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Fundamentals of Cutaneous Surgery

»	What does the term “dermatologic surgery” embrace?
»	Local anesthetics can be broadly classified into one of two groups. Name these two groups and give a few examples of each.
»	How do the local anesthetics work?
»	What are the onset of action and the duration of action of the most commonly used local anesthetics in skin surgery?
»	How are the amide and ester anesthetics metabolized?
»	What is the greatest practical drawback of the ester anesthetics?
»	What are the maximum total dosages for 1% lidocaine (10 mg/mL) in adults and children?
»	What are the symptoms and signs of lidocaine toxicity and how is it treated?
»	Do true allergic reactions to local anesthetics exist?
»	Describe the clinical features of true local anesthetic allergy. How is this best treated?
»	What is the clinical presentation of patients with a vasovagal response to local anesthesia? How is this presentation best treated?
»	How does one manage the patient who refuses, or is truly allergic to, both the ester and the amide anesthetics?
»	What concentrations of epinephrine are the most effective for skin surgery? What is the safe maximum total dose?
»	What is the onset of action for epinephrine?
»	What are the clinical features of epinephrine toxicity?
»	Are allergic reactions to epinephrine possible?
»	When should epinephrine be used with great caution?
»	Which local anesthetics are “the safest” to use in pregnancy?
»	Describe measures that can be employed to diminish the pain associated with the injection of local anesthetics.
»	Discuss injection techniques that can be used to diminish pain.
»	What are the two most commonly used skin preparation antiseptics in dermatologic surgery?
»	Describe the mechanisms of action and spectra of coverage for these two preparations.
»	What are the most important advantages and disadvantages of povidone-iodine and chlorhexidine gluconate?
»	What is meant by absorbable and nonabsorbable suture material?
»	How does multifilament suture differ from monofilament suture?
»	Which types of suture material are best suited for subcutaneous stitches?
»	Which types of suture material are best suited for cutaneous stitches?
»	Which sutures are good choices for mucosal surfaces, the vermilion lip, and intertriginous areas?
»	How is suture sized?
»	Which suture needles are best suited to skin surgery?
»	What are the indications for a punch biopsy?
»	Describe how a punch biopsy should be performed.
»	What is the preferred technique for removing the punch biopsy?
»	What is meant by electrosurgery, electrocautery, and electrocoagulation?
»	Describe what is meant by electrofulguration and electrodesiccation.
»	What precautions need to be taken in patients with pacemakers who require electrosurgery?
»	Is it necessary to discontinue anticoagulant medications before elective surgery of the skin?
»	What are the so-called relaxed skin tension lines (RSTLs)? Why are they important?
»	How does one determine the direction of the RSTLs in planning a surgical wound closure?
»	Which areas of the body typically scar worst?
»	What is the superficial muscular aponeurotic system (SMAS)?
»	Describe the boundaries of the danger area for transecting the temporal branch of the facial nerve.
»	Describe the clinical signs of damage to this nerve.

What are the onset of action and the duration of action of the most commonly used local anesthetics in skin surgery?

The amides, especially lidocaine and bupivacaine, are the most commonly used local anesthetics in skin surgery. Lidocaine has an onset of action of approximately 5 minutes. Its potency and duration of action is significantly greater than that of procaine. When combined with epinephrine, it provides anesthesia for 60 to 400 minutes (average: 180 minutes), compared to 30 to 120 minutes (average: 90 minutes) without epinephrine. Bupivacaine, which is more potent than lidocaine, has an onset of action of approximately 8 minutes, and an average duration of action of 120 to 140 minutes without epinephrine, and 240 to 480 minutes with epinephrine. This makes it an ideal agent for regional nerve blocks and Mohs micrographic surgery.