Acute injury or illness related to the inhalation of vaping aerosols among children and adolescents across Canada: A cross-sectional survey of Canadian paediatricians

Abstract

Background

Vaping prevalence rates have increased among Canadian youth. Evidence suggests that vaping poses significant health risks to children and adolescents.

Objectives

The objectives of the study were to investigate epidemiological characteristics of acute injury/illness cases due to the inhalation of vaping aerosols among children and adolescents across Canada and to explore factors contributing to severe cases.

Methods

Data from the 2019 Canadian Paediatric Surveillance Program cross-sectional survey on vaping-related injury/illness were used. Analyses focused on injury/illness cases (n=71) among children and adolescents aged 0 to 17 years who presented to participating paediatricians for a harm related to the inhalation of vaping aerosols. We conducted descriptive analyses and performed logistic regression to explore associations between severe presentations requiring hospitalization or intensive care unit (ICU) admission and selected case characteristics.

Results

Of the 71 reported injury/illness cases related to inhalation of vaping aerosols, 56% of patients were male, and 68% were aged 15 to 17 years. Nicotine vaping was reported in 42% of cases, and cannabis vaping in 24%. Fifty-four per cent presented with respiratory distress, 18% with symptoms of nicotine toxicity, and 41% required hospitalization and/or admission to the ICU. Cases presenting with respiratory distress were more likely to be hospitalized/admitted to the ICU (odds ratio [OR]=5.37, 95% confidence interval [CI]:1.76 to 16.39).

Conclusions

The inhalation of vaping aerosols among children and adolescents may contribute to acute injury/illness. Clear associations between study variables and severe cases could not be established due to a small sample size. Additional research is needed to determine predictors and preventable risk factors of severe vaping-related injuries.

Youth vaping is a dynamic public health issue, which poses significant health risks to children and adolescents. In Canada, past-30-day use of vaping devices among students (grades 7 to 12) has doubled from 10% in 2016 to 2017 (1) to 20% in 2018 to 2019 (2). Common reasons for children and adolescents to try vaping include experimentation, flavours, peer/social influence, and the low-risk perception of vaping products (3–7). While vaping was initially marketed to adults as a smoking cessation tool, it is not considered safe for non-smokers or youths (8). Vaping is the use of handheld battery-operated electronic-cigarette or other portable vaping devices, which deliver an inhalable aerosol by heating an ‘e-liquid’ solution. Vaping products typically contain nicotine, flavouring chemicals, propylene glycol and other additives (9–12), and may also contain cannabis products and other psychoactive substances (13). While the aerosolization of vaping products emits potentially toxic chemicals that may be harmful when inhaled, the long-term health effects of vaping are still relatively unknown (14–16). In Canada, vaping products are regulated under federal law and are subject to numerous acts and regulations (17), including the Tobacco and Vaping Products Act (TVPA) (18), the Canada Consumer Product Safety Act (CCPSA) (19), the Food and Drugs Act (FDA) (20), the Non-smokers’ Health Act (21), and the Cannabis Act (22).

Acute vaping-related health risks have become increasingly recognized (23–25). These harms include inhalation effects (26) and respiratory symptoms following the inhalation of vaping aerosols (14,25,27–29), burns (30,31) and severe ocular injuries (32) due to vaping device malfunctions, and poisonings and fatal events among children following the ingestion of e-liquids (25,33–38). Notably, children and adolescents are particularly susceptible to the harmful effects of nicotine, such as nicotine dependence and potential for altered brain development (39–41). Recently, an outbreak of e-cigarette, or vaping, product use-associated lung injury (EVALI) in the USA received attention, with over 2,800 hospitalized cases identified between August 2019 and February 2020, the majority of which were related to tetrahydrocannabinol (THC)-containing vaping product use (42). Approximately 15% of EVALI cases were diagnosed in youth under the age of 18 (43). In Canada, 20 vaping associated lung illness (VALI) cases (44) have been reported so far, five of which were in youth under the age of 20 (45). EVALI (term used in the USA) and VALI (Canadian term) are characterized by a history of vaping in the 90 days before symptom onset, pulmonary infiltrates such as opacities on plain film chest radiograph or ground-glass opacities on chest computed tomography, and the absence of pulmonary infection or evidence of other plausible causes (44,46,47). Both EVALI and VALI patients often present with a constellation of respiratory, gastrointestinal, and/or constitutional symptoms (45,48). Numerous factors could contribute to the risk of severe vaping-related injury/illness such as the vaping product characteristics, product use behaviours or patient demographics (49–51).

Given the high rates of youth vaping in Canada, and the occurrence of several vaping-related injuries and illnesses among youth, more information on the acute harms related to the inhalation of vaping aerosols is needed to further our understanding of this evolving public health issue. The aim of this study was to investigate the epidemiological characteristics of acute vaping-related injury/illness cases associated with the inhalation of vaping aerosols among children and adolescents presenting to Canadian paediatricians and to explore associations between case severity and selected case characteristics.

METHODS

Data source

The Canadian Paediatric Surveillance Program (CPSP) is a national voluntary reporting surveillance system which collects data from approximately 95% of all practising paediatricians and paediatric subspecialists in Canada, on diseases/conditions among patients under 18 years of age (52). This study used data from the 2019 cross-sectional CPSP survey on vaping-related injuries/illnesses (53). The survey was designed in collaboration with the authors of the 2015 CPSP vaping study (25) and members of the Canadian Paediatric Society, before the development of the VALI case definition. A total of 2,693 paediatricians participating in the CPSP received the cross-sectional survey and responses were submitted to the CPSP between October and December 2019. The response rate for the survey was 42% (n=1,131/2,693) (54,55). Participating paediatricians were asked to provide anonymous case-level data for patients under 18 years of age who sought medical attention in the previous 12 months for injuries/illnesses related to the inhalation of vaping aerosols, ingestion of e-liquids, or malfunction of a vaping device (53).

Study variables

The 2019 CPSP cross-sectional survey on vaping-related injury/illness identified 88 cases, 71 (81%) of which were related to the inhalation of vaping aerosols (54,55). The present analysis focused exclusively on the cases related to the inhalation of vaping aerosols (n=71). Severe vaping-related injury/illness was classified based on the treatment location variable and was defined as any case which required hospitalization and/or admission to the intensive care unit (ICU). Nonsevere cases did not require hospitalization or ICU admission, and received treatment at an emergency department, walk-in/outpatient clinic, other location, were referred to a specialist, or had a missing treatment value. Assuming that practicing paediatricians would have likely recalled the treatment of severe cases and would not have necessarily recalled the treatment of less severe cases, the cases with a missing treatment value (n=14, 20%) were classified as non-severe.

The case-level variables of interest included: sex at birth, age range (<15 years, 15 to 17 years), exposure (direct inhalation, second-hand exposure), access to vaping device (owned, borrowed, unknown), vaping substance(s) (flavouring, nicotine, cannabis, unknown), presenting symptom(s) (respiratory distress/lung injury, symptoms of nicotine toxicity other than nausea/vomiting (e.g., tachycardia, headache, dizziness), mouth/throat irritation/burn, abdominal pain, nausea/vomiting, central nervous system depression, other), treatment location(s) (walk-in/outpatient clinic, emergency room, hospital ward, ICU, referred to specialist, other), and patient outcome (full recovery (resolution of vaping-related symptoms), ongoing vaping-related health issue(s), unknown). The access, vaping substance, symptoms, and treatment variables were multiple response variables, where respondents could check all that applied. Binary classifications were used to code all variables (e.g., respiratory distress or not).

Statistical analysis

Descriptive analysis was conducted to investigate the distribution of selected case characteristics related to the inhalation of vaping aerosols, overall and stratified by case severity. Frequency distributions, including counts and percentages, were calculated for all variables. As per CPSP policy, counts of fewer than five cases were suppressed to maintain confidentiality. Descriptive cluster analysis was conducted to help illustrate salient characteristics among similar-presenting cases. Univariate logistic regression was performed to assess associations between case severity (severe or not) and selected case characteristics. A sensitivity analysis was completed to examine any differences in our outcome by excluding cases with missing treatment values. Regression analysis for the case characteristics was performed only where data were available. Analyses were conducted using SAS PC software version 9.4 (SAS Institute Inc., Cary, NC, USA).

RESULTS

Injury/illness case characteristics: Inhalation of vaping aerosols

Of the reported 71 injury/illness cases due to the inhalation of vaping aerosols, 56% of patients were male and 68% were between 15 and 17 years of age (Table 1). Forty-eight per cent owned/purchased a vaping device, and 24% borrowed/were given a vaping device from friends/family. Nicotine was reported to have been used in 42% of vaping-related injury/illness cases, cannabis in 24%, and an unknown substance in 47%. The most common presenting symptoms were respiratory distress/lung injury (54%) and symptoms of nicotine toxicity (18%). Full recovery (44%) was the most frequently reported outcome. There were 29 (41%) cases, which received treatment at a hospital ward and/or ICU and were classified as “severe.” The remainder of cases (n=42, 59%) were classified as ‘non-severe’. Characteristics of severe and nonsevere cases are outlined in Table 1.

Table 1.

Distribution of injury/illness case characteristics related to the inhalation of vaping aerosols among children and adolescents by case severity, reported by practicing paediatricians to the CPSP (2019)

Characteristic	Overall		Severe cases		Nonsevere cases
Sex, n (%)
Female	31	(43.7)	16	(55.2)	15	(35.7)
Male	40	(56.3)	13	(44.8)	27	(64.3)
Age group, n (%)
1–14 years	23	(32.4)	7	(24.1)	16	(38.1)
15–17 years	48	(67.6)	22	(75.9)	26	(61.9)
Access, n (%)a
Borrowed from/given by a friend or family member	17	(23.9)	6	(20.7)	11	(26.2)
Owned/purchased	34	(47.9)	17	(58.6)	17	(40.5)
Unknown access/Missing	22	(31.0)	7	(24.1)	15	(35.7)
Vaping substance, n (%)a
Flavouring	19	(26.8)	11	(37.9)	8	(19.0)
Nicotine	30	(42.3)	13	(44.8)	17	(40.5)
Cannabis	17	(23.9)	7	(24.1)	10	(23.8)
Unknown substance	33	(46.5)	16	(55.2)	17	(40.5)
Missing	5	(7.0)	*		*
Presenting symptoms, n (%)a
Respiratory distress/lung injury	38	(53.5)	23	(79.3)	15	(35.7)
Symptoms of acute nicotine toxicity (e.g., tachycardia, headache, dizziness) other than nausea/vomiting	13	(18.3)	*		*
Mouth/throat irritation and/or burn, or abdominal pain and/or nausea/vomiting	8	(11.3)	*		*
CNS depression	8	(11.3)	*		*
Otherb	9	(12.7)	*		*
Missing	6	(8.5)	*		*
Patient outcome, n (%)
Full recovery	31	(43.7)	21	(72.4)	10	(23.8)
Ongoing health issue(s)	13	(18.3)	*		*
Unknown outcome	12	(16.9)	*		*
Missing	15	(21.1)	*		*
Total, n (%)	71	(100.0)	29	(100.0)	42	(100.0)

There were few injury/illness cases related to second-hand exposure, therefore, the exposure variable (direct inhalation, second-hand exposure) was excluded from Table 1 to maintain confidentiality.

CNS Central nervous system; CPSP Canadian Paediatric Surveillance Program.

All percentages are column percentages.

*Indicates that one or both severity subgroup cells contain fewer than five cases (counts less than 5 were supressed to maintain confidentiality).

^aIndicates that this was a multiple response variable and respondents could select more than one option. The column percentage totals could exceed 100%.

^b‘Other’ presenting symptoms includes syncope, seizure, ischemic stroke, dyspnea/chest pain, mood/behavioural symptoms, hemoptysis.

Descriptive cluster analysis

To illustrate salient characteristics among similar-presenting cases, the data are shown in clusters (Supplementary Appendix 1). For example, among cases where nicotine vaping was reported, 73% of patients were 15 to 17 years old, and 30% presented with symptoms of nicotine toxicity. Among cases where cannabis vaping was reported, >70% were male, and 65% presented with respiratory distress. Among cases presenting with respiratory distress, 55% were female, nicotine vaping was reported in 45% of cases, 39% were hospitalized, and 21% had ongoing health issue(s). Among hospitalized cases, nicotine vaping and cannabis vaping were reported in 48% and 29% of cases, respectively. Among cases admitted to the ICU, the majority were female, and the majority presented with respiratory distress. Characteristics of the various clusters (i.e., males, 15 to 17 years of age, nicotine vaping, cannabis vaping, flavouring vaping, respiratory distress, symptoms of nicotine toxicity, hospitalization, ICU admission) are further described in Supplementary Appendix 1.

Exploring factors contributing to severe cases

Cases which presented with respiratory distress/lung injury were more likely to be hospitalized and/or admitted to an ICU (OR=5.37, 95%CI: 1.76, 16.39; Supplementary Appendix 2). Cases classified as severe had higher odds of making a full recovery (OR=4.46, 95%CI: 1.44, 13.79) (Appendix 2).

DISCUSSION

Paediatricians who responded to the survey reported seeing 71 injury/illness cases related to the inhalation of vaping aerosols, the majority of which were among males (56%), and patients aged 15 to 17 years (68%). This is consistent with the inhalation findings from the 2015 CPSP vaping survey (25). In addition, data from the 2018 to 2019 Canadian Student Tobacco, Alcohol and Drugs Survey (CSTADS) found that past-30-day vaping prevalence was highest among students in grades 10 to 12 (29%) compared to those in grades 7 to 9 (11%), though the data showed no significant difference between males (21%) and females (19%) (2). The TVPA was enacted on May 23, 2018 and includes various youth protection measures, including a ban on selling vaping products to those under the age of 18 and prohibiting the marketing of vaping products that could appeal to youth (18,56). Recent data suggest that the majority of youth report obtaining vaping products from social sources (2,57). In this study, paediatricians reported that almost half (48%) of patients experiencing a vaping-related injury/illness owned/purchased a vaping device, though we lacked data on the initial source. It is possible that some of the identified cases may have acquired a vaping device before the implementation of these regulations.

Nicotine vaping and cannabis vaping (either alone or with other vaping substance(s)) were reported to have occurred in 42% and 24% of vaping-related injury/illness cases, respectively. This is consistent with Canadian data as nicotine vaping among youth remains more common (2), though data from Ontario show an increase in past-year cannabis vaping among high school students from 5% in 2015 to 10% in 2019 (58). As high-nicotine-concentration vaping products (e.g., 50 mg/mL or higher) became more prevalent in Canada around the year 2018 (59), provincial and federal legislative action are in progress to establish a maximum nicotine concentration of 20 mg/mL for vaping products for sale by authorized sources (59–61). Furthermore, due to the vulnerability of lung tissue to certain chemicals, some regulatory requirements for vaping products containing cannabis are more strict than those for non-inhaled cannabis products (17). Many US reports suggest that vitamin E acetate, a chemical found in some THC-containing vaping products, particularly those acquired from informal sources, is linked to most EVALI cases (42).

In the present study, less than one quarter of patients were reported to have borrowed a vaping device from friends/family (24%) or engaged in cannabis vaping (24%). Participating paediatricians reported an unknown vaping substance (either alone or with other known vaping substance(s)) for almost half (47%) of injury cases. This may have occurred as some children and adolescents may not know what substances their vaping device contains (62–64), or may be reluctant to disclose certain information to a treating paediatrician perhaps due to stigma of substance use or fear of ramifications (65). Nevertheless, this finding emphasizes the importance of youth-oriented educational efforts to increase awareness of vaping-related harms, such as Health Canada’s 2020 Consider the Consequences of Vaping information campaign (66). With the recent legalization of cannabis paired with the evolvement of vaping products to include this substance, ongoing surveillance is essential to monitor and prevent youth exposure and related harms.

Injuries and illnesses related to vaping products can be serious, especially among children and adolescents. The present study identified 29 (41%) severe cases involving hospitalization and/or admission to an ICU. This finding emphasizes the health burden associated with injuries due to the inhalation of vaping aerosols. Moreover, this study found that cases presenting with respiratory distress were more likely to receive treatment at a hospital ward and/or ICU. This is likely because respiratory distress is not a condition that can typically be managed in outpatient settings or at home. This study contributes to the existing literature by providing a descriptive overview of injury cases related to the inhalation of vaping aerosols observed by Canadian paediatricians, and identifying potential risk factors, though clear associations between study variables and severe cases could not be established due to a small sample size.

Limitations

Limitations of the 2019 CPSP survey have been previously described in other recent studies (54,55). All data were obtained from a treating paediatrician based on the information that was available to them at the time of completing the CPSP survey. The present analysis may have underestimated severe cases, as some of the cases with a missing treatment location could have been severe. The response rate for the survey was 42%, or 1,131 of the 2,693 paediatricians participating in the CPSP responding. Furthermore, the CPSP surveys are not representative of all children in the Canadian population and hence our study may not fully capture the true burden of vaping-related injury/illness, especially in remote or underserved populations. This study was limited by a small sample size and most of the univariate regression analysis results were not significant, which may in part be due to a type II error and low power (67). Next steps include conducting a multi-year study with repeated measures to increase power and sample size and conducting a longitudinal cohort analysis of children and adolescents with vaping-related injuries to determine the long-term outcomes and risk factors of these injuries. Additionally, the use of multiple surveillance data sources, such as provincial or federal inpatient hospital discharge summary data, may provide a broader scope and understanding of this important public health issue.

CONCLUSION

The inhalation of vaping aerosols among children and adolescents in Canada may contribute to acute injury and illness, some requiring hospitalization and/or ICU admission. Using data from the 2019 CPSP vaping-related injury/illness cross-sectional survey of Canadian paediatricians, this study provided a descriptive overview of injury cases related to the inhalation of vaping aerosols and identified several potential risk factors, though clear associations between study variables and severe cases could not be established due to a small sample size. Future work should seek to gain a better understanding of the risk and protective factors for these injuries/illnesses, which may help to inform preventive clinical, public health, and policy interventions to reduce the harms associated with youth use of vaping devices.