Sleep and anesthesia

While sleep and anesthesia are different states, they have shared characteristics. Sleep is a natural state of unconsciousness, subject to homeostatic drive and circadian variability. It is influenced by psychological and environmental factors, inhomogeneous and readily terminated by environmental disturbances or once sleep need is met. In contrast, general anesthesia is drug induced, relatively homogenous and independent of homeostatic, circadian, psychological or environmental factors and its termination requires drug elimination. The unconsciousness of either state involves similar neurological pathways. They exhibit similar changes in muscle tone and ventilatory drive with conscious state change and vulnerability to upper airway obstruction or hypoventilation in one state suggests similar vulnerability in the other. While ability to arouse protects the sleeping individual, deeply sedated/anesthetized patients with such susceptibilities are at risk because of drug-induced suppression of arousal responses, demanding close monitoring until their restoration.