Vasoactive Drugs

The purpose of vasoactive drugs in the ICU is to improve the mean arterial pressure (MAP) and cardiac output (CO) by affecting left ventricular contractility, volume status, and systemic vascular resistance (SVR). MAP is related to CO and SVR by an equation. Vasopressors are generally indicated in the setting of circulatory shock. There are four different types of shock: cardiogenic, distributive, hypovolemic, and obstructive. Mixed forms of shock can also occur. Vasoactive medications often work as agonists or antagonists of adrenergic or parasympathetic receptors. These selected receptors represent the principal targets for vasoactive therapy in the intensive care setting. Physical examination, urine output, laboratory testing, imaging, and invasive hemodynamic monitoring can be important tools to differentiate the nature of the patient's shock.