Evaluation of lidocaine spinal anesthesia in the rhesus monkey.

The present study was undertaken to determine whether a nonhuman primate model could be developed that would allow reproducible spinal anesthesia with determination of onset and duration of both sensory and motor anesthesia, using techniques for evaluation common in clinical practice. Recently, Feldman and Covino (1) reported the development of a chronic dog model for evaluation of spinal anesthesia. However, their model was used for determination of onset and duration of motor anesthesia only. They were not able to measure either sensory or autonomic blockade. A review of the limited Iiterature relating to spinal anesthesia in primates reveals examination of narrow aspects of the technique. Some of those studies examined systemic and regional blood flow during spinal anesthesia, but there was no attempt to measure neural blockade (2). Another study was conducted using hyperbaric ketamine in the rhesus mon-