Sedation encourages a state of relaxation. It ranges along a spectrum from minimal on one end to general anesthesia on the other (this generally applies to surgery patients in a hospital setting). During minimal sedation patients can still hear, see and respond to the action taking place around them. Sedated patients are much less likely to experience anxiety as a result of these environmental stimuli.
Nitrous oxide and oxygen sedation falls within the mildest category of sedation. Patients may feel tingling or a sense of well-being. However they remain alert. Once inhalation is discontinued the effects end also, often within seconds.