Search results
Results From The WOW.Com Content Network
An antihypotensive, also known as vasopressor, is an agent that raises blood pressure by constricting blood vessels, thereby increasing systemic vascular resistance. This is different from inotropes which increase the force of cardiac contraction. Some substances do both (e.g. dopamine, dobutamine).
Vasoconstrictors are also used clinically to increase blood pressure or to reduce local blood flow. Vasoconstrictors mixed with local anesthetics are used to increase the duration of local anesthesia by constricting the blood vessels, thereby safely concentrating the anesthetic agent for an extended duration, as well as reducing hemorrhage. [4] [5]
A vasoactive substance is an endogenous agent or pharmaceutical drug that has the effect of either increasing or decreasing blood pressure and/or heart rate through its vasoactivity, that is, vascular activity (effect on blood vessels).
(vasoconstriction and mydriasis; used as vasopressors, nasal decongestants and during eye exams). Selected examples are: Adrenoswitch-1 (photoswitchable partial α 1 agonist and light-controlled mydriatic) [ 1 ]
Although both vasopressors, vasopressin and epinephrine differ in that vasopressin does not have direct effects on cardiac contractility as epinephrine does. [18] Thus, vasopressin is theorized to be of increased benefit over epinephrine in cardiac arrest due to its properties of not increasing myocardial and cerebral oxygen demands. [18]
Vasodilation and vasoconstriction are complex phenomena; they are functions not merely of the fluid mechanics of pressure and tissue elasticity but also of active homeostatic regulation with hormones and cell signaling, in which the body produces endogenous vasodilators and vasoconstrictors to modify its vessels' compliance.
Vascular resistance is the resistance that must be overcome for blood to flow through the circulatory system.The resistance offered by the systemic circulation is known as the systemic vascular resistance or may sometimes be called by another term total peripheral resistance, while the resistance caused by the pulmonary circulation is known as the pulmonary vascular resistance.
The definition of refractory shock or vasodilatory shock varies. In 2018, the American College of Chest Physician stated that it is presents if there is an inadequate response to high-dose vasopressor therapy defined as ≥ 0.5 mg/kg/min norepinephrine-equivalent dose. [4]