life-support

of or pertaining to equipment or measures that sustain or artificially substitute for essential body functions, as breathing or disposal of body wastes: Without life-support equipment, the patient might die.

of or pertaining to equipment or measures that provide, within a surrounding hostile environment, as outer space or ocean depths, a life-sustaining environment similar to that found on the earth's surface: the life-support system of a spacecraft or submarine.

of or pertaining to anything that fosters or sustains life, success, or continued existence, as of a person, thing, or nation: the life-support system of the economy.