The Hip: Preservation, Replacement and Revision

Inotropic Agents

Agent Alpha/Beta Dilution Dose Range Comments Norepinephrine a > b 2 mg/250 ml 0.02-0.2 ug/kg/min Rarely useful (8 ug/ml) periph. vasoconstr. Epinephrine a & b 1 mg/250 ml 0.01-0.1 ug/kg/min Useful (4 ug/ml) Dopamine a & b 200 mg/250 ml 1-30 ug/kg/min Dose Related Effect (800 ug/ml) 1-2 ug/kg/ml: Renal 2-10 ug/kg/ml: b agonist 10-15 ug/kg/ml: a & b Dobutamine a & b 250 mg/ 250 ml 1-30 ug/kg/min No renal effect (1000 ug/ml) Little Tachycardia isoproterenol beta 1 mg/250 ml 0.01-0.1 ug/kg/min "the Beta agonist" (4 ug/ml) -------------------------------- - improvements in cardiac fuction by these means are generally achieved at the expense of increased myocardial oxygen demand, which should always be considered; - inotropic agents should, therefore, only be used when manipulations of heart rate, Preload, and After-Load are ineffective; - Dopamine and Dobutamine are agents of first choice; - dobutamine may be preferred in pts in whom After-Load & Preload reduction are indicated; - combination of inotropic & afterload reducing agent is a method of functionally reclaiming preload reserve; - Epinephrine is usually reserved for pts with severe cardiac impairment, and is usually the first drug weaned in a mult-inotropic agent environment;

Original Text by Clifford R. Wheeless, III, MD.