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Reasonable Doubt

Vaping Injury Progressively Worsens Despite Aggressive Treatment

Stress Return Precautions

Runde, Dan MD

doi: 10.1097/01.EEM.0000616460.99862.8e
Reasonable Doubt

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Our current understanding of e-cigarette or vaping-associated lung injury, known as EVALI, is constantly evolving, as Leon Gussow, MD, pointed out in his most recent column. (EMN. 2019;41[11]:10; http://bit.ly/EMN-ToxRounds.) News of this increasing phenomenon is popping up more frequently with headlines about severe illness and death, and the Centers for Disease Control and Prevention recently released a new update with interim guidance for those of us tasked with diagnosing and treating this elusive new disease. (MMWR. 2019;68[41];919; http://bit.ly/2MpHmkA.)

I am far from an expert in this arena, and rather than continuing to perform bronchoalveolar lavage on every patient who presents to my ED with a cough (great for the RVUs but murder on patient satisfaction), I thought I'd ask someone who was. Thankfully, I work two doors down from such a person: Dan McCabe, MD, a clinical toxicologist and recent addition to our faculty who happens to be actively studying, collaborating, and adding to our growing knowledge of EVALI. Most days he can be seen leaving the PICU or MICU with a collection of vaping devices. He claims this is for academic purposes, and I've chosen to believe him because I wanted him to agree to be interviewed. So, let's dive right in to our discussion of this new CDC guidance.

Dr. Runde: I think we're not surprised in terms of clinical presentation that the patients in 95 percent of cases had respiratory symptoms, but what do you think is going on with the 77 percent with GI symptoms and the 85 percent with constitutional symptoms like fevers, chills, and weight loss?

Dr. McCabe: The GI symptoms are fascinating, though at this point we do not have an explanation. Anecdotally, we have seen this with each of the five patients at our institution since July. Unfortunately, we are not sure if these symptoms are due to the inflammation, an infectious process, or something entirely unique to EVALI.

Dr. Runde: Just about half of patients presented with tachycardia, tachypnea, or hypoxia less than 95% (55%, 45%, and 57%), and reports are that pulmonary auscultation is usually normal “even among patients with severe lung injury.” How in the world are we supposed to make this diagnosis? Do you have any specific tips for folks trying to figure out which patients to work up?

Dr. McCabe: From our experience, I think this diagnosis can be made if the patients are provided with good return precautions. This appears to be a progressive process, so the most important thing may be stressing the importance of returning if symptoms worsen. Making this diagnosis sometimes requires humility on our part, and we should remind everyone in the health care world that we need to reevaluate a patient who doesn't fit neatly into a specific box or respond as expected to our usual treatments.

Dr. Runde: What's your take on the utility of labs for evaluating potential EVALI patients? As a toxicologist, do you think the urine tox screen for THC is a clinically useful recommendation?

Dr. McCabe: I rarely find clinical utility in the urine drug screen. Even if these tests were not fraught with inaccuracies, I would never become more aggressive in my management due to a positive screen, and I certainly would not medically clear a symptomatic patient with a negative screen.

Dr. Runde: This guidance makes clear that all of these patients need a chest x-ray. It was less clear to me exactly who should get a CT. I would love your interpretation and thoughts about when to pull the trigger on a CT for these folks.

Dr. McCabe: It's difficult to determine if all these patients have abnormal radiography early in the course. We do not know if EVALI is similar to pneumonia where the radiograph can lag behind the clinical course, especially in dehydrated patients. I agree with the recommendation for a chest x-ray, though, because the opacities are bilateral and can appear different from a usual community-acquired pneumonia. (See this letter in the New England Journal of Medicine: 2019;381[15]:1486; http://bit.ly/32ky92x.) The subtle differences may help the astute clinician. I would recommend performing a CT when the patient does not respond to treatment in a way you expected and you need more information that may change management.

Dr. Runde: About half of the patients in this series (47%) were admitted to the ICU, and a fifth (22%) were intubated. Do you think this represents selection bias based on cases getting reported to the CDC, or is EVALI really just a high morbidity player?

Dr. McCabe: It's really hard to say right now. From our experience managing these patients, there tends to be a progressive worsening of clinical status despite aggressive treatment. Presumably, there is a selection bias in reporting this disease with the severe cases being identified while the mild cases are missed. It is difficult to know, but the mild cases may improve with the usual treatments for bronchitis or community-acquired pneumonia despite the diagnosis of EVALI not being made.

Dr. Runde: It looks like supportive care is key, but maybe steroids are magic yet again. What were your take-home points for treating these patients?

Dr. McCabe: If there is a complete lack of understanding regarding the pathophysiology of this disease, it is difficult to recommend any treatment except the usual treatments for ARDS. We honestly don't know if steroids are key or if they are noncontributory to recovery once we have initiated aggressive supportive care, positive pressure ventilation, and early antibiotics. We do not know the toxin, and we can't offer a specific antidote.

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Dr. Runde: Now that we've been through the weeds a bit here, what are your first impressions on this new CDC guidance?

Dr. McCabe: Overall, I think this interim guidance was an important and needed step. Unfortunately, there is not a single specific toxin, clinical data point, or treatment that we can hang our hats on at present. The truth is that no one knows what is causing this epidemic, how (or when) patients are going to present, or how they will respond to treatment. That means clinicians need to go back to the basics: perform a thorough history (including social history while parents are not in the room for our younger patients) and a complete exam (with recognition of unexpected findings), and stress the importance of returning if the patient's symptoms worsen. When EVALI is on the differential, we need to be a little more conservative, even if that means a slight decrease in efficiency.

The most important part of this guideline is probably that the CDC is increasing awareness about this issue. Hopefully, clinicians and the public are paying attention.

Dr. Rundeis the assistant residency director and an assistant professor of emergency medicine at the University of Iowa Hospitals and Clinics, where he serves as co-director for the associate fellowship in medical education. He creates content for and is a member of the editorial board forwww.TheNNT.com, and is a content contributor forwww.MDCalc.com.Follow him on Twitter @Runde_MC, and read his past articles athttp://bit.ly/EMN-MythsinEM.

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