title: The effects of postoperative epidural analgesia versus centrally acting opiate on physiological shunt after upper abdominal operation.
mesh_terms: D000136:Acid-Base Equilibrium / Q000187:drug effects; D000698:Analgesia; D000767:Anesthesia, Epidural; D002245:Carbon Dioxide / Q000097:blood; D003061:Codeine / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D009019:Morphinans / Q000494:pharmacology*; D010100:Oxygen / Q000097:blood; D012119:Respiration / Q000187:drug effects*; D014692:Ventilation-Perfusion Ratio / Q000187:drug effects
chemical_list: D009019:Morphinans; D002245:Carbon Dioxide; D010100:Oxygen; D003061:Codeine