Continuous spinal anaesthesia: what's new and what's not.

Continuous spinal anaesthesia combines the advantages of single-dose spinal anaesthesia, rapid onset and a high degree of success, with those of a continuous technique. The introduction of micro-catheters invigorated interest in the technique and allowed its expansion to additional populations and surgical procedures. However, multiple cases of cauda equina syndrome associated with micro-catheters and (primarily) hyperbaric lidocaine solution led to withdrawal of micro-catheters from the US market, casting doubt over the safety of continuous spinal anaesthesia as a whole. A decade after these events it is possible to look back at the experience with continuous spinal anaesthesia for operative anaesthesia and postoperative analgesia and to compare it with the available alternatives. From this perspective, continuous spinal anaesthesia remains a useful and safe technique. Future research should focus on the comparison of continuous spinal anaesthesia with the combined spinal/epidural technique and the use of newer spinal agents.