Electronic Cigarettes and Risk of Acute Pulmonary Injury: An Update on Available Data

A recent report by the Centers for Disease Control (CDC) in the US raised concerns regarding the use of E-cigarettes and their association with Acute Pulmonary Injury (API) related to Emergency Department visits (1). In this report, data obtained from the National Syndromic Surveillance Program (NSSP) indicated an “outbreak” of Acute Pulmonary Injury (API) related ED visits in September of 2019. Interestingly, most of the patients presenting to EDs were aged 10-19 years old. It is also reported that the number of ED visits has markedly declined in October and November of 2019, but has not returned to pre-outbreak values. 

Beyond the fact that the outbreak involved adolescents and young adults, another interesting finding was that 80% of patients were using Tetra-Hydro-Cannabinol (THC) products. At the same time, 35% were exclusively using THC containing products. On the other hand, 13% were exclusively using nicotine products. This finding is highly suggestive that THC containing products are the culprit behind this outbreak. Furthermore, bronchoalveolar fluid lavage samples identified vitamin E in 48 of the 51 samples tested, while it was not traced in the samples of the 99 healthy controls. This could indicate vitamin E as the causative agent, but the available data is far from providing conclusive evidence in that matter. 

The CDC has subsequently issued interim guidance for health care professionals evaluating and caring for patients with suspected E-cigarette or vaping product use associated lung injury (3) in December of 2019. They have also provided an updated algorithm for the management of patients with such symptoms (4) as well as a discharge readiness list (5)

Since their first appearance in the market in 2003, electronic cigarettes have been gaining increasing popularity, with global sales of around $7 billion in 2014 (6). What is of particular concern is that as much as 13% of high school students in the US reported using an electronic cigarette at least once in the previous month (7). 

Today, the use of E-cigarettes remains controversial. The scientific community has had mixed feelings regarding their use, both as a smoking cessation aid as well as recreationally. E-cigarettes seem to be less harmful than tobacco. This was demonstrated in a report by Public Health England in 2015, which concluded that E-cigarettes were 95% less harmful than tobacco (8). However, there are several potential risks that have to be addressed. In terms of smoking cessation, a systematic review and meta-analysis of 20 relevant trials reported that E-cigarette users were 28% less likely to quit smoking than those who did not use E-cigarettes (9). Overall, the currently available data do not provide sufficient evidence for the utilization of E-cigarettes in smoking cessation programs (10). 

One of the main arguments of those who oppose the use of E-cigarettes is based on the “Gateway Theory” (11). This refers to E-cigarettes opening up a gateway towards the use of much more illicit as well as toxic drugs through vaping devices. The recent outbreak reported by the CDC could very well be a manifestation of such an event. Physicians around the world should be aware of this particular situation as well as keep up to date with the signs and symptoms as well as the management of patients presenting to the ED with Acute Pulmonary Injury (API) related to the use of THC containing vaping products.  

References

1. https://www.cdc.gov/tobacco/basic_information/e-cigarettes/severe-lung-disease.html Accessed 27/12/2019
2. Hartnett KP, Kite-Powell A, Patel MT, Haag BL, Sheppard MJ, Dias TP, King BA,  Melstrom PC, Ritchey MD, Stein Z, Idaikkadar N, Vivolo-Kantor AM, Rose DA, Briss  PA, Layden JE, Rodgers L, Adjemian J. Syndromic Surveillance for E-Cigarette, or  Vaping, Product Use-Associated Lung Injury. N Engl J Med. 2019 Dec 20. doi: 10.1056/NEJMsr1915313. [Epub ahead of print] PubMed PMID: 31860794.
3. https://www.cdc.gov/mmwr/volumes/68/wr/mm685152e2.htm?s_cid=mm685152e2_w Accessed 27/12/2019
4. https://www.cdc.gov/tobacco/basic_information/e-cigarettes/pdfs/Algorithm-EVALI-Dec-2019-p.pdf Accessed 27/12/2019
5. https://www.cdc.gov/tobacco/basic_information/e-cigarettes/pdfs/evali-discharge-readiness-checklist-508.pdf Accessed 27/12/2019
6. Peter Evans (February 20, 2015). “E-Cigarette Makers Face Rise of Counterfeits”. The Wall Street Journal. Accessed 27/12/2019
7. https://www.cdc.gov/media/releases/2015/p0416-e-cigarette-use.html Accessed 27/12/2019
8. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/454517/Ecigarettes_a_firm_foundation_for_evidence_based_policy_and_practice.pdf Accessed 27/12/2019
9. Kalkhoran S, Glantz SA. E-cigarettes and smoking cessation in real-world and clinical settings: a systematic review and meta-analysis. Lancet Respir Med. 2016 Feb;4(2):116-28. doi: 10.1016/S2213-2600(15)00521-4. Epub 2016 Jan 14. Review. PubMed PMID: 26776875; PubMed Central PMCID: PMC4752870.
10. National Academies of Sciences, Engineering, and Medicine, Health and Medicine Division, Board on Population Health and Public Health Practice, Committee on the Review of the Health Effects of Electronic Nicotine Delivery Systems; Eaton DL, Kwan LY, Stratton K, editors. Public Health Consequences of E-Cigarettes. Washington (DC): National Academies Press (US); 2018 Jan 23. PubMed PMID: 29894118.
11. Vanyukov MM, Tarter RE, Kirillova GP, Kirisci L, Reynolds MD, Kreek MJ, Conway KP, Maher BS, Iacono WG, Bierut L, Neale MC, Clark DB, Ridenour TA. Common liability to addiction and “gateway hypothesis”: theoretical, empirical and evolutionary perspective. Drug Alcohol Depend. 2012 Jun;123 Suppl 1:S3-17. doi: 10.1016/j.drugalcdep.2011.12.018. Epub 2012 Jan 18. Review. PubMed PMID: 22261179; PubMed Central PMCID: PMC3600369.