or in combination with nicotine was identified in nearly 80% of
early cases in the US.
Only seven of 19 cases in Canada were
associated with THC-containing products.
Although no deaths
had been reported in Canada, severe cases had emerged including
one patient with vaping-associated acute bronchiolitis who
required intubation and extracorporeal membrane oxygenation,
and developed chronic airway obstruction after resolution of
the critical illness.
In November 2019, the CDC reported
that laboratory testing of bronchoalveolar lavage samples from
29 patients with evidence of EVALI from across the US found
vitamin E acetate in all samples.
The results showed 82% of
samples contained THC and 62% contained nicotine.
products linked to cases of EVALI in the US were obtained from
the black market, leading to concern that vitamin E acetate was
used to thicken or dilute illicit THC-based vaping liquids.
While vitamin E acetate has been highly associated with EVALI, it
still appears that no single product accounts for all case findings
in Canada and the US. In view of the outbreak, the CDC has
recommended that individuals completely abstain from THC-
Health Canada has issued a warning
about potential risks of pulmonary illness associated with vaping
and recommended avoiding vaping products obtained from
illegal or unregulated sources.
While the long-term health effects of inhaling aerosolized
compounds remain unknown, evidence is clear that vaping
among youth is on the rise. An analysis of cross-sectional
surveys showed that the prevalence of smoking tobacco and
vaping among Canadian youth aged 16–19 years increased
between 2017 and 2018 (P < 0.001).
It has been speculated
that targeted advertising of vaping products to youth may play
a key role in this observation. For example, one study found
that young people who recalled seeing e-cigarette marketing in
retail stores were more likely to initiate vaping up to 2.5 years
later (adjusted odds ratio [aOR] 1.99, P < 0.05) (aOR 1.30, P <
Furthermore, e-cigarette use is linked to increased use
of tobacco cigarettes among youth.
Although a direct causal
pathway has not been proven, a prospective cohort study found
an association between 30-day use of e-cigarettes and smoking
a whole cigarette (aOR 2.12) and daily smoking (aOR 1.79).
In summary, e-cigarette use has increased in recent years,
particularly among young people and smokers who are attempting
to quit. While evidence evolves about the risks and benefits
of vaping, studies suggest e-cigarettes are associated with the
development of acute, sub-acute, and chronic lung disease
and increased tobacco use among youth. More robust research
is needed to determine the short-term and long-term health
consequences of vaping in view of the growing array of substances
and products available in regulated and illicit markets. This
will give physicians the information to better counsel patients
and contribute to future public health discussions and policies.
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Canadian Journal of General Internal Medicine
26 Volume 15, Issue 4, 2020
Deschner, Tunks and Yamashita
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