The purpose of this study is to determine the benefit, if any, of buffering lidocaine (adding
sodium bicarbonate) when used for local anesthesia prior to percutaneous breast needle core
biopsies. The medicine doctors use to reduce the pain of breast biopsies, lidocaine, can
cause pain for approximately 15 seconds until the numbing effect begins. It is possible that
this pain is caused because lidocaine is acidic. Some physicians believe that reducing the
acidity of lidocaine by mixing it with sodium bicarbonate will reduce the initial pain of
injecting the lidocaine. Both approaches - injecting 1% lidocaine alone and injecting 1%
lidocaine mixed with sodium bicarbonate - are used as routine standard of care by
radiologists today. The purpose of this study is to determine if either approach is more
comfortable for patients having breast procedures.