The Basics of Critical Care
Critical and intensive care medicine is an integrated discipline that requires the clinician to examine a number of important basic interactions. These include the interactions among organ systems, between the patient and his or her environment, and between the patient and life-support equipment. Gas exchange within the lung, for example, is dependent on the matching of ventilation and perfusion—in quantity, space, and time. Thus, neither the lungs nor the heart are solely responsible; rather, it is the cardiopulmonary interaction that determines the adequacy of gas exchange.