title: Patient-controlled analgesia--the value of a background infusion.
authors: M Y
authors: MY
authors: Wu
authors: G J
authors: GJ
authors: Purcell
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016058:Analgesia, Patient-Controlled; D006801:Humans; D007262:Infusions, Intravenous; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage / Q000627:therapeutic use*; D010149:Postoperative Pain / Q000517:prevention & control*
chemical_list: D009020:Morphine