Toxicology is the study of toxic or poisonous substances and their effects on the body and a topic you should know for the EMT exam. The signs and symptoms associated with toxic exposure and poisoning range very widely, from simple annoyances to life-threatening conditions.
As an EMT, your primary goals are to ensure your own safety and identify the possibility of a toxic exposure while preserving the patient’s airway, breathing, and circulation.
Toxins and poisons enter the body through the following routes:
Ingestion: Swallowing
Inhalation: Being breathed in
Absorption: Passing through the surface of the skin
Injection: Directly entering the blood stream
As a rule, the fastest route is inhalation; the slowest is ingestion. However, depending upon the substance, any of these routes can cause serious harm.
One number you should always keep handy while working is the one to reach your local poison control center. There are 56 centers across the United States; the universal number is 800-222-1222.
Poison control staff have immediate access to a tremendous amount of information about poisonous substances. They can help you identify the substance, determine how dangerous the situation is, and decide whether the patient should seek further attention. They’re a great resource for EMS providers in the field.
Check out this list of toxic and poisonous substances that you should be familiar with, along with their symptoms and treatments.
| Substance | Signs and Symptoms | Specific Treatment |
|---|---|---|
| Alcohol ingestion | Recreational sedative that causes initial euphoria followed by sleepiness and an altered level of consciousness; produces slurred speech, loss of balance and coordination, nausea, vomiting. Can dangerously magnify effects of other drugs, especially if they’re also sedatives. | Protect airway; prepare to suction if needed. Assist ventilations if needed. Try to determine whether other drugs were involved. Some intoxicated patients can be unpredictably violent; be aware of your own safety. |
| Carbon monoxide inhalation | Gas that causes headache, nausea, vomiting, sleepiness that worsens into unconsciousness. | If found in a confined space, evacuate patient and yourself to a safe place. Provide high-flow oxygen and assist ventilation if necessary. Consider transport to a bariatric chamber. |
| Food poisoning | Onset from within a few minutes to hours of ingestion. Vomiting, diarrhea, abdominal pain, cramping. | Suction as needed. In cases of botulism, patients may suffer respiratory arrest and require assistance with ventilations. |
| Marijuana, hallucinogens | Mind-altering substances that can be inhaled or ingested. Can cause paranoia, anxiety. | Offer reassurance and remain calm to help reduce anxiety in patient. Try to determine whether there is other drug use. |
| Narcotic overdose by ingestion, injection, or inhalation | Prescribed painkillers and illegal heroin cause euphoria followed by sleepiness and an altered level of consciousness. In larger doses, patients stop breathing. Constricted pupils; loss of gag reflex; injection sites (track marks) on arms, legs. | If the patient is “nodding,” gently stimulate him to keep him breathing spontaneously. If respiratory arrest occurs, insert oropharyngeal airway or nasopharyngeal airway and begin bag-valve-mask ventilations. |
| Nerve agents | Include pesticides and fertilizers that can be absorbed through
skin and chemical weapons that are inhaled. Cause a series of signs
that can be remembered as SLUDGE-M (salivation, lacrimation, urination, defecation, GI motility, emesis, and meiosis — constricted pupils). |
For a nerve agent attack, EMTs may have specific antidote kits containing atropine autoinjectors to combat the effects on themselves. For pesticides and fertilizers, decontaminate the patient prior to care. Suction as needed and assist ventilations if necessary. |
| Sedative-hypnotic drug ingestion | Prescription sedative overdoses cause sleepiness that worsens into unconsciousness. Breathing may be compromised. Pupils may become dilated. | Maintain airway patency, ventilate as needed. |
| Stimulant ingestion | Stimulants such as cocaine, methamphetamines, MDMA, bath salts, and crack can cause paranoia, severe tachycardia, hypertension, and high fevers and can precipitate heart attacks and strokes. Patients may have chest pain, difficulty breathing, and profuse sweating. | Manage airway and breathing; assist ventilations if needed. Be careful of potentially violent behavior. |