What is the recommended anesthesia approach for patients with aortic stenosis undergoing surgery?

Anesthetic Management for Patients with Aortic Stenosis

For patients with aortic stenosis undergoing surgery, anesthetic techniques and agents should be tailored to individual patient needs, with careful hemodynamic monitoring to maintain stable cardiac output and avoid rapid hemodynamic changes. 1

Hemodynamic Goals in Aortic Stenosis

The primary anesthetic considerations for patients with aortic stenosis include:

• Maintain adequate preload: Patients with aortic stenosis depend on adequate preload to maintain cardiac output across the stenotic valve 2
• Avoid tachycardia: Faster heart rates reduce diastolic filling time
• Maintain sinus rhythm: Atrial contraction contributes significantly to ventricular filling
• Maintain systemic vascular resistance: Avoid vasodilation which can precipitate hypotension
• Avoid myocardial depression: Choose anesthetic agents with minimal negative inotropic effects

Monitoring Recommendations

Invasive monitoring is essential for patients with significant aortic stenosis:

• Arterial line: For beat-to-beat blood pressure monitoring 1
• Transesophageal echocardiography (TEE): Reasonable for all open surgical procedures unless contraindicated 1
• Central venous access: For administration of vasoactive medications and volume
• Consider pulmonary artery catheter: For complex cases or patients with poor ventricular function 3

Choice of Anesthetic Technique

General Anesthesia

General anesthesia is often preferred for patients with severe aortic stenosis, particularly for major surgeries:

• Induction: Etomidate or carefully titrated propofol with opioids to blunt sympathetic response
• Maintenance: Balanced technique with volatile agents at low to moderate concentrations supplemented with opioids
• Avoid: Rapid boluses of induction agents that can cause significant vasodilation

Regional Anesthesia

Traditionally considered contraindicated in severe aortic stenosis, but recent evidence suggests it may be used with caution:

• Epidural anesthesia: Can be used with careful titration to avoid rapid sympathetic blockade 4
• Spinal anesthesia: Higher risk due to rapid onset of sympathetic blockade, but case reports show successful use with careful technique 4
• Regional anesthesia is contraindicated in patients on anticoagulants or antiplatelet therapy due to risk of neuraxial hematoma 1

Fluid Management

Proper fluid management is critical:

• Start with small boluses (250-500 mL) administered slowly with continuous hemodynamic monitoring 2
• Evaluate for signs of hypovolemia before fluid administration 2
• Consider echocardiographic evaluation of ventricular filling before major fluid shifts 2
• Monitor for signs of pulmonary congestion during fluid administration 2

Vasoactive Medications

Have readily available:

• Phenylephrine: First-line agent for treating hypotension due to vasodilation 5
• Norepinephrine: For cases requiring both vasoconstriction and inotropic support
• Inotropes: Consider if hypotension persists despite adequate volume status 2
• Beta-blockers: To control tachycardia if needed

Special Considerations for TAVR Procedures

For transcatheter aortic valve replacement (TAVR):

• Conscious sedation vs. general anesthesia: Conscious sedation is associated with fewer requirements for inotropes/vasopressors, shorter hospital stays, and earlier mobilization 1
• Conscious sedation should only be used in highly experienced centers using the transfemoral approach 1
• Avoid conscious sedation in patients requiring TEE guidance, those with borderline vascular access, cognitive barriers, inability to lie flat, chronic pain, or morbid obesity 1

Complications and Management

Anticipate and prepare for potential complications:

• Hypotension: Treat promptly with phenylephrine 5
• Arrhythmias: Maintain access to temporary pacing capabilities 6
• Myocardial ischemia: Monitor ECG continuously and maintain coronary perfusion pressure
• Heart failure: Have inotropic support readily available

Perioperative Risk Stratification

The risk of adverse events increases with the severity of aortic stenosis:

• Very severe AS (Vmax ≥5 m/sec or mean gradient ≥60 mmHg): Highest risk 1
• Reduced LVEF (<50%): Significantly increases perioperative risk 1
• Symptomatic patients: Higher risk than asymptomatic patients 1

While aortic valve replacement remains the primary treatment for severe aortic stenosis before non-cardiac surgery, selected patients can undergo necessary procedures with acceptable risk when appropriate anesthetic management is employed 5, 3.