Life Support Systems: Systems that provide all or most of the items necessary for maintaining life and health. Provisions are made for the supplying of oxygen, food, water, temperature and pressure control, disposition of carbon dioxide and body waste. The milieu may be a spacecraft, a submarine, or the surface of the moon. In medical care, usually under hospital conditions, LIFE SUPPORT CARE is available. (From Webster's New Collegiate Dictionary)Ecological Systems, Closed: Systems that provide for the maintenance of life in an isolated living chamber through reutilization of the material available, in particular, by means of a cycle wherein exhaled carbon dioxide, urine, and other waste matter are converted chemically or by photosynthesis into oxygen, water, and food. (NASA Thesaurus, 1988)Space Flight: Travel beyond the earth's atmosphere.Life Support Care: Care provided patients requiring extraordinary therapeutic measures in order to sustain and prolong life.Heart-Lung Machine: Apparatus that provides mechanical circulatory support during open-heart surgery, by passing the heart to facilitate surgery on the organ. The basic function of the machine is to oxygenate the body's venous supply of blood and then pump it back into the arterial system. The machine also provides intracardiac suction, filtration, and temperature control. Some of the more important components of these machines include pumps, oxygenators, temperature regulators, and filters. (UMDNS, 1999)Decision Support Systems, Clinical: Computer-based information systems used to integrate clinical and patient information and provide support for decision-making in patient care.Advanced Cardiac Life Support: The use of sophisticated methods and equipment to treat cardiopulmonary arrest. Advanced Cardiac Life Support (ACLS) includes the use of specialized equipment to maintain the airway, early defibrillation and pharmacological therapy.Decision Support Systems, Management: Computer-based systems that enable management to interrogate the computer on an ad hoc basis for various kinds of information in the organization, which predict the effect of potential decisions.Cardiopulmonary Resuscitation: The artificial substitution of heart and lung action as indicated for HEART ARREST resulting from electric shock, DROWNING, respiratory arrest, or other causes. The two major components of cardiopulmonary resuscitation are artificial ventilation (RESPIRATION, ARTIFICIAL) and closed-chest CARDIAC MASSAGE.Expert Systems: Computer programs based on knowledge developed from consultation with experts on a problem, and the processing and/or formalizing of this knowledge using these programs in such a manner that the problems may be solved.Decision Making, Computer-Assisted: Use of an interactive computer system designed to assist the physician or other health professional in choosing between certain relationships or variables for the purpose of making a diagnostic or therapeutic decision.Advanced Trauma Life Support Care: The initial life support care of the severely injured patient.Withholding Treatment: Withholding or withdrawal of a particular treatment or treatments, often (but not necessarily) life-prolonging treatment, from a patient or from a research subject as part of a research protocol. The concept is differentiated from REFUSAL TO TREAT, where the emphasis is on the health professional's or health facility's refusal to treat a patient or group of patients when the patient or the patient's representative requests treatment. Withholding of life-prolonging treatment is usually indexed only with EUTHANASIA, PASSIVE, unless the distinction between withholding and withdrawing treatment, or the issue of withholding palliative rather than curative treatment, is discussed.Heart Arrest: Cessation of heart beat or MYOCARDIAL CONTRACTION. If it is treated within a few minutes, heart arrest can be reversed in most cases to normal cardiac rhythm and effective circulation.Extracorporeal Membrane Oxygenation: Application of a life support system that circulates the blood through an oxygenating system, which may consist of a pump, a membrane oxygenator, and a heat exchanger. Examples of its use are to assist victims of smoke inhalation injury, respiratory failure, and cardiac failure.Euthanasia, Passive: Failing to prevent death from natural causes, for reasons of mercy by the withdrawal or withholding of life-prolonging treatment.Liver, Artificial: Devices for simulating the activities of the liver. They often consist of a hybrid between both biological and artificial materials.Drug Therapy, Computer-Assisted: Adjunctive computer programs in providing drug treatment to patients.Quality of Life: A generic concept reflecting concern with the modification and enhancement of life attributes, e.g., physical, political, moral and social environment; the overall condition of a human life.Traumatology: The medical specialty which deals with WOUNDS and INJURIES as well as resulting disability and disorders from physical traumas.