The use of e-cigarettes has surged worldwide since 2000.1, 2 E-cigarettes are devices that allow users to aerosolise (vape) liquid, which can contain nicotine or other substances, and are sometimes flavoured (e-liquid).3 Since their introduction in 2007, the USA has seen an increase in number of e-cigarette users and in vaping of non-nicotine liquids, such as tetrahydrocannibidiol (THC), cannabidiol (CBD), and other unknown substances.3, 4
Many e-cigarette formulations come in attractive flavours to appeal to young adults and teenagers who tend to experiment and modify the product being vaped and the vaping method itself. New methods of inhalation, such as dabbing, have changed the content and properties of the compounds delivered to the pulmonary system. Dabbing is defined as the “consumption of cannabis whereby a cannabis concentrate is volatilised via application to a hot platform (holder) and the vapour is subsequently passed through a water pipe and inhaled by the end user”.5 The use of a metal platform during dabbing introduces the risk of inhaling solder, rust, and benzene, which are released at higher temperatures.3, 6, 7
Research in context
Evidence before this study
We first searched PubMed on Sept 10, 2019, with the search terms “e-cigarette”OR “e-cigarettes”OR “vaping” AND “pulmonary disease”. We have been repeating this search to ensure we have included the most relevant and up-to-date information. This search revealed several case reports or case series detailing other cases of e-cigarette, or vaping, product use associated lung injury (EVALI). The US Centers for Disease Control and Prevention (CDC) has been tracking cases nationally and provided clinical guidance via its website and series of publications in the Morbidity and Mortality Weekly Report (MMWR). This guidance gave helpful information regarding the presenting symptoms of cases and the types of exposures patients encountered. Current data on EVALI are limited by challenges in accurate patient and provider reporting in part due to a lack of a standardised algorithm for workup and management of this condition. We independently developed a clinical algorithm for the diagnosis, medical management, and reporting of EVALI based upon our case series of 12 patients reported presently, as well as the emerging information on this outbreak available statewide and nationally.
Added value of this study
To our knowledge, this is the first study presenting a clinical practice algorithm meant for direct patient care of EVALI. The current case definition and clinical guidance available from CDC provides useful general principles, which has been enhanced presently through the experience we have gained in the 12 patient case series. We present a practical algorithm for efficient screening, diagnosis, and medical management of EVALI. This case series also highlights the important challenge of post hospitalisation follow up on patients and the degree to which the severe changes in imaging and symptoms can improve with the cessation of vaping and systemic corticosteroids (in severe cases).
Implications of all the available evidence
A significant proportion of the EVALI cases reported here had exposure to aerosolised tetrahydrocannabinol oil, also consistent with national reports by the CDC. Most patients improved within 1–2 weeks of initial presentation after vaping cessation and administration of systemic corticosteroids when needed. Our clinical practice algorithm is similar in content to the recommendations provided by the CDC, though our algorithm focuses on vaping activity within the past 30 days and is arranged to allow for efficient exclusion of cases that bear no similarity to our current understanding of EVALI. Further research is needed to identify the inciting toxins of EVALI, underlying pathophysiology behind acute hypoxaemic respiratory failure, and the susceptibility of hospitalised individuals.
One of the most popular methods of vaping involves a cartridge-based device normally filled with nicotine salts to deliver an aerosol to the user.8 Although cartridge-based systems are normally a closed non-modifiable system, users can modify the liquid composition within the cartridges. For the third-generation and fourth-generation refillable tank-based systems, users can enhance battery power and add any liquid that they choose. Any modification to either the e-liquid or the device itself has the potential to substantially change the chemical profile of the aerosol created.
Lung disease related to vaping has been previously documented mainly via isolated case reports with varied presentations, including mechanical injury (spontaneous pneumothorax), pneumonias (organising, eosinophilic, and lipoid), or hypersensitivity pneumonitis without any single uniting entity.9, 10 Additionally, some additives have been shown to cause oxidative stress on lung epithelium.5
Since June, 2019, health-care professionals have documented 1888 cases of acute lung injury related to vaping in the USA.11 Presentations range from mild dyspnoea to acute hypoxaemic respiratory failure requiring mechanical ventilation, and have been associated with the use of THC-containing e-liquids among other types.11 Despite maximal medical therapy, 37 patients have died.12, 13, 14, 15 The accumulation of cases of e-cigarette, or vaping, product use associated lung injury (EVALI) has attracted the attention of the general public, elected public officials, and law makers.16 Given the recency of these cases, there is no evidence-based approach to the diagnosis and management of patients who present with a history of vaping and dyspnoea. With the vast expansion of available devices and liquids (including THC oil), it is not surprising that the heterogeneity in presentation and case severity has in turn increased in the USA.17 With the strict regulations on e-liquids and e-cigarettes present in other countries, such as the UK, the risk of a similar outbreak of illness is likely to be lower; however, at least one case has been reported of lipoid pneumonia due to vaping.18
The presentation of a respiratory illness without any other known factors except vaping history leaves a broad differential diagnosis to consider. In this article, we summarise the clinical presentations of patients with probable and confirmed EVALI seen at a single academic medical centre, with a focus on diagnostic testing and clinical management. Additionally, we describe how coordination of efforts between multiple departments within the institution, the New York State Department of Health, and the New York City and Upstate New York Poison Control Centers has led to a consensus on testing and work up of patients in New York State.