“Fingers, toes, ears, and nose are places where epinephrine never goes,” Thomas Ehlers, DPM, wrote in Podiatry Today. “That is an adage I heard during podiatry school, my clerkships, and from various attendings throughout my training.”
But as Dr. Ehlers added, epinephrine gets a bad rap. The catchy admonition “has been proven a myth time and time again.”
So Although medical trainees across multiple disciplines are taught to fear the practice, citing the potential for gangrene, its reputation for harm is not supported by the evidence.
Lack of Feeling Doesn’t Care About Your Facts
The debate surfaced anew in response to a recent column by Kenny Lin, MD, MPH, family physician and associate director of the Lancaster General Hospital Family Medicine Residency, in Lancaster, Pennsylvania, about the rather pedestrian topic of why he no longer performs surgery to correct ingrown toenails. Dr. Lin’s admission that he used to do the procedure with a combination of epinephrine and lidocaine turned into a major focus of the comments — many of them harshly critical of the practice:
“Epinephrine is not an appropriate drug to use for podiatry or use in any peripheral area. Gangrene?” one commenter posted.
“Leave epi out of lidocaine to fingers, toes, nose, and ear lobes,” another wrote.
“No lido with epi, whether or not it is contraindicated, because: If there’s any adverse outcome, a lawyer will find plenty of references saying it was contraindicated,” a reader chimed in.
Other commenters disagreed, with one saying, “Please, folks, don’t show that you trained 50 years ago and haven’t changed practice since…”
For Dr. Lin, the response was surprising given what he believes to be the lack of evidence supporting the purported dangers.
“When I think about this, it’s something that was taught to me during residency — that they should not be used on certain areas,” Dr. Lin said. “But since then, studies have been published looking at thousands of cases of people using epinephrine with lidocaine and haven’t found any cases of necrosis.”
Many doctors, like Dr. Lin, say they were cautioned against this in their training. Others don’t remember exactly where they’ve heard it but recognize the idea has a nebulous hold on practice.
Combining epinephrine with lidocaine helps make the numbing last longer, stops bleeding, and reduces the use of lidocaine required, all of which improve the chances of an effective and comfortable intervention for the patient, Dr. Lin said. The approach also reduces the use of tourniquets, which come with their own risks including nerve injury.
However, in areas with limited circulation, this vasoconstrictive effect may be more pronounced, potentially leading to complications for patients with complicating factors.
Clinicians who regularly use the combination of epinephrine and lidocaine for surgery do concede that it can pose certain hazards and considerations in areas without robust blood flow.
But the literature largely points to its safety.
In 2001, California-based plastic and reconstructive surgeon Keith Denkler, MD, published a deep dive on the topic starting in the 19th century, including a review of Index Medicus from 1880 to 1966, a computer review of the National Library of Medicine database from 1966 to 2000, and major textbooks from 1900 to 2000.
He found a total of 48 cases of digital gangrene — but most involved the use of cocaine or procaine. Of the 48 cases, 21 involved the use of epinephrine, and 17 used an unknown concentration based on manual dilution.
“Multiple other concurrent conditions (hot soaks, tight tourniquets, and infection) existed in these case reports, making it difficult to determine the exact cause of the tissue insult,” Dr. Denkler wrote.
In a 2010 retrospective review in the Journal of the American Society of Plastic Surgeons, authors examined 1111 cases involving digital and hand surgery. Of the 611 patients who received injections of 1% lidocaine with epinephrine, none experienced digital necrosis.
Another review from 2003 touted the combination’s safety, in hopes to “help dispel the myth that epinephrine has no place in podiatric anesthesia.” But authors noted limitations of use, including “known sensitivity, thyrotoxicosis, and use of either tricyclic antidepressants or monoamine oxidase inhibitors.”
James Christina, DPM, executive director and CEO of the American Podiatric Medical Association, echoed that sentiment. He said he regularly used the combination to correct bunions, hammer toes, and ingrown toenails over his 20 years of practicing but acknowledged the technique is not appropriate for all such patients.
“There’s always been caution when using epinephrine with local anesthetic,” Dr. Christina told this news organization. “You need a healthy patient with normal circulation and no other complications; someone without vascular compromise.”
Marie Hanna, MD, MEHP, chief of regional anesthesia and acute pain management at Johns Hopkins University, Baltimore, counts herself among the cautious. Citing Principles of Office Anesthesia: Part I. Infiltrative Anesthesia, Dr. Hanna said epinephrine should never be used in digital and penile blocks or in skin flaps with marginal viability.
“It is perfectly fine in certain areas, like the wrist or the arm,” Dr. Hanna said. “But specifically for use in end organs like nose, fingers, ears, toes — all of these with tenuous blood supply — it is not good practice.”
The divide among doctors comes down to theoretical concern, rather than empirical basis, said Rebecca Johnson, MD, chair of the American Society of Anesthesiologists committee on Regional Anesthesia and Acute Pain Medicine and a faculty member at Mayo Clinic, in Rochester, Minnesota.
“It’s just one of those myths we have in practice,” she said.
And legally, Dr. Johnson noted, the mere existence of a myth can be enough of a deterrent for medical practitioners: “Like anything, when you’re trying to do the right thing, if a complication would occur for another reason, you’d want to make sure a jury of your peers didn’t bring up that myth.”
The sources in this story reported no relevant financial conflicts of interest.
A version of this article appeared on Medscape.com.