Making a choice of inotropes and vasodilators in clinical situations

There are five variables affecting cardiac output: heart rate and rhythm; contractility; ventricular preload; and ventricular afterload. The choice of specific drugs to augment myocardial performance is based on the spectra of their effects on these variables. In order to use inotropes and vasodilators efficiently in clinical situations, it is important to recognize the dose-response relationship, to consider route and rate of administration, and to take into account the presence of other drugs as well as the abnormal pathophysiology of the patient. The safe and effective use of inotropes and vasodilators in critically ill patients is most readily achieved when there is a systematic plan for introducing the drug, evaluating its effects, and adjusting those hemodynamic variables that can be controlled.