What are the anaesthesia considerations for a cardiac patient undergoing non-cardiac surgery?

Anaesthesia Considerations in Cardiac Patients for Non-Cardiac Surgery

For cardiac patients undergoing non-cardiac surgery, use a systematic stepwise approach prioritizing urgent surgery assessment, active cardiac condition screening, surgical risk stratification, functional capacity evaluation, and targeted preoperative optimization with continuation of beta-blockers and statins, while selecting volatile anesthetics like sevoflurane and maintaining strict hemodynamic control intraoperatively. 1, 2

Preoperative Risk Stratification

Step 1: Assess Urgency

• Proceed immediately to surgery for urgent/emergency cases without delaying for cardiac testing, implementing optimal medical management and perioperative monitoring instead 1, 2
• For elective surgery, continue with systematic evaluation through the remaining steps 1

Step 2: Screen for Active Cardiac Conditions

Identify and manage unstable cardiac conditions before elective surgery 1:

• Unstable angina or recent myocardial infarction
• Decompensated heart failure
• Significant arrhythmias
• Severe valvular disease

If active conditions present: Discuss treatment options in multidisciplinary team; consider coronary intervention with dual antiplatelet therapy if surgery can be delayed, or proceed with optimal medical therapy if delay impossible 1

Step 3: Stratify Surgical Risk

Classify the planned procedure 1, 3:

• Low risk (<1% cardiac event rate): Proceed to surgery; baseline ECG may be considered if clinical risk factors present 1
• Intermediate risk (1-5%): Continue to functional capacity assessment 1
• High risk (>5%): Continue to functional capacity assessment 1

Step 4: Evaluate Functional Capacity

• >4 METs (metabolic equivalents): Patient can proceed to surgery with appropriate medical optimization 1
• <4 METs: Proceed to clinical risk factor assessment, particularly for intermediate or high-risk surgery 1

Step 5: Clinical Risk Factor Assessment

For patients with poor functional capacity, count clinical risk factors 1:

• <2 risk factors with intermediate-risk surgery: Proceed to surgery with baseline ECG monitoring 1
• ≥3 risk factors or high-risk surgery: Consider non-invasive stress testing to guide management 1

Use RCRI score ≥2 to identify patients requiring intensive hemodynamic monitoring, goal-directed therapy, and postoperative cardiac biomarker measurement 3

Preoperative Medical Optimization

Beta-Blocker Management

• Continue beta-blockers in all patients already taking them for angina, arrhythmias, hypertension, or heart failure throughout the perioperative period 1, 2, 3
• Initiate beta-blockers in patients with known ischemic heart disease or myocardial ischemia undergoing intermediate or high-risk surgery, starting 30 days to at least 2 days preoperatively 1, 2
• Titrate to target resting heart rate of 60-70 bpm 1
• Avoid high-dose beta-blockade initiation without adequate time for dose titration 1

Statin Therapy

• Continue statins in patients already taking them 3
• Initiate statin therapy preoperatively in all patients undergoing vascular surgery, regardless of clinical risk factors 1, 2

ACE Inhibitors/ARBs

• Continue in heart failure patients but consider omitting on the morning of surgery, carefully monitoring blood pressure and providing appropriate volume replacement 1
• Large perioperative blood pressure fluctuations should be avoided 1

Antiplatelet Management

• Continue aspirin perioperatively based on individual assessment weighing bleeding risk against thrombotic complications 1
• For patients with coronary stents 1:
  • Balloon angioplasty: Surgery >2 weeks after intervention with aspirin continuation
  • Bare-metal stent: Surgery >4 weeks with dual antiplatelet therapy for ≥4 weeks
  • Drug-eluting stent: Surgery >6 months (new-generation) or >12 months (old-generation)

Blood Pressure Management

• Do not defer surgery for grade 1-2 hypertension (systolic <180 mmHg, diastolic <110 mmHg) 1
• Screen new hypertension diagnoses for end-organ damage and cardiovascular risk factors 1
• Maintain perioperative blood pressure at 70-100% of baseline, avoiding excessive tachycardia 1

Intraoperative Anesthetic Management

Anesthetic Agent Selection

• Use volatile anesthetic agents, particularly sevoflurane, due to cardioprotective effects 2, 4
• Sevoflurane demonstrated equivalent safety and efficacy to isoflurane in patients at risk for myocardial ischemia, with no significant differences in hemodynamics, cardioactive drug use, or ischemic incidents 4
• Consider neuroaxial anesthesia alone when not contraindicated, as it reduces perioperative mortality and morbidity by 29% compared to general anesthesia 3

Hemodynamic Monitoring and Goals

• Maintain mean arterial pressure (MAP) ≥60 mmHg, ideally 10% above baseline 5
• Avoid MAP <60 mmHg for >30 minutes, as this significantly increases myocardial infarction, stroke, and death risk 3, 5
• Avoid MAP decreases >20 mmHg for >1 hour in hypertensive and diabetic patients 1
• Patients with RCRI ≥2 require intensive hemodynamic monitoring and goal-directed therapy 3

Temperature Management

• Maintain normothermia to reduce perioperative cardiac events, except during periods requiring mild hypothermia for organ protection 2

Glucose Control

• Target blood glucose <180 mg/dL (10.0 mmol/L) in high-risk surgical patients requiring ICU care 5
• Avoid overly strict targets <110 mg/dL (6.1 mmol/L) that increase hypoglycemia risk 5

Ventilation Strategy

• Use lung-protective ventilation with tidal volume 6-8 mL/kg predicted body weight and positive end-expiratory pressure (PEEP) to reduce pulmonary complications 5

Monitoring Considerations

• Baseline ECG recommended for patients with clinical risk factors undergoing intermediate or high-risk surgery 1
• Avoid routine pulmonary artery catheter use in low-to-moderate risk patients, as it increases interventions and costs without improving outcomes 5

Postoperative Management

Cardiac Biomarker Surveillance

• Measure high-sensitivity troponin and natriuretic peptides after surgery in high-risk patients to improve risk stratification 3

Pain Management

• Consider neuroaxial analgesia for postoperative pain when not contraindicated 3
• Avoid NSAIDs, especially COX-2 inhibitors, as first-line analgesics in patients with ischemic heart disease or stroke 3

Management of Perioperative MI

• Recognize that perioperative MI carries high mortality risk with nearly one-third mortality or readmission rate at 30 days 2
• Initiate aspirin, beta-blockers, and ACE inhibitors immediately 2
• Consider emergency coronary angiography and PCI or CABG for Type 1 MI 2
• Perform urgent echocardiography to assess ventricular function and detect mechanical complications 2
• Evaluate left ventricular function before discharge and perform risk stratification with stress testing 2

Venous Thromboembolism Prophylaxis

Risk-Based Prophylaxis

• Minor surgery in patients <40 years without risk factors: Early ambulation only 1
• Moderate-risk surgery in patients >40 years: Low-dose heparin every 12 hours or intermittent pneumatic compression 1
• Major surgery with clinical risk factors: Low-dose heparin every 8 hours or low-molecular-weight heparin; use intermittent pneumatic compression if bleeding-prone 1
• Very high-risk surgery with multiple conditions: Combine pharmacologic prophylaxis with mechanical methods 1

Common Pitfalls to Avoid

• Do not routinely perform cardiac testing in low-risk patients or those with good functional capacity, as it is time- and cost-consuming without improving outcomes 6
• Do not initiate high-dose beta-blockers immediately preoperatively without adequate titration time 1
• Do not allow prolonged hypotension (MAP <60 mmHg for >30 minutes) intraoperatively 3, 5
• Do not defer surgery unnecessarily for mild-to-moderate hypertension 1
• Do not discontinue chronic cardiac medications (beta-blockers, statins) perioperatively 2, 3