Toxicology

A poison is a substance whose chemical action could damage structures or impair function when introduced into the body. A toxin, a poison or harmful substance, is a poisonous substance produced by bacteria, animals, or plants that acts by changing the normal metabolism of cells or by destroying them. An overdose – taking too much of a medication or substance or drug interaction, toxic or lethal doses.

Some common signs of poisoning or toxic exposure for different types of toxics and medications are as follows. With opiates expect hypoventilation or respiratory arrest, pinpoint pupils, sedation or coma in combination with hypotension. For sympathomimetics (mephedrone, cocaine, methamphetamine) expect hypertension, tachycardia, dilated pupils, agitation or seizures, and hyperthermia. For sedative-hypnotics (diazepam, secobarbital, temazepam, midazolam) you typically see slurred speech, sedation or coma, hypoventilation, and hypotension. In anticholinergics (atropine, diphenhydramine, chlorpheniramine, doxylamine) you experience tachycardia, hyperthermia, hypertension, dilated pupils, dry skin and mucous membranes, sedation, along with decreased bowel sounds. With cholinergics (organophosphate, pilocarpine, nerve gas) – airway compromise, SLUDGEM. Salivation, sweating, L – lacrimation (excessive tearing of the eyes), U – urination, D – defecation, drooling, diarrhea, G – gastric upset and cramps, E – emesis (vomiting), M – muscle twitching.

There are a few different methods poisons and toxins can enter the body, the first of which being inhalation of natural gas, sewer gas, certain pesticides, carbon monoxide, and chlorine – immediately move to fresh air and provide supplemental oxygen. If you suspect airborne poison contact the hazmat team who are trained to go in and then decontaminate the patient. Gas can get trapped in both clothing and skin. Scene safety is always a priority. Any time there is more than one patient and no evidence of the mechanism of injury (MOI) or nature of illness (NOI) be suspicious.

You can also be poisoned through absorption. Some of the ways this could happen are acids, alkalis, and hydrocarbons, poison ivy or poison oak. Try to distinguish between contact burns and contact absorption. Signs and symptoms of absorbed poison include a history of exposure, liquid or powder on the patient’s skin, burns, itching, and irritation. Avoid contaminating yourself or others. Make sure to remove all clothing that has been contaminated with poisons or irritating substances; if in the eye, irrigate them quickly and thoroughly. Always ensure you are decontaminated prior to transport.

We are all relatively familiar with the ingestion route. Poison enters by something you ate or drank. Could be a foodborne illness or some type of toxic like bleach or nightshade. 80% of all poisonings are ingestion based. When this happens sometimes activated charcoal can be used to dilute. Not indicated for patients who have ingested alkali poisons, cyanide, ethanol, iron, lithium, methanol, mineral acids, or organic solvents. 1 g per kilogram of body weight; the usual adult dose is 30 to 100 g and the usual pediatric dose is 15 to 30 g for children younger than age 13. Please make sure to obtain permission from medical control. EMTs never induce vomiting. The injection route cannot be diluted or removed. If opioids you can use naloxone. Also provide high-flow oxygen and remove rings and jewelry from around the swelling site.

When treating a patient with suspected overdose, provide oxygen and watch the airway while considering prompt transport. Obtain SAMPLE en route to the hospital. If unresponsive attempt to obtain history from coworkers, bystanders, friends, or family members. Ask the following questions: What is the substance involved? When did the patient ingest or become exposed to the substance? How much did the patient ingest or what was the level of exposure? Over what period did the patient take or was the patient exposed to the substance? Has the patient or a bystander performed any intervention on the patient? Has the intervention helped? How much does the patient weigh? When doing the secondary assessment be alert for burns or inspect the mouth, rash or burn, auscultate the lungs to make sure there is good air movement. A complete set of baseline vital signs is important. Alterations in LOC, pulse, respirations, blood pressure, and skin are more sensitive indicators that something serious is wrong.

Some of the following are major toxins.

Alcohol – Dangers of drinking – Central Nervous System depressant, sedative, and hypnotic, induces sleep, aggressive and inappropriate behavior. May cause hypoglycemia; look for signs of head trauma, mental illness, toxic reactions, or uncontrolled diabetes. Cannot refuse transport. Increases the effects of many drugs and is taken with other substances. OTC drugs including antihistamines and diet medications can cause serious complications when combined with alcohol. Blood clot issues. A patient in alcohol withdrawal may experience frightening hallucinations, or delirium tremens (DTs) for 1 to 7 days after the person stops drinking.

Opiates and opioids – produces sleep or altered mental consciousness. CNS depressants and can cause severe respiratory depression. Typically appear sedated or unconscious and exhibit cyanosis with pinpoint pupils. Naloxone is an antidote that reverses the effects of opiate or opioid overdose. Intranasal route is preferred to alternative routes for the administration of naloxone. Be aware that this drug can cause harm and should only be used when the patient has agonal respirations or apnea. When patient goes into cardiac arrest, administer naloxone if it is available and provide ventilations and rapid transportation.

Sedative-hypnotic drugs (barbiturates and benzodiazepines) are sedative-hypnotics – they alter the level of consciousness with effects similar to those of alcohol. They are often taken to boost the effects of alcohol or an opioid. They can be used as a knock-out drink to incapacitate them without their knowledge. Sedate in the hospital. Ensure airway and give supplemental oxygen when appropriate.

Abused inhalants – huffing, glues, cleaning compounds, and paint thinners. CNS and act as other sedative-hypnotics. The effective dose and the lethal dose are very close, making these extremely dangerous drugs. Effects may range from mild drowsiness to coma but can cause seizures, ventricular fibrillation. Hydrogen sulfide – rotten egg odor – naturally occurs in sewers. You need to be alert to containers, buckets, or pots. There is no antidote and must get a hazmat team involved.

Sympathomimetics are CNS stimulants that mimic the effects of the sympathetic fight-or-flight nervous system. A stimulant is an agent that produces an excited state. Some examples are methamphetamine and amphetamine. Taken to make the user “feel good”, improve task performance, suppress appetite, or prevent sleepiness. May see high blood pressure 250/150 mm Hg. Synthetic cathinone (bath salts) produces euphoria, increased mental clarity, and sexual arousal.

Marijuana euphoria progresses to depression and confusion. Be aware that it could be laced. Cannabinoid hyperemesis syndrome, extreme nausea and vomiting. Spice and K2 are a problem and have no medical benefit.

Hallucinogens alter a person’s sensory perceptions. Can cause people to inflict injury on themselves; altered mental state can be terrifying. Have hypertension, tachycardia, anxiety, and paranoia. Use a professional, calm manner and provide emotional support.

Anticholinergic agents: hot as a hare, blind as a bat, dry as a bone, and red as a beet. Some examples are Benadryl, jimsonweed, amitriptyline. Often seen when patients overdose. Patients with acute tricyclic antidepressant overdose must be transported immediately to the ED; they may appear “normal” but seizure and death can occur within 30 minutes. This occurs because medication blocks the electrical conduction system in the heart, leading to lethal cardiac dysrhythmias.

Cholinergic agents are used in chemical warfare and in insecticide. Excessive salivation or drooling, mucous membrane oversecretion, resulting in a runny nose, excessive urination, excessive tearing of the eyes, uncontrolled diarrhea, and an abnormal heart rate. DUMBELS – D – diarrhea, U – urination, M – miosis (constriction of the pupils), muscle weakness, B – bradycardia, E – emesis, L – lacrimation, S – seizures. Antidote treatment: nerve agent auto-injector (ATNAA) or DuoDote auto-injector if you expose yourself. Treat with pralidoxime to reverse the nerve agent. Priorities are decontamination to decrease the secretions in the mouth and provide airway support.

There are two main types of food poisoning. In one, the organism itself causes disease; in the other, the organism produces toxins that cause disease. Salmonellosis is a condition characterized by severe gastrointestinal symptoms within 72 hours of ingestion; some people are carriers of certain bacteria they may transmit. Proper cooking kills bacteria and proper cleanliness in the kitchen. The most common cause of food poisoning is the ingestion of powerful toxins produced by bacteria, often in leftovers, staphylococcus. Foods left unrefrigerated. Symptoms include nausea, vomiting, and diarrhea. Botulism is an often fatal disease, usually results from eating improperly canned food, in which the spores of clostridium bacteria have grown.