RT Journal Article SR Electronic T1 Transdermal Nitroglycerine Enhances Spinal Sufentanil Postoperative Analgesia Following Orthopedic Surgery JF Regional Anesthesia & Pain Medicine JO Reg Anesth Pain Med FD BMJ Publishing Group Ltd SP 23 OP 23 DO 10.1136/rapm-00115550-199823031-00023 VO 23 IS Suppl 1 A1 G R. Lauretti A1 A L. Mattos A1 M P. Reis A1 W A. Prado YR 1998 UL http://rapm.bmj.com/content/23/Suppl_1/23.abstract AB