From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
In patients with severe aortic stenosis and shock, phenylephrine is generally the preferred first-line vasopressor, as it provides pure alpha-adrenergic vasoconstriction without the chronotropic or inotropic effects that can worsen the hemodynamics in aortic stenosis, as suggested by a study published in Anesthesia and analgesia 1.
Key Considerations
- Starting at 0.1-0.5 mcg/kg/min and titrating to effect, phenylephrine can help maintain adequate systemic vascular resistance and coronary perfusion pressure without tachycardia.
- Norepinephrine (starting at 0.01-0.3 mcg/kg/min) can be considered as an alternative but must be used cautiously due to its beta effects, as noted in a study published in the Journal of intensive care medicine 2.
- Vasopressin (0.01-0.04 units/min) may also be appropriate as a second-line agent, as discussed in a study published in Seminars in respiratory and critical care medicine 3.
- Medications with predominant beta-adrenergic effects like dobutamine or epinephrine should generally be avoided as they can increase heart rate and contractility, which may reduce diastolic filling time and coronary perfusion while increasing myocardial oxygen demand.
Hemodynamic Monitoring and Management
- Careful hemodynamic monitoring is essential, ideally with arterial line placement and consideration of echocardiographic guidance, as emphasized in a study published in the Journal of the American Heart Association 4.
- The underlying cause of shock should be addressed simultaneously, and definitive management of severe aortic stenosis (valve replacement) should be expedited once the patient is stabilized.
- A study published in BMC anesthesiology 5 highlights the importance of timely bolus vasopressors in elderly patients with severe aortic stenosis, further supporting the use of phenylephrine as a first-line vasopressor in this population.