Specialized health care for critically ill or injured patients. Nearly 80 percent of all Americans will experience a critical illness or injury, either as the patient, family member, or friend of a patient. Critical care can be provided wherever life is threatened–at the scene of an accident, in an ambulance or medivac helicopter, in a hospital's emergency room or operating room. Most critical care today, however, is delivered in intensive care units (ICU) and trauma centers. Critical care is provided by multiprofessional teams who use their unique expertise, ability to interpret important therapeutic information, access to highly sophisticated equipment, and services of support personnel to provide care that leads to the best outcome for the patient.