Early results of a recent study warn of serious lung damage (now identified as an e-cigarette or vaping product use-associated lung injury or “EVALI”) from e-cigarettes with heating elements made of nickel-chromium alloys. The life-threatening complications occurred without the use of nicotine or THC, which had previously been held mainly responsible.
Researchers from the University of California, Irvine (UCI), and the Huntington Medical Research Institutes (HMRI) were in the process of conducting a larger study to investigate the effects of e-cigarettes and other vaping products on the cardiovascular system. Vaping can increase blood pressure, endothelial dysfunction, and the risk of myocardial infarction and apoplexy.1-3
By chance, however, another discovery was made, which the authors felt was so significant that they wanted to publish the first results as soon as possible and thus inform as many physicians and e-cigarette consumers worldwide as possible.4-5 The study was recently published in the Journal of the American Heart Association (JAHA).
In autumn 2019, the e-cigarette device with which the scientists had previously carried out their studies for a year was taken off the market. A technically comparable device was offered as a replacement. This time, the heating element was now made of a nickel-chrome alloy instead of stainless steel.
"Within an hour of starting an experiment, we saw signs of severe shortness of breath, labored breathing, and wheezing," says first author Prof. Michael Kleinman, Ph.D. Subsequent analysis of the lung tissue showed severe compromise and serious changes that had not been observed before the device was changed, including lung lesions with thickening of the alveolar walls, inflammatory foci, congestion of erythrocytes, obliteration of alveolar spaces, and in some cases pneumonitis. Accumulations of fibrin, inflammatory cells, and mucus plugs were found in the bronchi.
Since June 2019, a potentially life-threatening complication known as EVALI (E-cigarette or vaping product use-associated lung injury) has been known in the USA. Typically, young men who have recently used e-cigarettes are affected and present with acute shortness of breath. Symptoms include shortness of breath, chest tightness, coughing, fever, and fatigue. In particular, the authors point out that an EVALI can thus also mimic the different manifestations of COVID-19.
Bilateral pulmonary infiltrates are characteristic in the chest X-ray and ground-glass opacity (GGO) infiltrates in the CT. Histologically, pneumonitis, bronchiolitis, and alveolar damage are noticeable. As of March 2020, 2,800 of these lung damages and 68 deaths have been reported in the USA.
As 82% of the EVALI cases described were preceded by, among other things, vaporizing THC (tetrahydrocannabinol), the US health protection agency CDC (Centers for Disease Control and Prevention) suspected that THC or cannabidiol or the vitamin E acetate oil used to extend these additives could be the culprits. Furthermore, 57% of the EVALIs were related to the steaming of nicotine.
However, in the current study, the severe complication was induced in the experimental animals (rats) in the absence of all these substances under controlled laboratory conditions that reproduce many of the clinical findings in patients with EVALI. The condition of one of the animals developed in such a way that the veterinary team had to euthanize it. This suggests that the blame cannot be put solely on the additives, although they are likely to pose risks as well.
This could also be related to a higher wattage in the settings of the e-cigarettes. This initial research will be followed by additional trials to find out what is causing the lung problem.
"Although further studies are needed, these results suggest that specific devices and power settings could play as central a role in the development of EVALIs as the additives. The damage associated with e-cigarettes and vaping simply cannot be overestimated," concludes Prof. Robert A. Kloner, Ph.D., Scientific Director of the HMRI.
E-cigarette users should be warned that high-power operation poses potential hazards, that certain types of heating elements may be harmful, and that serious lung damage may occur independently of THC, vitamin E acetate, or nicotine.
References:
1. Alzahrani, T., Pena, I., Temesgen, N. & Glantz, S. A. Association Between Electronic Cigarette Use and Myocardial Infarction. American Journal of Preventive Medicine 55, 455–461 (2018).
2. Ndunda Paul M & Muutu Tabitha M. Abstract 9: Electronic Cigarette Use is Associated With a Higher Risk of Stroke. Stroke 50, A9–A9.
3. Wang, J. B. et al. Cigarette and e-cigarette dual-use and risk of cardiopulmonary symptoms in the Health eHeart Study. PloS One 13, e0198681 (2018).
4. Kleinman Michael T. et al. E‐cigarette or Vaping Product Use–Associated Lung Injury Produced in an Animal Model From Electronic Cigarette Vapor Exposure Without Tetrahydrocannabinol or Vitamin E Oil. Journal of the American Heart Association 9, e017368 (2020).
5. Heating in vaping device as a cause for lung injury, study shows: Nicotine, THC or Vitamin E oil may not be the primary factor in e-cig or vaping product use-associated lung injury (EVALI). ScienceDaily https://www.sciencedaily.com/releases/2020/09/200928163756.htm.