By Dr. Liji Thomas, MD

The US has witnessed a spate of patients presenting with acute lung injury associated with e-cigarettes or vaping product use. A new study published in the journal JAMA Internal Medicine shows the pattern of the outbreak in California where recreational cannabis use is legal and which has among the maximum cases of the strange illness.

Vaping is the practice of using electronic or e-cigarettes, which has exploded into prominence among the younger generation in the US. The basic principle is the heating of the liquid within the device’s canister to produce an aerosol that is then inhaled. The fluids may contain one or more of a variety of ingredients, including nicotine, various cannabis constituents, flavorings, and other chemicals. The chief danger of vaping is the lack of regulation.

From August 2019 to date, over 2,700 patients have been reported with e-cigarette, or vaping, associated lung injury (EVALI) in all the states of the US.

The study
The investigators used data on 160 patients admitted in hospital with EVALI between August 7 and November 8, 2019. The patient data came from treating doctors who reported them to the local health department, which in turn transmitted the information to the California Department of Public Health.

The data included epidemiologic and laboratory data on the patients, who underwent interviews based on a standard format. The questions assessed the types of vaping products used, how often they were used, and how the patients acquired them. The vaping products provided for investigation by some of the patients also underwent testing for active ingredients.

The results
The investigators found that among 160 patients with EVALI of whom approximately 60% were male, with a median age of 27 years, about half received intensive care, and a little less than a third had to be put on mechanical ventilation. Four of them died in hospital.

The study
The investigators used data on 160 patients admitted in hospital with EVALI between August 7 and November 8, 2019. The patient data came from treating doctors who reported them to the local health department, which in turn transmitted the information to the California Department of Public Health.

The data included epidemiologic and laboratory data on the patients, who underwent interviews based on a standard format. The questions assessed the types of vaping products used, how often they were used, and how the patients acquired them. The vaping products provided for investigation by some of the patients also underwent testing for active ingredients.

The results
The investigators found that among 160 patients with EVALI of whom approximately 60% were male, with a median age of 27 years, about half received intensive care, and a little less than a third had to be put on mechanical ventilation. Four of them died in hospital.

Of the 160 patients, 86 were subject to interview. Among this group, 83% said they vaped products containing tetrahydrocannabinol (THC), which is the psychoactive component of cannabis. 43% had vaped products containing cannabidiol (CBD), another principal constituent of the same plant. 47% had vaped products containing nicotine.

Of the 87 products that showed only the presence of THC, over 90% were prefilled cartridges but only 48% of nicotine-only cartridges.

Where did they get the products from? 75% of them had got their THC-containing vaping products from friends, unlicensed vendors, and other informal sources.

87 vaping products tested were obtained from only 24 of the 160 patients. The results showed that 56% had THC. 84% of this subset had vitamin E or vitamin E acetate, but none of the nicotine-containing subset. Flavorings were added to 56% and 76% of the THC- and nicotine-containing products, respectively.

The median period from the last use of the vaping product to the onset of EVALI symptoms and hospital admission was 3 and 5 days, respectively. About 40% had smoked or were smoking conventional cigarettes as well. Common symptoms included cough, shortness of breath, and fever with chills, besides one or more gut symptoms. Laboratory criteria of intense inflammation were present.

Implications
The pattern of use of vaping product by type, as well as the clinical features of the patients, were broadly similar to the overall trends seen in other US states. It is noteworthy that though California permits the recreational use of cannabis by adults, most of the THC-containing products came from informal sources. The authors emphasize, “These findings underscore the importance for all clinicians, including outpatient health care providers, to consider EVALI in patients with a history of vaping who present with typical findings of infection, as well as monitor their clinical course and respiratory status closely for decompensation, in accordance with CDC guidance.”

Secondly, more female than male patients seemed to require ICU admission, suggesting that females fare worse on exposure to tobacco smoke and other environmental toxins.

Thirdly, depression, and anxiety are the most common illnesses found in patients with EVALI in California, which could indicate that such patients vape at higher rates or that such patients are at higher risk of EVALI.

Again, vitamin E or vitamin E acetate proved to be present in most products containing THC.

The study concludes, “The California Department of Public Health recommends that individuals refrain from using any vaping or e-cigarette products, particularly THC-containing products from informal sources, while this investigation is ongoing.”

Journal reference:
Heinzerling A, Armatas C, Karmarkar E, et al. Severe Lung Injury Associated With Use of e-Cigarette, or Vaping, Products—California, 2019. JAMA Intern Med. Published online March 06, 2020. doi:10.1001/jamainternmed.2020.0664