Transient neurologic symptoms (TNS) following spinal anaesthesia with lidocaine versus other local anaesthetics
Abstract
Background
Spinal anaesthesia has been in use since the turn of the late nineteenth century. During the last decade there has been an increase in the number of reports implicating lidocaine as a possible cause of temporary and permanent neurologic complications after spinal anaesthesia. Follow‐up of patients who received uncomplicated spinal anaesthesia revealed that some of them developed pain in the lower extremities after an initial full recovery. This painful condition that occurs in the immediate postoperative period was named "transient neurologic symptoms" (TNS).
Objectives
To study the frequency of TNS and neurologic complications after spinal anaesthesia with lidocaine, compared to other local anaesthetics.
Search methods
We searched the Cochrane Controlled Trials Register (CENTRAL), (The Cochrane Library, Issue 1, 2005); MEDLINE (1966 to January 2005); EMBASE (1980 to week 6, 2005); LILACS (March 2005); and handsearched the reference lists of trials and review articles.
Selection criteria
We included all randomized and pseudo‐randomized studies comparing the frequency of TNS and of neurologic complications after spinal anaesthesia with lidocaine as compared to other local anaesthetics.
Data collection and analysis
Two authors independently evaluated the quality of the relevant studies and extracted the data from the included studies.
Main results
Fifteen trials, reporting 1437 patients, 120 of whom developed transient neurologic symptoms, were included in the analysis. The use of lidocaine for spinal anaesthesia increased the risk of developing TNS. There was no evidence that this painful condition was associated with any neurologic pathology; the symptoms disappeared spontaneously by the fifth postoperative day. The relative risk (RR) for developing TNS after spinal anaesthesia with lidocaine as compared to other local anaesthetics (bupivacaine, prilocaine, procaine, levobupivacaine and ropivacaine) was 7.16 (95% confidence interval (CI) 4.02, 12.75).
Authors' conclusions
The risk of developing TNS after spinal anaesthesia with lidocaine was significantly higher than when bupivacaine, prilocaine and procaine were used. The term "TNS", which implies a positive neurologic finding, should not be used for this painful condition. One study about the impact of TNS on patient satisfaction and functional impairment demonstrated that non‐TNS patients were more satisfied and had less functional impairment after surgery than TNS patients, but this did not influence their willingness to recommend spinal anaesthesia.
PICOs
Plain language summary
Lidocaine is more likely than bupivacaine, prilocaine or procaine to induce transient neurologic symptoms (TNS) when used for spinal anaesthesia
Lidocaine is the drug of choice for inducing spinal anaesthesia in ambulatory surgery because of its rapid onset of action, intense nerve blockade and short duration of action. The possible side effects of spinal anaesthesia in adults, which develop after recovery, are: backache, postdural puncture headache and transient neurologic symptoms that are characterized by slight to severe pain in the buttocks and legs. TNS symptoms develop within a few hours up to 24 hours after anaesthesia and last, in most cases, up to two days. The present review shows that lidocaine is more likely to cause transient neurologic symptoms than bupivacaine, prilocaine and procaine.
