Vaping-associated pulmonary injury

To reduce the risk of EVALI public health agencies such as CDC have recommended several precautionary measures. Avoidance of e-cigarette or vaping products containing tetrahydrocannabinol (THC) has been emphasized, particularly those obtained from informal or unregulated sources, which have been strongly linked to EVALI cases. Vitamin E acetate, an additive sometimes used in THC vaping liquids, has also been identified as a primary chemical of concern due to its association with lung injury. Health authorities further advise that all vaping products should be purchased from licensed and reputable retailers to minimize the risk of contamination or mislabeling. Educational campaigns targeting adolescents and parents have been implemented to raise awareness of the health risks associated with vaping, in an effort to reduce youth initiation. In addition, public health experts have advocated for policy measures such as age restrictions and bans on flavored vaping products to help curb youth access and use. ==Signs and symptoms==

Commonly reported symptoms include shortness of breath, cough, fatigue, body aches, dizziness, fever, nausea, vomiting, diarrhea, weight loss, chest pain, abdominal pain, and chills. Symptoms can initially mimic common pulmonary diagnoses like pneumonia, but individuals typically do not respond to antibiotic therapy. In some patients, gastrointestinal symptoms can precede respiratory symptoms. Individuals typically present for care within a few days to weeks of symptom onset. At the time of hospital presentation, the individual is often hypoxic and meets systemic inflammatory response syndrome (SIRS) criteria, including fever. Physical exam can reveal rapid heart rate or rapid breathing. Auscultation of the lungs tends to be unremarkable, even in patients with severe lung disease. In some cases, the affected individuals have progressive respiratory failure, leading to intubation. Several affected individuals have needed to be placed in the intensive care unit (ICU) and on mechanical ventilation. Time to recovery for hospital discharge has ranged from days to weeks. ==Possible causes==

No single cause of these illnesses has been established . • MCT oil: In vivo mouse exposure of inhaled MCT oil induces acute pulmonary inflammation and toxicity. • Vitamin E acetate: which had been used as a thickening agent by illicit THC vape cartridge manufacturers. The CDC states that vitamin E acetate is a very strong culprit of concern in VAPI, having been found in 29 out of 29 lung biopsies tested from ten different states, but evidence is not yet sufficient to rule out contribution of other chemicals of concern to VAPI. • Psychoactive substances: • CBD is one among the most suspected ingredients involved in VAPI. Conversion of CBD to THC can occur when CBD is heated to temperatures between 250–300 °C, potentially leading to its partial transformation into THC. • Synthetic cannabinoids: Can cause pneumonia via CB1 activation. Synthetic cannabinoids are increasingly offered in e-cigarette form as "c-liquid". • Unknown chemicals • THC cartridges (not THC itself): An outbreak of lipid pneumonia occurred in North Carolina between July–August 2019 Pathogens Products have been found to be contaminated with fungi and bacteria, which may cause fungal pneumonia, and bacterial pneumonia respectively. Nicotine-containing e-liquids are extracted from tobacco that may contain impurities. Tobacco-specific impurities such as cotinine, nicotine-N'-oxides (cis and trans isomers), and beta-nornicotyrine are believed to be the result of bacterial action or oxidation during the extracting of nicotine from tobacco. Re-used vapes, and vape sharing Infectious diseases by pathogens uncleaned vapes and/or vape sharing: • Bacterial pneumonia. • Fungal pneumonia • Viral pneumonia (from vape sharing). • SARS-CoV-2: Shared vaping devices are linked to COVID-19. Heat In addition to vaping, some individuals have also experienced VAPI through "dabbing". Dabbing uses a different type of device to heat and extract cannabinoids for inhalation. It is a process that entails superheating and inhaling particles into the lungs that contain THC and other types of cannabidiol plant materials. == Mechanism ==

|alt=Schematic of a typical e-cigarette with a cartridge containing nicotine dissolved in propylene glycol. Vaping refers to the practice of inhaling an aerosol from an electronic cigarette device, VAPI appears to be a type of acute lung injury, similar to acute fibrinous pneumonitis, organizing pneumonia, or diffuse alveolar damage. VAPI appears to be a general term for various causes of acute lung damage due to vaping. There is no evidence of an infectious etiology causing VAPI. == Diagnosis ==

High clinical suspicion is necessary to make the diagnosis of VAPI. There are non-specific laboratory abnormalities that have been reported in association with the disease, including elevations in white blood cell count (with neutrophilic predominance and absence of eosinophilia), transaminases, procalcitonin, and inflammatory markers. In the few cases in which lung biopsies were performed, the results were consistent with acute lung injury and included a broad range of features, such as acute fibrinous pneumonitis, diffuse alveolar damage, lipid-laden macrophages, and organizing pneumonia. Differential diagnosis As VAPI was, as of October 2019, a diagnosis of exclusion, a variety of respiratory diseases must be ruled out before a diagnosis of VAPI can be made. • Diffuse alveolar hemorrhage • Giant cell pneumonitis • Hypersensitivity pneumonitis • Lipoid pneumonia • Organizing pneumonia • Respiratory bronchiolitis interstitial lung disease The use of imaging and other diagnostic modalities, including chest CT, bronchoscopy with bronchoalveolar lavage, and lung biopsy, may provide additional information to determine the presence of these processes and potentially establish a definitive diagnosis, but are generally not performed unless clinically indicated. == Treatment ==

, the CDC has published updated interim guidance based on the most current data to provide a framework for healthcare providers in their management and follow-up of persons with symptoms of VAPI. Among 140 cases reported nationally to the CDC that received corticosteroids, 82% of patients improved. Special consideration should be given to high-risk patients such as the elderly, those with a history of cardiac or lung disease, or pregnant individuals. Follow-up care Due to reports of relapse during corticosteroid tapers after hospitalization, the CDC recommends scheduling a follow-up visit no later than one to two weeks after discharge from inpatient hospital treatment for VAPI, with considerations for performing pulse-oximetry testing and repeat CXR. Public health recommendations The CDC and the FDA recommend that people not use e-cigarettes or other vaping products that contain THC, particularly products purchased off the street or obtained from informal sources like friends, family, or online sellers. In addition, CDC recommends that individuals not modify or add any substances to e-cigarettes or other vaping products that are not intended by the manufacturer. == Epidemiology ==

The outbreak of vaping-related lung injuries in 2019 and 2020 mainly affected young people, primarily in the United States. , there have been 2,758 cases of VAPI A number of other probable cases have been reported in British Columbia and New Brunswick as of October 2019. In September 2019, a US Insurance Journal article stated that at least 15 incidents of vaping related illnesses have been reported worldwide prior to 2019, occurring from Guam to Japan to the UK to the US. One lipoid pneumonia-related death in the UK was associated with e-cigarettes in 2010. Medical officials in continental Europe have reported two cases serious medical problems related to vaping products, one early case related to e-cigarettes documented in Northern Spain in 2015 and a second in Belgium in 2019. Since many of the cases in North America were traced to THC cartridges as well as the use of e-cigarette vape products, but THC remains illegal in European countries, the disease burden related to vaping has been significantly lower in Europe despite the prevalence of e-cigarette use. Before the outbreak, one lipoid pneumonia-related death in the UK was associated with e-cigarettes in 2010. after developing pneumonia His doctor stated Pauwaert's fatal lung infection probably resulted from the CBD vapor. Pauwaert's CBD oils were tested for vitamin E at the Saint-Luc Hospital in November 2019. "Vitamin E (alpha tocopherol) and vitamin E acetate were not detected in the vaping fluid by ultraperformance liquid chromatography coupled with UV detection." The death is under investigation by the Brussels Public Prosecutor's Office. A friend of Pauwaert's was also hospitalized with the identical symptoms after using the same type of e-cigarette, but he survived. The first case of a vaping-related lung illness in the Philippines was reported in November 2019. == Footnotes ==