Lipoid Pneumonia from Vaping
Electronic cigarettes (e-cigarettes) are electronic nicotine delivery systems. They were patented in the United States in 2005. Since then, their popularity has exploded. Most e-cigarettes are airflow-activated, battery powered atomizers. Inhaling on the mouthpiece activates an airflow sensor, which triggers a battery powered atomizer to heat a liquid solution to approximately 55 °C and produce a vapor containing micro-droplets of nicotine. The process of inhaling nicotine vapor into the lungs is referred to as vaping. For this reason, they are sometimes referred to as vape pens.
Many people have decided to vape instead of smoke tobacco because they perceive vaping to be healthier, cleaner and cheaper than smoking. In addition, e-cigarettes circumvent smoke-free policies in many workplaces. Nearly one-third of e-cigarette users have never smoked tobacco cigarettes. The popularity of e-cigarettes has the potential to reverse the gains achieved in the public campaign against smoking.
E-cigarettes are not currently subject to regulation by the FDA. E-cigarette refill liquids typically contain glycerol or propylene glycol, nicotine, and flavoring, but ingredients and concentrations can vary by brand. Some refills are labeled with a nicotine concentration while others use a low-medium-high designation. Nicotine concentrations vary widely and often do not match the concentration stated on the label. Some refills contain high concentrations of other tobacco alkaloids such as cotinine and anabasine.
Cartridges can be purchased in stores or on the street. Cartridges containing cannabinoids such as marijuana, THC, THC concentrate, CBD, CBD oil, synthetic cannabinoids, hash oil, and Dank vapes are also available. Aerosols produced by e-cigarettes may contain other harmful substances including heavy metals such as lead, volatile organic compounds, ultrafine particles, or chemicals used for cleaning the device.
CDC is currently investigating 380 confirmed and probable cases of acute pulmonary disease related to vaping. Six patients have died. Cases have been reported from 36 states and one U.S. territory. The latest death, reported on Sept. 10, involved an adult residing in Kansas.
Patients have typically experienced several days of worsening dyspnea, nausea, vomiting, abdominal discomfort and fever. Examination has revealed tachypnea with increased work of breathing, hypoxemia (pulse oximetry <90% on room air), and bilateral lung infiltrates on chest x-ray. White blood cell count is elevated, and the differential count shows a neutrophilic predominance and absence of eosinophilia. Blood and sputum cultures have been negative for bacterial pathogens and tests for influenza,Mycoplasma,andLegionellahave been negative.
Computed tomography of the chest demonstrated diffuse basilar-predominant infiltrates with a range of “ground glass” opacities and nodular or “tree-in-bud” infiltrates. Bronchoalveolar lavage fluid contained neutrophils, lymphocytes, and vacuole-laden macrophages but no evidence of hemorrhage and eosinophilia. Cytology stained with oil red O demonstrated the presence of numerous lipid laden alveolar macrophages. Based on all of these findings, a diagnosis of acute exogenous lipoid pneumonia was made.
Patients have not responded to antibiotics but have improved within 24 to 72 hours after treatment with intravenous methylprednisone (120 mg–500 mg daily).
Acute lipoid pneumonia may be caused by inhalation of aerosolized oils. Deposition of this oil in distal airways and alveoli incites inflammation that impairs gas exchange. Presently it is not known whether the intracellular lipid is exogenous from inhaled oils or endogenous from altered lipid metabolism.
References
Davidson K, Brancato A, Heetderks P, et al. Outbreak of Electronic-Cigarette–Associated Acute Lipoid Pneumonia — North Carolina, July–August 2019. MMWR Morb Mortal Wkly Rep 2019;68:784–786. DOI: http://dx.doi.org/10.15585/mmwr.mm6836e1
Schier JG, Meiman JG, Layden J, et al. Severe Pulmonary Disease Associated with Electronic-Cigarette–Product Use — Interim Guidance. MMWR Morb Mortal Wkly Rep 2019;68:787–790. DOI: http://dx.doi.org/10.15585/mmwr.mm6836e2
