Chapter 21 Toxicology

1 Chapter 21 Toxicology Identifying the Patient and the Poison Toxicology: study of toxic or poisonous substances - Poison: any substance whose chemical action can damage body structures or impair function Toxin: a poisonous substance produced by bacteria, animals, or plants that acts by changing the normal metabolism of cells or by destroying them Substance abuse: the misuse of any substance to produce a desired effect Overdose: a toxic dose of a drug Agent Opiates (morphine, codeine) Opioids (heroin, methadone, oxycodone) Sympathomimetics (epinephrine, albuterol, cocaine, methamphetamine) Sedative-hypnotics (diazepam, secobarbital, flunitrazepam, midazolam) Anticholinergics (atropine, diphenhydramine, chlorpheniramine, doxylamine, jimsonweed) Cholinergics (organphosphates, pilocarpine, nerve gas) Signs and Symptoms -hypoventilation or respiratory arrest -pinpoint pupils -sedation or coma -hypotension -hypertension -tachycardia -dilated pupils -agitation or seizures -hyperthermia -slurred speech -sedation or coma -hypoventilation -hypotension -tachycardia -hyperthermia -hypertension -dilated pupils -dry skin and mucous membranes -decreased bowel sounds -airway compromise -SLUDGEM S- salvation, sweating L- lacrimation (excessive tearing of the eyes) U- urination D- defection, drooling, diarrhea G- gastric upset and cramps E- emesis (vomiting) M- muscle twitching/miosis (pinpoint pupils) How Poisons Enter the Body Poisons are either inhaled, absorbed, ingested, or injected. If inhaled, the patient should be moved to fresh air immediately. Supplemental oxygen may be needed. If a poison has been absorbed, you should avoid contaminating yourself or others, as well as remove the irritating or corrosive substance from the 2 patient as soon as possible. If ingested, activated charcoal can be given to slow the process. You should asses ABCs. And if injected, you should do BLS until arrival. Material safety data sheet (MSDS): a form, provided by manufacturers and compounders of chemicals, containing info about chemical composition, physical and chemical properties, health and safety hazards, emergency response, and waste disposal of certain materials When taking history, you should ask questions such as- 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 bystander performed any intervention on the patient? Has the intervention helped? How much does the patient weigh? Specific Poisons Over time, a person who routinely misuses a substance may need increasing amounts of it because they have developed a tolerance. A person with an addiction has an overwhelming desire or need to continue using the substance. Alcohol Alcohol is both a sedative and a hypnotic. It may also cause aggression and inappropriate behavior and lack of coordination. Over the counter drugs, including antihistamines and diet medications, can cause serious complications when combined with alcohol. - Sedative: a substance that decreases activity and excitement Hypnotic: something that induces sleep Delirium tremens (DTs): a severe withdrawal syndrome seen in alcoholics who are deprived of ethyl alcohol; characterized by restlessness, fever, sweating, disorientation, agitation, and seizures; can be fatal if untreated Those under the influence of alcohol may experience hallucinations and/or delusions, agitation, fever, sweating, tremors, confusion, and even seizures. Opiates and Opioids Narcotic: a drug that produces sleep or altered mental consciousness Opioid: a type of narcotic medication used to relieve pain Opiate: a subset of the opioid family, and refers to a natural, non-synthetic opioids 3 Naloxone (Narcan) is an antidote that reveres the effects of opiate or opioid overdose. It can be given intravenously, intramuscularly, or intranasally. Ideally, it is done IV. Although, a vein can sometimes be difÏcult to obtain in a frequent user. Sedative- Hypnotic Drugs Barbiturates and benzodiazepines have been a part of legitimate medicine for a long time because they are easy to obtain and relatively cheap. These drugs are CNS depressants and alter the level of consciousness, with effects like those of alcohol. These are usually taken by mouth. You should assure the airway is patent, assist ventilations, and provide prompt transport. Abused Inhalants This is called hufÏng. More common agents include acetone, toluene, xylene, and hexane, which are found in glues, cleaning compounds, paint thinners, and lacquers. Hydrogen Sulfide Hydrogen sulfide is a highly toxic, colorless, and flammable gas with a distinctive rotten-egg odor. It usually occurs by inhalation, and mostly affects the lungs and CNS. It naturally occurs in sewers, swamps, volcanoes, and crude petroleum. Sympathomimetics These are CNS stimulants that mimic the effects of the sympathetic (fight or flight) nervous system. These stimulants frequently cause hypertension, tachycardia, and dilated pupils. They are usually taken to make the patient “feel good”, improve task performance, suppress appetite, or prevent sleepiness. Stimulant: an agent that produces an excited state Popular examples include cocaine, ecstasy, methamphetamine, etc. Synthetic Cathinone’s (Bath Salts) These refer to an emerging class of drugs like MDMA. Bath salts produce euphoria, increased mental clarity, and sexual arousal. Most users of this drug snort or insufÒate the powder nasally. Symptoms can last up to 48 hours. Marijuana 4 With very high doses, some patients may experience hallucinations or become very anxious or paranoid. Several states have legalized the use of marijuana, and many others allow for the medical use and products that contain THC. Hallucinogens Hallucinogens: an agent that produces false perceptions in any one of the five senses Common hallucinogens include lysergic acid diethylamide (LSD) and phencyclidine (PCP, or angel dust). They intensify vision and hearing, cause visual hallucinations, and generally separate the user from reality. Anticholinergic Agents These are medications that block the parasympathetic nerves. - “Hot as a hare, blind as a bat, dry as a bone, red as a beet, and mad as a hatter”.  This means hyperthermia, dilated pupils, dry skin and mucous membranes, reddened skin, and agitation or delirium. Cholinergic Agents These are medications that overstimulate the normal body functions controlled by the parasympathetic nervous system. A patient who has been poisoned by this will exhibit excessive salivation or drooling, mucous membrane over secretion, resulting in a runny nose (rhinorrhea), excessive urination, excessive tearing of the eyes, uncontrolled diarrhea, and an abnormal heart rate. Diarrhea Urination Mitosis (constriction of the pupils), muscle weakness Bradycardia, bronchospasm, bronchorrhea (discharge of mucus from the lungs) Emesis (vomiting) Lacrimation (excessive tearing) Seizures, salivation, sweating Miscellaneous Drugs Accidental or intentional overdose with cardiac medications has become popular because there are so many patients who have these prescribed for them. Another common issue is older patients forgetÝng they have already taken medication, so they take it again. Aspirin poisoning is another potentially lethal 5 condition. Acetaminophen becomes toxic when consumed in excess. Some alcohols, such as methyl and ethylene are even more toxic than drinking alcohol. If left untreated, both will cause tachycardia, blindness (methyl), renal failure (ethylene), and eventually death. Food Poisoning In one type of food poisoning, the organism itself causes disease; in the other, the organism produces toxins that cause disease. Salmonellosis is a common one that is characterized by severe gastrointestinal symptoms within 72 hours of ingestion, including nausea, vomiting, abdominal pain, and diarrhea. The most severe type is botulism. This often- fatal disease usually results from eating improperly canned food. Plant Poisoning Some poisonous plants cause skin irritation, while others affect the circulatory system, the gastrointestinal tract, or the CNS. You should assess the patient’s airway, notify the regional poison center for assistance in identifying the plant, take the plant to the emergency department, and provide prompt transport.