Levels of Sedation: Definitions
Basic, Clinical Sciences: Anesthesia Procedures, Methods, and Techniques
According to the ASA Continuum of Depth of Sedation, the levels of sedation/analgesia are separated into 4 categories based on responsiveness, airway patency, adequacy of spontaneous ventilation, and cardiovascular function.
Minimal sedation/anxiolysis is a drug-induced state during which patients respond normally to verbal commands with intact airway reflexes and unaffected ventilatory and cardiovascular functions.
Moderate sedation/analgesia or “conscious sedation” is a drug-induced depression of consciousness during which patients respond purposefully to verbal commands +/- light tactile stimulation. Importantly, airway patency remains intact, and spontaneous ventilation is adequate. Cardiovascular function is usually maintained.
Deep sedation/analgesia is a drug-induced depression of consciousness during which patients cannot be easily aroused but respond purposefully to repeated or painful stimulation. Of note, reflex withdrawal from a painful stimulus is NOT considered a purposeful response. Intervention may be necessary to maintain airway patency, and spontaneous ventilation may be inadequate. Cardiovascular function is usually maintained.
General anesthesia is a drug-induced loss of consciousness during which patients are not arousable even to painful stimulation. Intervention is often required to maintain airway patency, and spontaneous ventilation is frequently inadequate. Cardiovascular function may be impaired.