[Safety and efficacy of low dose intrathecal morphine].
D000328:Adult; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007278:Injections, Spinal; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage*; D010149:Postoperative Pain / Q000517:prevention & control*
D009020:Morphine