An ongoing outbreak of lung injury associated with e-cigarettes or vaping (also known as E-VALI or VALI) has been reported in the USA, starting in March, 2019, and including 1888 cases as of Oct 29, 2019.1
An initial case series of 53 patients described severe acute lung injury in those who had vaping exposure in the past 90 days.2 The cause of lung injury associated with e-cigarettes or vaping is still unknown, and thus the original case definition described in the case series remains the basis for diagnosing the condition—namely, lung injury associated with e-cigarettes or vaping is a clinical diagnosis that comprises use of an e-cigarette (ie, vaping) in the 90 days before symptom onset, pulmonary infiltrates on plain chest radiograph or chest CT, and absence of another known cause, such as infection.2
Although the cause of lung injury associated with e-cigarettes or vaping remains unclear, patterns consistent with toxic inhalational pulmonary injury suggest direct injury rather than an infectious cause.1, 3 Lipoid pneumonia due to vaping has been previously reported,4 and initial reports of this outbreak have reported lipid laden macrophages staining with oil red O on bronchoalveolar lavage samples;5 however, the clinical course and radiographic6 and pathological samples7 do not support lipoid pneumonia as the mechanism of the lung injury in this outbreak of lung injury associated with e-cigarettes or vaping.
Research in context
Evidence before this study
A nationwide outbreak of lung injury associated with e-cigarettes or vaping was first reported in March, 2019, in the USA and more than 1880 cases have been reported to date. Although vaping is widespread globally, almost all cases have been reported in the USA. Initial reports noted severe cases of acute lung injury with constitutional and gastrointestinal symptoms, otherwise negative infectious diagnostic testing, and potential improvement with steroids. Increased disease recognition has led to subsequent small case series outlining the cases assessed at single institutions and public health reports of demographic data and vaping or e-cigarette use information. No pathognomonic test for this disease exists and bronchoscopy findings are non-specific. Uncertainty remains about disease course, appropriate diagnostic testing, the need for invasive testing, and treatment recommendations.
Added value of this study
In this study, we report the largest single health system cohort of patients with lung injury associated with e-cigarettes or vaping to date. Public awareness of the outbreak has led to increased recognition, and an evolving clinical picture of disease severity at presentation. Milder disease at presentation, whether due to earlier recognition or other reasons, was associated with less invasive testing (such as bronchoscopy) and shorter courses of lower doses of steroids. Most patients were treated with antibiotics and steroids, with perceived clinical improvement within days. We showed that a system resource (telecritical care) could be used to rapidly identify patients across multiple hospitals in an integrated health system, expediting recognition of this outbreak in one state in the USA. Using a specialised task force, we assessed cases at the system level rather than at individual hospitals, which facilitated validation of cases, shared expertise on the disease across the system, reporting of health outcomes to national bodies, and development of a standardised system approach around a guideline for diagnosis and treatment of lung injury associated with e-cigarettes or vaping. We also developed, and share, a practical clinical guideline for the diagnosis and treatment of lung injury associated with e-cigarettes or vaping.
Implications of all the available evidence
The collective evidence points to a possible opportunity to modify disease course in lung injury associated with e-cigarettes or vaping by faster recognition, cessation of vaping exposure at first symptom onset, and prompt initiation of steroid therapy. Additionally, in less severely ill patients with rapid improvement on steroids, extensive invasive testing, or even admission to hospital might not be necessary. Furthermore, while health systems globally determine whether this outbreak could be affecting their patients, the use of a system resource might help identify and increase the speed of response to an outbreak in which few severe cases accumulate at any single facility.
The prevalence of vaping tetrahydrocannabinol and nicotine compounds has been increasing among children and adults since 2014; however, the scale and severity of this new outbreak of acute lung injury indicates a more recent change in the composition of the e-liquid, and thus e-cigarette vapour, being vaped.1, 8, 9 The number of cases of lung injury associated with e-cigarettes or vaping in Utah, USA, is one of the highest in the USA, despite the state having a similar proportion of adults who use e-cigarettes as the national average and being among the least populated states in the country.10
In 2017, 5·1% (95% CI 4·5–5·7; age-adjusted 4·9% [4·4–5·5]) of adults in Utah reported currently using e-cigarettes compared with 4·6% nationally.11 The US Centers for Disease Control and Prevention (CDC), the US Food and Drug Administration, and other bodies are attempting to identify the chemical, metal, or other substances newly present in e-devices that might be causing this outbreak.1, 9
Vaping involves heating an e-liquid that contains solvents such as glycol and propylene glycol; active agents, such as nicotine and tetrahydrocannabinol; flavourings; and other additives. The e-liquid is heated and aerosolised, creating an e-cigarette vapour for inhalation.8
With increased awareness, clinicians are more consistently obtaining vaping histories in patients who present with acute lung injury in medical centres throughout the USA and building experience with individual case series of patients with lung injury associated with e-cigarettes or vaping.12 However, individual medical centres are most likely to recognise only the most severe cases in any outbreak and might not have the broader picture of the full range of disease presentations.2, 13
Telehealth has been increasingly implemented across different hospital systems with resulting standardisation of care and intensive care unit (ICU) processes, and improvements in mortality and clinical care have been observed.14 However, the role of telecritical care in expediting recognition of outbreaks and rapid dissemination in core competencies of treatment has not been previously reported.
The objectives of this study were to report the clinical course, treatment, and outcomes of the largest single health system cohort of patients with lung injury associated with e-cigarettes or vaping to date. Additionally, we note the key role of telecritical care in facilitating the rapid recognition of an outbreak, establishment of a system response via a specialised task force, dissemination of knowledge, and implementation of a proposed guideline for evaluation and treatment of lung injury associated with e-cigarettes or vaping for clinicians in an integrated health system.