Characteristics of a Multistate Outbreak of Lung Injury Associated with E-cigarette Use, or Vaping - United States, 2019

Contemporary Concise Review 2023: Environmental and occupational lung diseases

Air pollutants have various effects on human health in environmental and occupational settings. Air pollutants can be a risk factor for incidence, exacerbation/aggravation and death due to various lung diseases, including asthma, chronic obstructive pulmonary disease (COPD), hypersensitivity pneumonitis or pneumonia (HP), pulmonary fibrosis such as pneumoconiosis and malignant respiratory diseases such as lung cancer and malignant pleural mesothelioma. Environmental and occupational respiratory diseases are crucial clinical and social issues worldwide, although the burden of respiratory disease due to environmental and occupational causes varies depending on country/region, demographic variables, geographical location, industrial structure and socioeconomic situation. The correct recognition of environmental and occupational lung diseases and taking appropriate measures are essential to their effective prevention.

The impact of recreational cannabis legalization on youth: the Colorado experience

Over the past two decades, cannabis policies have liberalized in the United States, culminating in the legalization of recreational cannabis in Colorado and Washington state in 2012. This review will focus on the impact of recreational cannabis legalization in Colorado. While the prevalence of past-year and past-month cannabis use has remained relatively steady among adolescents post-legalization, the prevalence of young adult use has continued to rise. Cannabis products with increased potency have become more prevalent and widely used. There are concerns that the use of products with increased potency will increase risk for cannabis use and comorbid mental health disorders, particularly cannabis-induced psychosis and suicidal behavior, although more research is needed to fully understand the impact of high-potency products. Since the legalization of recreational cannabis, numerous additional public health concerns have emerged: unintentional overdoses requiring acute care visits, electronic vaping-associated lung injury, increased motor vehicle collisions related to cannabis consumption, and higher rates of cannabis use during pregnancy. Lessons learned from the first decade of cannabis legalization emphasize the need for research efforts to provide evidence-based guidelines, inform prevention strategies, and implement selective interventions for at-risk populations including youth, individuals with comorbid mental health disorders, and individuals who are pregnant.

Cannabis Use Disorder in Adolescents

With increasing cannabis potency, increasing variety of methods of cannabis use, and lower perceived risk of cannabis use, it is increasingly important clinicians who work with adolescents remain up-to-date on the latest literature regarding cannabis use and its associated outcomes. Adolescent cannabis use is associated with chronic cognitive, psychosocial, psychiatric, and physical outcomes. Clinicians working in this field should be able to recognize cannabis use disorder, understand how adolescent cannabis use can impact the developing mind, and have informed discussions with patients and families regarding risks of use.

Sex Differences in E-Cigarette Use and Related Health Effects

BACKGROUND

Electronic cigarettes (e-cigarettes) comprise a variety of products designed to deliver nicotine, flavorings, and other substances. To date, multiple epidemiological and experimental studies have reported a variety of health issues associated with their use, including respiratory toxicity, exacerbation of respiratory conditions, and behavioral and physiological effects. While some of these effects appear to be sex- and/or gender-related, only a portion of the research has been conducted considering these variables. In this review, we sought to summarize the available literature on sex-specific effects and sex and gender differences, including predictors and risk factors, effects on organ systems, and behavioral effects.

METHODS

We searched and selected articles from 2018-2023 that included sex as a variable or reported sex differences on e-cigarette-associated effects.

RESULTS

We found 115 relevant studies published since 2018 that reported sex differences in a variety of outcomes. The main differences reported were related to reasons for initiation, including smoking history, types of devices and flavoring, polysubstance use, physiological responses to nicotine and toxicants in e-liquids, exacerbation of lung disease, and behavioral factors such as anxiety, depression, sexuality, and bullying.

CONCLUSIONS

The available literature supports the notion that both sex and gender influence the susceptibility to the negative effects of e-cigarette use. Future research needs to consider sex and gender variables when addressing e-cigarette toxicity and other health-related consequences.

E-Cigarettes and Associated Health Risks: An Update on Cancer Potential

The potential cancer risk associated with electronic-cigarette (e-cigarette) use is ongoing and remains a subject of debate. E-Cigarettes work by heating a liquid that usually contains nicotine, flavorings, and other chemicals. When the liquid is heated, users inhale an aerosol into their lungs. While e-cigarettes are generally considered less harmful than traditional tobacco products, they still contain potentially harmful chemicals, which can damage DNA and lead to cancer. Several studies have investigated the potential cancer risk associated with e-cigarette use, while other studies have suggested that e-cigarette aerosol may contain carcinogenic chemicals that could increase the risk of lung and bladder cancer in humans. However, these studies are limited in their scope and do not provide conclusive evidence. Overall, the long-term cancer risk associated with e-cigarette use remains uncertain, more research is needed to fully understand the potential risks and benefits of e-cigarettes. However, this review will allow the investigator to get more recent updates about e-cigarettes.

E-cigarette explosions: patient profiles, injury patterns, clinical management, and outcome

Background

E-cigarette abuse, also known as vaping, is a widespread habit. Recently, there have been increasing reports of explosions of these devices resulting in serious burn injuries, especially to the groin, hand, and face. Overheating rechargeable lithium-ion batteries are supposed to be the responsible mechanism, especially in low quality fabrications.

Methods

In this single-center retrospective study, data of 46 patients are presented and analyzed. In addition to information on demographics, injury patterns, and treatment options, this is the first study investigating outcome after an average of 13 months via a standardized telephone interview of 31 patients (67%). Patients were specifically asked regarding their outcome, vaping habits, technical modifications to their devices and supply source.

Results

Patients were mainly male (98.2%) with a median age of 36 years. Typical injury patterns included the groin region (n = 32; 69%), hands (n = 12; 25%) and face (n = 3; 7%). All patients underwent debridement, in nine cases hydrotherapeutically. 61% (n = 28) underwent consecutive tangential necrectomy and subsequent split thickness skin graft transplantation. Wound infection was observed in 18 patients (39%), with burn depth as a significant risk factor (p < 0.001). 91% of the followed-up patients were satisfied. Surprisingly, 38% were still using e-cigarettes. 42% (n = 13) reported manual modifications of their devices to prolong battery life or increasing smoke production.

Conclusions

Injuries from exploding e-cigarettes can be serious and should be treated in a specialized burn center. E-cigarette explosions lead to characteristic injury patterns and often need surgical treatment. This should be made more public to reduce their use and keep people from modifying the devices. The counterintuitive and irrational observation of a high rate of abuse even after the injury underlines their addiction potential.

Changes in Quantity Measures of Various Forms of Cannabis Consumption among Emerging Adults in Canada in Relation to Policy and Public Health Developments

Limited research examines changes in quantities of various forms of smoked/vaped cannabis among regular consumers, including emerging adults (EAs; 18 to 29) in Canada. This information is particularly relevant in the current context of emerging cannabis behaviors among EAs related to political amendments (legalization of cannabis), vaping-related lung illnesses (EVALI), and unprecedented pandemics (COVID-19). This study investigated the impact of legalizing recreational cannabis use in Canada, the EVALI epidemic, and the COVID-19 pandemic on the quantity of smoked/vaped forms of cannabis in relation to gender differences. EAs retrospectively self-reported the quantity of herb, hash, concentrates, joint size, and the number of joints and vaping cartridges in relation to three consecutive developments: pre-legalization, post-legalization; pre-EVALI, post-EVALI, pre-COVID-19, and during COVID-19. The quantity of herb use significantly increased among heavy users, and vaping quantity significantly increased among light users. Overall, an increasing incremental trend was observed in the average quantity of cannabis forms used over time. Males consumed higher quantities of all cannabis forms than females. More males than females reported using concentrates (p < 0.05). These findings reveal unique aspects of the amount of various cannabis forms smoked/vaped in relation to gender and provides preliminary evidence of cannabis consumption behaviors in relation to changing social and cultural contexts.

Alveolar macrophages from EVALI patients and e-cigarette users: a story of shifting phenotype

Exposure to e-cigarette vapors alters important biologic processes including phagocytosis, lipid metabolism, and cytokine activity in the airways and alveolar spaces. Little is known about the biologic mechanisms underpinning the conversion to e-cigarette, or vaping, product use-associated lung injury (EVALI) from normal e-cigarette use in otherwise healthy individuals. We compared cell populations and inflammatory immune populations from bronchoalveolar lavage fluid in individuals with EVALI to e-cigarette users without respiratory disease and healthy controls and found that e-cigarette users with EVALI demonstrate a neutrophilic inflammation with alveolar macrophages skewed towards inflammatory (M1) phenotype and cytokine profile. Comparatively, e-cigarette users without EVALI demonstrate lower inflammatory cytokine production and express features associated with a reparative (M2) phenotype. These data indicate macrophage-specific changes are occurring in e-cigarette users who develop EVALI.

Transcriptomic responses in the blood and sputum of cigarette smokers compared to e-cigarette vapers

RATIONALE

Electronic (e)-cigarettes are popular among youth and cigarette smokers attempting to quit. Studies to date have focused on the utility of e-cigarettes as a smoking cessation tool, but the biological effects are largely unknown.

OBJECTIVES

To identify transcriptomic differences in the blood and sputum of e-cigarette users compared to conventional cigarettes smokers and healthy controls and describe biological pathways affected by these tobacco products.

METHODS

Cross-sectional analysis of whole blood and sputum RNA-sequencing data from 8 smokers, 9 e-cigarette users (e-cigs) and 4 controls. Weighted gene co-network analysis (WGCNA) identified gene module associations. Ingenuity Pathway Analysis (IPA) identified canonical pathways associated with tobacco products.

MAIN RESULTS

In blood, a three-group comparison showed 16 differentially expressed genes (DEGs); pair-wise comparison showed 7 DEGs between e-cigs and controls, 35 DEGs between smokers and controls, and 13 DEGs between smokers and e-cigs. In sputum, 438 DEGs were in the three-group comparison. In pair-wise comparisons, there were 2 DEGs between e-cigs and controls, 270 DEGs between smokers and controls, and 468 DEGs between smokers and e-cigs. Only 2 genes in the smokers vs. control comparison overlapped between blood and sputum. Most gene modules identified through WGCNA associated with tobacco product exposures also were associated with cotinine and exhaled CO levels. IPA showed more canonical pathways altered by conventional cigarette smoking than by e-cigarette use.

CONCLUSION

Cigarette smoking and e-cigarette use led to transcriptomic changes in both blood and sputum. However, conventional cigarettes induced much stronger transcriptomic responses in both compartments.

Bronchoalveolar Lavage (BAL) and Pathologic Assessment of Electronic Cigarette or Vaping Product Use-associated Lung Injury (EVALI): The EVALI-BAL Study, A Multicenter Cohort

BACKGROUND

E-cigarette or vaping-use related acute lung injury (EVALI) is a spectrum of radiographic and histologic patterns consistent with acute to subacute lung injury. However, limited data exist characterizing bronchoalveolar lavage (BAL) findings. The goal of this study is to further define the pathologic findings from BAL and biopsy samples of subjects with EVALI across 7 institutions.

METHODS

A multicentered registry of patients admitted with EVALI who underwent flexible bronchoscopy with BAL+/-transbronchial biopsy from July 2019 to April 2021 was compiled for retrospective evaluation from 7 academic institutions throughout the United States. Radiographic and cytopathologic findings and frequencies were correlated with the substance vaped.

RESULTS

Data from 21 subjects (42.9% women) who were predominantly White (76.2%) with a median age of 25 years (range, 16 to 68) with EVALI were included in this study. Sixteen patients (76.2%) reported use of tetrahydrocannabinol; the remainder used nicotine. BAL was performed in 19 of the 21 subjects, and transbronchial lung biopsy was performed in 7 subjects. BAL findings revealed neutrophilic predominance (median, 59.5%, range, 3.1 to 98) in most cases. Ten BAL samples demonstrated pulmonary eosinophilia ranging from 0.2% to 49.1% with one subject suggesting a diagnosis of acute eosinophilic pneumonia associated with the use of e-cigarettes. Lipid-laden macrophages were noted in 10 of 15 reports (66.7%). Transbronchial biopsy most frequently demonstrated patterns of organizing pneumonia (57.1%).

CONCLUSION

EVALI-associated BAL findings typically demonstrate a spectrum of nonspecific inflammatory changes, including neutrophilia, lipid-laden macrophages, and in some cases eosinophilia.

Cannabis Use Disorder in Adolescents

With increasing cannabis potency, increasing variety of methods of cannabis use, and lower perceived risk of cannabis use, it is increasingly important clinicians who work with adolescents remain up-to-date on the latest literature regarding cannabis use and its associated outcomes. Adolescent cannabis use is associated with chronic cognitive, psychosocial, psychiatric, and physical outcomes. Clinicians working in this field should be able to recognize cannabis use disorder, understand how adolescent cannabis use can impact the developing mind, and have informed discussions with patients and families regarding risks of use.

An examination of the social perceptions and vaping preferences of young electronic nicotine delivery system users

Background

Little research has been conducted on social aspects and preferences of electronic nicotine delivery system (ENDS) use among young ENDS users, and none have examined differences in these aspects and preferences by gender and tobacco use status.

Methods

A total of 558 young regular vapers (ages 16-24; vaped at least once a week for the last 3 months) from Nova Scotia were recruited to complete a demographic and vaping questionnaire. A 2 x 3 study design was used to compare participants on social aspects and vaping preferences based on gender (male or female) and tobacco use status (never, former, or current smoker). Chi-square tests were used to determine significant differences, and Bonferroni tests were used to assess over- and under-representation within significant variables.

Results

Current tobacco-using male vapers had a higher frequency of experiencing pressure to vape from friends and current employment as compared to females. Former and never tobacco-using male vapers had a higher frequency of parental awareness of their vaping behavior than females. Former tobacco-using female vapers had a higher frequency of being influenced to vape by others they know on social media than males. Both never and former tobacco-using females reported a higher frequency of exposure to vaping content on social media than males. Never tobacco-using female vapers preferred vape pen devices relative to males.

Conclusions

Important gender differences by tobacco use status exist and demonstrate differential patterns of social influence for ENDS use and their experiences within this demographic.

E-cigarette aerosol impairs male mouse skeletal muscle force development and prevents recovery from injury

To date, there has been a lag between the rise in E-cigarette use and an understanding of the long-term health effects. Inhalation of E-cigarette aerosol delivers high doses of nicotine, raises systemic cytokine levels, and compromises cardiopulmonary function. The consequences for muscle function have not been thoroughly investigated. The present study tests the hypothesis that exposure to nicotine-containing aerosol impairs locomotor muscle function, limits exercise tolerance, and interferes with muscle repair in male mice. Nicotine-containing aerosol reduced the maximal force produced by the extensor digitorum longus (EDL) by 30%-40% and, the speed achieved in treadmill running by 8%. Nicotine aerosol exposure also decreased adrenal and increased plasma epinephrine and norepinephrine levels, and these changes in catecholamines manifested as increased muscle and liver glycogen stores. In nicotine aerosol exposed mice, muscle regenerating from overuse injury only recovered force to 80% of noninjured levels. However, the structure of neuromuscular junctions (NMJs) was not affected by e-cigarette aerosols. Interestingly, the vehicle used to dissolve nicotine in these vaping devices, polyethylene glycol (PG) and vegetable glycerin (VG), decreased running speed by 11% and prevented full recovery from a lengthening contraction protocol (LCP) injury. In both types of aerosol exposures, cardiac left ventricular systolic function was preserved, but left ventricular myocardial relaxation was altered. These data suggest that E-cigarette use may have a negative impact on muscle force and regeneration due to compromised glucose metabolism and contractile function in male mice.NEW & NOTEWORTHY In male mice, nicotine-containing E-cigarette aerosol compromises muscle contractile function, regeneration from injury, and whole body running speeds. The vehicle used to deliver nicotine, propylene glycol, and vegetable glycerin, also reduces running speed and impairs the restoration of muscle function in injured muscle. However, the predominant effects of nicotine in this inhaled aerosol are evident in altered catecholamine levels, increased glycogen content, decreased running capacity, and impaired recovery of force following an overuse injury.

Chronic health effects associated with electronic cigarette use: A systematic review

Introduction

Over the last decade, e-cigarette use has been on the rise but with growing health concerns. The objective of this systematic review was to update findings for chronic health outcomes associated with e-cigarette use from the 2018 National Academies of Sciences, Engineering, and Medicine (NASEM) report.

Methods

Three bibliographic databases were searched to identify studies comparing the chronic health effects of e-cigarette users (ECU) to non-smokers (NS), smokers, and/or dual users indexed between 31 August 2017 and 29 January 2021. Two independent reviewers screened abstracts and full texts. Data were extracted by one reviewer and verified by a second one. Outcomes were synthesized in a narrative manner using counts and based on statistical significance and direction of the association stratified by study design and exposure type. Risk of bias and certainty of evidence was assessed. The protocol was prospectively registered on Open Science Framework https://osf.io/u9btp.

Results

A total of 180 articles were eligible. This review focused on 93 studies for the 11 most frequently reported outcomes and from which 59 reported on daily e-cigarette use. The certainty of evidence for all outcomes was very low because of study design (84% cross-sectional) and exposure type (27% reported on exclusive ECU, i.e., never smoked traditional cigarettes). Overall, the summary of results for nearly all outcomes, including inflammation, immune response, periodontal and peri-implant clinical parameters, lung function, respiratory symptoms, and cardiovascular disease, suggested either non-significant or mixed results when daily ECU was compared to NS. This was also observed when comparing exclusive ECU to NS. The only notable exception was related to oral health where most (11/14) studies reported significantly higher inflammation among daily ECU vs. NS. Compared to the smokers, the exclusive-ECUs had no statistically significant differences in inflammation orperiodontal clinical parameters but had mixed findings for peri-implant clinical parameters.

Conclusions

This review provides an update to the 2018 NASEM report on chronic health effects of e-cigarette use. While the number of studies has grown, the certainty of evidence remains very low largely because of cross-sectional designs and lack of reporting on exclusive e-cigarette exposure. There remains a need for higher quality intervention and prospective studies to assess causality, with a focus on exclusive e-cigarette use.

Tobacco Product Use and Functionally Important Respiratory Symptoms Among US Adolescents/Young Adults

OBJECTIVE

The relation between respiratory symptoms and the range of tobacco product use among US adolescents/young adults is not yet clear. This cross-sectional analysis examines tobacco product use and respiratory symptoms in a nationally representative sample of 21,057 adolescents/young adults aged 12-24 years from Wave 4 (2016-17) of the Population Assessment of Tobacco and Health Study.

METHODS

Presence of functionally important respiratory symptoms was defined by questions regarding wheezing and nighttime cough at a cutoff score associated with poorer functional health status. Past-30-day tobacco use was analyzed 2 ways: never-tobacco users (reference) versus combustible users, noncombustible-only users, and former users; or frequency of use of cigarettes and/or e-cigarettes. Weighted Poisson regression adjusted for past-30-day marijuana use, secondhand smoke exposure, and asthma.

RESULTS

Functionally important respiratory symptoms were present in 10.0% overall: 13.8% of combustible users, 9.0% of noncombustible users, 8.2% of noncurrent users and 9.7% of never users. Functionally important respiratory symptoms were associated with combustible tobacco use (relative risk [RR] = 1.52[95% CI 1.29, 1.80]), marijuana use (RR = 1.54[1.34, 1.77]) and secondhand smoke exposure (RR = 1.04[1.03, 1.05]). Higher cigarette smoking frequency was also associated with functionally important respiratory symptoms for frequency categories >14 days/month (eg, RR = 1.93[1.50, 2.49] for 15-29 days/month). Frequency of e-cigarette use was not associated with functionally important respiratory symptoms.

CONCLUSIONS

During 2016-17, smoking cigarettes, marijuana use, and secondhand smoke exposure were cross-sectionally associated with functionally important respiratory symptoms in adolescents/young adults. Risk increased with increased frequency of cigarette use but not e-cigarette use. Given changes to contemporary e-cigarettes and use, findings may not generalize to newer products.

Impact of vaping on respiratory health

Widespread uptake of vaping has signaled a sea change in the future of nicotine consumption. Vaping has grown in popularity over the past decade, in part propelled by innovations in vape pen design and nicotine flavoring. Teens and young adults have seen the biggest uptake in use of vape pens, which have superseded conventional cigarettes as the preferred modality of nicotine consumption. Relatively little is known, however, about the potential effects of chronic vaping on the respiratory system. Further, the role of vaping as a tool of smoking cessation and tobacco harm reduction remains controversial. The 2019 E-cigarette or Vaping Use-Associated Lung Injury (EVALI) outbreak highlighted the potential harms of vaping, and the consequences of long term use remain unknown. Here, we review the growing body of literature investigating the impacts of vaping on respiratory health. We review the clinical manifestations of vaping related lung injury, including the EVALI outbreak, as well as the effects of chronic vaping on respiratory health and covid-19 outcomes. We conclude that vaping is not without risk, and that further investigation is required to establish clear public policy guidance and regulation.

Association Between E-Cigarettes and Asthma in Adolescents: A Systematic Review and Meta-Analysis

INTRODUCTION

Numerous studies have revealed the relationship between E-cigarettes and asthma but have shown inconsistent results. This study systematically evaluated the potential association between E-cigarette use and asthma in adolescents.

METHODS

PubMed, Embase (Ovid), Cochrane Library, and the China Biological Medicine Database were searched for relevant articles published between database inception and February 28, 2021. The quality of included studies was evaluated using the Agency for Healthcare Research and Quality assessment, and a quantitative meta-analysis was conducted to pool outcomes of ORs with 95% CIs.

RESULTS

A total of 10 cross-sectional studies incorporating a total of 483,948 participants were included. All the study participants were middle- and high-school students with a mean age of 15-16 years. The median prevalence of ever E-cigarette use was 11.2% (range=2.2%, 45%), and that of current use was 7.5% (range=2.7%, 25%). Overall, E-cigarette use was associated with significantly higher odds of having asthma (pooled OR=1.31, 95% CI=1.22, 1.42) than nonuse, and both current use (OR=1.36, 95% CI=1.26, 1.48) and ever use (OR=1.20, 95% CI=1.12, 1.28) showed similar associations.

DISCUSSION

This study shows that both current and ever E-cigarette use have significant associations with asthma in adolescents. This knowledge might provide potential evidence for developing primary prevention strategies and serve as a reference for public health policy.

Adolescent Vaping-Associated Trauma in the Western United States

INTRODUCTION

Electronic cigarettes (e-cigarettes) are handheld, battery-powered vaporizing devices. It is estimated that more than 25% of youth have used these devices recreationally. While vaping-associated lung injury is an increasingly recognized risk, little is known about the risk of traumatic injuries associated with e-cigarette malfunction.

METHODS

A multi-institutional retrospective study was performed by querying the electronic health records at nine children's hospitals. Patients who sustained traumatic injuries while vaping from January 2016 through December 2019 were identified. Patient demographics, injury characteristics, and the details of trauma management were reviewed.

RESULTS

15 children sustained traumatic injuries due to e-cigarette explosion. The median age was 17 y (range 13-18). The median injury severity score was 2 (range 1-5). Three patients reported that their injury coincided with their first vaping experience. Ten patients required hospital admission, three of whom required intensive care unit admission. Admitted patients had a median length of stay of 3 d (range 1-6). The injuries sustained were: facial burns (6), loss of multiple teeth (5), thigh and groin burns (5), hand burns (4), ocular burns (4), a radial nerve injury, a facial laceration, and a mandible fracture. Six children required operative intervention, one of whom required multiple operations for a severe hand injury.

CONCLUSIONS

In addition to vaping-associated lung injury, vaping-associated traumatic injuries are an emerging and worrisome injury pattern sustained by adolescents in the United States. This report highlights another means by which e-cigarettes pose an increasing risk to a vulnerable youth population.

Longitudinal transition outcomes among adult dual users of e-cigarettes and cigarettes with the intention to quit in the United States: PATH Study (2013-2018)

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Many dual users of e-cigarettes/cigarettes report using e-cigarettes with the ITQ.

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Data was from 3,542 adults (≥18 years) from the PATH cohort (2013–2018).

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Dual users with ITQ were compared with mono cigarette smokers with ITQ.

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Dual users with ITQ were less likely to transition to cessation.

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This needs to be considered when assessing the population impact of e-cigarettes.

Many adult dual users of e-cigarettes and cigarettes in the United States report using e-cigarettes with the intention to quit (ITQ) smoking. This study examined transition outcomes among adult dual users of e-cigarettes and cigarettes with the ITQ compared to mono cigarette smokers with ITQ. We conducted a longitudinal analysis of 3,542 adults aged ≥ 18 years with data from Waves 1 and 4 of the United States Population Assessment of Tobacco and Health study (2013–2018) between May 2021 and January 2022. Current dual users (e-cigarettes and cigarettes use on ≥ 20 days in the past month) with the ITQ were compared to current mono cigarette smokers with the ITQ for transition outcomes (cessation, mono e-cigarette, mono cigarette and dual use) three years later. We conducted multinomial logistic regression modeling adjusting for potential confounders and reported the adjusted relative risk ratios (aRRR) with 95% confidence intervals (CI) for the transition outcomes. Approximately 10.7% (7.8–14.3) of dual users with the ITQ (in 2013) reported cessation (no past-month use of any tobacco) three years later, compared to 16.1% (14.6–17.7) of mono cigarette smokers. Dual users were 83% and 79% less likely to transition to cessation (aRRR: 0.17, 95% CI:0.09–0.32) or mono cigarette use (0.21, 0.14–0.32), respectively, compared to mono cigarette smokers. Our findings show that in a real-world scenario, dual e-cigarette and cigarette use may hinder rather than facilitate smoking cessation among those interested in quitting. This needs consideration when assessing the population impact of e-cigarettes and their role in harm reduction.

E-cigarette vaping associated acute lung injury (EVALI): state of science and future research needs

"E-Cigarette (e-cig) Vaping-Associated Acute Lung Injury" (EVALI) has been linked to vitamin-E-acetate (VEA) and Δ-9-tetrahydrocannabinol (THC), due to their presence in patients' e-cigs and biological samples. Lacking standardized methodologies for patients' data collection and comprehensive physicochemical/toxicological studies using real-world-vapor exposures, very little data are available, thus the underlying pathophysiological mechanism of EVALI is still unknown. This review aims to provide a comprehensive and critical appraisal of existing literature on clinical/epidemiological features and physicochemical-toxicological characterization of vaping emissions associated with EVALI. The literature review of 161 medical case reports revealed that the predominant demographic pattern was healthy white male, adolescent, or young adult, vaping illicit/informal THC-containing e-cigs. The main histopathologic pattern consisted of diffuse alveolar damage with bilateral ground-glass-opacities at chest radiograph/CT, and increased number of macrophages or neutrophils and foamy-macrophages in the bronchoalveolar lavage. The chemical analysis of THC/VEA e-cig vapors showed a chemical difference between THC/VEA and the single THC or VEA. The chemical characterization of vapors from counterfeit THC-based e-cigs or in-house-prepared e-liquids using either cannabidiol (CBD), VEA, or medium-chain triglycerides (MCT), identified many toxicants, such as carbonyls, volatile organic compounds, terpenes, silicon compounds, hydrocarbons, heavy metals, pesticides and various industrial/manufacturing/automotive-related chemicals. There is very scarce published toxicological data on emissions from THC/VEA e-liquids. However, CBD, MCT, and VEA emissions exert varying degrees of cytotoxicity, inflammation, and lung damage, depending on puffing topography and cell line. Major knowledge gaps were identified, including the need for more systematic-standardized epidemiological surveys, comprehensive physicochemical characterization of real-world e-cig emissions, and mechanistic studies linking emission properties to specific toxicological outcomes.

Unique effects of nicotine across the lifespan

Smoking remains the leading cause of preventable death in the United States. Although combustible cigarettes are largely being replaced by tobacco-free products, nicotine use continues to increase in vulnerable populations, including youth, adolescents, and pregnant women. Nicotine exerts unique effects on specific brain regions during distinct developmental periods due to the dynamic expression of nicotinic acetylcholine receptors (nAChRs) throughout the lifespan. Nicotine exposure is a health concern not only for adults but also has neurotoxic effects on the fetus, newborn, child, and adolescent. In this review, we aim to highlight the dynamic roles of nAChRs throughout gestation, adolescence, and adulthood. We also provide clinical and preclinical evidence of the neurodevelopmental, cognitive, and behavioral consequences of nicotine exposure at different developmental periods. This comprehensive review highlights unique effects of nicotine throughout the lifespan to help elucidate interventions and public health measures to protect sensitive populations from nicotine exposure.

Do professional perspectives on evidence-based smoking cessation methods align? A Delphi study among researchers and healthcare professionals

The use of evidence-based smoking cessation interventions (SCIs) can significantly increase the number of successful smoking cessation attempts. To obtain an overview of the knowledge and viewpoints on the effectiveness and use of SCIs, a three-round online Delphi study was conducted among researchers and primary care professionals (PCPs). The four objectives of this study are to gain an overview of (i) the criteria important for recommending SCIs, (ii) the perceptions of both groups on the effectiveness of SCIs, (iii) the factors to consider when counseling different (high-risk) groups of smokers and (iv) the perceptions of both groups on the use of e-cigarettes as an SCI. We found a high level of agreement within groups on which smoker characteristics should be considered when recommending an SCI to smokers. We also found that PCPs display a lower degree of consensus on the effectiveness of SCIs. Both groups see a value in the use of special protocols for different (high-risk) groups of patients, but the two groups did not reach consensus on the use of e-cigarettes as a means to quit. Making an inventory of PCPs' needs regarding SCIs and their usage may provide insight into how to facilitate a better uptake in the primary care setting.

Chemical Emissions From Heated Vitamin E Acetate—Insights to Respiratory Risks From Electronic Cigarette Liquid Oil Diluents Used in the Aerosolization of Δ9-THC-Containing Products

As of February 18, 2020, the e-cigarette, or vaping, product use associated lung injury (EVALI) outbreak caused the hospitalization of a total of 2,807 patients and claimed 68 lives in the United States. Though investigations have reported a strong association with vitamin E acetate (VEA), evidence from reported EVALI cases is not sufficient to rule out the contribution of other chemicals of concern, including chemicals in either THC or non-THC products. This study characterized chemicals evolved when diluent oils were heated to temperatures that mimic e-cigarette, or vaping, products (EVPs) to investigate production of potentially toxic chemicals that might have caused lung injury. VEA, vitamin E, coconut, and medium chain triglyceride (MCT) oil were each diluted with ethanol and then tested for constituents and impurities using a gas chromatograph mass spectrometer (GC/MS). Undiluted oils were heated at 25°C (control), 150°C, and 250°C in an inert chamber to mimic a range of temperatures indicative of aerosolization from EVPs. Volatilized chemicals were collected using thermal desorption tubes, analyzed using a GC/MS, and identified. Presence of identified chemicals was confirmed using retention time and ion spectra matching with analytic standards. Direct analysis of oils, as received, revealed that VEA and vitamin E were the main constituents of their oils, and coconut and MCT oils were nearly identical having two main constituents: glycerol tricaprylate and 2-(decanoyloxy) propane-1,3-diyl dioctanoate. More chemicals were measured and with greater intensities when diluent oils were heated at 250°C compared to 150°C and 25°C. Vitamin E and coconut/MCT oils produced different chemical emissions. The presence of some identified chemicals is of potential health consequence because many are known respiratory irritants and acute respiratory toxins. Exposure to a mixture of hazardous chemicals may be relevant to the development or exacerbation of EVALI, especially when in concert with physical damage caused by lung deposition of aerosols produced by aerosolizing diluent oils.

Association between electronic nicotine delivery systems (ENDS) device and E-liquid alterations and flavor use with clinical and EVALI-like symptoms

Studies reporting clinical symptoms related to electronic nicotine delivery systems (ENDS) usage, especially types of devices and e-liquids, are sparse. The sample included 1,432 current ENDS users, ages 18-64, from a nationwide online survey conducted in 2016. ENDS use included device types, nicotine content, flavors, and e-liquid used. Outcomes included any e-cigarette, or vaping, product use-associated lung injury (EVALI)-like symptoms (e.g., cough, shortness of breath, nausea) as well as any clinical symptoms. Of the sample, 50% were female, 23% non-Hispanic (NH) White, 23% NH Black, 54% Hispanic, 18% aged 18-24, 17% LGBTQ, 41% with <$50 K income, 55% 1 + any symptoms, and 33% 1 + any EVALI-like symptoms. Cough and nausea were most prevalent among EVALI-like symptoms (27% and 7.3%, respectively). The proportion having any EVALI-like symptoms was higher in the following groups: younger, Hispanic, current smokers, and current other product users. With multiple adjustments, participants who used refillable devices, varied nicotine content, used flavored products, or made their own e-liquids were more likely to have clinical symptoms than their counterparts. For example, the odds (95% CI) of having 1 + EVALI-like symptoms in participants who used refillable devices with e-liquid pour or e-liquid cartridge replacement were 1.70 (1.13, 2.56) and 1.95 (1.27, 2.99), respectively, compared to the non-refillable group. Use of products (devices and e-liquids) that can be altered and flavored products are associated with higher odds of having clinical symptoms, including EVALI-like symptoms.

Cannabis Vaping Among Youth and Young Adults: a Scoping Review

Purpose of Review

The purpose of this review was to describe the state-of-the-literature on research specific to cannabis vaping among youth and young adults.

Recent Findings

Out of 1801 records identified, a total of 202 articles met eligibility criteria for inclusion in this review. Most of this literature (46.0% of studies) was specific to the health effects of cannabis vaping, particularly EVALI (e-cigarette and vaping associated lung injury). Other research areas identified in the review included the etiology (24.3%) and epidemiology (24.8%) of cannabis vaping, in addition to articles on regulation (8.4%) and marketing (5.5%) of the same.

Summary

Cannabis vaping is increasingly common among youth and young adults and more prevalent is settings where recreational use for adults has been legalized. The literature documents a number of negative health effects of cannabis vaping for young people, along with risk factors and reasons for the same.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40429-022-00413-y.

Modeled Respiratory Tract Deposition of Aerosolized Oil Diluents Used in Δ9-THC-Based Electronic Cigarette Liquid Products

Electronic cigarette, or vaping, products (EVP) heat liquids ("e-liquids") that contain substances (licit or illicit) and deliver aerosolized particles into the lungs. Commercially available oils such as Vitamin-E-acetate (VEA), Vitamin E oil, coconut, and medium chain triglycerides (MCT) were often the constituents of e-liquids associated with an e-cigarette, or vaping, product use-associated lung injury (EVALI). The objective of this study was to evaluate the mass-based physical characteristics of the aerosolized e-liquids prepared using these oil diluents. These characteristics were particle size distributions for modeling regional respiratory deposition and puff-based total aerosol mass for estimating the number of particles delivered to the respiratory tract. Four types of e-liquids were prepared by adding terpenes to oil diluents individually: VEA, Vitamin E oil, coconut oil, and MCT. A smoking machine was used to aerosolize each e-liquid at a predetermined puff topography (volume of 55 ml for 3 s with 30-s intervals between puffs). A cascade impactor was used to collect the size-segregated aerosol for calculating the mass median aerodynamic diameter (MMAD) and geometric standard deviation (GSD). The respiratory deposition of EVP aerosols on inhalation was estimated using the Multiple-Path Particle Dosimetry model. From these results, the exhaled fraction of EVP aerosols was calculated as a surrogate of secondhand exposure potential. The MMAD of VEA (0.61 μm) was statistically different compared to MCT (0.38 μm) and coconut oil (0.47 μm) but not to Vitamin E oil (0.58 μm); p < 0.05. Wider aerosol size distribution was observed for VEA (GSD 2.35) and MCT (GSD 2.08) compared with coconut oil (GSD 1.53) and Vitamin E oil (GSD 1.55). Irrespective of the statistical differences between MMADs, dosimetry modeling resulted in the similar regional and lobular deposition of particles for all e-liquids in the respiratory tract. The highest (~0.08 or more) fractional deposition was predicted in the pulmonary region, which is consistent as the site of injury among EVALI cases. Secondhand exposure calculations indicated that a substantial amount of EVP aerosols could be exhaled, which has potential implications for bystanders. The number of EVALI cases has declined with the removal of VEA; however, further research is required to investigate the commonly available commercial ingredients used in e-liquid preparations.

Modeling the public health impact of e-cigarettes on adolescents and adults

Since the introduction of electronic cigarettes to the U.S. market in 2007, vaping prevalence has surged in both adult and adolescent populations. E-cigarettes are advertised as a safer alternative to traditional cigarettes and as a method of smoking cessation, but the U.S. government and health professionals are concerned that e-cigarettes attract young non-smokers. Here, we develop and analyze a dynamical systems model of competition between traditional and electronic cigarettes for users. With this model, we predict the change in smoking prevalence due to the introduction of vaping, and we determine the conditions under which e-cigarettes present a net public health benefit or harm to society.

Cannabinoid Use Among Liver Transplant Recipients

The effect of cannabinoids on liver transplant outcomes is an area of active research. We aimed to investigate marijuana (MJ) and cannabidiol (CBD) use among liver transplant recipients at the University of Colorado Hospital (UCH), specifically prevalence, habits, and predictors of use. Liver transplant recipients followed at UCH with valid email addresses were sent an informed consent postcard and survey invitation. This exploratory survey was conducted using REDCap. IBM SPSS Statistics software was used for statistical analysis. Of 1227 recipients who were sent surveys, 538 people responded. On average, respondents were 59 years old, with 63.7% male and 81.7% White. Hepatitis C virus (HCV; 30.4%) and alcohol use (17.7%) were the most common etiologies of liver disease. Among respondents, 23.8% reported current MJ use. Methods of use included smoking (72.4%), ingestion (55.3%), and vaporization (31.7%). Top reasons for MJ use were recreation (56.5%), anxiety (54.8%), and pain (53.2%). Among respondents, 21.0% currently used CBD, usually in the form of creams or lotions (58.9%) and to relieve pain (84.9%) and anxiety (31.1%). In multivariable analysis, age (odds ratio [OR], 0.941; 95% confidence interval [CI], 0.923-0.959; P < 0.001), diabetes mellitus (OR, 0.357; 95% CI, 0.171-0.746; P = 0.01), HCV cirrhosis (OR, 3.949; 95% CI, 2.281-6.835; P < 0.001), alcohol-related cirrhosis (OR, 2.101; 95% CI, 1.202-3.671; P = 0.01), and current tobacco use (OR, 2.918; 95% CI, 1.065-7.990; P = 0.04) were significant predictors of MJ use. Our study shows that cannabinoid use after liver transplant is common. MJ use is associated with decreasing age, alcohol-related and HCV cirrhosis, and tobacco use. Anxiety, pain, and recreation were top reasons for its use. Transplant teams should address reasons why their patients use MJ and CBD and develop programs to mitigate anxiety and pain after transplant. Further studies are needed to examine effects of cannabinoids on liver transplant outcomes.

Environmental Factors

The acute respiratory distress syndrome (ARDS) remains a major cause of morbidity and mortality in the intensive care unit. Improving outcomes depends on not only evidence-based care once ARDS has already developed but also preventing ARDS incidence. Several environmental exposures have now been shown to increase the risk of ARDS and related adverse outcomes. How environmental factors impact the risk of developing ARDS is a growing and important field of research that should inform the care of individual patients as well as public health policy.

Pulmonary Function Testing in Patients With E-Cigarette, or Vaping, Product Use-Associated Lung Injury

In 2019 there was an outbreak of respiratory illnesses amongst people who used E-cigarettes. This phenomenon was labeled 'EVALI' which stands for "Electronic cigarette (E-cigarette), or Vaping, Product Use-Associated Lung Injury" and is a life-threatening illness of the lungs associated with E-cigarette use. It is believed to be caused by certain chemicals in E-cigarette cartridges, such as vitamin E acetate, but the exact pathophysiological mechanism is yet to be elucidated. Since 2019, the CDC has recorded over 2800 cases in the United States with over 60 deaths. Though many people recover from EVALI, the long-term implications on pulmonary health are unknown. The purpose of this retrospective study was to demonstrate the pulmonary function test (PFT) findings in a group of patients who recovered from a diagnosis of EVALI. We reviewed the cases of 23 adult patients who presented to two major academic hospitals of the Northwell Health System with confirmed EVALI and followed up in our outpatient clinics with PFTs. Most patients had significantly reduced diffusion capacity (DLCO) demonstrating loss of functioning alveolar units. Given that average follow-up was over a month after discharge, this leads us to believe that EVALI can lead to persistent lung damage. However, further follow-up would be necessary to identify the full impact of E-cigarette use on the pulmonary function. 

Electronic cigarette smoke reduces ribosomal protein gene expression to impair protein synthesis in primary human airway epithelial cells

The widespread use of electronic cigarettes (e-cig) is a serious public health concern; however, mechanisms by which e-cig impair the function of airway epithelial cells-the direct target of e-cig smoke-are not fully understood. Here we report transcriptomic changes, including decreased expression of many ribosomal genes, in airway epithelial cells in response to e-cig exposure. Using RNA-seq we identify over 200 differentially expressed genes in air-liquid interface cultured primary normal human bronchial epithelial (NHBE) exposed to e-cig smoke solution from commercial e-cig cartridges. In particular, exposure to e-cig smoke solution inhibits biological pathways involving ribosomes and protein biogenesis in NHBE cells. Consistent with this effect, expression of corresponding ribosomal proteins and subsequent protein biogenesis are reduced in the cells exposed to e-cig. Gas chromatography/mass spectrometry (GC/MS) analysis identified the presence of five flavoring chemicals designated as 'high priority' in regard to respiratory health, and methylglyoxal in e-cig smoke solution. Together, our findings reveal the potential detrimental effect of e-cig smoke on ribosomes and the associated protein biogenesis in airway epithelium. Our study calls for further investigation into how these changes in the airway epithelium contribute to the current epidemic of lung injuries in e-cig users.

JUUL and other e-cigarettes: Socio-demographic factors associated with use and susceptibility in California

This study examined which socio-demographic factors are associated with susceptibility (lack of commitment to avoid future use), past-12-month and past-30-day use of JUUL and other e-cigarettes, and reasons for and against using JUUL. An online survey of 3,075 Californians ages 15-29, including 24.3% who identified as LGBTQ, were recruited via social media in January-March 2019. Multi-level weighted logistic regression models suggest that LGBTQ participants were more likely to be susceptible to JUUL [AOR = 2.11 (1.60, 2.79) (parentheses include 95% Confidence Intervals)] and other e-cigarettes [AOR = 2.31 (1.75, 3.05)], and more likely to use JUUL [AOR = 1.27 (1.02, 1.58)] and other e-cigarettes [AOR = 1.66 (1.35, 2.05)] in the past 12 months. Susceptibility to using JUUL was more likely among adolescents (ages 15-17) [AOR = 1.72 (1.30, 2.28)] and young adults (ages 18-20) [AOR = 1.26 (1.00,1.58)] than adults (ages 21-29). At the community level, living in jurisdictions with higher median household income was associated with a higher likelihood of being susceptible to using JUUL and other e-cigarettes. Compared to non-Hispanic Whites, Asian/Pacific Islanders were less likely to use JUUL [AOR = 0.68 (0.54, 0.86)] and other e-cigarettes [AOR = 0.60 (0.48, 0.76)] in the past 12 months. Past-30-day JUUL use was more likely among males than females [AOR = 1.44 (1.11, 1.88)]. Common reasons for using JUUL were: friends' use, flavors, "safer" than cigarettes, no one will notice, and nicotine rush is greater than other devices. Common reasons against using JUUL were: harmful to self/others, contains nicotine and is addictive. E-cigarette prevention and cessation efforts should include tailored messaging for people who identify as LGBTQ and reinforce reasons for not vaping nicotine.

Longitudinal trajectories of E-cigarette use among adolescents: A 5-year, multiple cohort study of vaping with and without marijuana

E-cigarette use harms adolescent health, yet it continues to escalate rapidly among teens nationwide. This longitudinal study sought to identify and differentiate between developmental trajectories of past 30-day e-cigarette use with and without marijuana (i.e., liquid THC) across adolescence (11-19 years old). Three population-based cohorts of adolescents (n = 3907; N = 461,069) living in major metropolitan areas of Texas (Houston, Dallas-Ft. Worth, San Antonio, Austin) completed up to 9 Waves of an e-cigarette use survey, from 2014 to 2019. Growth curve models (GCMs) were used to identify average trajectories of past 30-day e-cigarette use, by cohort. Growth mixture models (GMMs) were used to investigate developmental patterns in these trajectories, by cohort. Sociodemographic differences in trajectories were also investigated. Stable trajectories of e-cigarette use with and without marijuana were identified, from 11 through 19 years of age. Trajectories varied by age of onset; frequency and escalation in use; and substance used. With one exception, all trajectories of e-cigarette use escalated with age. Moreover, age of onset and progression in use were positively related. The most problematic trajectories, corresponding to more frequent use, were observed among the younger cohorts compared to the oldest. Primary prevention is critical. Interventions to prevent the onset and progression in e-cigarette use among teens must begin early (e.g., in middle school) and be sustained throughout adolescence.

Analysis of a Vaping-Associated Lung Injury Outbreak through Participatory Surveillance and Archival Internet Data

The US Centers for Disease Control and Prevention alerted of a suspected outbreak of lung illness associated with using E-cigarette products in September 2019. At the time that the CDC published its alert little was known about the causes of the outbreak or who was at risk for it. Here we provide insights into the outbreak through analysis of passive reporting and participatory surveillance. We collected data about vaping habits and associated adverse reactions from four data sources pertaining to people in the USA: A participatory surveillance platform (YouVape), Reddit, Google Trends, and Bing. Data were analyzed to identify vaping behaviors and reported adverse events. These were correlated among sources and with prior reports. Data was obtained from 720 YouVape users, 4331 Reddit users, and over 1 million Bing users. Large geographic variation was observed across vaping products. Significant correlation was found among the data sources in reported adverse reactions. Models of participatory surveillance data found specific product and adverse reaction associations. Specifically, cannabidiol was found to be associated with fever, while tetrahydrocannabinol was found to be correlated with diarrhea. Our results demonstrate that utilization of different, complementary, online data sources provide a holistic view of vaping associated lung injury while augmenting traditional data sources.

Adolescents' Substance Use and Physical Activity Before and During the COVID-19 Pandemic

Importance

Stay-at-home policies related to the COVID-19 pandemic could disrupt adolescents' substance use and physical activity.

Objective

To compare adolescents' substance use and physical activity behaviors before and after stay-at-home restrictions.

Design, Setting, and Participants

Ongoing prospective cohort study of tobacco use behaviors among ninth- and tenth-grade students enrolled at 8 public high schools in Northern California from March 2019 to February 2020 and followed up from September 2019 to September 2020. Race/ethnicity was self-classified from investigator-provided categories and collected owing to racial/ethnic differences in tobacco and substance use.

Exposures

In California, a COVID-19 statewide stay-at-home order was imposed March 19, 2020. In this study, 521 six-month follow-up responses were completed before the order and 485 were completed after the order.

Main Outcomes and Measures

The prevalence of substance use (ie, past 30-day use of e-cigarettes, other tobacco, cannabis, and alcohol) and physical activity (active ≥5 days/week) was compared at baseline and follow-up. A difference-in-difference approach was used to assess whether changes from baseline to 6-month follow-up varied if follow-up occurred after the stay-at-home order, adjusting for baseline behaviors and characteristics. All models were weighted for losses to follow-up using the inverse probability method. Weights were derived from a logistic regression model for having a follow-up response (dependent variable), as predicted by baseline characteristics and behaviors.

Results

Of 1423 adolescents enrolled at baseline, 1006 completed 6-month follow-up (623 [62%] were female, and 492 [49%] were non-Hispanic White). e-Cigarette use declined from baseline to 6-month follow-up completed before the stay-at-home order (17.3% [89 of 515] to 11.3% [58 of 515]; McNemar χ2 = 13.54; exact P < .001) and 6-month follow-up completed after the stay-at-home order (19.9% [96 of 482] to 10.8% [52 of 482]; McNemar χ2 = 26.16; exact P < .001), but the extent of decline did not differ statistically between groups responding before vs after the stay-at-home order (difference-in-difference adjusted odds ratio, 0.84; 95% CI, 0.47-1.52; P = .58). In contrast, being physically active was unchanged from baseline if follow-up was before the order (53.7% [279 of 520] to 52.9% [275 of 520]; McNemar χ2 = 0.09; exact P = .82) but declined sharply from baseline if follow-up was after the order (54.0% [261 of 483] to 38.1% [184 of 483]; McNemar χ2 = 30.72; exact P < .001), indicating a pronounced difference in change from baseline after the stay-at-home order (difference-in-difference adjusted odds ratio, 0.49; 95% CI, 0.35-0.69; P < .001). Overall in the cohort, reported use of other tobacco, cannabis, and alcohol did not differ meaningfully before and after the order.

Conclusions and Relevance

In this cohort, a reduction in e-cigarette use occurred independently of COVID-19 stay-at-home restrictions, but persistent cannabis and alcohol use suggest continued need for youth substance use prevention and cessation support. Declining physical activity during the pandemic is a health concern.

E-cigarette, or vaping, product use associated lung injury and the risks and benefits of a thorough infectious work-up

As of February 2020, over 2800 cases of lung injury associated with vapes have been reported in all 50 states (Cullen et al., 2019) [1]. This case is about a 29-year-old female with a five-year history of vaping tetrahydrocannabinol (THC) who presented with symptoms consistent with e-cigarette, or vaping, product-use associated lung injury (EVALI). This case report is unique because this patient clinically improved on a lower dose of corticosteroids compared to other reported cases of EVALI. Additionally, this case report highlights the importance and difficulty of excluding other disease processes prior to treating patients for EVALI, particularly during the coronavirus disease 2019 (COVID-19) global pandemic.

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Patients with EVALI may experience resolution of their disease with a lower dose of systemic corticosteroids.

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EVALI is a diagnosis of exclusion that requires a thorough infectious disease workup, which may hinder timely treatment.

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While steroids have been used to treat EVALI, there are currently no evidence-based treatment guidelines for EVALI.

The Clinical Assessment of Vaping Exposure

: Vaping, the inhalation of a nicotine or tetrahydrocannabinol (THC), cannabidiol (CBD), or non-drug infused solution delivered by vaping devices, is a growing phenomenon across many segments of the US population. Complications associated with vaping are newly emerging and relatively unstudied; little guidance exists on how clinicians may best elicit information related to vaping practices and associated medical problems. This publication, therefore, provides physicians and other treatment clinicians with direction for obtaining the medical history that can guide clinical decision-making for patients at risk for adverse effects associated with vaping.

Association between electronic cigarette use and tobacco cigarette smoking initiation in adolescents: a systematic review and meta-analysis

BACKGROUND

This systematic review of prospective longitudinal primary studies sought to determine whether electronic cigarette (e-cigarette) use by teenagers who had never smoked conventional tobacco cigarettes (tobacco cigarettes) at baseline was associated with subsequently commencing tobacco cigarette smoking.

METHODS

The review followed the principles of a systematic review and meta-analysis. A key word search identified peer-reviewed articles published between 1 January 2005 and 2 October 2019 from seven bibliographic databases and one search engine. Using pre-prepared inclusion/exclusion criteria two researchers independently screened abstracts, and subsequently, full text papers. Selected articles were quality assessed in duplicate. Data on study participants characteristics, exposure and outcome measures were recorded in an adapted Cochrane Data Extraction Form. Feasibility assessment was done to detect clinical heterogeneity and choose an approach to meta-analysis. Analysis comprised pairwise random effects meta-analyses, and sensitivity and subgroup analyses.

RESULTS

From the 6619 studies identified, 14 one-off primary studies in 21 articles were suitable for inclusion. The participants ages ranged from 13 to 19 years and comprised teenagers based in Europe and North America. Nine of the 14 one-off studies, with follow-up periods between 4 and 24 months, met the criteria for inclusion in a meta-analysis of the association between ever use of e-cigarettes and subsequent initiation of tobacco cigarette use. Based on primary study adjusted odds ratios, our meta-analysis calculated a 4.06 (95% confidence interval (CI): 3.00-5.48, I2 68%, 9 primary studies) times higher odds of commencing tobacco cigarette smoking for teenagers who had ever used e-cigarettes at baseline, though the odds ratio were marginally lower (to 3.71 times odds, 95%CI: 2.83-4. 86, I2 35%, 4 primary studies) when only the four high-quality studies were analysed.

CONCLUSION

The systematic review found that e-cigarette use was associated with commencement of tobacco cigarette smoking among teenagers in Europe and North America, identifying an important health-related harm. Given the availability and usage of e-cigarettes, this study provides added support for urgent response by policymakers to stop their use by teenagers to decrease direct harms in this susceptible population group, as well as to conserve achievements in diminishing tobacco cigarette initiation.

Friendship influence moderating the effect of a web-based smoking prevention program on intention to smoke and knowledge among adolescents

PURPOSE

Web-based tobacco prevention programs for adolescents have stressed human-computer interaction, but they have not yet extensively applied social interactivity (i.e., computer-mediated or face-to-face interactions). This study examines if prior tendencies for positive social influence (PSI), negative social influence (NSI), and having friends who smoke (HFS) moderate the success of a web-based program for smoking prevention.

METHODS

Participants were 101 adolescents (aged 12-18 years) from the ASPIRE-Reactions study, a randomized controlled trial comparing a program called ASPIRE with its text-based version. Knowledge of tobacco consequences and intention to smoke were assessed at baseline and end-of-treatment. Tendency for PSI (i.e., avoid tobacco when advised by friends) and NSI (i.e., accept tobacco when offered by friends) were measured at baseline. Repeated-measures mixed-effect modeling was used for hypothesis-testing.

RESULTS

While controlling for ASPIRE effects, both NSI and PSI predicted lower intention to smoke. Adolescents with high NSI were more likely to show a group difference with respect to change in intention to smoke, but not knowledge. Although not significant, this moderation effect was observed in the expected direction with PSI, predicting intention to smoke and knowledge. HFS significantly moderated the effect of ASPIRE on knowledge. Associations with depression and internet use are also described.

CONCLUSION

The results suggest that adolescents with high tendencies for NSI may particularly benefit from web-based interventions such as ASPIRE. Also, web-based interventions may benefit from peer-to-peer interactions, boosting PSI. While current web-based programs include human-computer interaction as their main feature, this study suggests considering social interactivity.

Examining proximity exposure in a social network as a mechanism driving peer influence of adolescent smoking

BACKGROUND

Adolescent peers' influence on tobacco smoking is a dynamic process affected by close friends and other network peers. Although research has examined the influence of immediate friends on smoking behavior (i.e., by cohesion exposure), the influence of all peers according to closeness (i.e., proximity exposure) remains unknown. This study introduces proximity exposure as a potential driver of peer influence.

METHODS

Using the Teenage Friends and Lifestyle Study dataset, we examined 160 adolescents followed for 3 years and assessed their friendship ties and health behavior. Proximity exposure was calculated as the proportion of an individual's network peers who smoked, considering their distance from the individual. Path analysis was conducted with cross-lagged models testing the effect of proximity exposure on smoking frequency over time.

RESULTS

Among nonsmokers without cohesion exposure (n = 80), proximity exposure at year 1 was significantly associated with smoking initiation by year 3. Path analysis (n = 160) indicated that smoking at year 1 predicted cohesion exposure by year 3. When proximity exposure was included, the effect of smoking on cohesion exposure was lost. Early smoking predicted future proximity exposure. However, the predictive value of early proximity toward future smoking was stronger.

CONCLUSION

These results suggest that proximity exposure can predict smoking even among nonsmokers without direct ties to friends who smoke. In support of a peer selection hypothesis, early smoking predicted friendship formation with smokers through cohesion. Conversely, in support of a peer influence hypothesis, proximity exposure predicted smoking. Researchers may consider developing interventions that decrease proximity exposure among adolescents.

Compositional Differences in the Oral Microbiome of E-cigarette Users

Electronic (e)-cigarettes have been advocated as a safer alternative to conventional tobacco cigarettes. However, there is a paucity of data regarding the impact of e-cigarette aerosol deposition on the human oral microbiome, a key component in human health and disease. We aimed to fill this knowledge gap through a comparative analysis of the microbial community profiles from e-cigarette users and healthy controls [non-smokers/non-vapers (NSNV)]. Moreover, we sought to determine whether e-cigarette aerosol exposure from vaping induces persistent changes in the oral microbiome. To accomplish this, salivary and buccal mucosa samples were collected from e-cigarette users and NSNV controls, with additional oral samples collected from e-cigarette users after 2 weeks of decreased use. Total DNA was extracted from all samples and subjected to PCR amplification and sequencing of the V3-V4 hypervariable regions of the 16S rRNA gene. Our analysis revealed several prominent differences associated with vaping, specific to the sample type (i.e., saliva and buccal). In the saliva, e-cigarette users had a significantly higher alpha diversity, observed operational taxonomic units (OTUs) and Faith's phylogenetic diversity (PD) compared to NSNV controls, which declined with decreased vaping. The buccal mucosa swab samples were marked by a significant shift in beta diversity between e-cigarette users and NSNV controls. There were also significant differences in the relative abundance of several bacterial taxa, with a significant increase in Veillonella and Haemophilus in e-cigarette users. In addition, nasal swabs demonstrated a trend toward higher colonization rates with Staphylococcus aureus in e-cigarette users relative to controls (19 vs. 7.1%; p = n.s.). Overall, these data reveal several notable differences in the oral bacterial community composition and diversity in e-cigarette users as compared to NSNV controls.

Lessons from the public health responses to the US outbreak of vaping-related lung injury

AIM

To describe an outbreak of lung injuries in 2019 among people who vaped in the United States (type of injuries, people afflicted, substances vaped and cause of the injuries) and to analyse critically the regulatory responses of public health authorities and the media reporting of the outbreak.

METHODS

Case studies of the reporting of the e-cigarette or vaping product use associated lung injury (EVALI) outbreak. We examined data on the number of cases of lung injury provided by the US Centers for Disease Control (CDC), public advice on the causes of the outbreak provided by the CDC and the Food and Drug Administration (FDA), major media reports of the outbreak and proposed regulatory responses by governments in the United States, Australia and the United Kingdom.

RESULTS

The CDC initially suggested that the cause of the outbreak was nicotine vaping because the outbreak followed a large increase in nicotine vaping among US adolescents. Case-control studies revealed that the majority of cases had vaped illicit cannabis oils that were contaminated by vitamin E acetate. The CDC's public advice and the media were slow to report the evidence on the role of cannabis vaping. Popular government regulatory proposals-bans on sales of nicotine flavours and vaporizers-were based on the assumption that nicotine vaping was the cause of the outbreak.

CONCLUSIONS

Media reporting in the United States, Australia and the United Kingdom of the US Centers for Disease Control's analysis of the causes of the e-cigarette or vaping product use associated lung injury outbreak contributed to regulatory over-reactions to nicotine vaping by the public health community.

Evaluating the psychometric properties of the e-cigarette barriers to cessation scale

Evidence suggests that electronic cigarette (e-cigarette) users have difficulty quitting e-cigarettes. The Electronic Cigarette Barriers to Cessation Scale (E-BCS) was developed to assess barriers to cessation among e-cigarette users. Yet, no work has evaluated the psychometric properties of the E-BCS. The current study utilized data from two independent samples of adult e-cigarette users to evaluate the psychometric properties and structure of the E-BCS. In Study 1, competing models of the E-BCS were evaluated, and initial construct validity and reliability were explored using data from 599 adult e-cigarettes users (52.3% female, M_age = 35.16 years, SD = 10.30). Results supported a unidimensional structure for the E-BCS comprised of 18 items. In Study 2, the unidimensional structure of the 18-item E-BCS and construct validity were evaluated among a sample of 516 current e-cigarette using adults (52.3% female; M_age = 34.74, SD = 11.37). Results confirmed the unidimensional structure, measurement invariance across sex, and construct validity across related e-cigarette behavior constructs and psychopathology for the E-BCS. These findings suggest that the E-BCS is a potentially useful clinical instrument for measuring barriers that may interfere with e-cigarette cessation.

Identification of newly formed toxic chemicals in E-cigarette aerosols with Orbitrap mass spectrometry and implications on E-cigarette control

The increasing use of electronic nicotine delivery systems (ENDS) is of concern due to multiple emerging adverse health effects. Most analyses of the harmful chemicals of ENDS have targeted metals or carbonyls generated by thermal decomposition of carrier liquids such as propylene glycol. However, new complex compounds not routinely identified and with unknown health consequences could be formed. ENDS aerosol samples were collected by the direct aerosol droplet deposition method. Untargeted analysis was performed using Orbitrap mass spectrometry with high mass accuracy. We identified more than 30 "features" in the aerosol characterized by pairs of the mass-to-charge ratio "m/z" of the compound and the retention time. We identified several compounds containing nicotine and propylene glycol (NIC-PG), whose abundance relative to nicotine increased along with vaping power used. On the basis of the prediction by the Environmental Protection Agency Toxicity Estimation Software Tool, these compounds exert developmental toxicity. In addition, a nitrogen-containing compound, likely tributylamine (a known lung irritant), was identified based on the molecular weight. This compound has not been previously identified in ENDS e-liquids and aerosols. ENDS produce not only small toxic compounds such as aldehydes, but also large complex toxic compounds such as NIC-PG. Predicted development toxicity for NIC-PG is concerning for fetal development in pregnant women who use ENDS, children exposed to secondhand or thirdhand ENDS aerosols, and teenage ENDS users whose brains are still developing. The strong positive association between NIC-PG levels and ENDS power output supports regulating high-powered ENDS.

Electronic Cigarettes and Vaping-Associated Lung Injury (EVALI): A Rural Appalachian Experience

Background: Electronic cigarette use has increased dramatically since their introduction in 2007. Respiratory complications, particularly lipoid pneumonia, have been reported as early as 2012. An outbreak of pulmonary injury in 2019 has been reported in patients using vaping products.Research Question: To describe a rural Appalachian tertiary center's experience of EVALI and to identify novel mechanisms of pulmonary injury patterns.Study Design and Methods: We present a consecutive case series of 17 patients admitted to our rural, academic, tertiary care institution with EVALI from August 2019 to March 2020. Demographics, baseline characteristics, co-morbidities, vaping behavior, and hospital course were recorded. Broncho-alveolar lavage specimens were assessed for lipid-laden macrophages and hemosiderin-laden macrophages with stains for Oil-Red-O (n = 15) and Prussian Blue (n = 14) respectively.The patient volunteered e-liquid materials (n = 6), and vapors were analyzed using a proton transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS) to describe the chemical profile. Post-discharge interviews were conducted.Results: The most common CT finding was bilateral ground-glass opacities with a predilection for lower lung zones. The most frequent pulmonary injury pattern was lipoid pneumonia. The majority of EVALI patients were critically ill requiring ventilation or ECMO. The most severely ill patients were noted to be positive for iron stains in macrophages and showed higher volatile organic compound (VOC) levels in chemical analysis.Interpretation: Based on our experience, EVALI in rural Appalachia presented with relatively severe respiratory failure. Worse outcomes appear to be correlated to high levels of VOCs, iron deposition in lungs, and concomitant infection.

The Cardiovascular Effects of Electronic Cigarettes

PURPOSE OF REVIEW

Electronic cigarettes (e-cigarettes) are gaining rapid popularity among all age groups, especially among youth. They have evolved into technologically advanced devices capable of delivering nicotine concentration and other substances. In addition to nicotine, e-cigarettes' constituents possess variety of toxic chemicals that have adverse effects on human body.

RECENT FINDINGS

In recent years, steady downward trend in tobacco usage has been observed; however, e-cigarette use is on upward trend. E-cigarettes are advertised as "safer" alternatives to conventional smoking and as an aid to smoking cessation. Emerging studies have, however, shown that e-cigarettes have harmful effects on the cardiovascular system and that most of the e-cigarette users are dual users, concurrently using e-cigarettes and smoking conventional cigarettes. Despite a gap in clinical studies and randomized trials analyzing adverse cardiovascular effects of e-cigarette use, the existing literature supports that different constituents of e-cigarettes such as nicotine, carbonyls, and particulate matters carry potential risk for cardiovascular diseases (CVD) on its users.

E-cigarette, or Vaping, Product Use-Associated Lung Injury: Looking Back, Moving Forward

Implications In this commentary, we describe the evidence-based approach used to identify the primary cause of EVALI and to curb the 2019 outbreak. We also discuss future research opportunities and public health practice considerations to prevent a resurgence of EVALI.