Unfortunately, although the popularity of smoking has been on the decline for decades, vaping is becoming extremely popular, especially among young patients. More than 20% of high-school students and about 5% of middle school students admit to using an e-cigarette in the past 30 days. (Cullen 2018) When compared to smoking – one of the most unhealthy activities known – if would not be surprising if vaping resulted in fewer adverse health effects, although the true effects will not be known until we have long term studies. However, “safer than cigarettes” is not the same as “safe”. When talking about smoking and vaping, we are usually focused on long term health outcomes. However, there has been a recent flood of case reports of young patients with significant lung disease after vaping. What is vaping associated lung disease and what do we need to know in the emergency department?
Please note: This post was written on September 11, 2019. I will endeavour to keep it up to date as more information becomes available, but our understanding of vaping associated lung disease is evolving rapidly, and there is a reasonable chance this information will be out of date soon.
What is going on?
We don’t know yet. There is a clear outbreak of pulmonary illness in young patients associated with vaping. The numbers are changing quickly, and are almost certainly underestimates, but as of early September more than 450 cases have been reported in 33 states and the US Virgin Islands. There have been 5 reported deaths so far. (Tanne 2019)
This isn’t the first time vaping associated lung injury has been reported. There are a number of prior case reports, dating back to 2012, with various underlying pathologies. (McCauley 2012; Flower 2017; Agustin 2018; Sommerfeld 2018; Viswam 2018; Arter 2019) Possible causes of this outbreak include chemical pneumonitis, acute eosinophilic pneumonia, acute and subacute hypersensitivity pneumonitis, lipoid pneumonia, metal fume fever, and polymer fume fever. (Christiani 2019; Layden 2019)
The demographics are as expected, considering the population who vapes. The disease has predominantly affected young male patients. The average age in a recent large case series in the NEJM was 19, and 83% were males. There is a high rate of reported THC use (80%), which is a primary suspect as the underlying etiology. (Layden 2019)
What is the presentation of vaping associated lung disease?
Patients generally present with a combination of respiratory, gastrointestinal, and constitutional symptoms. Respiratory symptoms include shortness of breath, cough, chest pain, and occasionally hemoptysis. GI symptoms, including nausea, vomiting, diarrhea, and abdominal pain, occur in more than 80% of patients. Subjective fever is common (80%), but objective fever at triage is less so (29%). Other constitutional symptoms include chills, weight loss, fatigue, and headache. (Layden 2019)
Vital signs are likely to be deranged. 70% of patients had an oxygen saturation less than 95% and about ⅓ had a saturation of 88% or lower. Tachycardia was present in ⅔ of patients, and tachypnea in about half. (Layden 2019)
Lab findings were nonspecific, but most patients had an elevated white blood cell count with neutrophil predominance. ESR is more than 30 in 93% of patients. All patients had abnormal chest imaging (by definition), and infiltrates were bilateral in 100% of the reported cases. (Layden 2019)
CDC case definition (Layden 2019)
- Use of e-cigarette or vaping in the 90 days before symptom onset
- Pulmonary infiltrate (opacities on chest x ray or ground glass opacities on CT)
- Absence of infection after workup
- (It is considered a probable case if there is an infection, but the treating clinicians do not believe it is the sole cause of the patient’s respiratory symptoms)
- No evidence of an alternative cause (cardiac, rheumatologic, or neoplastic)
What is the prognosis?
This group was pretty sick. (We would expect that only the sickest patients are currently being identified as vaping associated lung injury. There are presumably milder presentations going undiagnosed at this time.) In this cohort, almost 90% of the population required oxygen, ⅓ required noninvasive positive pressure ventilation, and ⅓ needed to be intubated. 2 patients were placed on ECMO, and 1 died (2%). Most patients recovered, but we obviously don’t know the long term outcomes yet. (Layden 2019)
What should I do?
When seeing a young patient with a respiratory illness, be sure to ask about recent e-cigarette or vape use, and specifically ask about THC. Perform your usual assessment of their symptoms. (Don’t anchor on this new diagnosis too early). The majority of the reported cases have been hospitalized. We may start seeing cases in less sick patients, but for the time being I would be conservative and err on the side of admitting if there is any question. Although we don’t yet know the cause, most patients seem to be responding to supportive care and glucocorticoid therapy. (Layden 2019)
In the emergency department, our primary job is to rule out alternative diagnoses (this is a diagnosis of exclusion). Investigations to consider are blood cultures, sputum cultures, respiratory viral PCR, urine for legionella and pneumococcal antigens, and HIV serology. Not all of these tests are required for every patient. (Layden 2019) Treat empirically with antibiotics and steroids. Manage oxygenation and ventilation as necessary. Finally, involve the ICU and respirology teams where you work, as these patients may require further investigations, such as bronchoscopy.
You can find up to date information on the CDC website: https://www.cdc.gov/tobacco/basic_information/e-cigarettes/severe-lung-disease.html
Update October 3, 2019
There have been a number of news reports circulating that the etiology has been discovered. The fungicide myclobutanil has been found in numerous THC vaping products, and becomes hydrogen cyanide when burned. Although this is a possible mechanism, I believe the only evidence of this comes from an independent lab during an NBC investigation. The same lab also found other potential causes, like vitamin E. So far, the CDC website still lists the cause as unknown.
Other FOAMed Resources
Arter ZL, Wiggins A, Hudspath C, Kisling A, Hostler DC, Hostler JM. Acute eosinophilic pneumonia following electronic cigarette use. Respiratory medicine case reports. 2019; 27:100825. [pubmed] [free full text]
Christiani DC. Vaping-Induced Lung Injury N Engl J Med. 2019;
Cullen KA, Ambrose BK, Gentzke AS, Apelberg BJ, Jamal A, King BA. Notes from the Field: Use of Electronic Cigarettes and Any Tobacco Product Among Middle and High School Students – United States, 2011-2018. MMWR. Morbidity and mortality weekly report. 2018; 67(45):1276-1277. [pubmed]
Flower M, Nandakumar L, Singh M, Wyld D, Windsor M, Fielding D. Respiratory bronchiolitis-associated interstitial lung disease secondary to electronic nicotine delivery system use confirmed with open lung biopsy. Respirology case reports. 2017; 5(3):e00230. [pubmed]
McCauley L, Markin C, Hosmer D. An unexpected consequence of electronic cigarette use. Chest. 2012; 141(4):1110-1113. [pubmed]
Tanne JH. Don’t vape, CDC says, as US lung disease epidemic grows BMJ. 2019;
Viswam D, Trotter S, Burge PS, Walters GI. Respiratory failure caused by lipoid pneumonia from vaping e-cigarettes. BMJ case reports. 2018; 2018:. [pubmed]