Electronic cigarettes and vaping associated pulmonary illness (VAPI): A narrative review

On the extension of the use of a standard operating procedure for nicotine, glycerol and propylene glycol analysis in e-liquids using mass spectrometry

INTRODUCTION

Standard operating procedures (SOP), accessible to several laboratories, are essential for product verification. EU-JATC (European-Joint Action on Tobacco Control) SOP and the WHO TobLabNet (World Health Organization Tobacco Laboratories Network) SOP (SOP11) are available standard methodologies to measure nicotine, glycerol, and propylene glycol, and propose mass spectrometer (MS) as an alternative method to flame ionization detector (FID). This study conducted a comparison between FID and MS concentration results, following the MS method described in SOP11.

METHODS

In May 2020, five test e-liquids in replicates (A-E) were prepared at the Istituto di Ricerche Farmacologiche Mario Negri and sent, with SOP 11, validation document and results datasheet to 32 different laboratories all over the world from WHO TobLabNet and EU-JATC (18 from JATC, ten from WHO TobLabNet and four academic laboratories). Among thirty-two independent laboratories that participated in the study, results were received from 30 laboratories.

RESULTS

The e-liquids analyses, using the two approaches, were compared. Of the 30 laboratories surveyed, 21 utilized the FID approach exclusively, 7 opted for MS detection, and 2 employed both methods. The findings demonstrated that the gas chromatography-mass spectrometry (GC-MS) method offers comparable analytical capabilities regarding accuracy and precision for nicotine, glycerol, and propylene glycol to the FID approach. Through Pearson's correlation test with r≃1 showing a positive correlation between GC-FID and GC-MS data, and the Student's t-test, no significant differences between the two approaches were revealed, showing p>0.005 for almost all three analytes in all samples.

CONCLUSIONS

This study indicates that it is possible to apply the available EU-JATC SOP and the WHO TobLabNet SOP11 even in laboratories that do not have access to an FID, for example, to analyze flavors, trace compounds or carcinogenic, mutagenic, or toxic for reproduction (CMR) in electronic cigarette liquids.

Plasmapheresis as therapeutic option in a 16-year-old with EVALI: A case report

Since 2019 when a cluster of cases with acute respiratory distress syndrome (ARDS) associated with e-cigarettes in the United States was reported, there have been increasing numbers of reports. Electronic-cigarette or Vaping Use-associated Lung Injury (EVALI) represents a recent entity of respiratory clinical syndromes, primarily in young adults. We report a previously healthy 16-year-old boy who developed severe ARDS following a brief nonspecific prodromal phase after excessive consumption of e-cigarettes. Despite maximum intensive care therapy, including several weeks of venovenous extracorporeal membrane oxygenation, plasmapheresis and repeated administration of immunoglobulins seemed the only way to achieve therapeutic success. Although many case reports have been published, to our knowledge, there are none to date on the therapeutic use of plasmaphoresis in severe EVALI. This case highlights the clinical features of EVALI and the diagnostic dilemma that can arise with EVALI occurring against the background of an expired SARS-CoV-2 infection, with a paediatric inflammatory syndrome (PIMS) as differential diagnosis. EVALI is a diagnosis of exclusion, and the medical history of vaping and e-cigarette use can provide valuable clues. Ethical approval for this case report (protocol number 23-145 RS) was provided by the Ethical Committee of the Department of Medicine, Philipps-Universität Marburg, Germany on 13 th of June 2023. Written informed consent to publish this case and the associated images was obtained from the patient and his mother.

Particulate matter in aerosols produced by two last generation electronic cigarettes: a comparison in a real-world environment

The design of e-cigarettes (e-cigs) is constantly evolving and the latest models can aerosolize using high-power sub-ohm resistance and hence may produce specific particle concentrations. The aim of this study was to evaluate the aerosol characteristics generated by two different types of electronic cigarette in real-world conditions, such as a sitting room or a small office, in number of particles (particles/cm3). We compared the real time and time-integrated measurements of the aerosol generated by the e-cigarette types Just Fog and JUUL. Real time (10s average) number of particles (particles/cm3) in 8 different aerodynamic sizes was measured using an optical particle counter (OPC) model Profiler 212-2. Tests were conducted with and without a Heating, Ventilating Air Conditioning System (HVACS) in operation, in order to evaluate the efficiency of air filtration. During the vaping sessions the OPC recorded quite significant increases in number of particles/cm3. The JUUL e-cig produced significantly lower emissions than Just Fog with and without the HVACS in operation. The study demonstrates the rapid volatility or change from liquid or semi-liquid to gaseous status of the e-cig aerosols, with half-life in the order of a few seconds (min. 4.6, max 23.9), even without the HVACS in operation. The e-cig aerosol generated by the JUUL proved significantly lower than that generated by the Just Fog, but this reduction may not be sufficient to eliminate or consistently reduce the health risk for vulnerable non e-cig users exposed to it.

[Vaping and vaping-associated lung injury: A review]

Vaping, i.e. the use of electronic nicotine/other substances delivery systems, increases a risk of vaping-associated lung injury. The review describes clinical manifestation, methods of diagnosis and diagnostic criteria, treatment of patients with this disease as well as risk stratification of vapers and approaches to their management based on Worchester classification and clinical guidance. The pathogenetic mechanisms of vaping-associated lung injury have been analyzed.

The main e-cigarette component vegetable glycerin enhances neutrophil migration and fibrosis in endotoxin-induced lung injury via p38 MAPK activation

We investigated the effects of vegetable glycerin (VG), a main e-cigarette constituent, on endotoxin-induced acute lung injury (ALI). Mice received intratracheal administration of 30% VG in phosphate buffered saline (PBS) vehicle or only PBS (control) for 4 days. On Day 5, mice received an intratracheal instillation of lipopolysaccharide (LPS) (LPS group and VG + LPS group) or PBS (VG group and control group). Lung histopathology, expression of chemokine receptors, and regulatory signaling were analyzed 24 h after the Day 5 treatment. VG significantly increased ALI-associated histopathological and fibrotic changes in both the VG group and LPS-induced ALI mice (VG + LPS group). Immunohistochemistry (IHC) and western blot analyses revealed that VG administration resulted in upregulation of neutrophil markers [lymphocyte antigen 6 complex locus G6D (Ly6G) and myeloperoxidase (MPO)] as well as upregulation of the expression of transforming growth factor-β (TGF-β), a central mediator of fibrogenesis, in the lungs of both VG and VG + LPS groups. VG enhanced the expression of adhesion molecules [very late antigen 4 (VLA-4) and vascular cell adhesion molecule 1 (VCAM-1)] and increased activation of p38 mitogen-activated protein kinase (p38 MAPK) to prompt neutrophil recruitment in the lungs of mice with ALI. Intraperitoneal administration of a p38 inhibitor attenuated these histopathological changes significantly as well as VG-induced upregulation in expression of Ly6G, MPO, VLA-4, VCAM-1, TGF-β, and collagen-1 in mice with ALI. In conclusion, VG enhances neutrophil chemotaxis and fibrosis and it amplifies the inflammatory response associated with LPS-induced ALI in the lungs via enhancement of p38 MAPK activity.

Chemical Interactions and Cytotoxicity of Terpene and Diluent Vaping Ingredients

Vaping devices have risen in popularity since their inception in 2007. The practice involves using a variety of commercially available devices. Internal heating systems in devices aerosolize e-liquid formulations of complex mixtures including an active ingredient (e.g., THC, CBD, and nicotine), diluents (or cutting agents), solvents, and flavoring agents (e.g., terpenes and aldehydes). The vaping toxicology literature consists of cytotoxicity studies of individual chemicals and commercial formulas. Because of the variation of e-liquid composition, there is a limited understanding of the toxicity of ingredient combinations. This study analyzed the cytotoxic effects after exposure to individual and binary mixtures of a representative terpene (+-R-limonene) and diluent (triethyl citrate) on human lung cell models. Data were analyzed to determine the effects of 97:3 and 80:20% v/v (triethyl citrate/limonene) binary mixtures. BEAS-2B cells, a bronchial epithelial cell, and A549 cells, a type II alveolar epithelial cell, served as models for comparison. LC₅₀ values were calculated and isobolograms were used to assess chemical interactions. Results show that limonene was more cytotoxic than triethyl citrate. Isobolographic analyses confirmed that the 97:3% v/v mixture resulted in an antagonistic chemical interaction. The 80:20% v/v mixture resulted in a similar result. Further testing of different ratios of binary mixtures is needed for chemical interaction screening to inform safety assessments.

Urinary level of heavy metals in people working in smoking cafés

Previous researches have reported significant levels of heavy metals in indoor air of smoking cafés. The current research aimed to evaluate the potential exposure of smoking cafés workers to heavy metals through quantifying amounts of these pollutants in urine samples. To this end, 35 waterpipe/cigarette cafés workers were selected as the exposed population, 35 employees from non-smoking cafe' as the control group 1 (CG1) and 25 cases of the normal citizens as the control group 2 (CG2); and their urine samples were taken. Samples were then prepared by acid digestion approach and measured by the ICP in order to determine amount of heavy metals in them. The findings of the current work show the significant difference among urinary levels of metals in the exposed and both CG1 and CG2 (P value < 0.05). Furthermore, urinary metal levels in samples collected from smoking café workers after the exposure were considerably higher than those were collected before the exposure (P-value <0.05). According to the findings, "tobacco type" could be considered as a leading factor for heavy metal exposure in studied smokers. Additionally, a positive and significant association was found between urinary metals and urinary levels of 8-OHdG (a markers of DNA degradation through oxidative stress). Therefore, workers in waterpipe/cigarette café can be classified as high risk people in terms of DNA oxidative damage.

Reporting of pneumothorax in association with vaping devices and electronic cigarettes

Vaping may lead to spontaneous pneumothorax, but there are few published reports on this phenomenon. We present a case of vaping-related pneumothorax and make recommendations for structured reporting of this emerging cause for pneumothorax. A normal-weight 34-year-old male presented to our emergency department with dyspnoea and back pain increasing over 24 hours. Chest X-ray showed a large right-sided pneumothorax. Three years ago, he had quit smoking cigarettes and switched to vaping. CT scan revealed bullae, and the patient received apical lung resection. Histology revealed mild alveolitis. Vaping is an emerging cause of lung injury. This report demonstrates a potential association between vaping and pneumothorax. However, structured reporting and future research are needed to establish a definitive (or causal) relationship between vaping and pneumothorax.

Associations between vaping and eating disorder diagnosis and risk among college students

Vaping is common among college-age young adults. Preliminary research has shown associations between vaping and eating disorder symptoms, however, there remain gaps in this knowledge among college students. The aim of this study was to determine the associations between vaping and a self-reported lifetime eating disorder diagnosis and eating disorder risk among a large sample of college students. Cross-sectional data from the 2018-2019 national (U.S.) Healthy Minds Study (n = 51,231) were analyzed. Multiple logistic regression analyses were conducted to determine the unadjusted and adjusted associations between vaping or e-cigarette use in the past 30 days and a self-reported lifetime eating disorder diagnosis (any diagnosis, anorexia nervosa, bulimia nervosa, binge-eating disorder) and eating disorder risk (SCOFF). Among the sample, 19.0% of participants reported vaping or e-cigarette use in the past 30 days, 3.7% self-reported any lifetime eating disorder diagnosis, and 25.0% were at elevated risk for an eating disorder. Vaping or e-cigarette use was associated with higher odds of all eating disorder measures, including the self-reported lifetime eating disorder diagnosis items (any diagnosis, anorexia nervosa, bulimia nervosa, binge-eating disorder) and elevated eating disorder risk, while adjusting for demographic and confounding variables. Among a large sample of college students, vaping or e-cigarette use was associated with a self-reported lifetime eating disorder diagnosis and elevated eating disorder risk, which may exacerbate the many medical complications associated with eating disorder behaviors. Clinical professionals should screen for eating disorder behaviors among college students who report vaping or e-cigarette use to monitor symptoms and medical complications.

The vaping product use associated lung injury: is this a new pulmonary disease entity?

In the summer of 2019, an epidemic of e-cigarette or vaping product use associated lung injury (EVALI) broke out in the United States of America. EVALI is a lung disease that can be severe and life-threatening. It should be emphasized that EVALI is not a clinical diagnosis, but surveillance case definition. Due to the profile of users of such devices, the pathology mainly affects young adults, although cases of EVALI have been reported in almost all age groups, from teenage children to seniors. The worst prognosis is in patients over 35 years of age, with accompanying diseases. A significant number of patients declared the use of products containing tetrahydrocannabinol (THC). The most likely factor responsible for the occurrence of EVALI is vitamin E acetate, which is sometimes added to liquids necessary for the use of electronic cigarette type devices, especially those liquids that contain THC. Nevertheless, it is possible that other substances used in liquids may also be a causative factor. Typical for EVALI are respiratory, gastrointestinal and systemic symptoms, while in imaging tests, a characteristic feature of EVALI is the presence of opacities on the chest radiogram and ground-glass clouds on computed tomography scans. In the course of this disease, respiratory failure often occurs (58%). In the vast majority of cases oxygen substitution is necessary. Currently, the best treatment of EVALI is considered to be the administration of systemic glucocorticosteroids. Over 90% of patients with EVALI required hospitalization, while the mortality rate was about 2.42%. Median age of the fatalities was 51 years. The aim of this review is to summarise the available information on EVALI and to consider possible causative factors and pathomechanism.

CBD, a precursor of THC in e-cigarettes

The use of cannabidiol (CBD) in electronic cigarettes is widespread. Previously, it was reported that CBD is partly transformed to THC in case smoking as a cigarette, however, the pyrolysis of this compound has not been assessed extensively. The aim of our study was to investigate the effect of temperature on the composition of pyrolysis products of CBD. The experiments were performed in the typical operating temperature range of e-cigarettes (250–400 °C) and at 500 °C under both inert and oxidative conditions, and the pyrolysis products were identified and quantified by GC–MS. Depending on the temperature and atmosphere, 25–52% of CBD was transformed into other chemical substances: Δ⁹-THC, Δ⁸-THC, cannabinol and cannabichromene were the predominant pyrolysates in both conditions, all formed by cyclization reaction. THC was the main pyrolysis product at all temperatures under both oxidative and inert conditions. Our results point out that CBD in e-cigarettes can be considered as a precursor of THC, thus it bears all the dangers related to this psychoactive compound. Our findings are fundamental contributions to the safety profile of CBD-based e-cigarettes.