When do you start inotropes and vasopressors (vasoactive medications) in patients with cardiac dysfunction, and in what order?

From the Guidelines

Inotropes should only be started in patients with cardiac dysfunction who are hypotensive (systolic blood pressure <85 mmHg), hypoperfused, or shocked, due to safety concerns. The initiation of inotropes and vasopressors in patients with cardiac dysfunction is guided by the principle of addressing hemodynamic instability. According to the ESC guidelines for the diagnosis and treatment of acute and chronic heart failure 2012 1, the use of inotropic agents is not recommended unless the patient is hypotensive, hypoperfused, or shocked. When inotropes are required, an i.v. infusion of an inotrope (e.g. dobutamine) should be considered in patients with hypotension (systolic blood pressure <85 mmHg) and/or hypoperfusion to increase cardiac output, increase blood pressure, and improve peripheral perfusion. Some key points to consider when initiating vasoactive medications include:

• The general order of initiation starts with addressing fluid resuscitation and then moving to inotropes or vasopressors as needed.
• Norepinephrine may be considered in patients who have cardiogenic shock, despite treatment with an inotrope, to increase blood pressure and vital organ perfusion 1.
• The choice of inotrope or vasopressor depends on the specific clinical scenario, including the presence of cardiogenic shock, pulmonary hypertension, or right ventricular dysfunction.
• Continuous hemodynamic monitoring is essential during administration of these medications, with regular assessment of blood pressure, heart rate, cardiac output, and tissue perfusion markers.
• Titration should target the minimum effective dose to achieve hemodynamic goals while minimizing side effects such as tachyarrhythmias, myocardial ischemia, and peripheral ischemia. It's also worth noting that the 2008 ESC guidelines for the diagnosis and treatment of acute and chronic heart failure 1 provide additional context on the use of vasopressors, but the 2012 guidelines 1 take precedence due to their more recent publication and higher quality evidence.

From the FDA Drug Label

Milrinone lactate is a positive inotrope and vasodilator, with little chronotropic activity different in structure and mode of action from either the digitalis glycosides or catecholamines The suggested dosing infusion rate of intravenously administered epinephrine is 0.05 mcg/kg/min to 2 mcg/kg/min, and is titrated to achieve a desired mean arterial pressure (MAP)

The decision to start inotropes and vasopressors in patients with cardiac dysfunction depends on the individual patient's condition and the specific goals of treatment.

• Milrinone is used to increase myocardial contractility and improve diastolic function in patients with congestive heart failure.
• Epinephrine is used to provide hemodynamic support in septic shock associated hypotension. The order of administration is not explicitly stated in the provided drug labels, and the choice of which medication to use first should be based on the patient's specific needs and medical condition 2 3.

From the Research

Initiation of Inotropes and Vasopressors

• In patients with cardiac dysfunction, the initiation of inotropes and vasopressors (vasoactive medications) is crucial for restoring adequate tissue perfusion 4.
• The choice of vasopressor and inotrope therapy should be based on the individual patient's pathophysiology and hemodynamic response 5.

Order of Initiation

• Norepinephrine (NE) is often used as the first-line vasopressor, titrated to achieve an adequate arterial pressure, due to its reliable vasoconstrictor effects and minimal impact on heart rate 4, 5.
• If tissue and organ perfusion remain inadequate, an inotrope such as dobutamine may be added to increase cardiac output 4, 6.
• Low doses of epinephrine or dopamine may be used for inotropic support, but high doses of these drugs carry an excessive risk of adverse events and should be avoided 4.
• Levosimendan, a calcium sensitizer agent, can be used as a second-line agent or preferentially in patients previously treated with beta-blockers 6.

Considerations for Therapy

• The use of vasoactive agents should take both arterial pressure and tissue perfusion into account when choosing therapeutic interventions 4.
• Excessive vasoconstriction should be avoided, and the effects of vasopressors on blood flow must be considered 5.
• Parenteral positive inotropic therapy is indicated for short-term treatment of cardiovascular decompensation secondary to ventricular systolic dysfunction, low-output heart failure 7.
• The positive inotropic responses of individual patients to different agents can vary, and the choice of agent should be tailored to the individual patient's response 8.