• The primary outcome is a measurement of the total dose of lidocaine (measured in mg) administered to the patient over the course of Mohs micrographic surgery. [ Time Frame: One day ] [ Designated as safety issue: No ]
  

• The secondary outcome is subject pain, as assessed by a visual analog pain scale and by the volume of extra rescue lidocaine needed during surgery. [ Time Frame: One day ] [ Designated as safety issue: No ]
  

The purpose of the study will be to demonstrate whether Mohs micrographic surgery can be performed with a lower total dose of local anesthesia (and greater patient safety) when using 0.5% lidocaine with 1:200,000 epinephrine versus 1% lidocaine with 1:100,000 epinephrine. Mohs micrographic surgery is a multi-staged, same-day procedure used to remove skin cancers under local anesthesia. Reconstruction of the surgical wound is also performed under local anesthesia, usually immediately after achieving tumor clearance.

This randomized, double-blind study will systematically compare the total dose of 1.0% lidocaine with 1:100,000 epinephrine versus 0.5% of lidocaine with 1:200,000 epinephrine needed to achieve local anesthesia during Mohs micrographic surgery (MMS). All healthy adult volunteers (18 years or older) undergoing Mohs micrographic surgery at the Hospital of the University of Pennsylvania's Department of Dermatology and Dermatologic Surgery between June 1, 2007 and August 31, 2007 will be eligible to participate in the study. Our primary intervention will be to record the total dose of lidocaine administered throughout all of the MMS stages and reconstructions using either of the two lidocaine concentrations. A secondary intervention will be to record each patient's level of pain control in order to demonstrate that patient comfort is effectively achieved with a lower total dose of local anesthesia. Pregnant or breast-feeding subjects, those with a history of allergic or other adverse reaction to lidocaine or epinephrine, and those who are cognitively impaired will be excluded. In addition, if the surgeon believes that a patient has a tumor which, due to size or anatomic site, may put him at risk for requiring a dose of lidocaine that approaches the threshold of toxicity, this patient will be excluded from the study.