Epidural Butorphanol Augments Lidocaine Sensory Anesthesia during Labor
T. K. Abboud, A. Reyes, Vera R. Cruz, J. Zhu, G. Sherman, Z. Steffens, A. Afrasiabi, R. Khan
Regional Anesthesia: The Journal of Neural Blockade in Obstetrics, Surgery, & Pain Control Sep 1991, 16 (5) 265-267; DOI: 10.1136/rapm-00115550-199116050-00005