Continuous microspinal anaesthesia: another perspective on mechanisms inducing cauda equina syndrome.

Continuous spinal anaesthesia through a microspinal catheter technique has been criticised on several grounds and is now rarely used. This paper reviews the possible causes of the cauda equina syndrome which have been described and, on the basis of research in cadaver preparations, a glass 'spine' model and clinical experience in over 200 cases, suggests how these problems might be avoided. The use of careful insertion techniques, limiting the length of catheter inserted into the subarachnoid space and the use of no stronger than 0.5% bupivacaine solution are recommended.