Application of lumbosacral spinal anesthesia for ovine Caesarian surgery and for vasectomy under field conditions.

A 2% lignocaine solution infused at a dose of 2 mg/kg at the lumbosacral site gave excellent analgesia in 28 vasectomy operations and in 33 of 38 (87%) Caesarian operations at a dose of 4 mg/kg. Failure of the anesthetic technique in 4 sheep (6% of all operations) was associated with poor positioning of the ewe and incorrect identification of the epidural space. One fatality was recorded and was considered to result from lignocaine overdosage and the probable pooling of blood in the splanchnic vasculature. Pelvic limb paresis persisted for 2 to 4 h post epidural injection in all ewes, but no permanent paralysis was encountered. Lumbosacral epidural anesthesia gave excellent analgesia for vasectomy, and was indicated for Caesarian surgery when a dystocia was associated with severe vaginal prolapse or the delivery of a fetal monster. Further work is needed to find an analgesic preparation which has a shorter duration than the 2% lignocaine solution.