The purpose of this study is to determine peak plasma bupivacaine concentrations in a similar
fashion for PECS I/II blocks. The investigators hypothesis is that the mean peak plasma
levels for patients undergoing PECS I/II blocks will be less than the levels reported to
cause early neurotoxicity of [2.2 (0.9) micrograms/ml]6 in patients receiving intravenous
bupivacaine infusions.