Síguenos en Twitter     Síguenos en Facebook     Síguenos en YouTube     Siguenos en Linkedin     Correo Salutsantjoan     Gmail     Dropbox     Instagram     Google Drive     StumbleUpon     StumbleUpon     StumbleUpon     StumbleUpon     StumbleUpon     StumbleUpon     StumbleUpon


My photo
FACP. Colegio de médicos de Tarragona Nº 4305520 / fgcapriles@gmail.com




Thursday, June 2, 2016

Agents For Digital Nerve Blocks

NUEM - May 31, 2016 - By Bode J - Edited by: Weygandt L - Expert Commentary: Lank P
Citation: [Peer-Reviewed, Web Publication] Bode J, Weygandt L (2016, May 31). The Best Agent For Digital Nerve Blocks [NUEM Blog. Expert Commentary by Lank P]. Retrieved from http://www.nuemblog.com/blog/digital-nerve-block/
"Lidocaine vs Bupivacaine vs Both
A decade ago it was believed that the optimal anesthetic for digital blocks involved a mixture of one part lidocaine with one part bupivacaine, under the theory that by combining the two you could take advantage of the former’s quickness of onset and the latter’s duration of action. Still, this method has some very real disadvantages, namely that it is disruptive and takes time for a busy clinician to prepare, and it also introduces user error and uncertainty in terms of exactly which amounts of which anesthetic the patient is receiving. In light of the risks, do the theoretical advantages hold water?
One 1996 study compared this lidocaine/bupivacaine cocktail to bupivacaine alone and found that the median time to onset for both groups was almost identical - about 4 minutes, suggesting no advantage of the cocktail. Furthermore, when it comes to duration, bupivacaine again has the clear upper hand. A 2006 study from Thompson and Lalonde showed bupivacaine’s mean duration of action, defined as time from injection to time at which the patient could feel discernible pinpricks, was 24.9 hours compared 4.9 hours for lidocaine alone. 
Based on these findings, the theoretical faster onset advantage of lidocaine is unrealized while the duration of action of bupivacaine is clearly superior. However, bupivacaine is not without drawbacks, and at least one study found that patients reported statistically significant increased pain levels with bupivacaine vs. other agents. If only there were a third option...
Take home points
  • There are no data supporting the use of a lidocaine/bupivacaine cocktail as compared to lidocaine with epinephrine or bupivacaine alone
  • Bupivacaine is a good choice, but limited data suggests that this agent causes more pain with administration than does lidocaine with epinephrine
  • The dogma against epinephrine use in digital blocks is largely unfounded and outdated
  • Use commercially available preparations with standardized concentrations
  • Be wary of epinephrine in patients with peripheral artery disease or other causes of poor peripheral perfusion, and work within your hospital guidelines and local practice patterns"