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

From the Guidelines

For patients with aortic stenosis undergoing surgery, the recommended anesthesia approach focuses on maintaining hemodynamic stability with careful attention to preload, afterload, heart rate, and contractility. General anesthesia with a carefully titrated induction is preferred, using etomidate (0.2-0.3 mg/kg) or reduced doses of propofol for induction to minimize hypotension, as supported by the guidelines from the American College of Cardiology and American Heart Association 1. Opioids like fentanyl (2-5 mcg/kg) or sufentanil (0.25-0.5 mcg/kg) help blunt sympathetic responses. Maintenance can be achieved with volatile agents at 0.5-0.7 MAC combined with opioids, or with total intravenous anesthesia.

Key Considerations

• Invasive monitoring is essential, including arterial line placement before induction and central venous pressure monitoring for major surgeries.
• Hemodynamic goals include maintaining sinus rhythm at 60-70 beats/minute, adequate preload, avoiding significant decreases in systemic vascular resistance, and supporting myocardial contractility.
• Phenylephrine (50-100 mcg boluses or 0.1-0.5 mcg/kg/min infusion) is the vasopressor of choice for hypotension, as indicated by recent guidelines 1.
• Fluid management should be judicious, with small boluses (250 mL) guided by hemodynamic response.

Rationale

This approach is critical because aortic stenosis patients have limited ability to increase cardiac output, are preload dependent, and are vulnerable to hypotension with vasodilation, making careful anesthetic management essential to prevent cardiovascular collapse, as highlighted in the studies 1. The guidelines also suggest that for patients who meet indications for aortic valve replacement (AVR) before noncardiac surgery but are considered high risk or ineligible for surgical AVR, options include proceeding with noncardiac surgery with invasive hemodynamic monitoring and optimization of loading conditions, percutaneous aortic balloon dilation as a bridging strategy, and transcatheter aortic valve replacement (TAVR) 1.

Decision Making

The decision-making process should consider the severity of the aortic stenosis, the presence of symptoms, and the type of surgery being performed, as outlined in the appropriate use criteria for the treatment of patients with severe aortic stenosis 1. By prioritizing hemodynamic stability and carefully managing anesthesia, the risk of perioperative morbidity and mortality can be minimized, improving the quality of life for patients with aortic stenosis undergoing surgery.

From the Research

Anesthesia Approaches for Aortic Stenosis

• The use of neuraxial anesthesia in patients with severe aortic stenosis has traditionally been contraindicated due to concerns about decreased systemic vascular resistance and cardiac output 2, 3, 4.
• However, general anesthesia can also be risky for these patients, particularly in the prone position, as it can cause a major reduction in cardiac output secondary to diminished preload 2.
• Combined spinal-epidural anesthesia with careful titration of the local anesthetic dose can be a safe and efficient anesthetic method for managing patients with aortic stenosis 2, 3.
• The American College of Cardiology-American Heart Association 2007 guidelines recommend postponing or canceling elective noncardiac surgery in patients with symptomatic aortic stenosis 5.
• Appropriate choice of anesthetic technique and agent can optimize anesthetic management of patients with aortic stenosis, even in emergency situations 5.
• Continuous spinal anesthesia can be tailored to minimize potentially dramatic consequences of decreased systemic vascular resistance, and has been used successfully in patients with severe aortic stenosis 3.
• A systematic review found that carefully managed neuroaxial blockade could become a useful alternative to general anesthesia in patients with aortic stenosis, but noted that evidence is sparse and of questionable quality 4.

Considerations for Anesthetic Management

• Patients with aortic stenosis require careful monitoring of anesthesia to minimize the risk of perioperative complications 6.
• The use of local anesthesia with intravenous sedation, general anesthesia, and spinal anesthesia have all been reported in patients with aortic stenosis, with varying degrees of success 6.
• The choice of anesthetic technique and agent should be individualized based on the patient's specific condition and the type of surgery being performed 5, 6.
• Further research is needed to establish best practices for anesthetic management of patients with aortic stenosis, particularly with regards to the use of neuroaxial blockade 4.