Postoperative demand analgesia.
D000698:Analgesia; D000700:Analgesics / Q000008:administration & dosage*; D006801:Humans; D007275:Injections, Intravenous; D008614:Meperidine / Q000008:administration & dosage; D010146:Pain; D011182:Postoperative Care; D012651:Self Medication; D013997:Time Factors
D000700:Analgesics; D008614:Meperidine