Skin tears are a common injury treated in the elderly in the emergency department (ED). Often the skin is paper thin, and the area involved can have a large flap. By the time the patient has arrived, the may blood have dried with a retracted and rolled-in skin flap. Often the surface area is too big and skin to thin to inject local anesthesia around the entire site.
Trick of the Trade: Use topical 2% lidocaine jelly
Each 5 mL tube contains 100 mg of lidocaine. Uro-Jet® is a popular alternative to this and has a 2% concentration.
Case 1: The elderly patient with skin tears
A 75-year-old female presents to the ED with complaints of a mechanical trip and fall. She presents with 2 large skin tears – one to her right lower leg and another on her right upper arm. Each skin tear is approximately 7-10 cm, and the area has been bandaged with gauze by the ambulance service. The flaps are thin and appear folded and retracted, leaving a large open wound. She is on blood thinners and prednisone. The provider prepares for repair of the skin tear and will attempt to reapproximate the flaps.
Apply topical lidocaine jelly liberally to the skin tear area and allow to sit on the wound for 10-15 minutes with loose gauze over the area. The jelly will anesthetize the area so that the patient can tolerate manipulation of the skin. It will also allow the flap to rehydrate. The inactive ingredient hydroxypropylmethylcellulose, also known as hypromellose, is a water-soluble solution that retains water and creates lubrication, and acts as emulsifier.1
Gently irrigate the wound and reapply another small layer of lidocaine jelly. This allows the provider to unroll and slide the flap over the open area for optimal wound coverage. Clean off the remaining lidocaine jelly before applying steri-strips or repair the wound per routine.
Case 2: Road Rash
A 17-year-old boy presents to the ED with his father after falling off his bike on a gravel road. He sustained a large abraded area along his left thigh and left torso with debris from the road embedded in the road rash. The provider prepares to irrigate and debride the wounds.
Apply 2% lidocaine jelly liberally to the skin tear areas and allow to sit in the wound for 10-15 minutes. The lidocaine will make irrigating more comfortable and hydroxypropylmethylcellulose will provide lubrication and help loosen debris. It also softens dried blood to help with wound visualization prior to primary repair. Use a soft surgical prep sponge with irrigation to facilitate wound debridement.
Caution: Lidocaine systemic absorption
Lidocaine toxicity is always a concern when injecting or applying topically. The amount required depends on the size of the area being anesthetized, the patient’s pain tolerance, and the vascularity of the tissue.2 Notably heat can increase absorption.
The maximum recommended dose of lidocaine is 4.5 mg/kg. This means on average you can safely use up to 15 mL of 2% lidocaine jelly in the average 70 kg adult. To avoid excessive lidocaine systemic absorption, irrigate off the remaining lidocaine after skin flaps are cleaned and reapproximated.
References
- 1.Hogan JE. Hydroxypropylmethylcellulose sustained release technology. Drug Development and Industrial Pharmacy. January 1989:975-999. doi:10.3109/03639048909043660
- 2.Lidocaine hydrochloride – Drug Summary. Physician’s Digital Reference (PDR). https://www.pdr.net/drug-summary/Xylocaine-Topical-Solution-lidocaine-hydrochloride-2418#topPage. Published 2019. Accessed November 30, 2019.