How Vaping Causes Serious Lung Disorders

Across the U.S., an epidemic of severe lung disease is affecting people who vape. Although vapers don't expect to end up in the intensive care unit with respiratory and gastrointestinal problems, that's been the experience for some. Lung injuries and a spate of deaths are the result of what's now called EVALI (e-cigarette, or vaping, product use-associated lung injury).

The outbreak has raised nationwide concern and questions about the effects of vaping on the lungs. As of Oct., 29, 49 states, the District of Columbia and the U.S. Virgin Islands had reported EVALI cases; 24 states have confirmed EVALI-associated deaths. Alaska is the only state without a reported EVALI case.

Scientists with the Centers for Disease Control and Prevention and the Food and Drug Administration are working to identify patterns that are common to EVALI patients and their vaping and e-cigarette use.

With 1,888 cases and 37 deaths reported to the CDC as of Oct. 29, at least one common factor has emerged: Most -- but not all -- EVALI patients report recent use of vaping products containing THC, the marijuana compound that causes a high.

Young people have been more likely to develop EVALI. The median age for all patients is 24. As a group, those who died were older, with a median age of 53. However, young people have died, too. Overall, fatal cases have occurred in people ranging from 17 to 75 years old.

It's not surprising that higher proportions of young people are affected by EVALI, as vaping given that many teens and young adults vape. About 1 in 5 young adults between ages 18 to 38 uses e-cigarettes either daily or recreationally, according to survey data released by the American Society of Clinical Oncology in September. Nearly 1 in 4 young adults believes that the products are harmless and not addictive, the ASCO survey found.

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EVALI Symptoms

Recent vaping is the key connection. For those who've developed EVALI, symptom have started from a few days to several weeks after use, Brian King, deputy director for research translation in the CDC's Office on Smoking and Health and the senior official for the agency's lung injury response, said in an interview with U.S. News.

If you've recently used e-cigarettes or other vaping devices, what could make you suspect that you might have EVALI? Shortness of breath and cough are primary symptoms. Some patients also have symptoms of gastric illness and even weight loss.

"The majority of individuals report gastrointestinal symptoms, nausea, vomiting, stomach pain or diarrhea preceding their hospital admissions or the worsening of their lung symptoms," Dr. Anne Schuchat, principal deputy director of the CDC, told reporters in a CDC media briefing held in late October.

As CDC gleaned data from medical records, they found that patients eventually diagnosed with EVALI initially had some of the following symptoms:

-- Cough.

-- Chest pain.

-- Shortness of breath.

-- Abdominal pain.

-- Nausea.

-- Vomiting.

-- Diarrhea.

-- Fever.

-- Chills.

-- Weight loss.

On examination, clinicians found signs like these in some patients:

-- Rapid heart rate (tachycardia).

-- Abnormally rapid breathing (tachypnea).

-- Decreased oxygen levels in the blood (measured by a pulse-oximeter device).

Stethoscope exams typically didn't reveal any remarkable respiratory changes, even among patients with severe lung injury.

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Toxic Aerosol?

E-cigarette devices work by turning liquids to vapor for users to inhale. Basic vaping devices consist of a heating component, battery and cartridge containing the e-liquid.

Vaping liquids contain a variety of substances that can include water, propylene glycol, glycerin, flavorings and nicotine. It's also possible to find vaping liquids containing THC or devices that heat dry THC to vaporize it.

"It is obvious from this recent lung injury outbreak that vaping in general can cause acute lung injury," says Irina Stepanov, an associate professor in the division of environmental health sciences at the University of Minnesota School of Public Health.

"It's probably not (caused by) all vaping devices or liquids, or not all types of uses that people engage in," says Stepanov, whose team is looking at the chemical profiles of e-cigarette aerosol. "So that's why we don't see mass reports of lung injuries across everyone who is using these devices, even though there is a growing number."

People actually don't know what they're inhaling, Stepanov says. "There is really no regulatory oversight over who is making these liquids, where and how they are making these liquids, and what kind of components are present in these liquids," she says. "Sometimes, people who make these liquids have no idea what these ingredients can do to the lung when the liquid is converted to aerosol and inhaled."

A big difference exists between what's in a liquid and what's in the aerosol it produces, Stepanov explains. "Some of the components of liquid decompose when they are subject to high temperatures, forming other chemicals. Some of them are respiratory toxicants. Then, all of these byproducts can react with each other and with some components of the liquid."

For example, propylene glycol is a safe food ingredient, Stepanov says. "But there's not enough knowledge about what happens when you inhale it for a very long period of time," she adds. "I don't necessarily say that it is highly toxic -- just that there is not enough knowledge about long-term exposures to propylene glycol itself, or when it decomposes and forms byproducts."

THC Connection

These figures from the Oct. 28 issue of CDC's Morbidity and Mortality Weekly Report suggest but don't make a definitive EVALI-THC connection for patients who developed the condition:

-- Most (86%) based on available data reported using products with THC within three months of their symptoms beginning.

-- 64% recently used nicotine-containing products.

-- 52% recently used nicotine and THC products.

-- 34% reported exclusively using THC-containing products.

-- 11% said they exclusively used nicotine-containing products.

"At the national level, we don't have information on where products were acquired," Schuchat said in the briefing. But a CDC investigation in Utah "found that most patients there had gotten the THC-containing vaping products from informal sources or online, rather than from brick-and-mortar stores or dispensaries."

That's fairly consistent with patterns described in Illinois and Wisconsin investigations, Schuchat said, where about 89% of patients reported getting THC-containing products from friends, family, illicit dealers or off the street.

In the briefing, Mitch Zeller, director of the Food and Drug Administration's Center for Tobacco Products, said that learning about the supply chain and source of products involved in these cases is an agency priority. "FDA has received or collected over 900 samples from 25 states to date," Zeller noted. "Those numbers continue to increase. The samples collected directly from consumers, hospitals and from state offices include vaping devices and products that contain liquid as well as packaging and some nearly empty containers."

It's possible that some people who have EVALI may be hesitant to disclose that they recently used THC.

"We don't know what the risky material or substance is," Schuchat emphasized. "THC may be a marker for the way that cartridges were prepared or (a) way that devices are producing harm. Whether there are similar activities going on for cartridges that don't contain THC, for instance, remains to be seen." With all the uncertainty, we feel it is very important for people to consider refraining from using any kind of e-cigarettes," she said.

Public Recommendations

In light of the EVALI epidemic, as well as other established findings on vaping, these are the latest CDC recommendations:

-- Don't use e-cigarette or vaping products that contain THC.

-- Don't buy any type of e-cigarette or vaping products -- particularly those containing THC, off the street.

-- Don't modify or add any substances to e-cigarette or vaping products not intended by the manufacturer.

-- While the EVALI investigation continues and until all the facts are known, consider refraining from using all e-cigarette or vaping products to ensure you're not at risk.

-- If you do continue to use e-cigarette or vaping products, monitor yourself and see a health care provider immediately if you develop any EVALI-type symptoms.

-- Youth, young adults and pregnant women should never use e-cigarettes or vaping products. "We know that nicotine levels in e-cigarettes are quite harmful for the developing brain, which continues to develop through age 25," Schuchat said.

-- Adults who do not currently use tobacco products should not start using e-cigarette or vaping products.

Smokers who have switched to e-cigarettes in an effort to reduce harm to their health might not be sure where they stand.

"We do acknowledge that there are some adult smokers or former smokers who are using e-cigarettes to help them quit," King says. "We certainly do not want those individuals to go back to smoking when they quit using e-cigarettes. It's critical that those individuals monitor themselves for symptoms and consult with a health care professional if they have any concerns, and also to consider using FDA-approved medications to help them quit."

To learn more about EVALI and vaping, and keep abreast of the latest findings, check out CDC's comprehensive online resources.

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If you see your health provider for EVALI-type symptoms, guidelines are now in place to help clinicians evaluate its possibility, rule out other respiratory conditions -- like pneumonia -- and make the diagnosis.

Health care providers should take a history that includes asking questions about the use of e-cigarette or vaping products. Questioning should be "empathetic, nonjudgmental and private," according to updated CDC guidelines.

A chest X-ray is recommended for patients with suspected EVALI. Patients who have reduced blood oxygen levels or who are in respiratory distress should be admitted to the hospital, the guidelines say. For some patients, corticosteroids are an effective treatment option.