1Woodhouse A, Mather LE. The minimum effective concentration of opioids: a revisitation with patient-controlled analgesia fentanyl. Reg Anesth Pain Med, 2000, 25: 259-267.
2Graves DA, Arrigo JM, Foster TS, et al. Relationship between plasma morphine concentrations and pharmacologic effects in postoperative patients using patient-controlled analgesia. Clin Pharmacokinet, 1985, 4:41-47.
3Eisenach JC, Grice SC, Dewan DM. Patient-controlled analgesia following cesarean section: a compared with epidural and intramuscular narcotics. Anesthesiology, 1988, 68: 444-446.
4Weller R, Rosenblum M, Grss JB. Comparsion of epidural and patient-controlled intravenous morphine following joint replacement surgery. Can J Anaesth, 1991, 38: 582-584.