Guidelines for Preoperative Clearance
Preoperative evaluation should not simply provide "medical clearance" but rather assess the patient's current medical status, make recommendations for perioperative management, and provide a clinical risk profile to optimize outcomes. 1
Purpose of Preoperative Evaluation
The primary goal of preoperative evaluation is to:
- Identify and optimize conditions that increase perioperative morbidity and mortality
- Assess short and long-term cardiac risk
- Provide information for decision-making by the patient and surgical team
- Avoid unnecessary testing that doesn't change management
Risk Assessment Framework
Step 1: Clinical Risk Assessment
- Age consideration: More extensive assessment for patients ≥50 years old 1
- Surgical risk stratification:
- High-risk procedures (vascular, prolonged surgeries with large fluid shifts)
- Intermediate-risk procedures (intraperitoneal, intrathoracic, orthopedic)
- Low-risk procedures (endoscopic, superficial, cataract)
Step 2: Patient-Specific Risk Factors
- Cardiac risk factors:
- History of coronary artery disease
- Heart failure
- Cerebrovascular disease
- Diabetes mellitus
- Renal insufficiency
Step 3: Functional Capacity Assessment
- Evaluate ability to perform daily activities (metabolic equivalents)
- Poor functional capacity (<4 METs) indicates higher risk
Recommended Testing Guidelines
Cardiovascular Testing
- ECG recommendations 1:
- Class I: Patients with ≥1 clinical risk factor undergoing vascular surgery
- Class I: Patients with known coronary disease, peripheral arterial disease, or cerebrovascular disease undergoing intermediate-risk procedures
- Not recommended: Patients undergoing low-risk procedures
Cardiac Function Testing
- Echocardiography 1:
- Class IIa: Patients with dyspnea of unknown origin
- Class IIa: Patients with current/prior heart failure with worsening symptoms if not performed within 12 months
- Class IIb: Reassessment in clinically stable patients with previously documented cardiomyopathy
Laboratory Testing 1
- Complete blood count: Only for patients with diseases increasing anemia risk or anticipated significant blood loss
- Electrolytes and creatinine: Only for patients with chronic disease or on medications predisposing to electrolyte abnormalities/renal failure
- Coagulation studies: Only for patients with history of bleeding, medical conditions predisposing to bleeding, or on anticoagulants
- Urinalysis: Only for patients undergoing invasive urologic procedures or implantation of foreign material
- Glucose testing: Only for patients at high risk of undiagnosed diabetes
- A1C: Only in diagnosed diabetics if results would change management
Pulmonary Testing
- Chest radiography: Only for patients at risk of postoperative pulmonary complications if results would change management 1
Special Considerations
Role of the Consultant
The consultant must not simply "clear" the patient but should:
- Review all available data
- Perform a comprehensive cardiovascular examination
- Determine stability of cardiovascular status
- Recommend medication changes if needed
- Suggest appropriate level of postoperative care 1
Common Pitfalls to Avoid
- Providing vague "clearance": 40% of cardiology consultations contain no specific recommendations beyond "cleared for surgery" 1
- Ordering unnecessary tests: No test should be performed unless it will change management 1
- Delaying surgery unnecessarily: Patients with multiple comorbidities should undergo thorough but efficient preoperative evaluation to prevent same-day cancellations 2
- Failing to communicate: Ensure clear communication between surgeon, anesthesiologist, primary care provider, and consultants 1
Key Principle
The overriding theme is that intervention is rarely necessary simply to lower the risk of surgery unless such intervention is indicated irrespective of the preoperative context. 1