Tumescent Antibiotic Delivery (TAD) is a technique for improving the prevention of surgical site infections (SSI). TAD involves the subcutaneous infiltration of tumescent local anesthesia (TLA) containing water soluble antibiotic(s) such as cefazolin and metronidazole. TLA consists of the subcutaneous infiltration of very dilute lidocaine (≤ 1 gram/liter) and epinephrine (≤ 1 milligram/liter) with sodium bicarbonate (10 milliequivalents/liter) in a physiologic solution of sodium chloride which produces intense local anesthesia associated with profound wide-spread vasoconstriction lasting for more than 12 hours. Compared to intravenous antibiotic delivery (IVAD), TAD is expected to produce higher local tissue concentrations of the antibiotic(s) for longer periods of time and lower systemic/serum antibiotic concentrations. This clinical trial will compare TAD to IVAD with respect to pharmacokinetic evidence for possible improved SSI prevention.