Life-threatening bronchiolitis related to electronic cigarette use in a Canadian youth

Abstract

Background: Although electronic cigarettes (e-cigarettes) were initially marketed as a potential smoking-cessation aid and a safer alternative to smoking, the long-term health effect of e-cigarette use ("vaping") is unknown. Vaping e-liquids expose the user to several potentially harmful chemicals, including diacetyl, a flavouring compound known to cause bronchiolitis obliterans with inhalational exposure ("popcorn worker's lung").

Case description: We report the case of a 17-year-old male who presented with intractable cough, progressive dyspnea and malaise after vaping flavoured e-liquids and tetrahydrocannabinol intensively. Initial physical examination showed fever, tachycardia, hypoxemia, and bibasilar inspiratory crackles on lung auscultation. Computed tomography of the chest showed diffuse centrilobular "tree-inbud" nodularity, consistent with acute bronchiolitis. Multiple cultures, including from 2 bronchoalveolar lavage samples, and biopsy stains, were negative for infection. He required intubation, invasive mechanical ventilation and venovenous extracorporeal membrane oxygenation (ECMO) for refractory hypercapnia. The patient's condition improved with high-dose corticosteroids. He was weaned off ECMO and mechanical ventilation, and discharged home after 47 days in hospital. Several months after hospital discharge, his exercise tolerance remained limited and pulmonary function tests showed persistent, fixed airflow obstruction with gas trapping. The patient's clinical picture was suggestive of possible bronchiolitis obliterans, thought to be secondary to inhalation of flavouring agents in the e-liquids, although the exact mechanism of injury and causative agent are unknown.

Interpretation: This case of severe acute bronchiolitis, causing near-fatal hypercapnic respiratory failure and chronic airflow obstruction in a previously healthy Canadian youth, may represent vaping-associated bronchiolitis obliterans. This novel pattern of pulmonary disease associated with vaping appears distinct from the type of alveolar injury predominantly reported in the recent outbreak of cases of vaping-associated pulmonary illness in the United States, underscoring the need for further research into all potentially toxic components of e-liquids and tighter regulation of e-cigarettes.

Conflict of interest statement

Competing interests: None declared.

© 2019 Joule Inc. or its licensors.

Figures

Figure 1:

Portable frontal chest radiograph in a 17-year-old male taken on day 2 of a community hospital admission showing diffuse micronodular opacities in both lungs.

Figure 2:

Computed tomography chest imaging on day 1 of hospital admission. Axial (panels A, B and C) and coronal (panel D) images show diffuse bronchiolitis manifested by innumerable tree-in-bud opacities throughout both lungs with subpleural sparing. Note the absence of mosaic attenuation, ground-glass opacity and consolidation.

Figure 3:

Histological sections of a transbronchial biopsy of the right lower lobe on day 8 of hospital admission at low (panel A, original magnification × 2), medium (panel B, original magnification × 4), high (panel C, original magnification × 10) and highest magnification (panel D, original magnification × 20) (hematoxylin and eosin stain). There is mild interstitial septal thickening secondary to acute inflammatory cells in the septi and type 2 pneumocyte hyperplasia (panel C). The airspaces are distended by a mixture of fibrin balls, neutrophils, macrophages and myofibroblast proliferation, with incorporation of myofibroblasts into the septi (panel D). These findings represent nonspecific acute inflammation and reactive changes in the airspaces. No bronchial mucosa is present for evaluation. The etiology of the findings is not identified. No infectious organisms are identified. Vasculitis and granulomatous inflammation is not identified. Hyaline membranes are not identified. Note the absence of viral cytopathic changes and paucity of foamy macrophages.

Figure 4:

Flow-volume loop at 1-month follow-up showing severe airflow obstruction.

Figure 5:

Flow diagram showing selection of relevant published case studies.

Figure 6:

Number of published case reports and case series on vaping-associated pulmonary disease, by year published.