Serum Samples: Sequential sampling of serum and fat will be obtained at 0, 1, 3, 6, 9, 12, 18, and 24 hour (T0, T1, T3, T6, T9, T12, T15, T18 and T24), where T0 = time of completion of tumescent infiltration or IV infusion. Serum samples will be obtained from a peripheral vein via an indwelling catheter and analyzed for cefazolin concentration by HPLC.