title: 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).
  
  
  OBJECTIVE
  To study the frequency of TNS and neurologic complications after spinal anaesthesia with lidocaine, compared to other local anaesthetics.
  
  
  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.
  
  
  METHODS
  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.
  
  
  METHODS
  Two authors independently evaluated the quality of the relevant studies and extracted the data from the included studies.
  
  
  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).
  
  
  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.
authors.affiliation: Frederiksberg Hospital, Dept. of Anaesthesiology, Ndr. Fasanvej 57, Frederiksberg, Denmark. Dusanka.Zaric@fh.hosp.dk
authors.forename: D
authors.initials: D
authors.lastname: Zaric
authors.forename: C
authors.initials: C
authors.lastname: Christiansen
authors.forename: N L
authors.initials: NL
authors.lastname: Pace
authors.forename: Y
authors.initials: Y
authors.lastname: Punjasawadwong
mesh_terms: D000775:Anesthesia, Spinal / Q000009:adverse effects*; D000779:Anesthetics, Local / Q000009:adverse effects*; D006801:Humans; D007866:Leg / Q000294:innervation*; D008012:Lidocaine / Q000009:adverse effects*; D010146:Pain / Q000139:chemically induced*; D010523:Peripheral Nervous System Diseases / Q000139:chemically induced*; D016032:Randomized Controlled Trials as Topic
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine