Vasopressorien

Vasopressorien are pharmacologic agents that constrict blood vessels and raise blood pressure, primarily used in the management of shock and other states of severe hypotension. They act by stimulating vascular smooth muscle through adrenergic receptors or other vasoconstrictive pathways, thereby increasing systemic vascular resistance and, in some cases, cardiac output.

Common agents include norepinephrine, epinephrine, dopamine, phenylephrine, and vasopressin. Norepinephrine is typically the first-line vasopressor in septic shock due to strong alpha-adrenergic vasoconstriction with modest effect on heart rate. Epinephrine provides both alpha and beta effects and is used in cardiac arrest, anaphylaxis, and refractory shock. Phenylephrine is a pure alpha-agonist useful when tachyarrhythmias limit beta activity or when other agents are unsuitable. Dopamine has a dose-dependent profile but is used less due to arrhythmia risk. Vasopressin is a non-adrenergic vasoconstrictor often added as an adjunct to reduce catecholamine requirements. In some contexts, newer agents like angiotensin II have been employed for refractory vasodilatory shock.

Administration and monitoring: vasopressors are administered by IV infusion, usually via central venous access, and doses are titrated to achieve a target mean arterial pressure (often around 65 mmHg). Continuous monitoring includes arterial pressure, heart rate, urine output, lactate, and signs of adequate organ perfusion. Fluids and source control are also important components of management.

Safety and limitations: vasopressors can cause peripheral ischemia, mesenteric or renal hypoperfusion if overused, and may worsen myocardial oxygen consumption. They require careful monitoring and assessment of volume status before and during use.