What Lies Beneath: The Sorcerer’s Apprentice and… : Emergency Medicine News – LWW Journals

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dexamethasone, back pain, pathophysiology

Few movies lodged themselves in my childhood brain the way Fantasia did. A psychedelic 1940s Disney animation set to a thundering score played by a maniacal Philadelphia Orchestra, it broke artistic ground as quickly as it laid it.

The scene that branded itself on my memory, though, was that of the sorcerer's apprentice. Set to freshly composed symphonic torment, it follows Mickey Mouse playing understudy to a great magician (based on a 1797 ballad by Goethe, Der Zauberlehrling, which means the sorcerer's apprentice in German), and, with Mickey being too lazy or perhaps too enterprising to fetch the buckets of water that were part of his job description, he steals his master's wizardly hat and conjures a spell to have a mop do the work for him.

In a (mildly, now that I have rewatched it for research) terrifying escalation, however, Mickey hacks at the mop with an axe to halt its autonomous and uncontrolled toil against a seizure of blood-red backdrop, shadows billowing up like nightmares on the walls behind them, while the mop replicates like a clone army, trampling over our poor mouse as he succumbs to the purgatory of his decision.

The reason I relate this disturbing memory is to illustrate what tends to happen when a simple question is posed in emergency medicine. Today's cascade of questions arose during a discussion about the possibility of using intravenous dexamethasone to treat acute back pain. The question, Is dexamethasone effective in treating acute back pain? then splintered into a thousand further questions. Let us watch them reproduce, without the soaring soundtrack.

The totality of the current evidence says probably not. A few small-scale studies are desperately trying to prove the affirmative, but they are, as is so often the case, meager in number, negative on primary outcomes, single-centered, and nonreplicable.

It is at this point, however, that the questions begin to split off.

There has to be an inflammatory component, right? So surely there's some biological plausibility in here.

Good point.

It gets a little fuzzy here. We were all taught that steroids need to be transported into the nucleus to exert their conformational change and effect, so we also know that steroids work in at least three ways: slow, quick, and hey, that's weird.

It is likely that the patients we see in the ED with acute (not chronic) back pain have a cornucopia of pathological mechanisms resulting in the pain we are assessing. The most common likely mechanism is the sudden wrenching of the facet joints, which have a rich neural network around them causing, among many things, severe muscle spasm. But they also have a relatively poor blood supply, delivering not much of anything to them.

There are other paths to pain, though. Herniated discs expose a hugely inflammatory core. Discs impinge on nerve roots, causing neuropathic pain. Hitting the inflammatory pathways will only modulate some of these, and without the benefit of advanced imaging in the ED (appropriately), we will not be sure how much each of these is contributory.

Horses need to be held here. Much of this is about the acute injury. We don't give steroids for acute ligamentous sprains. We (definitely) don't give steroids in acute brain injury. The risk-benefit profile must be way in the negative here. The side effects and risks of steroids are well known.

Man, this could be true. Sore throats, swollen throats, viral neuropathies, bronchospasm, cerebral edema, spinal cord compression, COVID requiring oxygen, arthritides, altitude sickness, all of them exquisitely responsive to dexamethasone. We give it when there's too much thyroxine; we give it when there's too little thyroxine. We give it for skin problems, eye problems, allergic problems, blood problems....

It is at this point that the questions begin marching over us, unyielding, heedless of the existential pain they might be inflicting.

You see where this is going: nowhere good. Like Mickey Mouse, who opened a Pandora's box, to thoroughly mix story and myth, a seemingly benign question has become something horrifying.

Let us return to the original question. Parenteral dexamethasone for acute back pain in ED: probably not justified. Perhaps the best treatment for back pain is avoidance, such as finding an alternative to back pain-inducing activities, like carting buckets of water.

Dr. Johnstonis a board-certified emergency physician, thus the same as you but with a weird accent. She works in a trauma center situated down the unfashionable end of Perth, Western Australia. She is the author of the novel Dustfall, available on her website, http://michellejohnston.com.au/. She also contributes regularly to the blog, Life in the Fast Lane, https://lifeinthefastlane.com. Follow her on Twitter@Eleytherius, and read her past columns athttp://bit.ly/EMN-WhatLiesBeneath.

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What Lies Beneath: The Sorcerer's Apprentice and... : Emergency Medicine News - LWW Journals