According to the American College of Physicians: Critical care medicine encompasses the diagnosis and treatment of a wide variety of clinical problems representing the extreme of human disease. Critically ill patients require intensive care by a coordinated team. The critical care specialist (intensivist) may be the primary provider of care or a consultant. The intensivist needs to be competent not only in a broad range of conditions common among critically ill patients but also with the technological procedures and devices used in the intensive care setting. The care of critically ill patients raises many complicated ethical and social issues, and the intensivist must be competent in areas such as end-of-life decisions, advance directives, estimating prognosis, and counseling of patients and their families.