Topic

• Introduction
• Recommendations to Reduce Discomfort of Local Anesthesia
• Procedure
• Coding Information

Figure(s)

• Stretching the Skin
• Needle Insertion
• Angle of Needle Insertion
• Needle Insertion at Laceration Site
• Administering Local Anesthetic for a Shave Excision

• Techniques for minimizing discomfort during local anesthetic administration are often overlooked in modern clinical practice. Proper administration technique can reduce patient discomfort, improve patient satisfaction with service, and improve the procedure's outcome.
• The 2 main classes of injectable local anesthetics are amides and esters. Amides are more widely used and include lidocaine (Xylocaine) and bupivacaine (Marcaine). Esters, represented by procaine (Novocain), have a slower onset of action than amides and a higher rate of allergic reactions.
• Individuals with allergy to 1 class of anesthetics generally can receive another class safely.
• Many patients claim allergy to "caine" drugs, but they actually have experienced a vagal response or other systemic response to receiving an injection.
  • If the exact nature of a prior reaction cannot be ascertained, administration of diphenhydramine hydrochloride (Benadryl) can provide sufficient anesthesia for small surgical procedures. 1–2 mL of diphenhydramine (25 mg/mL) solution is diluted with 1–4 mL of normal saline for intradermal (not subdermal) injection.
• Epinephrine in a local anesthetic solution prolongs the duration of the anesthetic and reduces bleeding by producing local vasoconstriction. Use of epinephrine also permits use of larger volumes of anesthetic. An average-sized adult (70 kg) can safely receive up to 28 mL (4 mg/kg) of 1% lidocaine and up to 49 mL (7 mg/kg) of 1% lidocaine with epinephrine.
• Historically, physicians have been taught to avoid administering solutions with epinephrine to body sites served by single arteries—e.g., "fingers, toes, penis, and end of nose." The safety of administering epinephrine to the tip of the nose or to digits has been documented in some reports, but limiting use of epinephrine in these sites is prudent in the current medicolegal climate.
• Local anesthetics can be injected intradermally or subdermally.
  • Intradermal administration produces a visible wheal in the skin, and the onset of action of the anesthetic is almost immediate.
  • Intradermal injection of a large volume of solution can stretch pain sensors in the skin, aiding in anesthetic effect.
  • Intradermal injection is especially useful for shave excisions, because anesthetic solution effectively thickens dermis, elevates the lesion, and prevents inadvertent penetration beneath dermis.

Recommendations to Reduce Discomfort of Local Anesthesia

• Stretch skin using nondominant hand during administration.
• Encourage the patient to talk as a distraction and for monitoring for vagal responses.
• Talk to the patient during administration; silence increases patient discomfort.
• Use the smallest gauge needle possible (preferably 30 gauge).
• Consider spraying aerosol refrigerant onto the skin before needle insertion.
• Consider vibrating nearby skin or patting distant sites to distract the patient during administration.
• Administer anesthetic at room temperature (i.e., nonchilled solutions).
• Insert the needle through enlarged pores, a scar, or hair follicles (i.e., less sensitive sites).
• Pause after the needle penetrates the skin to allow for patient recovery and relaxation.
• Inject a small amount of anesthetic and pause, allowing the anesthetic to take effect.
• Empower the patient by temporarily stopping the injection when burning is detected.
• Inject anesthetics slowly.
• Begin the injection subdermally and then withdraw the needle tip for intradermal injection.
• Consider addition of bicarbonate to buffer the acidity of the anesthetic.
• Permit adequate time for the anesthetic to take effect before initiating the surgical procedure.

• Stretch the skin with the nondominant hand before insertion of the needle into the skin. Patients dread having a needle inserted; discomfort is reduced if pain sensors in the skin are stretched (Fig. 9-1).
• Pitfall: Replace the needle used for drawing anesthetic from the stock bottle with a smaller (30-gauge) needle before injection into the patient.
• Hold the syringe in your dominant hand in a position ready to inject (Fig. 9-2A). The thumb should be near (but not on) the plunger.
• After the needle is inserted into the skin, some physicians prefer to withdraw the plunger to ensure that the needle tip is not in an intravascular location. The thumb can be slipped under the back edge of the plunger and pulled back (Fig. 9-2B), looking for blood to enter the syringe to ensure that the needle tip is not in a blood vessel. The thumb then slips onto the plunger for gentle injection.
• It is very unlikely that a short, 30-gauge needle tip will enter a significant vessel, and many physicians prefer to inject without withdrawing, because pulling back on the plunger moves the needle tip and causes discomfort for the patient.
• Pitfall: Avoid movement of the needle after it enters skin. Many physicians hold the syringe like a pencil for needle insertion. After insertion, they stop stretching the skin with the nondominant hand and grab the syringe, shift the dominant hand back onto the plunger, and pull back on the plunger to check for vascular entry of the needle tip. They then shift hands again and move the dominant hand into position for injection. All of these shifts cause movement of the needle tip in the skin and substantially increase discomfort for the patient. Insert the needle with the hand in position ready to inject.
• Insert the needle into the skin at a 15- or 30-degree angle (Fig. 9-3). The depth of the needle tip is more difficult to control at a 90-degree angle of entry.
• When injecting laceration sites for repair, insert the needle into the wound edge, rather than intact skin (Fig. 9-4). Insertion of a needle into the wound edge produces less discomfort.
• Pause after the needle enters the skin. Try to make the patient laugh. Patients fear needle entry; after they realize that discomfort was less than anticipated, they often relax. Maintain skin stretch with the nondominant hand for injection.
• Pitfall: Plunging in anesthetic immediately after needle entry causes continued discomfort and anxiety. Most vagal or syncopal episodes are related to catecholamine storm produced by the patient's anxiety. Pausing after needle insertion and slow administration allow patients to relax, reducing catecholamine production and complications.
• Administer local anesthetic for a shave excision below the center of the lesion to be removed (Fig. 9-5A). Anesthetic fluid effectively increases the depth of the dermis, reducing the chances for subdermal penetration at the shave excision. Fluid also floats the lesion upward, facilitating removal by shave technique (Fig. 9-5B).

• Work of local anesthesia administration generally is included in codes for most office surgical procedures and cannot be billed as a separate procedure.
• Anesthesia codes (00100–01999) in the CPT book generally reflect general, regional, or supplementation of local anesthesia by an anesthesiologist. Anesthesia codes generally are not billed for office procedures.