Despite the factors that influence physicians to treat critically ill patients whenever possible, the idea that life must be supported at all costs has become increasingly less persuasive in the ICU. One reason for this is dissatisfaction with the technologies that have given to ICU its present prominence; a case in point is the pulmonary artery catheter. At the same time, the evolution of critical care medicine as a specialty represents in part an attempt to concentrate medical responsibility in a few physicians who are knowledgeable about withholding and withdrawing life support, among other things. Retrospective reimbursement for hospitals has been replaced by prospective, uniform payment for Medicare patients and may discourage the intensive care of these persons. Similarly, as more physicians become salaried and less financially dependent on performing procedures, they may be disinclined to favor ICU admission. Support for this position comes from several studies demonstrating the limited therapeutic benefits of critical care.
Perhaps the most important reason that the concept of life support at all costs is being reappraised is that life and death are being redefined in our society. Ironically, this redefinition has resulted in large part from the technologic advances that helped establish the ICU in the first place. For example, death once was thought of as a stopping of the flow of vital body fluids, as manifested by a failure of breathing and heartbeat, and was defined medically as “the cessation of cardiopulmonary function.” However, with the advent of cardiopulmonary resuscitation (CPR) and post-CPR adjuncts such as mechanical ventilation, some patients survived what was called “sudden death.” Although the word “irreversible” then was added to the definition of death, confusion regarding the concept remained.
The confusion intensified with the introduction of transplantation, which allowed physicians to support the lives of some patients by removing vital organs from others. However, the potential organ donors were not dead, because their cardiopulmonary function was intact, even though they required CPR and mechanical ventilation to stay alive. At this point, the concept of death was extended to include not only irreversible cessation of cardiopulmonary function but also “the irreversible cessation of all functions of the entire brain, including the brain stem.”