title: Letter: Nitrous oxide-oxygen analgesia.
mesh_terms: D000698:Analgesia; D000766:Anesthesia, Dental; D000769:Anesthesia, Inhalation / Q000009:adverse effects*; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D009609:Nitrous Oxide / Q000008:administration & dosage / Q000009:adverse effects*; D010100:Oxygen / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D009609:Nitrous Oxide; D010100:Oxygen