SGEM#307: Buff up the lido for the local anesthetic

Date: October 29th, 2020 Guest Skeptic: Martha Roberts is a critical and emergency care, triple-certified nurse practitioner currently living and working in Sacramento, California. She is the host of EM Bootcamp in Las Vegas, as well as a usual speaker and faculty member for The Center for Continuing Medical Education (CCME). She writes a blog called The Procedural Pause for Emergency Medicine News and is the lead content editor and director for the video series soon to be included in Roberts & Hedges' Clinical Procedures in Emergency Medicine. Reference: Vent et al. Buffered lidocaine 1%, epinephrine 1:100,000 with sodium bicarbonate (hydrogencarbonate) in a 3:1 ratio is less painful than a 9:1 ratio: A double-blind, randomized, placebo-controlled, crossover trial. JAAD (2020) Case: A 35-year-old female arrives to the emergency department with a 3 cm laceration to the palmar surface of her left forearm sustained by a clean kitchen knife while emptying the dishwasher. The patient reports a fear of needles and has concerns about locally anaesthetizing the area because, “I got stitches on my arm once before and that shot burned like crazy”! The patient asks the practitioner if there is any chance, she can get a shot that “burns less” than her last one. Background: We have covered wound care a number of times on the SGEM. This has included some myth busing way back in SGEM#9 called Who Let the Dogs Out. That episode busted five myths about simple wound care in the Emergency Department: Patients Priorities: Infection is not usually the #1 priority for patients. For non-facial wounds it is function and for facial wounds it is cosmetic. This is in contrast to the clinicians’ #1 priority that is usually infection. Dilution Solution: You do not need some fancy solution (sterile water, normal saline, etc) to clean a wound. Tap water is usually fine. Sterile Gloves: You do not need sterile gloves for simple wound treatment. Non-sterile gloves are fine. Save the sterile gloves for sterile procedures (ex. lumbar punctures). Epinephrine in Local Anesthetics: This will not make the tip of things fall off (nose, fingers, toes, etc). Epinephrine containing local anesthetics can be used without the fear of an appendage falling off. All Simple Lacerations Need Sutures: Simple hand lacerations less than 2cm don’t need sutures. Glue can be used in many other areas including criss-crossing hair for scalp lacerations. Other SGEM episodes on wound care include: SGEM#63: Goldfinger (More Dogma of Wound Care) This episode looked at how long do you have to close a wound. The bottom line was that there is no good evidence to show that there is an association between infection and time from injury to repair. SGEM#156: Working at the Abscess Wash The question from that episode was: does irrigation of a cutaneous abscess after incision and drainage reduce the need for further intervention? Answer: Irrigation of a cutaneous abscess after an initial incision and drainage is probably not necessary.  SGEM#164: Cuts Like a Knife – But you Might Also Need Antibiotics for Uncomplicated Skin Abscesses. SGEM Bottom Line: The addition of TMP/SMX to the treatment of uncomplicated cutaneous abscesses represents an opportunity for shared decision-making. The issue of buffering lidocaine was covered on SGEM #13. This episode briefly reviewed a Cochrane SRMA that looked at buffering 9ml of 1% or 2% lidocaine with 1ml of 8.4% sodium bicarbonate (Cepeda et al 2010). The SRMA of buffering lidocaine contained 23 studies with 8 of the 23 studies having moderate to high risk of bias. The SGEM bottom line was that patients might appreciate the extra effort of buffering the lidocaine. Interestingly, this Cochrane Review was withdrawn from publication in 2015. The reason provided was that the review was no longer compliant with the Cochrane Commercial Sponsorship Policy.