From the Guidelines
To numb skin in preparation for sutures, lidocaine 1-2% with or without epinephrine is the most commonly used local anesthetic, with a maximum dose of 4.5 mg/kg (or 7 mg/kg with epinephrine) for adults and 3 mg/kg (or 4.5 mg/kg with epinephrine) for children, as recommended by the American Academy of Pediatrics 1. When administering local anesthetics, it is essential to consider the patient's age, weight, and medical history to determine the appropriate dose and potential risks.
- For adults, inject 3-5 mL of lidocaine 1-2% around the wound edges, taking care not to exceed the maximum recommended dose.
- For children, use 0.5-1% lidocaine, limiting to 3 mg/kg (or 4.5 mg/kg with epinephrine), and consider using topical anesthetics like EMLA cream or LET gel for needle-phobic patients. The use of epinephrine (1:100,000 concentration) can help prolong anesthesia and reduce bleeding, but it should be avoided in end-arteries like fingers, toes, nose, and ears due to the risk of ischemia 1. Allow 5-10 minutes for the full effect of the local anesthetic to take place, and consider buffering lidocaine with sodium bicarbonate (9:1 ratio) to reduce injection pain. It is crucial to monitor the patient's vital signs and be prepared for potential complications, such as local anesthetic toxicity, which can be treated with a 20% lipid emulsion 1.
From the FDA Drug Label
Adult Patients-Intact Skin A thick layer of Lidocaine and Prilocaine Cream USP, 2.5%/2.5% is applied to intact skin and covered with an occlusive dressing. Minor Dermal Procedures: For minor procedures such as intravenous cannulation and venipuncture, apply 2.5 grams of Lidocaine and Prilocaine Cream USP, 2.5%/2. 5% (1/2 the 5 g tube) over 20 to 25 cm2 of skin surface for at least 1 hour. Major Dermal Procedures: For more painful dermatological procedures involving a larger skin area such as split thickness skin graft harvesting, apply 2 grams of Lidocaine and Prilocaine Cream USP, 2.5%/2. 5% per 10 cm2 of skin and allow to remain in contact with the skin for at least 2 hours.
The recommended dosage for numbing skin in preparation for sutures is:
- For minor procedures: 2.5 grams of Lidocaine and Prilocaine Cream USP, 2.5%/2.5% over 20 to 25 cm2 of skin surface for at least 1 hour.
- For more painful dermatological procedures: 2 grams of Lidocaine and Prilocaine Cream USP, 2.5%/2.5% per 10 cm2 of skin for at least 2 hours. 2
From the Research
Topical Anesthetics for Suturing
- LAT (lidocaine, adrenaline, and tetracaine) gel is a topical anesthetic that can be applied on lacerations before suturing, considered easy to use and less painful than infiltrative anesthesia 3
- Tetracaine-lidocaine-phenylephrine (TetraLidoPhen) is a new topical anesthetic that appears to be safe when applied on or near mucous membranes, although its performance was statistically inferior to that of lidocaine infiltration 4
- Tetraphen (tetracaine-phenylephrine) is a topical anesthetic that offers an effective alternative to tetracaine-adrenaline-cocaine (TAC) during laceration repair in children, with no statistical difference demonstrated between the effectiveness of tetraphen and that of TAC 5
Dosage and Application
- The application of LAT gel seems to be specifically suitable for short lacerations (<4 cm), lacerations located on the head, and simple finger lacerations 3
- The effectiveness of topical anesthetics may vary depending on the location of the laceration, with some studies suggesting that they perform better on the face and scalp than on the extremities 5
- The use of topical anesthetics should be considered as part of a comprehensive approach to wound closure, taking into account factors such as wound type, location, skin thickness, and cosmetic considerations 6
Considerations for Use
- Topical anesthetics should be used in accordance with local procedures and departmental protocols 6
- Nurses should have a comprehensive understanding of the relevant anatomy and underlying structures, and the expertise to determine that suturing, rather than other methods of wound closure, is appropriate in each case 6
- The use of topical anesthetics should be audited and reflected on to ensure that their use is evidence-based and effective 6