EXPERIMENTAL EPIDURAL ANAESTHESIA IN CAT WITH LIGNOCAINE AND AMETHOCAINE

Summary: In cats with permanently implanted catheters in the lumbar epidural space, the typical responses to the epidural administration of lignocaine and amethocaine were a flaccid paralysis of the hind limbs and a block of the flexion reflex. The responses to periodic injections of lignocaine were consistent up to fourteen weeks after surgery. The effects of lignocaine were enhanced (1) when the total dose was increased from 7.5 to 37.5 mg, (2) when the pH of the injection solution was increased from 3.4 to 7.5, and (3) in the presence of adrenaline 1: 100,000. Amethocaine was distinctly more potent and more toxic than lignocaine. Although the criteria for measuring the responses in the cat and in man differ, it is concluded that epidural anaesthesia in the two species is remarkably similar. © 1969 John Sherratt and Son Ltd.