Review of Health Consequences of Electronic Cigarettes and the Outbreak of Electronic Cigarette, or Vaping, Product Use-Associated Lung Injury.

Electronic cigarettes (e-cigarettes) are battery-operated devices to insufflate nicotine or other psychoactive e-liquid aerosols. Despite initial claims of e-cigarettes as a nicotine-cessation device, aggressive marketing of e-cigarettes has led to an explosion in adolescents' and young adults' use over the last few years. Coupled with a lack of adequate investigation and regulation of e-cigarettes, the USA is facing an outbreak of e-cigarette, or vaping, product use-associated lung injury (EVALI) starting in mid-2019. While little long-term health hazard data are available, the components and constituents of e-cigarettes may adversely impact health. Propylene glycol and glycerin are humectants (water-retaining excipients) that generate pulmonary irritants and carcinogenic carbonyl compounds (e.g., formaldehyde, acetaldehyde, and acrolein) when heated in e-cigarettes. Metals contained in heating coils and cartridge casings may leach metals such as aluminum, chromium, iron, lead, manganese, nickel, and tin. Flavoring agents are considered safe for ingestion but lack safety data for inhalational exposures. Diacetyl, a common buttery flavoring agent, has known pulmonary toxicity with inhalational exposures leading to bronchiolitis obliterans. In 2019, clusters of lung injury associated with e-cigarette use were identified in Wisconsin and Illinois. Patients with EVALI present with a constellation of respiratory, gastrointestinal, and constitutional symptoms. Radiographically, patients have bilateral ground glass opacifications. As of February 18, 2020, the Centers for Disease Control has identified 2807 hospitalized patients diagnosed with either "confirmed" or "probable" EVALI in the US. Currently, vitamin E acetate (VEA) used as a diluent in tetrahydrocannabinol vape cartridges is implicated in EVALI. VEA cuts tetrahydrocannabinol oil without changing the appearance or viscosity. When inhaled, pulmonary tissue lacks the mechanism to metabolize and absorb VEA, which may lead to its accumulation. While most EVALI patients were hospitalized, treatment remains largely supportive, and use of corticosteroids has been associated with clinical improvement. The outbreak of EVALI highlights the need for regulation of e-cigarette devices and e-liquids. Clinicians need to be aware of the health hazards of e-cigarettes and be vigilant in asking about vaping.

Severe E-Cigarette, or Vaping, Product Use Associated Lung Injury Requiring Venovenous Extracorporeal Membrane Oxygenation.

OBJECTIVES: To report a severe case of e-cigarette or vaping product use-associated lung injury with complex course requiring venovenous extracorporeal membrane oxygenation. DESIGN: Case report. SETTING: PICU in an academic medical center. PATIENTS: A 16-year-old girl presenting with gastrointestinal and respiratory symptoms was admitted to our PICU after having progressive respiratory failure and bilateral pulmonary ground-glass opacities on chest CT. INTERVENTIONS: Venovenous extracorporeal membrane oxygenation MEASUREMENTS AND MAIN RESULTS:: After extensive infectious workup was unrevealing, she reported a history of vaping e-cigarette containing either nicotine or delta-9-tetrahydrocannabinol oil prior to symptom onset. She was given a presumptive diagnosis of e-cigarette or vaping product use-associated lung injury. The PICU team in consultation with pulmonology and medical toxicology started high-dose IV methylprednisolone 1 mg/kg bid. Despite initial improvements, she continued to require positive pressure ventilation and developed pneumomediastinum with progression to tension pneumothoraces and a persistent air leak. Unable to maintain her oxygenation, she was placed on venovenous extracorporeal membrane oxygenation for a prolonged course and had a tracheostomy placement. The clinical course, severity, and range of interventions in affected patients around the country have varied widely. Respiratory symptoms have been the most severe, but the constellation of symptoms in e-cigarette or vaping product use-associated lung injury include constitutional symptoms (fevers, weight-loss) and gastrointestinal symptoms (nausea, vomiting, diarrhea). In many cases, steroid use led to rapid clinical improvements. However, other cases with severe illness, like our patient, necessitated high-dose IV steroids, intubation, and venovenous extracorporeal membrane oxygenation. The underlying etiology and pathophysiology of e-cigarette or vaping product use-associated lung injury remains unknown. The Centers for Disease Control and Prevention in conjunction with state/local health departments and the Food and Drug Administration is actively investigating the outbreak. CONCLUSIONS: Clinicians need to be aware of the current outbreak of e-cigarette or vaping product use-associated lung injury and ask about vaping in patients presenting with gastrointestinal and respiratory symptoms. Treatment options are anecdotal and necessitate a multidisciplinary approach.