Altering epidural morphine side effects with butorphanol in children.
D000005:Abdomen / Q000601:surgery; D015360:Analgesia, Epidural; D002077:Butorphanol / Q000008:administration & dosage*; D002648:Child; D006801:Humans; D011446:Prospective Studies; D011537:Pruritus / Q000517:prevention & control; D013903:Thoracic Surgery / Q000379:methods
D002077:Butorphanol