Emergency Care Textbook Professional Responders PDF

14 Poisoning Key Content Poison Control Centres........... Recognizing Poisoning........... General Care for Poisoning Emergencies......................... Ingested Poisons.................. Inhaled Poisons.................... Absorbed Poisons................. Injected Poisons................... Sub...

14 Poisoning Key Content Poison Control Centres........... Recognizing Poisoning........... General Care for Poisoning Emergencies......................... Ingested Poisons.................. Inhaled Poisons.................... Absorbed Poisons................. Injected Poisons................... Substance Misuse and Abuse............................ Crowd Management Agents.................................. 261 261 261 262 262 263 265 270 274 Introduction A poison is a substance that causes injury, death, or impairment of an organism through chemical action (as opposed to the biological action of a bacteria or virus). The effects range from mild irritation to death. A poisonous substance could be a solid, liquid, or fume (gas or vapour). POISONING There are four routes through which a poison can enter the body (Figure 14–1, a-d): Ingestion Inhalation Absorption Injection 259 d Figure 14–1, a-d: A poison can enter the body by a, ingestion; b, inhalation; c, absorption; and d, injection. POISONING Ingested poisons are swallowed and enter the body through the digestive system. Examples include foods (e.g., toxic mushrooms, contaminated shellfish), many drugs and medications (e.g., alcohol, ASA), and household substances that could be accidentally ingested, especially by children (e.g., cleaning products, pesticides). 260 Poisoning by inhalation occurs when a person breathes in toxic gas or fumes. Inhaled poisons include carbon monoxide (a by-product of combustion), chlorine (found in commercial swimming facilities), and fumes from household products such as glue and paint. Hydrogen sulfide (H2S) is a common inhaled poison found in many spray chemicals, which also occurs naturally as a result of organic decomposition in closed environments. Absorbed poisons enter the body through the skin or other membranes (e.g., mucous membrane in the mouth or nose). Sources of absorbed poisons include plants (e.g., poison ivy, giant hogweed), fertilizers and pesticides, and drugs that are absorbed through the mucous membranes (e.g., cocaine). © iStockphoto.com/toddmedia © iStockphoto.com/Michael Pettigrew c b © iStockphoto.com/savageultralight a Injected poisons enter the body through bites or stings of insects, spiders, ticks, snakes, and other animals. They can also be drugs or medications that are injected into the body with a hypodermic syringe. The signs and symptoms of poisoning vary greatly depending on the substance that entered the body and the route by which it entered: A person who has inhaled carbon monoxide will have a very different presentation when compared with a person who has touched poison ivy. POISON CONTROL CENTRES In general, a patient who has been poisoned will often display signs and symptoms common to other sudden illnesses, including: Sweating. Nausea. Vomiting. Diarrhea. Chest or abdominal pain. Dyspnea. Altered level of responsiveness. Seizures. Dispatchers may be able to connect to the Poison Control Centre directly. A dispatcher may also monitor discussion with the Poison Control Centre and provide additional information to responders. In some instances, this eliminates the need for a second call and saves time. If you suspect that a patient has been poisoned, try to get answers to the following questions: 1. What type of poison was it? 2. How did the contamination occur (inhalation, ingestion, etc.)? 3. When did it occur? 4. What was the quantity of poison (if known)? RECOGNIZING POISONING This information will ensure that the patient receives the most appropriate initial treatment, as well as any additional treatment that is necessary. The severity and presentation of the poisoning depends on the type and amount of the substance, how it entered the body, and the patient’s height, weight, and age. Many substances may be harmless (or even beneficial) in small quantities but poisonous in larger amounts. While some poisons act quickly and display characteristic signs and symptoms in patients, others act slowly and cannot easily be identified. Sometimes, identifying a specific poison based on the signs and symptoms may be difficult. It may not be obvious that a patient has been poisoned. As always, look for clues at the scene that could indicate the MOI. As you approach the patient, watch for any unusual odours, flames, smoke, open or spilled containers, open medicine cabinets, overturned or damaged plants, or other signs that could suggest poisoning. You may also see drug paraphernalia at the scene (e.g., rolling papers, pipes, syringes). GENERAL CARE FOR POISONING EMERGENCIES The specific interventions required for poisoning vary based on a number of factors, including the specific poison involved, the route through which it entered the body, and the amount of poison. In addition to providing the care described for each type of poison, there are general guidelines that should be followed for most patients with suspected poisoning. If you have the proper equipment and qualifications, limit further exposure to the poison. Never put yourself at risk: If necessary (or if you are unsure of the nature of the hazard), request properly qualified personnel. POISONING Poison Control Centres exist throughout Canada to help responders of all levels (and the general public) deal with suspected poisonings. Medical professionals in these centres have access to information about virtually all poisonous substances, and they can direct you on how to proceed. You should know the number of your closest Poison Control Centre. 261 Avoid giving the patient anything by mouth unless advised to do so by Poison Control Centre staff. Your scope of practice may indicate a specific oral intake as an intervention for a particular type of poison: This may be provided so long as you are certain of the type of poison involved. Sometimes the Poison Control Centre will advise you to induce vomiting. To do so, follow the Poison Control Centre’s instructions as well as local protocols. In addition, before you induce vomiting, ensure that the patient meets all of the following criteria: The patient is fully responsive and understands instructions. The patient is co-operative. The patient has not had a seizure or vomited spontaneously. The patient is not exhibiting periods of instability with respect to pulse, respiration, or level of responsiveness. If the poison is unknown and the patient vomits, save some of the vomitus, as it may be analyzed later to identify the poison. Ensure that the container used is labelled with the patient’s name, the date, the time, and any other identifying details available. Ensure that it stays with the patient when care is transferred. The Poison Control Centre may direct you to neutralize the remaining poison in the patient’s stomach with activated charcoal. Activated charcoal is available in both liquid and powder forms and may be part of your response equipment. Use activated charcoal as directed by the Poison Control Centre and local protocol. It is also important to manage concurrent problems and monitor the patient closely. Administer oxygen if indicated. If directed to do so by the Poison Control Centre, you can dilute some ingested poisons by giving the patient water to drink. Diluting the substance decreases the potential for damaging tissues. Contact the Poison Control Centre and follow the directions provided. If the poison is a commercial product, it should have a clear label or corresponding Safety Data Sheet (SDS). These will detail first aid procedures for the substance: Follow any directions, and contact the Poison Control Centre for additional information. Ingested Poisons POISONING Signs and symptoms of ingested poisons, like those of all poison types, vary considerably, but the following are often present: An open container of poison nearby Burns around the mouth Unusual odour on the breath Increased production of saliva or saliva that is an abnormal colour Abdominal cramps, vomiting, or diarrhea Seizures Dizziness or drowsiness Unresponsiveness A burning sensation in the mouth, throat, or stomach 262 Food poisoning is one example of ingested poisoning. It occurs when a person ingests food that has been contaminated by infectious organisms or their toxins. If multiple people who have shared the same food become ill with signs and symptoms of ingested poisoning, you may suspect food poisoning as the cause. Inhaled Poisons General signs and symptoms of inhaled poisoning include: Respiratory distress or dyspnea. Respiratory arrest. Irritated eyes, nose, or throat. Dizziness. Vomiting. Seizures. A bluish colour (cyanosis) around the mouth. Unresponsiveness. An unusual smell in the air or on the patient’s breath. If you suspect that a patient has been poisoned by an inhaled substance, take steps to ensure that you are not exposed yourself. If you know or suspect that the substance is still in the air, the scene may not be safe for you to enter. Unless you have specialized training or equipment, request specially qualified and equipped personnel to make the scene safe or move the patient to a safe Any patient with suspected inhaled poisoning should be in the rapid transport category, as respiration is often impaired. Perform any indicated interventions for respiratory distress or arrest, as well as any specific interventions described by the Poison Control Centre. CARBON MONOXIDE POISONING A common inhaled poison is carbon monoxide (CO). CO is an odourless, colourless, tasteless gas. Because it is not detectable to the senses and is quite common, it is a frequent cause of accidental poisoning deaths. CO is found in fumes that are produced when fuel is burned in cars or trucks, small engines, stoves, lanterns, grills, fireplaces, gas ranges, and furnaces. CO replaces the oxygen (O2) bonded to a patient’s red blood cells, slowly depriving the body of oxygen. As a result, most signs and symptoms of CO poisoning are essentially signs and symptoms of hypoxia. CO poisoning mainly affects the central nervous system and the heart. CO poisoning may be either acute (e.g., a patient is in a closed garage with an engine running) or chronic (e.g., a patient’s furnace exhaust has a leak). Chronic CO poisoning may last months. The most common signs and symptoms of carbon monoxide poisoning include: Headaches. Dizziness. Weakness or fatigue. Pale or bluish skin colour. Nausea or vomiting. Chest pain. Confusion. Seizures. Impaired hearing and vision. Altered level of responsiveness. Tachycardia or arrhythmia. Low blood pressure. Dyspnea (especially shortness of breath). Respiratory arrest. However, some of these symptoms can be vague and non-specific, and diagnosis of CO poisoning can easily be missed. Mild CO poisoning is often mistaken for food poisoning or gastroenteritis. Pay attention to headaches and similar flu-like symptoms reported by multiple people living in the same dwelling, particularly in colder times of the year when homes are being actively heated. CO poisoning symptoms usually resolve themselves when a patient is removed from exposure, unless there has been an episode of acute poisoning. Absorbed Poisons People often come into contact with poisonous substances that can be absorbed through the skin. Many of these cause only minor irritation—for example, poison ivy (Figure 14–2, a), poison sumac (Figure 14–2, b), and poison oak (Figure 14–2, c). Other common poisons absorbed through the skin include dry and wet chemicals, such as those found in insecticides and toxic industrial chemicals. To treat general absorbed poisoning: 1. Wash the affected area with cool water immediately and pat dry. 2. Keep the area clean and dry. 3. Instruct the patient to see a physician if the condition worsens. If exposure to a wet or dry chemical immediately causes burns to the patient’s skin, refer to the care for chemical burns (page 189). RASH-CAUSING PLANTS Some plants produce chemicals that can cause absorbed poisoning on contact. These plants vary in appearance depending on the location, species of plant, and time of year. As prevention is the best strategy, it is a good idea to become familiar with the appearance of rash-causing plants in your area. Poison Ivy, Sumac, and Oak Plants such as poison ivy, poison sumac, and poison oak produce urushiol, an oil that causes skin irritation in most people. If a patient has come into contact with urushiol, he or she may have the following signs and symptoms in the exposed areas: POISONING area. In other cases, a simple step such as opening a garage door can allow fumes to escape and render the scene safe. 263 Itching Red rash Swelling Bumps, streaking, and weeping blisters Treatment for Poison Ivy, Sumac, or Oak Poisoning If a patient has absorbed poisoning caused by poison ivy, poison sumac, or poison oak, encourage the patient to apply a cream or ointment designed to reduce itching or blistering (e.g., calamine). Suggest the patient take an oral antihistamine to relieve itching. If the rash is severe or on a sensitive part of the body (e.g., the face or groin), the patient should be assessed by a physician. Giant Hogweed and Wild Parsnip POISONING The sap of giant hogweed and wild parsnip contains furanocoumarins (toxic photosensitizing compounds). Contact with either of these plants transfers these compounds to the skin. While they do not have an immediately visible effect, they cause the skin to react when exposed to the sun’s UV radiation, producing severe inflammation, intense burning, and weeping blisters. If any of these plants are found, their location should be reported to the local environmental or municipal authorities. 264 The specific signs and symptoms depend on the time since exposure to sunlight: 24 hours after exposure: ◆ Swelling of the skin ◆ Reddening of the skin 48 hours after exposure: ◆ Painful blistering ◆ Purplish scarring of the skin b c Figure 14–2, a-c: a, Poison ivy; b, poison sumac; and c, poison oak. © iStockphoto.com/AlpamayoPhoto a © iStockphoto.com/devdogg Plants containing urushiol should never be burned. The oil is carried in the smoke, and inhalation can cause inflammation of the throat and irritation of the lungs. © iStockphoto.com/NoDerog The severity of the rash can range from mildly irritating to unbearable, depending on the patient’s sensitivity, the amount of skin exposed, and the rash’s location. Treatment for Giant Hogweed or Wild Parsnip Poisoning If the patient’s skin has come in contact with the sap of giant hogweed or wild parsnip, protect the area from sunlight. Encourage the patient to see a physician following the incident. If sap gets into the patient’s eyes, the patient is in the rapid transport category: Rinse the eyes thoroughly with water for at least 15 minutes and ensure the patient receives prompt transportation to a medical facility. Injected Poisons Insect and animal stings and bites are among the most common sources of injected poisons. Care varies based on the species causing the sting or bite, as different creatures carry different toxins and deliver it in different ways. If the animal is still present, do not attempt to capture it, as this can put you at risk. Instead, make a note of any memorable features, such as distinctive patterns or colouration. This will help to determine the appropriate treatment. Antivenins are available for many particular types of venom. Identifying the species makes it possible to determine whether an antivenin is available. The following sections describe the care for common stings and bites of insects, spiders, marine life, snakes, mammals, and ticks. INSECTS Although insect stings are painful, they are rarely fatal. However, some people have anaphylactic reactions to insect stings, creating immediately life-threatening situations. To provide treatment for an insect sting, examine the affected area to see if the stinger is embedded in the skin. Some insects, such as bees, leave their stingers in the patient’s skin. Others, such as wasps, do not. If the stinger is embedded, prevent any further poisoning by scraping the stinger away from the skin with a plastic card (e.g., driver’s licence or credit card) to remove it. Often, the venom sac will still be attached to the stinger. Do not remove the stinger with forceps since putting pressure on the venom sac can inject additional toxins into the patient. Next, wash the site with water and cover it with a dressing. Apply a cold pack wrapped in a thin, dry towel to the area to reduce the pain and swelling. Monitor the patient for signs and symptoms of an allergic reaction, and provide care for anaphylaxis if any are present. Cimex lectularius (or bedbugs) are insects that trouble many Canadian homes. Their bites can cause skin irritation that can be intensely uncomfortable and creates the risk of infection. Following proper decontamination procedures for your clothing and equipment reduces the risk of carrying infestation from a patient’s home. SPIDERS While few spiders in North America produce venom that causes dangerous reactions, bites from black widow and brown recluse spiders can (in rare cases) be fatal. You can identify these spiders by the unique designs on their bodies. The black widow spider is black with a reddish hourglass shape on its underbody (Figure 14–3). The bite usually causes an immediate sharp pain, followed by dull pain in the area of the bite. However, a patient often does not know that he or she has been bitten until he or she starts to feel ill or notices a bite mark or swelling. Signs and symptoms of a black widow spider bite include: A raised, round, red mark. Cramping pain in the thighs, shoulders, back, and abdominal muscles. POISONING The affected area may be sensitive to sunlight for months or even years following the incident. Ensure the patient is aware of this and knows to protect the area by keeping it covered, wearing sunglasses (if the affected area is the eye), and applying sunscreen. 265 © iStockphoto.com/Clint Spencer © iStockphoto.com/Mark Kostich Figure 14–3: A black widow spider. Restlessness and anxiety. Dizziness. Headache. Excessive sweating. Weakness. The brown recluse spider is light brown with a darker brown violin-shaped marking on the top of its body (Figure 14–4). Its bite may initially produce little or no pain, with pain developing in the area of the bite an hour or more after it occurs. A blood-filled blister forms under the surface of the skin, sometimes in a target or bull’s-eye pattern. Over several hours, the blister increases in size. Eventually it ruptures, leading to tissue destruction and a black scab. Signs and symptoms of a brown recluse spider bite include: A slight stinging sensation (though bites may not be initially felt). A blood-filled blister that appears within 2 to 8 hours. A bull’s-eye pattern around the bite. POISONING Signs and symptoms of a severe reaction to a brown recluse spider bite occur within 72 hours of the bite and include nausea, vomiting, and joint pain. 266 Both spiders prefer dark, secluded places where they are seldom disturbed. Bites usually occur when a patient reaches into a wood, rock, or Figure 14–4: A brown recluse spider. brush pile, or is rummaging in a dark storage area. Often, the patient will not know that he or she has been bitten until signs or symptoms develop. To treat a bite from a non-venomous spider, wash the wound and apply a wrapped cold pack to the site. If the spider is identified as either a black widow or a brown recluse, the patient should be in the rapid transport category. Keep the bitten area elevated and as still as possible, and apply ice or a chemical cold pack. Place something such as a gauze pad or towel between the cold source and the skin to avoid freezing the tissues. The wound should be cleaned by medical personnel, and medication will usually be provided to reduce the pain and inflammation. MARINE LIFE Sting rays (Figure 14–5), sea anemones, certain fish, jellyfish, and other marine animals can give painful stings that may cause allergic reactions, paralysis, and even cardiac or respiratory arrest. A patient who has been stung in the water should be removed as soon as possible. If any of the following statements is true, place the patient in the rapid transport category: The patient has a history of allergic reactions to marine-life stings. The patient has been stung on the face or neck. The patient develops severe problems, such as dyspnea. SNAKES Figure 14–5: A stingray. The specific interventions that are indicated depend on the type of marine creature responsible for the wound. Jellyfish, Man-of-War, or Sea Anemone To treat a sting from a jellyfish, man-of-war, or sea anemone, soak the affected area in vinegar to deactivate the toxin. Rubbing alcohol or baking soda may also be used. Do not rub the wound or apply fresh water or ammonia, as this will increase pain. If pieces of the marine creature (e.g., tentacles) are still attached to the patient, deactivate the toxin before attempting to remove them. Otherwise, additional toxins may be released into the patient’s body when the pieces are disturbed. Stingray, Sea Urchin, or Spiny Fish For stings from a stingray, sea urchin, or spiny fish, flush the wound thoroughly: Sterile saline is preferred, but tap water or even ocean water may be used if other options are not available. Immobilize the injured part (often the foot), and soak the affected area in water that is as hot as the patient can tolerate for approximately 30 minutes or until the pain subsides. Then, carefully clean the wound and apply a bandage. Remind the patient to watch for signs of infection and check with a healthcare provider to determine whether a tetanus shot is required. There are three venomous snakes currently native to Canada (Figure 14–6, a-c). All three are rattlesnakes: 1. Northern Pacific Rattlesnake 2. Massasauga Rattlesnake 3. Prairie Rattlesnake If the patient has been bitten by a venomous or unidentified snake, place the patient in the rapid transport category and follow these guidelines: 1. Keep the injured site still. Position the patient so that the bite is at or below the level of the heart, if possible. 2. If the bite is on a limb, remove any jewellery or tight clothing from the limb and watch for inflammation. 3. Wash the wound with water. 4. Cover the bite with a clean (ideally sterile), dry dressing. Very few people die of snakebites. Most snakebite deaths occur because a patient has an allergic reaction to the venom or has a weakened body system, or because significant time passes before the patient receives medical care. Because time is a crucial factor, a patient who has been bitten by a venomous snake should be transported as rapidly as possible. If ground transportation will be delayed, or if you are in a remote area, consider requesting air evacuation (if local protocol allows). Avoid the following when treating a snakebite: Applying ice. Cooling the bite can cause further harm. Cutting the wound. Cutting the wound can further injure the patient and has not been shown to remove any significant quantity of venom. Applying a tourniquet. A tourniquet severely restricts blood flow to the extremity, which could result in the loss of the extremity. POISONING ©iStockphoto.com/Niko Guido Rattlesnakes account for most snakebites and nearly all snakebite fatalities in Canada. However, most snakes in Canada are not venomous, so a patient with a snakebite has not necessarily been poisoned. However, if the species of snake is unknown and venomous snakes are present in the region, treat the patient as if he or she was bitten by a venomous snake. 267 POISONING 268 c Figure 14–6, a-c: Venomous snakes native to Canada are a, the Northern Pacific Rattlesnake; b, the Massasauga Rattlesnake; and c, the Prairie Rattlesnake. © Reptilia Zoo and Education Centre b © Reptilia Zoo and Education Centre a © iStockphoto.com/Dave Rodriguez MAMMALS The bite of a domestic or wild animal carries the risk of infection, as well as soft tissue injury. One serious risk with mammal bites is rabies, which is a viral disease that is transmitted through the saliva of infected mammals. Wild mammals (e.g., raccoons, bats, and skunks) are most frequently affected, but domestic mammals (e.g., dogs, cats, and cattle) are also at risk. Animals with rabies may act in unusual ways. For example, nocturnal animals such as raccoons may be active in the daytime. A wild animal that usually tries to avoid humans may not run away when approached. Rabid animals may salivate, appear partially paralyzed, or act irritable, aggressive, or strangely quiet. If not treated, rabies can be fatal. Anyone bitten by an animal suspected of having rabies must seek medical attention. To prevent rabies from developing, the patient receives a series of injections to build up immunity. In the past, caring for rabies meant a lengthy series of painful injections that had many unpleasant side effects. However, modern vaccines usually require fewer injections and have less severe side effects. If a patient has been bitten by a mammal, follow these guidelines: Attempt to get the patient away from the animal without causing further harm to the patient or endangering yourself. If the animal is not present, try to get a good description of the animal and the area in which it was last seen. Treat any open wounds. Any person who has been bitten by an animal must see his or her physician. Local laws or protocols may require you to report the bite to the proper authorities, such as animal control. TICKS Ticks are arachnids that can carry and transmit disease to humans. If you find a tick, remove it by firmly grasping the tick with fine-tipped forceps (or a hook designed for tick removal), as close to the skin as possible, and pulling slowly and steadily (Figure 14–7). Figure 14–7: Remove a tick by grabbing it with tweezers as close to the skin as possible. Figure 14–8: Ticks can be as small as the head of a pin. Once the tick is removed, treat the resulting minor wound and remind the patient to watch for signs of infection. The first sign of Lyme disease typically appears a few days or a few weeks after being bitten by an infected tick. A rash usually forms as a small red area, centred on the site of the bite, that may spread to up to 13 to 18 cm (5 to 7 in.) across. In fair-skinned people, the centre is lighter in colour and the outer edges are red and raised, sometimes resembling a bull’s-eye (Figure 14–9). In darkerskinned people, the area may look black and blue, like a contusion. If you are unable to remove the tick, or if any of its mouthparts stay in the skin, the patient should see a physician. Lyme Disease While tick bites can become infected, the more serious concern is the risk of disease transmission. In particular, some ticks carry Lyme disease, a potentially fatal bacterial illness. The longer the tick is attached, the greater the risk of disease transmission: Ticks must remain attached for more than 24 hours to transmit Lyme disease. Further signs and symptoms of Lyme disease include: Fever. Headache. Weakness. Joint and muscle pain similar to that of a flu. Black-legged ticks are very tiny and difficult to see. They are much smaller than the common dog tick or wood tick. They can be as small as a poppy seed or the head of a pin (Figure 14–8). Even in the adult stage, they are only as large as a grape seed. A black-legged tick can attach itself to a patient without his or her knowledge. People who develop Lyme disease may not be aware of having been bitten. Figure 14–9: A rash in a bull’s-eye pattern is a common sign of Lyme disease infection in fair-skinned patients. POISONING Not all ticks carry Lyme disease. Lyme disease is spread primarily by the black-legged tick (also referred to as deer tick), which commonly attaches itself to field mice and deer. The black-legged tick is found near beaches and in wooded or grassy areas. When in contact with any warm-blooded animal—including humans—the black-legged tick will attach itself to the host’s skin. 269 These signs and symptoms may develop slowly and may not occur at the same time as a rash. A patient can have Lyme disease without developing a rash. In its advanced stages, Lyme disease may cause neurological conditions, including cognitive impairments, impaired sensory function, and impaired muscle movement. Irregular or rapid heartbeats can also develop. If a rash or flu-like symptoms develop after a patient has been bitten by a tick, he or she should consult a physician (even if signs and symptoms disappear). A physician will usually use antibiotics to treat Lyme disease. Antibiotics work most effectively when taken early: Treatment is less effective once the disease is in its advanced stages. If untreated, Lyme disease can continue to spread through the body over months or years, and it can ultimately be fatal. SUBSTANCE MISUSE AND ABUSE Alcohol and over-the-counter medications (such as ASA, cough syrup, and sleeping pills), are among the most frequently misused and abused substances (Figure 14–10). The misuse or abuse of a substance results in poisoning. POISONING Substance misuse is the use of a substance for purposes other than those intended by the manufacturer, or exceeding the recommended dosage. An example of substance misuse is taking a sleeping pill, and then taking an additional dose an hour later because the initial dose did not work. Substance misuse may be accidental or intentional. 270 Substance abuse is the deliberate, persistent, and/or excessive use of a substance without regard to health concerns or accepted medical practices. An example of substance abuse is taking a prescription drug, such as a painkiller, in order to gain a pleasant or euphoric feeling. Many substances that are abused or misused are legal when prescribed by a physician. Figure 14–10: Commonly misused and abused legal substances. A drug is any substance that is taken to affect the function of the body. A drug used to prevent or treat a disease or condition is called a medication. An overdose occurs when a person takes too much of a substance, producing toxic (poisonous) or fatal effects in the body. An overdose may occur after a person takes more of a drug than is needed for medical purposes. It may occur unintentionally when someone takes too much medication at one time—for example, if an older adult forgets that he or she has already taken the medication and takes another dose. An overdose may also be intentional, such as in a suicide attempt (i.e., a person may intentionally take a fatal amount of a certain substance). Withdrawal describes a condition that a person who is addicted to a substance may experience after refraining from using or abusing that substance. Withdrawal may occur because of a person’s deliberate decision to stop or because he or she is unable to obtain the specific drug. Withdrawal from certain substances, such as alcohol, can cause severe mental and physical discomfort and can become a serious medical condition. Commonly Misused and Abused Substances Commonly misused and abused substances are categorized according to their effects on the body. The three basic categories are: Stimulants. Depressants. Hallucinogens. Designer drugs are generally chemical variations on other drugs. They are often designed to circumvent drug laws by altering a drug’s composition so that it is no longer technically illegal or is more difficult to detect in drug tests. Designer drugs may fit into any of the three categories listed above. They may also be more potent than their parent drugs or have additional effects on the user’s mind or body. When the chemical makeup of a drug is altered, the user may experience a variety of unpredictable and dangerous effects. STIMULANTS Stimulants affect the central nervous system by speeding up physical and mental activity. They can produce temporary feelings of alertness, improve task performance, and prevent sleepiness. Some stimulants are used for medical purposes (e.g., to treat asthma). They are sometimes used for weight reduction because they suppress appetite. Many stimulants are ingested as pills, but some can be absorbed or inhaled. Amphetamine, dextroamphetamine, and methamphetamine are stimulants. There are many street names or slang terms for stimulants, (e.g., speed). Cocaine is one of the most publicized and powerful stimulants. It can be taken into the body in different ways, including injecting it into the blood or sniffing it in powder form, in which case it is then absorbed into the blood through Figure 14–11: Misused and abused substances. the capillaries in the nose. A purer and more potent form of cocaine is crack, which is inhaled through smoking. The vapours that are inhaled into the lungs reach the brain within 10 seconds. Crack poses a serious threat because it is highly addictive. The most common stimulants are legal. Leading the list is caffeine, which is present in coffee, tea, sodas, chocolate, diet pills, and pills used to combat fatigue. Next is nicotine, which is found in tobacco products. The misuse or abuse of stimulants can have many unhealthy effects on the body, including the following: Moist or flushed skin Sweating Chills Nausea Vomiting Fever Headache Dizziness Tachycardia (rapid pulse) Tachypnea (rapid breathing) High blood pressure Chest pain In some instances, misuse or abuse can disrupt normal heart rhythms, cause respiratory emergencies, or even be fatal. The person may appear very excited, restless, talkative, irritable, or combative, or may suddenly lose responsiveness. POISONING The category to which a substance belongs depends on the effects it has on the central nervous system (Figure 14–11). Some substances depress the nervous system whereas others hasten its activity. Some are not easily categorized because they have multiple effects. 271 DEPRESSANTS Depressants affect the central nervous system and slow down physical and mental activity. Depressants are commonly used for medical purposes. Common depressants are alcohol, barbiturates, benzodiazepines, narcotics, and inhalants. Most depressants are ingested or injected. All depressants alter a patient’s level of awareness to some degree. They can relieve anxiety and pain, and they also promote sleep and relax muscles. However, these drugs can also depress respiration and impair coordination and judgment. Like other substances, the larger the dose or the stronger the substance, the greater its effects. When taken in small amounts, alcohol’s effects are fairly mild; in higher doses, its effects can be toxic. Alcohol can have the same negative effects on the body and pose the same risks for overdose as other depressants. Frequent drinkers may become dependent on the effects of alcohol and become increasingly tolerant of them. If alcohol is used frequently in large amounts, alcohol consumption can lead to unhealthy consequences and may become life threatening. For example, alcohol can cause the esophagus to rupture or the digestive system to become irritated. It can even injure the stomach lining, causing a patient to vomit blood. Chronic drinking can affect the brain and cause a lack of coordination, memory loss, and apathy. Other problems include liver diseases, such as cirrhosis. In addition, many psychological, family, social, and professional problems are related to chronic drinking. POISONING Narcotics have similar effects to other depressants. They are powerful and are used to relieve anxiety and pain. All narcotics are illegal without a prescription, and some are not medically prescribed at all. Common narcotics include morphine, codeine, and heroin. 272 Inhalants are substances, usually common commercial products, that produce chemical vapours with mind-altering effects. Inhalants include certain solvents, such as acetone, toluene, butane, gasoline, kerosene, lighter fluid, paints, nail polish and nail polish remover, and aerosol sprays. Inhalants have a depressing effect on the central nervous system and can damage the heart, lungs, brain, and liver. The effects of inhaled substances are similar to those of alcohol (i.e., the user appears to be drunk). Opioid Overdose and Naloxone Opioids are a class of depressants that includes morphine, heroin, and fentanyl. They pose a high risk of fatal overdoses because, in higher quantities, they bind to receptors in the brain that control respiration, rapidly causing respiratory arrest. Signs and symptoms of opioid overdose include: Severely reduced level of responsiveness, or unresponsiveness Severely constricted pupils or rolled-back eyes. Limp muscles. Slow or absent pulse. Slow or absent respiration (< 8 breaths per minute), possibly with gurgling or snoring sounds. Low SpO2 (< 92% on room air). Cold and pale or blue skin, especially on nail beds and lips. Vomiting. Naloxone is a drug that rapidly counteracts the effects of opioid overdose by binding to the same receptors in the brain, displacing the opioid and preventing respiratory arrest. It can be administered intranasally (as a spray), intramuscularly, or subcutaneously. If your scope of practice and protocols allow, administering naloxone is indicated for most cases of suspected opioid overdose. Because naloxone has no effect on a person who is not suffering from an opioid overdose, it is safe to use even if an overdose cannot be confirmed. Specific signs and symptoms of depressant misuse or abuse may include: Drowsiness. Brachycardia. Confusion. Brachypnea. Slurred speech. Poor coordination. An alcohol abuser may smell of alcohol, may be unresponsive or difficult to arouse, or may vomit violently. A patient suffering alcohol withdrawal can be confused and restless. He or she may also tremble and experience hallucinations. HALLUCINOGENS Hallucinogens do not have medical uses, but they can cause changes in mood, sensation, thought, emotion, and self-awareness. They can alter a person’s perception of time and space and produce delusions. Among the most widely abused hallucinogens are lysergic acid diethylamide (LSD, also known as acid), psilocybin (also known as mushrooms), and phencyclidine (PCP, also known as angel dust). These substances are usually ingested, but PCP is also often inhaled. Hallucinogens often have physical effects similar to those of stimulants but are classified differently because of their potential to produce additional effects. Specific signs and symptoms of hallucinogen use may include sudden mood changes and a flushed face. The patient may report seeing or hearing something that is not present and may be anxious and frightened. Hallucinogens can sometimes cause intense fear, panic, paranoid delusions, vivid hallucinations, profound depression, tension, and anxiety. The person may be irrational and feel threatened by any attempt others make to help. General Signs and Symptoms of Substance Misuse or Abuse Like other poisons, the general signs and symptoms of substance misuse and abuse are similar to other medical emergencies. To treat the patient, you need only recognize abnormalities in the patient’s respiration, pulse, pupils, temperature, bowel sounds, perspiration, and behaviour that may indicate a condition requiring professional help (Figure 14–12). Anticholinergic HR & BP RR TEMP PUPILS BOWEL SOUNDS DIAPHORESIS Cholinergic HR & BP RR TEMP PUPILS BOWEL SOUNDS DIAPHORESIS Opioid HR & BP RR TEMP PUPILS BOWEL SOUNDS DIAPHORESIS Sympathomimetic HR & BP RR TEMP PUPILS BOWEL SOUNDS DIAPHORESIS HR & BP RR TEMP PUPILS BOWEL SOUNDS DIAPHORESIS Low potency antipsychotics Oxybutynin, Ipratropium ACh receptor antagonists ACh receptor agonists AChEIs (e.g., Donepezil) Epinephrine Cocaine Amphetamine and methylphenidate Sedative-Hypnotic Benzos and “barbiturates” “Z-drugs” (e.g., zopiclone) Antihistamines Figure 14–12: General signs and symptoms of substance abuse and misuse. POISONING Morphine Heroin Hydromorphone 273 Treatment for Substance Misuse or Abuse Initial intervention for substance misuse or abuse does not require you to know the specific substance taken. Since substance misuse or abuse is a form of poisoning, treatment follows the same general steps as for other types of poisoning (outlined on page 261). Question the patient or bystanders during your secondary assessment to attempt to find out what substance was taken, how much was taken, and when it was taken. Contact the Poison Control Centre and follow their directions. A patient who is under the effects of a drug may be irrational, aggressive, or violent. Withdraw from the area if the patient becomes violent or threatening. If you suspect that a patient may have overdosed on a designer drug, be sure to include this information in the patient history when you are transferring the patient’s care. A patient who has overdosed on a designer drug may not respond to traditional medical treatment. CROWD MANAGEMENT AGENTS POISONING Crowd management agents, also referred to as riot control agents, are a group of substances used by law enforcement personnel to temporarily incapacitate groups of people. Because they cause 274 tearing of the eyes and are dispersed in the form of particles or droplets, they are often referred to as tear gas. Similar compounds are also used for personal protection (usually referred to as pepper spray). Crowd management agents may be inhaled, or they may be absorbed through the skin and/or eyes. Crowd management agents can have the following effects: Excessive tearing and blurred vision Eye pain and redness Swelling and irritation of the respiratory tract Rash or burning skin Nausea and vomiting Runny nose Chest tightness, dyspnea, and coughing These signs and symptoms generally diminish in intensity when the patient moves away from the crowd management area. To care for a patient who has been exposed to a crowd management agent: 1. Take full PPE precautions against both inhaled and absorbed poisons. 2. Remove any clothing that may have come into contact with the agent and seal it in a plastic bag. If the patient wears contacts, these should be removed and placed in the bag as well. 3. Wash the patient’s skin with soap and water. If the patient’s eyes are burning, rinse them with water for 10 to 15 minutes. SUMMARY FOUR TYPES OF POISONS Ingested Enter the body through the digestive system after being swallowed by the patient Examples: eating contaminated shellfish; consuming too much alcohol (substance abuse) Inhaled Enter the body after the patient breathes in toxic gas or fumes Examples: using chemical cleaning products in a poorly ventilated area; breathing carbon monoxide Absorbed Enter the body through the skin or other membranes Examples: touching poison ivy, sumac, or oak, or giant hogweed or wild parsnip Injected Enter the body through bites or stings, or through a hypodermic syringe Examples: getting stung by an insect or marine life (jellyfish), or bitten by a spider or tick; using intravenous drugs (substance abuse) General Signs and Symptoms of Poisoning Questions to Ask If Poisoning Is Suspected Sweating Nausea Vomiting Diarrhea Chest or abdominal pain Dyspnea Altered level of responsiveness Seizures General Treatment for Poisoning 1. Act within your scope of training. 2. Don appropriate PPE. 3. Contact the Poison Control Centre and follow  the staff’s instructions. 4. Avoid giving the patient anything orally, unless  your scope of training or the Poison Control  Centre staff indicates otherwise. 5. Save a sample of vomitus in a clearly labelled  container (if poison is unknown). 6. Administer oxygen if indicated. What type of poison was it? How did the contamination  occur? When was it taken? How much was taken (if known)? Treatment for Exposure to Crowd Management Agents 1. Take full PPE precautions against both inhaled  and absorbed poisons. 2. Remove any clothing that may have come into  contact with the agent and seal it in a plastic  bag. If the patient wears contacts, these should  be removed and placed in the bag as well. 3. Wash the patient’s skin with soap and water. If  the patient’s eyes are burning, rinse them with  water for 10 to 15 minutes. Common Substances Stimulants, depressants, and hallucinogens General Signs and Symptoms Similar to that of other poisons and medical emergencies; note abnormalities in respiration, pulse, skin’s appearance and moisture, temperature, and patient’s behaviour General Treatment Provide general treatment for poisoning POISONING SUBSTANCE MISUSE AND ABUSE 275