TY - CHAP M1 - Book, Section TI - Hypotensive Agents A1 - Butterworth IV, John F. A1 - Mackey, David C. A1 - Wasnick, John D. Y1 - 2022 N1 - T2 - Morgan & Mikhail’s Clinical Anesthesiology, 7e AB - KEY CONCEPTS Inhaled nitric oxide is a selective pulmonary vasodilator that is used in the treatment of reversible pulmonary hypertension. Acute cyanide toxicity is characterized by metabolic acidosis, cardiac arrhythmias, and increased venous oxygen content (as a result of the inability to utilize oxygen). Another early sign of cyanide toxicity is the acute resistance to the hypotensive effects of increasing doses of sodium nitroprusside (tachyphylaxis). By dilating pulmonary vessels, sodium nitroprusside may prevent the normal vasoconstrictive response of the pulmonary vasculature to hypoxia (hypoxic pulmonary vasoconstriction). Preload reduction makes nitroglycerin an excellent drug for the relief of cardiogenic pulmonary edema. Hydralazine relaxes arteriolar smooth muscle in multiple ways, including dilation of precapillary resistance vessels via increased cyclic guanosine 3′,5′-monophosphate. The body reacts to a hydralazine-induced fall in blood pressure by increasing heart rate, myocardial contractility, and cardiac output. These compensatory responses can be detrimental to patients with coronary artery disease and are minimized by the concurrent administration of a β-adrenergic antagonist. Fenoldopam (infusion rates studied in clinical trials range from 0.01 to 1.6 mcg/kg/min) reduces systolic and diastolic blood pressure in patients with malignant hypertension to an extent comparable to nitroprusside. Dihydropyridine calcium channel blockers preferentially dilate arterial vessels, often preserving or increasing cardiac output. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/29 UR - accessanesthesiology.mhmedical.com/content.aspx?aid=1190604712 ER -