CONTINUOUS SPINAL-ANESTHESIA

Continuous spinal anaesthesia (CSA) is a further means of central nerv e block for anaesthesia besides single-shot spinal (SSS), combined spi nal/epidural,and epidural anaesthesia. Major advantages compared to SS S are the possibility of subsequent injection of local anaesthetic via the indwelling catheter, which enables analgesia to be maintained ove r a longer period. Moreover, the haemodynamic effects are diminished b y this mode of application. The most important advantages of CSA compa red to continuous epidural anaesthesia are the more rapid onset of act ion, better quality of analgesia, and better muscle relaxation. Since small doses of local anaesthetic are used in CSA, there is less danger of systemic toxic reactions. The microcatheters used up to now for CS A are introduced via relatively large needles that cause perforation t rauma to the dura, resulting in loss of cerebrospinal fluid (CSF) and thus a higher incidence of post-dural punctive headache. Hence, furthe r technical developments must have the objectives of reducing needle d iameter and increasing catheter diameter. Perforation trauma to the du ra is reduced by using small needles. Use of a larger catheter enables better mixing of the local anaesthetic with the CSF, and it is easier to aspirate CSF in order to establish the correct position of the cat heter.