Patients never complain of being too numb, but we have all had patients say that they were not numb enough and that we were hurting them.

Strive to never have patients ask for “top-ups” or additional local anesthetic because they feel pain during the surgery. This creates an unnecessary, unpleasant memory for the patient. It is a sign of improper planning of the injection; the usual cause is not enough volume, with anesthetic not distributed widely enough.

If you stay within safe limits of the total dosage of lidocaine and epinephrine, erring on the side of too much volume will eliminate the risk of requiring a top-up additional injection of local anesthetic because the patient reports feeling pain during an operation.

The only exception to the rule of “too much local anesthetic is better than not enough” is in the fingers. No more than 2 ml of local anesthetic is required in each of the volar and dorsal sides of the proximal and middle phalanges of the fingers. Only 1 ml is required in the volar distal phalanx. If you inject too much volume of anesthetic in a finger, the pure compression effect of too much fluid can decrease blood flow. For nail bed work, a quarter-inch Penrose drain finger tourniquet works better than epinephrine injected in the dorsal distal phalanx.

Always have at least 1 cm of visible or palpable subcutaneous local anesthetic beyond the site where you plan to incise, dissect, insert sutures, manipulate fractures, or pass K-wires.

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  Do not cut or insert needles where the skin is pink. Never reinsert a local anesthetic needle where the skin is not solidly white when you reinsert needles to inject large areas. If there are not enough epinephrine molecules there to produce good vasoconstriction, there will likely not be enough functioning lidocaine molecules there either. The patient will feel the needles and scalpels in the pinkish skin.

  
  
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  It is ideal to give the local anesthetic 30 minutes or more to work. It takes an average of 26 minutes for maximal cutaneous vasoconstriction to occur with 1:100,000 epinephrine.1 It takes a similar amount of time for maximal numbness to occur with lidocaine. If you inject the patient in the recovery room or on a stretcher outside the operating room, the anesthetic will have time to work by the time you prep and drape the patient on the operating table.

  
  
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  For short procedures, inject the first three patients and do the paperwork before you operate on the first patient. After you operate on the first one, inject the fourth patient while the nurse brings the second injected patient into the room (see Chapter 14).

  
  
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  If your situation does not permit half an hour for the tumescent anesthetic to take effect, hemostasis is usually reasonable at 15 minutes after injection. The site will bleed a little more, but only an acceptably small amount.

Ask him or her to use only propofol. Inject the lidocaine with epinephrine as soon as the propofol permits pain-free injection of local anesthetic. The anesthesiologist can then wake the patient right away while you are scrubbing, prepping, and draping. This means you will have the benefit of an alert patient intraoperatively who can understand your teaching (see Chapter 8) and be fully cooperative with pain-free movement. This will also give the epinephrine a little time to become more effective. Suggest that the anesthesia provider avoid administering opiates and amnestics to prevent nausea and allow the patient to remember your intraoperative advice.