Critical care medicine is the multidisciplinary healthcare specialty that cares for patients with acute, life-threatening illness or injury (SCCM definition).
Critical care (medicine) is maturing into a separate specialty whose practitioners are "intensivists" and who practice is moving from consult based "open" units, to multidisciplinary "closed" units.
Critical Care Medicine is a term used in the North America to describe the practice of medicine in intensive care units (ICU). Elsewhere it is known as Intensive Care Medicine (ICM); in Great Britain, ICUs are often referred to Intensive Therapy Units (ITU). A specialist who practices intensive care medicine is known as an intensivist, and has usually been trained and board certified in anesthesiology, surgery, internal medicine or pediatrics.
Critical Care Medicine is a relatively modern specialty; the first intensive care units opened in Europe in the late 1950s and rapidly spread to North America. Certification of training in this field did not occur in the United States until 1986. By the late 1990s, there were approximately 5000 intensive care units in the USA. For many years intensive care was something of a "free for all" struggle between various interest groups, with the patient often caught in the middle. This arose from the mistaken view of many physicians that intensive care patients were merely sicker versions of the patients that they already looked after on the wards.
An open ICU model evolved, with the primary physician making the decisions and a support team of specialists acting as consultants. It has since been shown that the presence of a properly trained intensive care physician in the unit significantly reduces morbidity, mortality and cost.
There is an emerging body of evidence that "closing" units (the intensive care team look after all aspects of patient care, the primary team consult) may further improve outcomes and cost effectiveness. Critical care, as a specialty, has matured, and with the prevalence of cost containment as the major driving force in healthcare, the intensivist is becoming an essential component in cost control, and quality assurance, strategies.
Three factors differentiate intensive care from other wards in hospitals: 1) a very high nurse to patient ratio, 2) the availability of invasive monitoring, 3) the use of mechanical and pharmacological life sustaining therapies (mechanical ventilation, vasopressors, continuous dialysis).