Recent advances in local anaesthetics for spinal anaesthesia

Although local anaesthesia is mentioned in historical manuscripts, it is only a hundred years since Bier first reported the intrathecal use of local anaesthetic agents. This has been followed by a rapid progression in the art and science of spinal anaesthesia. Isomerically pure agents with favorable clinical profiles, such as ropivacaine and levobupivacaine are now available. Spinal anaesthesia is commonly used in a variety of situations, including orthopaedic, abdominal, gynaecological surgery, Caesarean section and the relief of pain in childbirth. Hyperbaric solutions of local anaesthetics appear to produce more consistent results than plain solutions and the addition of other drugs, such as opioids and clonidine may improve analgesia. In addition to traditional spinal anaesthesia, local anaesthetics are now being evaluated in continuous spinal anaesthesia and combined epidural-spinal anaesthesia. This article reviews clinical experience with levobupivacaine and ropivacaine. Compared with levobupivacaine, ropivacaine generally produces a less intense motor block of shorter duration, which has advantages for earlier mobilization and discharge from hospital and may be particularly useful in obstetrics and ambulatory surgery.