) is associated with increased complications 1
• Consider Charlson Comorbidity Index (CCI) - CCI ≥2 (pooled OR=1.9) indicates higher risk 1
• Assess nutritional status - low BMI may be associated with increased risk of complications 1
• Evaluate alcohol consumption - consumption of more than two units of alcohol per day increases risk of postoperative infections 1

Structured Approach to Preoperative Assessment

1. Risk stratification based on surgery type:

   • Low-risk procedures (e.g., cataract surgery, endoscopy) - minimal testing required 1
   • Intermediate-risk procedures - selective testing based on comorbidities 1, 4
   • High-risk procedures - comprehensive assessment recommended 1

2. Patient-specific risk assessment:

   • Evaluate functional capacity (ability to climb stairs, perform daily activities) 1, 2
   • Identify and optimize management of comorbidities 2, 3
   • Assess for frailty in elderly patients 3

3. Risk mitigation strategies:

   • Optimize medical therapy for known cardiovascular conditions 1, 4
   • Consider prehabilitation (nutrition supplementation, physical exercise, correction of anemia) 3
   • Plan for appropriate perioperative monitoring based on risk assessment 1

Common Pitfalls to Avoid

• Ordering routine tests without specific indications increases costs without improving outcomes 1, 5
• Failing to assess functional capacity, which is a strong predictor of perioperative complications 1, 6
• Delaying surgery unnecessarily for extensive cardiac testing in low-risk patients 1, 6
• Not documenting discussions with patients about cardiovascular risks involved in surgery 1
• Overlooking the importance of optimizing modifiable risk factors before elective procedures 1, 3