Table 1

 American Society of Anaesthetists classification of grades of conscious depression

Level of sedation1. Minimal sedation(anxiolysis)2. Moderate sedation(conscious sedation)3. Deep sedation4. General anaesthesia
ResponsivenessNormal response toPurposeful response toPurposeful response afterUnrousable even with
verbal stimulationverbal or tactilerepeated orpainful stimulus
stimulationpainful stimulation
AirwayUnaffectedNo intervention requiredIntervention may be requiredIntervention often required
Spontaneous ventilationUnaffectedAdequateMay be inadequateFrequently inadequate
Cardiovascular functionUnaffectedUsually maintainedUsually maintainedMay be impaired