title: Up-down sequential allocation technique to investigate the influence of opioids on the efficacy of epidural local anesthetics in labor pain.
authors.forename: H F
authors.initials: HF
authors.lastname: Wulf
mesh_terms: D015360:Analgesia, Epidural; D016362:Analgesia, Obstetrical; D000701:Analgesics, Opioid / Q000494:pharmacology*; D000779:Anesthetics, Local / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D011247:Pregnancy; D017409:Sufentanil / Q000494:pharmacology*
chemical_list: D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D017409:Sufentanil