**2.2 Anesthesia**

A key to allowing these procedures to be safely performed in the office as an elective procedure is great tumescent (to fill and make firm) anesthesia. Physicians from Gynecology, Dermatology and Plastic Surgery all take credit for this advancement at about the same time in history (late 1980's). Because lidocaine is so tightly bound in external fat compartments, profound anesthesia lasting hours can be derived from very dilute concentrations compared to typical derm and dental procedures. We all learned the 5 mg/kg body weight limit of Lidocaine without epinepherine and 7 mg/kg body weight limit for Lidocaine mixed with Epi, to avoid side effects including bradycardia. Interestingly, dilute solutions (0.05% lido with 1:1 M Epi and 12 mEq/L Sodium Bicarbonate mixed in Normal Saline or Lactated Ringers solution, works well below the waist; 0.1% lido etc. works fine for most torso lipo procedures; 0.15% lido for abdominoplasties, breast, male chest, axilla and upper arm procedures and 0.2% lido allows for pain free face and neck lipo and surgeries). A total of 35-50mgLido/kg body weight is generally considered safe. Comfort continues for 10–15 hours after the procedure, but that allows for peak levels and possible toxicity at 12 to 15 hours after your case started and the patient is at home otherwise oblivious to the cause of their peri-oral numbness, restlessness, nausea, tinnitus, seizures and even cardiac arrest. So these are discussed with the patient and in the after-surgery care-taker instructions to call the treating physician or facility if these symptoms occur. With conservative adherence to limiting lidocaine to 35-50 mg/kg body weight this should rarely be a problem. The treatment for lidocaine toxicity is IV 20% lipid emulsion solutions like IntraLipid with a loading dose of 1.5 ml/kg over 1 minute followed by and infusion of 15 ml/kg/hour while CPR is being performed throughout. An additional 2–3 boluses may be supplied every 5 minutes if needed for return of spontaneous circulation and the drip can be doubled up to 30 mg/kg/hour up to total dose of 10-12 ml/kg depending on the guidelines utilized for relief of symptoms. The IV lipids competitively bind the free lidocaine and pull it out of the neurologic, cardiac and GI systems [2].

Isotonic tumescent fluid volume should be limited to roughly 1.2 times the healthy patient's daily fluid requirements of 3–4 Liters/day for most men and women thereby avoiding cardio-pulmonary and renal issues. No additional IV fluids are desired, although IV access via saline lock is recommended for safety and to administer certain meds. This is based on understanding that a variable portion of the tumescent fluid will be suctioned out during the procedure, some will ooze out, and the patient will gradually utilize the rest.

Tranexamic Acid is often mixed into tumescent fluids (and even given IV) at 500-1000 mg/liter NS or RL to assist in hemostasis.

Injection of the tumescent fluid in small areas may simply be by 20 cc syringe and a spinal needle, but larger areas are more easily instilled with a pressure bag or peristaltic infusion pump with a foot pedal and 12–16-gauge, blunt, multiholed (Rainbird or similar configuration) cannula. Generally, keep the cannula parallel to the skin. It should slide through the fat compartment easily. If the tip end hits or snags, change the vector and depth of deployment and try again. Fluid may be infused on both antegrade and retrograde strokes. Start with deeper infusions in radial fashion and work towards the skin in with gentle deployment and retrograde strokes and a slow infusion rate for comfort and precision. Once the tissue is firm, move on to another insertion site and cross hatch the area for better anesthesia. Massage the tissue to spread the fluid evenly through the fat and allow 20–60 minutes for anesthetic effect to set up. Blanching of the skin is often observed from the epinephrine component and the tissue will soften and become more moldable.

#### **2.3 Sedation**

Small areas of adiposity can be lipo-sculpted comfortably after tumescent anesthesia is instilled. Fat for facial fat grafting, cellular medicine and research can be obtained in this fashion. Oral sedation with sedative-hypnotics or antihistamine (eg: diazepam or hydroxyzine) and opiates have been used safely for decades and are easily reversible. ProNox and other patient administered analgesia can assist in "awake" procedures.

If larger (1 to 4 Liters of supernatant fat, depending on state regulations) procedures are planned, they are safer when performed in an accredited officebased facility or ASC equipped to handle the potential adverse side effects of deeper sedation.

IV and IM sedation with continual monitoring and IV access are generally preferred over intubation, so the patient can assist in repositioning and flexing during the procedure and sitting or standing up in order to judge effect of procedure, symmetry and re-mark the patient to fine tune the result periodically [3–5].

#### **2.4 Placement of insertion sites**

3-5 mm insertion sites can be places surreptitiously in axillary, infra-mammary, gluteal and even flank folds after local wheals of 1% Lido with epi and bicarb have been raised at the point that a cross clamped 11 blade or 2 mm punch adits are intended. Inside the umbilicus is another useful insertion area for shaving down the lateral waist with a longer cannula. Insertion sites should be parallel to Langer's lines and made just large enough to admit the tips of a sharpened hemostat or small scissors which are used to stretch the opening (along lines of tension) slightly larger than any intended cannula. Doing so allows the skin edges to be less traumatized during the procedure. Have the patient put on typical bathing suits or underwear and outline their design. Hide lateral hip, lower waist and back insertion sites where they will at least be covered most of the time. Alternatively, freckles, moles and tattoos can be used to hide insertion sites.

Insertion sites may be placed symmetrically for ease of sculpting symmetrically or placed irregularly in attempt to mask the procedure. However, most insertion sites heal so well in a year as to barely be visible, so this author generally prefers symmetric placement.

Insertion sites in more friable (older) skin or darker skin types prone to produce pigment after trauma can be protected with a coating of mastic and Duoderm against the skin and Tegaderm on top of that to hold the dressing in place during suctioning. Insertion sites should be closed with a stitch if they get too irritated during the procedure. Remove the stitch in about a week so it does not leave a scar of its own [3–5].
