inotrope
A medication that affects the force of cardiac muscle contraction, used to support cardiac output in critically ill patients.
Full Definition
Inotropes are cardiovascular medications that alter myocardial contractility, classified as positive (increasing contractility) or negative (decreasing contractility). In surgical critical care, positive inotropes like dobutamine and milrinone are commonly used to improve cardiac output in patients with heart failure or cardiogenic shock. These agents work through different mechanisms—dobutamine primarily affects beta-adrenergic receptors while milrinone inhibits phosphodiesterase. Careful monitoring of cardiac rhythm and blood pressure is essential during administration.
Usage
Usage note: Distinguish from vasopressors, which primarily affect vascular tone rather than cardiac contractility.
In Context
- "Start dobutamine infusion at 2.5 mcg/kg/min and titrate based on cardiac index measurements." — Physician order
- "The patient's ejection fraction improved with positive inotrope therapy." — Cardiology consultation