“…Bupivacaine has the longest duration of action of all Associate Professor of Clinical Radiology and Chief of Angiography and Interventional Radiology, Department of Diagnostic Radiology Northwestern University Medical School and Northwestern Memorial Hospital, Chicago, Illinois local anesthetics; the addition of epinephrine prolongs the effects of the drug. 1,7 After selection of the catheter or needle entry site, nerve blocks are performed on the rib immediately superior to the punctured interspace, as well as one rib above and below the site, because there can be some sensory overlap of these nerves. The ribs are palpated, and the skin is punctured with a 25-gauge needle attached to an anesthetic-filled syringe.…”