When do patients given intrathecal morphine need postoperative systemic opiates.
D006801:Humans; D009020:Morphine / Q000627:therapeutic use*; D009892:Opium / Q000627:therapeutic use; D010149:Postoperative Pain / Q000188:drug therapy*; D012107:Research Design
D009020:Morphine; D009892:Opium