JEMS Clinical Review Features
This clinical review feature article is presented in conjunction with the Department of Emergency Medicine Education at the University of Texas Southwestern Medical Center, Dallas.
>> List and describe the three primary street terms associated with the inhalation of toxic chemicals.
>>List and describe the three general categories of abused inhalants and give examples of each.
>>Explain the two mechanisms of action for inhalants.
>>Identify the signs and symptoms of inhalant abuse.
>>List and explain the treatment and multiple complications of inhalant abuse.
Aerosols:Sprays that contain propellants and/or solvents.
Inhalant:A medication, anesthetic or other compound in vapor or aerosol form that is taken by inhalation.
Inhalant abuse:The practice of "sniffing/snorting," "huffing" or "bagging."Lipophilic:Having an attraction for, tending to combine with, or capable of dissolving in lipids (oil or fat).
Volatile solvents:Liquids that vaporize at room or relatively low temperatures.
The number and variety of items used asinhalantsis enormous, and most can be found as close as the kitchen sink or computer desk. The low cost, easy access and absence of paraphernalia makes inhalant abuse a favorite among pre-teens and young adolescents. And because it_s not detected by drug screens, it_s considered ideal for anyone looking to get high.
The 2007 National Survey on Drug Use and Health estimated that approximately 22.5 million individuals 12 years and older have used inhalants at least once in their lifetime. This is nearly 10% of the U.S. 12-and-older age group. Inhalants are the fourth most common substance abused by adolescents in grades eight through 12, behind alcohol, cigarettes and marijuana.
Before 1979, when state laws were enacted to ban the sale of products containing toluene to minors, identifying an abuser might have been relatively easy. Spray paint and model glue were the products of choice back then, and an abuser could be spotted from the glue or paint around their nose and mouth or on their clothing. Because most sources today are commonly found in the house, your only obvious sign that a patient has been huffing might be an unusual smell of air freshener or furniture polish on their breath.
With the recent economic downturn, the use of inhalants may be on the rise. A $2.50 container of air freshener is more affordable than a "dime bag" of marijuana, and users get a similar experience. It_s important for EMS providers to understand that inhalants are hazardous chemicals that individuals are breathing into their lungs. In many cases, their exposure also puts you at risk, for both internal and external exposure to the chemical. It also produces unpredictable changes in behavior. Your ability to identify the abuser may help save a life.
Sources & Mechanisms
Sniffing is breathing avolatile solventor aerosol directly from the source. It involves placing a straw or nozzle into the mouth or nose and releasing a propellant through it.
Huffing involves soaking a cloth in a chemical and holding it near the nose and mouth. The individual may put the cloth directly into the mouth, enhancing and prolonging the experience.
Bagging is filling a balloon or plastic bag with a chemical and then inhaling the contents. Putting the saturated cloth into the plastic bag before inhaling to prevent getting the chemical on clothing is another form of bagging. It_s also been reported that the bag can be placed over the head to enhance the user experience.
Inhalants fall into three general categories: volatile solvents,aerosolsand gases. Volatile solvents are liquids that vaporize at room temperature, such as felt tip markers, glue and paint thinner.
Spray cans containing a propellant are typically referred to as "aerosols"; this category includes hair spray, room deodorizer and spray paint. The propellant_s purpose is to maintain pressure in the can between uses. If the can is turned upside down before use, however, it will discharge primarily propellant. Individuals who abuse aerosols often have some residue of the can_s contents visible around their lips and mouth.
Inhaled gases range from cigarette lighter butane to propane from the backyard barbecue, as well as containers of whipped cream that use a nitrous oxide propellant. Butane and propane are aliphatic hydrocarbons (i.e., straight chain hydrocarbons). They_re readily absorbed by the lungs; however, unlike other hydrocarbons, they seldom cause injury to lung mucosa. Nitrous oxide, or laughing gas, works by binding to brain receptors. Its primary role is pain relief or anesthesia, but the euphoric feeling it can create puts it on the list as a popular inhalant.
Inhalants primarily work in two ways. First, the inhalation of these chemicals causes displacement of oxygen from the alveoli. The initial feelings of euphoria, dizziness, giddiness or light-headedness are the result of lack of oxygen to the brain. This "high" lasts for about 15Ï30 minutes. Repeated exposure is necessary to maintain the experience.
The second method is absorption into the blood stream. Most inhalants are lipid soluble, so when they enter the blood stream, they move rapidly throughout the body and specifically into the central nervous system (CNS). Once in the CNS, the chemicals act as depressants, increasing the risk of bradycardia or bradypnea with continued use.
Because many of these inhaled chemicals are absorbed into the bloodstream, removal occurs only through metabolism. The primary sites for metabolism are the liver and kidneys. Some of these products cause metabolic acidosis and hypokalemia by interfering with kidney function. Abusing inhalants can also result in kidney stones and glomerulonephritis, or inflammation of the filtration system of the kidney. Other long-term health effects include a Parkinson_s-like disorder, muscle weakness and wasting and chemical pneumonitis.
Repeated use or single use with high concentration is known to cause permanent brain damage. Specialized brain CT scans of chronic abusers has demonstrated changes in blood flow, loss of brain mass and degeneration of white matter.
EMS responds to the local mall for possible seizure activity. On arrival, the crew is directed by security to a group of young people near the food court. In the middle of the group, there_s a 13-year-old male who appears postictal. He_s pale and diaphoretic, and his vital signs are BP 110/72, pulse 112, respirations 26 and shallow.
His friends say that one minute he was talking, and the next minute he was on the ground "jerking." They don_t know of any past medical history of seizures, and they deny any recent head trauma. Blood sugar on scene is 112.
En route to the emergency department (ED) the young male becomes more coherent and tells the crew that in the last week he_s had two "blackouts"ƒdescribed as times when he couldn_t quite remember what was happening around himƒbut that he_s never had a seizure. He denies any recent drug or alcohol use. He doesn_t take any medications on a daily basis. When the crew asks if he_s been experimenting with anything new in the last two or three weeks, he thinks for a minute, and then asks if his episode could have anything to do with "huffing."
Discussion of Case #1
Seizures:Seizure activity is one of the more common responses to inhalation abuse. In this case, the initial use resulted in absent seizures, which then progressed to tonic-clonic seizure activity with continued use of the inhalant. This isn_t always the case. A tonic-clonic seizure can occur with the first or the 21st time someone inhales.
Absent and tonic-clonic seizures fall in the category of generalized seizure activity. In a generalized seizure, the abnormal electrical activity affects both hemispheres of the brain. Absent seizures are defined as a brief loss of awareness and activity, resulting in a blank stare, with no physical signs of seizure activity. Tonic-clonic seizures result in dramatic physical jerking, unconsciousness and loss of bowel and bladder control most commonly associated with seizure activity.
The worsening of seizure activity in the inhalant abuser is most commonly attributed to an ever-increasing cerebral hypoxia and consequent tissue death. Tissue death in the brain necessitates re-routing of electrical impulses, much like the heart re-routes electrical activity around an area of infarction. Like the electrical instability of the heart after a myocardial infarction, this re-routing of brain activity can result in the sudden random firing of brain cells and consequently seizure activity. Few studies have evaluated the long-term effects ofinhalant abuseon the brain and the permanence of seizure-related damage.
Systems effects:In addition to seizures, inhaled toxins can have other neurological effects. Because commonly used inhalants arelipophilic, the chemicals are attracted to neurons, which have a high fat content. Once absorbed by neurons, the chemicals can alter the function of the neuron or the speed with which it fires, resulting in slurred speech, agitation or violent behavior.
Your patient might also feel sleepy, as the toxins depress the CNS. Watch for decreases in respiratory rate and effort. Also watch for more subtle signs of inhalant abuse, such as red, watery eyes or unexplained confusion.
Signs and symptoms in long-term abusers include muscle tremors, spasms, difficulty walking and talking and loss of hearing and memory. These presentations are due to the destruction of the myelin sheath around the neurons of the brain.
Treatment for seizure activity resulting from inhalant abuse is the same as for any other seizure: supportive care. Abusers who are found while using the inhalant should be considered contaminated with a hazardous material. For these individuals, oxygen may be helpful in decontaminating the lungs, and clothing should be removed to prevent further absorption of the toxin.
EMS responds to a residence for a cardiac arrest; bystander CPR is in progress. On scene, the crew finds parents aggressively working on their 10-year-old son, who_s mottled and cyanotic. The crew decides to continue BLS and transport. The physician terminates the code shortly after arrival in the ED.
While the crew is writing up the patient care report, the physician asks if there was anything unusual about the scene. She says that when she attempted to intubate the child, she found a significant amount of edema in the throat and some sores on the tongue and roof of the mouth. One of the EMTs says he remembers moving some cans of compressed gas near the boy_s body. He thought they_d fallen off the desk in the commotion.
Discussion of Case #2
This young male died suddenly as a result of sniffing. Sudden sniffing death syndrome can occur any time an individual uses an inhalant, and even seasoned users are at risk of death each time they inhale. It_s thought that the inhaled chemical alters the function of the myocardium.
Chemicals affect the myocardium in two ways: hypoxia and catecholamine sensitivity. At rest, the myocardium utilizes 60Ï70% of the oxygen available in coronary circulation; under stress the percentage increases. As myocardial hypoxia develops, the muscle becomes weaker and is no longer able to effectively contract, and the cells of the electrical conduction system become erratic, allowing for the development of ectopic beats. This combination sets the stage for ventricular tachycardia, followed by ventricular fibrillation (V-fib) and ultimately asystole.
Second, research shows that many inhaled solvents can sensitize the myocardium to the effects of catecholamines. Catecholamines (like epinephrine) cause an increase in heart rate that prepares the body for the fight-or-flight response. So anything that might startle the individual can lead to a sudden increase in heart rate, which can result in ventricular tachycardia, V-fib and asystole.
Inhalation of volatile halogenated hydrocarbons, such as Freon, may produce life threatening cardiac and neurological toxicity. The cardiovascular toxicity of Freon includes arrhythmia, myocardial depression, and reduction in peripheral vascular resistance. Perhaps the most clinically relevant toxicological feature is the association with arrhythmias ranging from benign atrial tachycardias to ventricular extrasystoles and sudden cardiac death. These patients may present to prehospital crews with V-fib that cannot be reversed in the field.
All these cardiac events happen very quickly, and without warning. Most of the time, the individual is in asystole before the can falls from their face.
As described in this case, edema and sores in the mouth and throat are common. The force of the aerosol spray causes trauma to the tissue in the throat, resulting in a local inflammatory response. The injured tissue triggered a cascade of events that started with an increase in blood supply to the injured area, followed by an attraction of white blood cells. As white blood cells consume injured cells, they release chemical mediators that continue the inflammatory response until the damaged tissue is removed. In this case, the patient_s death halted the inflammatory response, leaving the tissue very edematous. The location of the inflammation may have contributed to the hypoxia and subsequent death.
Edema and sores can also be caused by frostbite. Many commonly abused inhalants are compressed air dustersƒthe spray cans used to clean computers or detail cars. Compressed gas in cold, and unless the can is warmed prior to use, the gas can freeze tissue. This is especially true when it_s concentrated on a small area, such as the back of the tongue, roof of the mouth or post-pharyngeal area. These extremely cold temperatures also damage and block blood vessels, causing further tissue injury.
Sudden sniffing death is treatable only with prevention. Unlike cardiac arrest due to myocardial infarction or arteriosclerosis, these cases are hypoxic and will probably not respond as expected to ACLS drugs due to the increased sensitivity of the heart to catecholamines. Even small amounts of epinephrine or atropine may produce uncontrollable tachycardia. If standard ACLS protocols are initiated, be cautious and consider smaller doses of all stimulating medications. Most of the time, however, treatment is futile.
The only prehospital treatment for inhalant abuse is supportive care for the patient_s signs and symptoms. Supplemental oxygen may help decontaminate the lungs, but there_s nothing that can be done to reverse the systemic effects. Inhalants are both physically and psychologically addictive, and there_s a very high rate of relapse, so be aware of repeat patients. Remember, 10% of your young population is at risk. Know how to detect inhalant abuse, and know what to expect clinically in these patients.
>>Signs & symptoms of inhalant abuse
>Increased irritation or aggression
>Forgetfulness or difficulty concentrating
>Dizziness or unsteady gait
>Nystagmus (involuntary side-to-side eyemovements)
>Blurred or double vision
>Anorexia or nausea
>Unexplained dry cough or wheezing
>Loss of coordination/clumsiness
>Slowed reflexes andmovements
>Dry, cracked skin and/orsores around the mouth
>Sores inside the mouth or throat
>Dried substances and/or staining around the mouth, hands or clothing
>Chemical odors on the breath, clothing
>Red, watery eyes
>Rhinorrhea (runny nose)
Elizabeth Criss, NP, MEd, MS, CEN, CCRN, is a nurse practitioner in the emergency department at Tucson Medical Center. She was a founding member of the Board of Advisors of the Prehospital Care Research Forum. Criss has been involved in emergency care and disaster management since 1982. Contact her firstname.lastname@example.org.
1.A teacher notices a 16-year-old girl weaving as she stands at her locker. The student tries to toss a piece of cloth into the locker, but it falls to the floor. Further investigation finds the girl with slurred speech and the intense smell of fingernail polish remover to her face and the dropped cloth. Which form of inhalant abuse is likely?
a. Sniffing b. Huffing
c. Fogging d. Bagging
2.An upset mother calls because she found her 13-year-old son in his closet with unrecognizable speech, laughter and red watery eyes. Beside him are two containers of whipped cream in aerosol cans. You find no other causes for his behavior and provide the following information to the mother:
a.The preservatives in the can be toxic when ingested in large amounts.
b.Her son is likely developing anaphylactic shock from the cream or additives.
c.Her son likely aspirated the whipped cream.
d.Her son is likely using the nitrous oxide propellant in the cans to get high.
3.Your 31-year-old female patient has just had a seizure. She reportedly inhales glue and gasoline. Her friends say that about two months ago, she began having quiet periods during which she simply "stared." A few weeks ago, she developed seizures. With this history of inhalant abuse, her seizures and neurological changes are most likely the result of:
a. Increasing cerebral hypoxia and brain death
b. Diabetes and hyperglycemia
c. Low potassium levels and arrhythmias
d. Psychosis and schizophrenia
4.A mom finds her 13-year-old daughter unconscious in bed with a plastic bag next to her face and a can of lighter fluid nearby. A washcloth found in the bag is heavily soaked with the lighter fluid. The girl has a weak, rapid pulse and when you tell the paramedic intern to quickly apply the ECG, she asks if it_s really needed because kids don_t typically have arrhythmias. Your best response to her would be:
a.Inhalant abuse creates myocardial hypoxia, which can lead to ventricular arrhythmias and death.
b.Children over the age of 13 are more prone to sudden arrhythmic deaths.
c.The ECG machine will be useful to continuously monitor her heart rate.
d.inhalants are known to cause unstable atrial flutter, fibrillation and arrhythmias.
5.After a student died of sudden sniffing death, school administrators ask that you speak to their students about inhalant abuse. During the discussion, one of the students says the death must have occurred from something else, because this was the first time the girl had ever "sniffed." Your best response is:
a.It_s likely her death was because she combined other drugs with the inhalant.
b.She probably had an undiagnosed heart condition that the drugs aggravated.
c.Death can occur with the first sniff or huff of inhalants, not just in addicted abusers.
d.She likely had pre-existing epilepsy and the drugs prolonged a seizure, causing her death.
1. B, 2. D, 3. A, 4. A, 5. C