Criticalcare is a medicine or intensive-care medicine, a branch of medicine concerned with life support for critically ill patients. A critical illness or injury acutely impairs one or more vital organ systems such that there is a high probability of imminent or life threatening deterioration in the patient’s condition.

It involves decision making of high complexity to assess, manipulate, and support vital organ system failure and/or to prevent further life threatening deterioration of the patient’s condition. Examples of vital organ system failure include, but are not limited to: central nervous system failure, circulatory failure, shock, renal, hepatic, metabolic, and/or respiratory failure.