What is the step‑by‑step approach to obtain cardiopulmonary clearance for surgery?

How to Obtain Cardiopulmonary Clearance for Surgery

Follow the 2014 ACC/AHA six-step algorithm for cardiac assessment combined with a three-step pulmonary evaluation protocol to systematically determine surgical candidacy and optimize perioperative risk. 1

Cardiac Clearance Algorithm

Step 1: Determine Surgical Urgency

• Emergency surgery: Proceed directly to the operating room with appropriate intraoperative monitoring based on clinical risk factors; no time for formal clearance 1
• Urgent or elective surgery: Continue through the full evaluation algorithm 1

Step 2: Screen for Acute Coronary Syndrome (ACS)

• Assess for unstable angina, recent myocardial infarction (<6 weeks), or active ischemic symptoms 1
• If ACS present: Refer immediately to cardiology for management per STEMI/NSTEMI guidelines before any elective surgery 1
• If no ACS: Proceed to Step 3 1

Step 3: Estimate Perioperative MACE Risk

Use the American College of Surgeons NSQIP risk calculator (preferred) or the Revised Cardiac Risk Index (RCRI) combined with surgical risk 1, 2

Surgical risk categories 1:

• Low risk (<1% MACE): Endoscopic procedures, cataract surgery, breast surgery, superficial procedures
• Intermediate risk (1-5% MACE): Intraperitoneal/intrathoracic surgery, carotid endarterectomy, orthopedic surgery, head-and-neck surgery
• High risk (>5% MACE): Aortic/major vascular surgery, emergency surgery in elderly, prolonged procedures with large fluid shifts

Action based on MACE risk 1, 2:

• MACE <1%: Proceed to surgery without further cardiac testing
• MACE ≥1%: Advance to Step 4 (functional capacity assessment)

Step 4: Assess Functional Capacity

Measure functional capacity using the Duke Activity Status Index (DASI) or assess ability to climb 2 flights of stairs 1, 2, 3, 4

≥4 METs capacity (can perform any of these activities) 1:

• Climb a flight of stairs or walk up a hill
• Run a short distance
• Do heavy housework (scrubbing floors, moving furniture)
• Participate in moderate recreation (golf, doubles tennis, dancing)
• Walk on level ground at 6.4 km/h

Action 1:

• ≥4 METs: Proceed to surgery without further cardiac evaluation
• <4 METs or unknown capacity: Advance to Step 5

Step 5: Consider Stress Testing

Stress testing should only be ordered if the results would either 1, 2:

1. Change the decision to proceed with surgery, OR
2. Influence willingness to undergo coronary revascularization

If yes to either question 1:

• Order pharmacologic stress testing (preferred for poor functional capacity)
• Consider exercise stress test if functional capacity is unknown
• Abnormal results warrant coronary angiography consideration

If no to both questions: Proceed to surgery without stress testing 1

Step 6: Obtain Supplemental Testing

12-lead ECG 1, 5:

• Required for: Known coronary disease, significant arrhythmias, peripheral arterial disease, cerebrovascular disease, structural heart disease—except in low-risk surgery
• Consider for: Asymptomatic patients with diabetes or recent chest pain undergoing intermediate/high-risk procedures

Left ventricular function assessment (echocardiogram) 1, 5:

• Required for: Current or decompensated heart failure
• Consider for: History of heart failure, dyspnea of unknown origin, audible cardiac murmur

Special cardiac considerations 1:

• Recent MI (<6 weeks): Surgery should normally be postponed 1
• MI within 6 months: Obtain cardiology consultation 1
• Prior CABG: Does not preclude surgery; assess as other cardiac risk patients 1

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Pulmonary Clearance Protocol

Step 1: Initial Spirometry Assessment

No further testing required if 1:

• Lobectomy: Post-bronchodilator FEV₁ >1.5 liters
• Pneumonectomy: Post-bronchodilator FEV₁ >2.0 liters
• AND no interstitial lung disease or unexpected dyspnea

If spirometry inadequate, proceed to full pulmonary function testing 1:

• Measure transfer factor (TLCO)
• Measure oxygen saturation on room air at rest
• Obtain quantitative isotope perfusion scan (for pneumonectomy)

Calculate estimated postoperative (epo) values 1:

• For pneumonectomy: Use perfusion scan data
• For lobectomy: Use anatomical equation (subtract segments removed from 19 total segments)
• Express epo FEV₁ and epo TLCO as % predicted

Step 2: Risk Stratification Based on Postoperative Predictions

Average risk 1:

• epo FEV₁ >40% predicted AND
• epo TLCO >40% predicted AND
• Oxygen saturation >90% on room air
• Action: Proceed to surgery

High risk 1:

• epo FEV₁ <40% predicted AND
• epo TLCO <40% predicted
• Action: Proceed to Step 3 exercise testing

Uncertain risk (all other combinations) 1:

• Action: Proceed to Step 3 exercise testing

Step 3: Exercise Testing for Borderline Cases

Shuttle walk test (perform twice, use best distance) 1:

• <25 shuttles (250 meters): High risk—surgery may be contraindicated
• Desaturation >4% during test: High risk—surgery may be contraindicated
• ≥25 shuttles without significant desaturation: Proceed to formal cardiopulmonary exercise testing

Cardiopulmonary exercise testing (CPET) 1, 6, 7:

• VO₂ peak >15 ml/kg/min: Average risk—proceed to surgery
• VO₂ peak <15 ml/kg/min: High risk—consider alternative treatments or accept elevated surgical mortality

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Additional Risk Factors Requiring Documentation

Nutritional and performance status 1, 5:

• Weight loss >10% preoperatively: High risk, requires multidisciplinary discussion
• WHO performance status ≥2: High risk, requires careful staging
• Body mass index and serum albumin: Low values increase complication risk

Age considerations 1:

• Age >70: Not a contraindication to lobectomy or wedge resection
• Age >80: Higher risk for pneumonectomy; age should factor into decision

Multiple adverse factors 1:

• Patients with >1 adverse medical factor require formal multidisciplinary team discussion (surgeon, pulmonologist, anesthesiologist, oncologist)

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Critical Pitfalls to Avoid

• Never use the phrase "cleared for surgery"—instead document "cardiovascular/pulmonary status optimized" with specific recommendations 5
• Do not order stress testing in low-risk patients (<1% MACE)—it will not change management and may lead to unnecessary interventions 1, 2
• Do not rely on subjective functional capacity assessment—use validated tools (DASI) or objective measures (stair climbing) 3, 4
• Do not proceed with elective surgery in patients with active cardiac conditions (unstable angina, decompensated heart failure, severe valvular disease) without cardiology optimization 1, 5
• Avoid high-dose β-blockers started 2-4 hours preoperatively—associated with increased stroke and mortality 8
• Do not assume adequate pulmonary function based on spirometry alone if interstitial lung disease is present 1