Chapter 4 Tumescent Local Anesthesia



10.1055/b-0037-142175

Chapter 4 Tumescent Local Anesthesia

Donald H. Lalonde, Alistair Phillips, Duncan McGrouther

Tumescent local anesthesia means injecting a large enough volume of local anesthetic that you can see it plump up the skin and feel its slightly firm consistency with your finger through the skin.

Clip 4-1 Principles of tumescent local anesthesia.



  • Tumescent local anesthesia is like an extravascular Bier block, but the anesthetic is placed only where you need it. This technique avoids the risk associated with intravascular injection and the pain of a tourniquet.



  • Always inject from proximal to distal so you are blocking nerves at the beginning of the injection process.



  • Never elicit paresthesia with the needle. The presence of paresthesia means that you may have lacerated nerve fascicles. If you inject tumescent local anesthetic near any nerve, it will numb if given time. The larger the nerve, the longer it takes for anesthesia to peak. Our yetunpublished studies have shown that median nerve anesthesia continues to increase 45 minutes after injection of tumescent local anesthetic.



  • Local anesthetic will not impair visibility, because it is as clear as water. In fact, tumescent local anesthetic hydrodissects the tissue planes for the surgeon and facilitates the dissection.



  • You can inject large areas such as the whole forearm and wrist with tumescent anesthetic in such a way that the patient only feels the first sting of a 27-gauge needle if you follow the simple guidelines presented in Chapter 5. Patients are amazed and delighted that the injection discomfort is minimal.



  • You can also inject large areas with tumescent local anesthetic much more quickly with less bruising and minimal pain using blunt-tipped cannula needles (see more on cannula injection in Chapter 5).



  • The use of tumescent local anesthetic injection with no tourniquet also helps significantly in cases requiring general anesthesia. It will decrease the bleeding, reduce the narcotic requirements administered by the anesthesiologist, and avoid having to deal with let-down bleeding that would occur when you release a tourniquet. The tumescent solution is simply injected as soon as the patient is asleep. You can then go scrub, prep, and drape the patient, and complete other tasks while the epinephrine takes effect.



TOO MUCH VOLUME IS BETTER THAN NOT ENOUGH VOLUME OF LOCAL ANESTHETIC—EXCEPT IN THE FINGERS




  • 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.




    • 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.



    • 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.



    • 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).



    • 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.



IF YOU ARE WORKING WITH AN ANESTHESIOLOGIST




  • 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.

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May 29, 2020 | Posted by in ORTHOPEDIC | Comments Off on Chapter 4 Tumescent Local Anesthesia
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