Assertion: nitrous oxide | /r/ObjectUse | used for analgesia
Facets:
value: historically
type: TEMPORAL
value: since the 18th century
type: TEMPORAL
value: safely
type: MANNER
Source sentences:
text: Nitrous oxide (N 2 O) has been used safely and effectively for analgesia and anesthesia since the 18th century.
text: Nitrous oxide has been used for 150 yr for analgesia and anesthesia and in the main has proven safe and efficacious.
text: Nitrous oxide (N 2 O), commonly known as “laughing gas,” has historically been used for medicinal purposes such as anesthesia, analgesia, and sedation.