Ultrasound Guided Supraclavicular Nerve Block

Patients will be randomized into one of two groups, Group M: Ropivacaine and Mepivacaine - subject will receive two injections before surgery begins. These two injections will consist of the mixture of mepivacaine (15 ml) and ropivacaine (15 ml). Group S: Mepivacaine followed by Ropivacaine. Subjects will receive two injections before surgery begins. One injection will contain mepivacaine (15 ml) and the other will contain ropivacaine (15 ml). On the first, second, and third mornings after surgery,subjects will be asked to rate their pain on a scale of 1 to 10. If the subject is discharged from the hospital, a telephone call will be made to the subject's home to collect this information.