title: Letter: Patient-controlled intravenous narcotic administration during labour.
mesh_terms: D000773:Anesthesia, Obstetrical; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D008614:Meperidine / Q000008:administration & dosage*; D011247:Pregnancy
chemical_list: D008614:Meperidine