After fluid resuscitation, a patient in septic shock has a decreasing blood pressure and cardiac output. The nurse anticipates the administration of which medication?

A. Sodium nitroprusside: Sodium nitroprusside is a potent arterial and venous vasodilator used primarily in hypertensive emergencies and acute heart failure. In septic shock, systemic vascular resistance is already profoundly decreased due to inflammatory-mediated vasodilation. Administering a vasodilator would further lower blood pressure and worsen hypoperfusion. B. Norepinephrine: Norepinephrine is the first-line vasopressor for septic shock when hypotension persists after adequate fluid resuscitation. It stimulates alpha-1 adrenergic receptors to increase systemic vascular resistance and beta-1 receptors to enhance myocardial contractility. This improves mean arterial pressure and supports organ perfusion in distributive shock states. C. Regular insulin: Regular insulin is used to manage hyperglycemia, which is common in critically ill patients due to stress-induced insulin resistance. While glucose control is important, insulin does not address the primary hemodynamic instability of septic shock. It has no direct effect on vascular tone or cardiac output in this context. D. Nitroglycerin: Nitroglycerin is a venous vasodilator that reduces preload and myocardial oxygen demand, typically used in acute coronary syndromes or heart failure. In septic shock with declining blood pressure and cardiac output, reducing preload would further compromise perfusion. Vasopressor support, not vasodilation, is indicated.