Electronic Vaping Delivery of Cannabis and Nicotine

Function

Electronic nicotine delivery systems come in an array of designs. The primary differences are nicotine concentration, various additives and flavorings, battery type, and superficial aesthetics. The classic e-cigarette comprises a compact lithium-ion battery, a vaporization chamber, and a solvent mixture cartridge. The liquid is heated in the chamber, vaporized, and then rapidly cooled. The aerosol is then directly inhaled orally by the user via a mouthpiece, leading to direct systemic absorption through the respiratory system.

Several generations of e-cigarette models have been created. The earlier designs closely resemble the classic cigarette and deliver lower levels of nicotine. The latest models contain larger cartridges, higher-powered batteries, and lower resistance coils—which enhance the concentration of nicotine consumed. Cartridges may be exchanged easily between or during usage.

The “pod-mod” class of devices that resemble a slick and modern universal serial bus drive is trendy among youth consumers. These super-compact vaporizers can deliver highly concentrated puffs at levels that would be aversive to even chronic tobacco users. Popular companies use nicotine formulations in their pod-mod devices that derive from the nicotine salts of loose-leaf tobacco. One pod can possess the same amount of nicotine as 20 classic combustible cigarettes. Nicotine salts, when combined with additives and flavorings, mask the noxious taste of the ultra-concentrated nicotine. Pods are about 9.4 cm x 1.5 cm x 0.8 cm and weigh approximately 0.01 kilograms.

The modern, ultra-compact, and customizable designs are slick pieces of technology and allow discreet transport of the pods. This concealability has become a hot area of contention in schools that struggle to prevent students from vaping in restrooms, hallways, and classrooms. Furthermore, commercial marketing targets children with colorful exteriors and sweet flavors, such as bubble gum and cartoon characters, to seductively increase the manufacturers' grip on this vulnerable demographic.[9]

Issues of Concern

Aerosols and liquids of e-cigarette cartridges have many constituents; the most common ones include glycerol, propylene glycol, and nicotine. Micro-constituents found in smaller concentrations include acrolein, formaldehyde, acetone, acetaldehyde, and heavy metals. Most ingredients in individual flavorings have not been tested for long-term safety. Results from one animal study showed that aerosolized glycerol and propylene glycol inhalation we associated with local squamous metaplasia in the upper airways. Known carcinogens like various aldehyde compounds have been found in lower but still present concentrations when compared to traditional cigarettes.

Heavy metals like chromium, nickel, and lead also appear in small quantities within the combustible vapor. These metals have known carcinogenic effects and are also associated with inflammation and damage.[10] Varying manufacturing practices have shown discrepancies between levels of these compounds. Most research regarding exposure to e-cigarette aerosols has been completed either in vitro with cell cultures or in vivo with rodents. One study in mice examined exposure to inhaled nicotine liquids, which were associated with significant inflammation and oxidative stress to the pulmonary endothelium. Other mouse studies data have shown reduced endothelial glutathione levels and increased inflammatory cytokines. Additionally, mice exposed to inhaled nicotine liquids showed higher rates of respiratory infections, including viruses and common bacteria.

Conventional cigarettes induce profound cardiovascular and respiratory harm. Thus, further research is critical for revealing the short- and long-term consequences of the new alternatives.[11] Early study results suggest a short-term increase in vital signs, such as blood pressure and heart rate, and results from other studies have shown that e-cigarette vapors induce platelet activation in the endothelium of healthy naïve participants. Such activation could have implications for the risk of thrombosis down the line.

Research on the long-term risks of e-cigarette use in humans is ongoing. However, short-term side effects of nicotine in e-cigarettes, including gastrointestinal distress, palpitations, and headaches, have been documented. If absorbed in a large enough dose, nicotine can cause seizures, respiratory depression, and severe bradycardia. Doses tolerable to adults can be life-threatening if consumed by small children. Sweet-flavored cartridges may tempt a young child and present a toxic hazard.[12]

Furthermore, exposure to any form of nicotine has been shown to undermine the development of neural circuits and lead to a permanent impairment of neurochemical and behavioral functioning. Teens and young adults are of particular concern for neurologic harm from nicotine in e-cigarettes because the human brain does not cease development until the mid-20s.

Some epidemiologic studies suggest that women who consume nicotine during pregnancy risk neurotoxic effects on the developing fetus. The cholinergic system of the central nervous system is distributed throughout the body and is vital for cognitive processes such as memory, attention, and executive processing. Nicotine itself can cross the placenta and bind to fetal nicotinic acetylcholine receptors. Evidence also exists that exposure to prenatal tobacco may harm fetal lung maturity, reduce lung compliance, impair overall lung function in infants, and possibly increase the risk of sudden infant death syndrome.[13]

Many women who were chronic cigarette users before becoming pregnant switch to e-cigarettes to reduce their exposure. This switch may have benefits but does not subvert the independent harm of nicotine that is further compounded by the increasing concentrations found in certain devices. Much anecdotal evidence exists suggesting e-cigarettes have associations with the development of chronic respiratory symptoms. Some components of the nicotine aerosol already have known pulmonary toxicity, as previously mentioned.

One study evaluated the association between adolescent e-cigarette use and symptoms of chronic bronchitis. Adolescents who consumed e-cigarette aerosols had a 2-fold increase (odds ratio, 2.02; 95% confidence interval, 1.42-2.88) in bronchitic symptoms (eg, cough and wheezing) when compared to never users. This effect persisted after adjusting for confounders, such as concurrent and past cigarette usage among the participants (odds ratio, 1.70; 95% confidence interval, 1.11-2.59). Overall, more research is needed, but to date, evidence supports the negative health consequences of e-cigarette use in novel users, particularly adolescent consumers. 

Outbreaks of vaping-associated lung injuries were reported in increasing numbers throughout the United States in 2019, and by 2020, 60 deaths had been reported in association with e-cigarette use.[14] Common characteristics of vaping-associated lung injury include pulmonary infiltrate seen on radiographic imaging without an alternative diagnosis (such as infection) and vaping use within the past 90 days. The exact cause of lung injury remains unknown as no single substance or device has been linked to all of the cases. The treatment primarily includes steroids and traditional respiratory support, such as supplemental oxygen, noninvasive ventilation, and intubation if necessary. Extracorporeal membrane oxygenation is sometimes required. 

Clinical Significance

E-cigarettes are frequently promoted as smoking cessation aids, with increasing evidence to contradict such claims.[15] E-cigarette users have been found to have little interest in quitting.[16] A systematic review found evidence that e-cigarettes can cause addiction in nonsmokers and that young nonsmokers who use e-cigarettes are more likely than nonusers to start smoking and become regular smokers. Little evidence supports using nicotine e-cigarettes as an effective aid to quit smoking.  

Since clinical guidance is unclear, clinicians should recommend smoking cessation aids approved by the United States Food and Drug Administration (FDA) due to their established efficacy and safety; therefore, the risks of e-cigarettes may be discussed with individuals who use them. Patients should be encouraged to use flavorless liquids to minimize additives and their unknown effects, and they should avoid secondhand vaping indoors and around children due to the unclear effects of second and third-hand exposure to vaping products. Emphasizing the lack of evidence on the risks associated with these devices is crucial, as is providing emotional and behavioral support during cessation efforts.[17]

Other Issues

Overall, cigarette usage rates were declining among high-school students before e-cigarettes entered the market in 2007. Anti-tobacco campaigns and public health restrictions on the packaging, advertisement, taxation, and promotion of tobacco products appeared highly effective. For example, since 2009, the FDA has prohibited advertising tobacco products on television and radio platforms. Many states and local communities have banned cigarette use in public areas such as restaurants and bars.

Attitudes toward smoking among adolescents have also shifted in the past couple of decades, and public health campaigns have succeeded in labeling cigarette use as unglamorous and unappealing. Unfortunately, attitudes towards e-cigarettes are not the same. Approximately 20% of high school youth now use some form of e-cigarette device, and far fewer view these products as dangerous when compared to traditional cigarettes. Nearly all e-cigarette companies are partly owned by other major tobacco companies. In the modern era, these companies have subverted previous restrictions using new-found advertising methods, including social media and youth influencers.

Tobacco companies view the youth demographic as a means to increase their lifetime customer base. These establishments go out of their way to reach consumers in developing nations, hoping to tighten and expand their grip on an already deeply addicted market. To respond to this crisis, public health organizations have been pushing to regulate the e-cigarette class of products the same as traditional tobacco products. This undertaking attempts to subvert tobacco companies' efforts to use modern media to reach easily influenced young consumers.

One study attempted to quantify the receptivity of never-smoking American adolescents to tobacco advertising. About 41% of the 12- to 13-year-old participants were found to be receptive to at least 1 tobacco advertisement, and the highest response was for the media that included e-cigarettes.[18] This evidence is concerning because the tobacco industry has historically relied on slowly building general interest among young consumers to cash in later when they come of age and develop full autonomy over their purchases.

We know from historical industry documents that tobacco companies target young adults at major transition points in life, including moving away from home, entering college, beginning new jobs, joining the military, and visiting bars.[19] At the same time as these major life changes, exposure to anti-tobacco public health efforts begins tapering off in this demographic, reducing the resiliency of never or light smokers from progressing to heavier patterns of use. These findings further support the idea that stricter regulatory measures toward e-cigarettes are required to protect susceptible adolescents and young adults from carefully crafted and targeted commercial advertising. Early evidence suggests that e-cigarette use in adolescents may lead to heavier cigarette smoking into adulthood.[20]

Enhancing Healthcare Team Outcomes

Interprofessional cooperation and education can positively benefit patients and improve outcomes. The more healthcare team members ask about e-cigarette use and educate patients, the better. Most interventions occur in primary care, where physicians and pharmacists discuss smoking cessation with patients. Each team member needs to be educated regarding the risks and benefits of electronic nicotine delivery devices. When questioning patients about their social history, all team members must ask specifically about e-cigarette use, as patients may not consider e-cigarettes to be harmful or in the same category as traditional cigarette smoking and thus may not disclose their use.

Asking and educating about e-cigarettes during well-child exams are crucial due to the rising popularity of these devices in the pediatric population. Some adolescents who would not have smoked may try e-cigarettes, which correlate with higher levels of smoking later in life. Interventions with adolescents aimed at smoking have demonstrated effectiveness in decreasing rates of e-cigarette users who later convert to traditional smoking.[21]

Currently, traditional cigarette use has far more proven negative health consequences than e-cigarettes, partly due to a lack of research on the latter. However, e-cigarettes are not benign. The adverse health effects of nicotine in e-cigarettes on the cardiovascular system and childhood neurologic development require emphasis. Clinicians should recommend that the public quit smoking altogether. Smoking offers no health benefits, and individuals interested in vaping should instead be offered methods for quitting smoking entirely. Not only does smoking discontinuation improve health, but it also saves money for both the individual and the healthcare system. Only through a concerted effort by clinicians at all levels can smoking-associated morbidity decrease. Patients require ongoing education that smoking is harmful to their health, and a coordinated effort from all members of the interprofessional team can contribute to that goal.

Nursing, Allied Health, and Interprofessional Team Interventions

Clinicians are essential in collecting and updating patients' social histories and relaying any e-cigarette use to the healthcare team. The healthcare team needs to be aware of the risks of e-cigarettes and how they relate to patient care and health. 

Nursing, Allied Health, and Interprofessional Team Monitoring

Patients who use e-cigarettes may need aggressive treatment while in the hospital because they are likely to experience nicotine withdrawal and cravings.