title: Anxiety, vocalization, and agitation following peripheral nerve block with ropivacaine.
abstract: OBJECTIVE
  Central nervous system (CNS) and cardiovascular toxicity are potential side effects of local anesthetics. However, ropivacaine has been reported to be less CNS toxic than bupivacaine in human volunteers.
  
  
  METHODS
  We describe three cases of peripheral nerve blockade with ropivacaine that resulted in unusual symptoms of CNS toxicity.
  
  
  RESULTS
  In three patients, unexpected behavioral changes occurred during administration of ropivacaine. The patients became extremely agitated, anxious, and screamed, and they did not respond to verbal commands.
  
  
  CONCLUSIONS
  This case report shows that ropivacaine may cause CNS toxicity that differs from classical signs of local anesthetic-induced toxicity. This effect might be related to the unique structure of ropivacaine, which is formulated in an S-enantiomer preparation. It has been shown that S-enantiomers bind differently to receptors in both the CNS and cardiovascular systems. This property may account for the disinhibition of select neural pathways that are specifically involved in mediation of anxiety and aggression.
authors: Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors: S M
authors: SM
authors: Klein
authors: H
authors: H
authors: Benveniste
mesh_terms: D000368:Aged; D000577:Amides / Q000009:adverse effects*; D000779:Anesthetics, Local / Q000009:adverse effects*; D001007:Anxiety / Q000139:chemically induced*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000009:adverse effects*; D010699:Phonation / Q000187:drug effects*; D011595:Psychomotor Agitation; D000077212:Ropivacaine
chemical_list: D000577:Amides; D000779:Anesthetics, Local; D000077212:Ropivacaine