Onset Time of Brachial Plexus Block Using Local Anaesthetic Diluted With 0.9% Saline vs 5% Dextrose

Summary

Regional anesthesia employs the use of local anesthetics (LA) to block specific nerves to enable pain free surgery to be performed, or for intra and post operative pain relief. Dilution of local anesthetics with normal saline (NS) is a common practice to enable larger volumes of LA to be given, for example, in instances where multiple nerve blocks are needed to be performed for optimal pain relief while avoiding toxic doses. A high sodium concentration is known to antagonize the analgesic effect of local anesthetics. 5% dextrose (D5W) on the other hand is painless on injection and does not cause any long-term effects in animals or humans when injected around neurological tissue. In the literature, only one study using dextrose 5% as diluent to produce 0.5% ropivacaine for axillary brachial plexus block showed a statistically significant reduction in the onset time for sensory blockade when compared with dilution with NS. In this study, 0.5% ropivacaine diluted with D5W or NS is used for ultrasound guided supraclavicular brachial plexus block, and the time for complete sensory and motor blockade was compared. 0.5% ropivacaine is easily diluted and is a common concentration used at our centre for nerve blocks. The aim of this study is to assess if 0.5% ropivacaine diluted with D5W results in a shorter onset time for sensory block which may change the current practice of dilution with NS

Timeline

Start

2011-12

Primary completion

2012-10

Completion

2012-10

Drugs

Indications

No indication recorded.