AN ESSENTIAL function of the intensive care unit (ICU) is to couple immediate diagnosis with rapid therapeutic reversal of acute abnormalities of vital organ function. Much of conventional ICU technology monitors rapid changes in the cardiovascular system. Continuous electrocardiographic monitoring facilitates immediate detection and reversal of arrhythmias. Indwelling arterial catheters provide continuous measurement of arterial pressure. The balloon-tipped, flow-directed thermodilution pulmonary artery catheter permits frequent assessment of ventricular filling pressure and cardiac output, as well as calculation of vascular resistance in the systemic and pulmonary circulations. The major purpose of this cardiovascular monitoring is to allow recognition and correction of major derangements in cardiovascular function before serious compromise of vital organ systems can develop.
During the past few years, the diagnostic and therapeutic capabilities of cardiovascular medicine have become more and more sophisticated. This enhanced diagnostic capability stems in part from the application of ultrasound and nuclear-medicine techniques to image
Parker MM, Cunnion RE, Parrillo JE. Echocardiography and Nuclear Cardiac Imaging in the Critical Care Unit. JAMA. 1985;254(20):2935-2939. doi:10.1001/jama.1985.03360200087035