Poisoning

Poisoning is the harmful effect that occurs when a toxic substance is swallowed, is inhaled, or comes in contact with the skin, eyes, or mucous membranes, such as those of the mouth or nose.

  • Possible poisonous substances include prescription and over-the-counter drugs, illicit drugs, gases, chemicals, vitamins, and food.
  • Some poisons cause no damage, whereas others can cause severe damage or death.
  • The diagnosis is based on symptoms, on information gleaned from the poisoned person and bystanders, and sometimes on blood and urine tests.
  • Medications should always be kept in original child-proof containers and kept out of the reach of children.
  • Treatment consists of supporting the person, preventing additional absorption of the poison, and sometimes increasing elimination of the poison.

Poisoning is the most common cause of nonfatal accidents in the home. More than 2 million people suffer some type of poisoning each year in the United States. Drugs—prescription, nonprescription, and illegal—are the most common source of serious poisonings and poisoning-related deaths. Other common poisons include gases, household products, agricultural products, plants, industrial chemicals, vitamins, and foods (particularly certain species of mushrooms and fish—see Gastroenteritis: Chemical Food Poisoning). However, almost any substance ingested in sufficiently large quantities can be toxic.

Young children are particularly vulnerable to accidental poisoning in the home, as are older people, often from confusion about their drugs. Also vulnerable to accidental poisoning are hospitalized people (from drug errors) and industrial workers (from exposure to toxic chemicals). Poisoning may also be a deliberate attempt to commit murder or suicide. Most adults who attempt suicide by poisoning take more than one drug and also consume alcohol.

The damage caused by poisoning depends on the poison, the amount taken, and the age and underlying health of the person who takes it. Some poisons are not very potent and cause problems only with prolonged exposure or repeated ingestion of large amounts. Other poisons are so potent that just a drop on the skin can cause severe damage.

Some poisons cause symptoms within seconds, whereas others cause symptoms only after hours or even days. Some poisons cause few obvious symptoms until they have damaged vital organs—such as the kidneys or liver—sometimes permanently.

Nontoxic Household Products*

  • Adhesives
  • Antacids
  • Bath oil
  • Bathtub toys (floating)
  • Bleach (less than 5% sodium hypochlorite)
  • Body conditioners
  • Bubble bath soaps (detergents)
  • Candles
  • Carboxymethylcellulose (dehydrating material packed with film, books, and other products)
  • Chalk (calcium carbonate)
  • Colognes
  • Cosmetics
  • Crayons
  • Deodorants
  • Deodorizers, spray and refrigerant
  • Fabric softeners
  • Hand lotions and creams
  • Hydrogen peroxide (3% medicinal)
  • Incense
  • Indelible markers
  • Ink (black, blue)
  • “Lead” pencils (which are really made of graphite)
  • Magic markers
  • Matches
  • Mineral oil
  • Modeling clay
  • Newspaper
  • Perfumes
  • Petroleum jelly
  • Putty
  • Sachets (essential oils, powders)
  • Shaving creams and lotions
  • Soap and soap products
  • Suntan preparations
  • Sweetening agents (saccharin, aspartame)
  • Toothpaste with or without fluoride
  • Vitamins (children's multiple with or without iron)
  • Water colors
  • Wax or paraffin
  • Zinc oxide
  • Zirconium oxide

*Almost any substance can be toxic if ingested in sufficient amounts.

Moderately viscous (thick) substances like oils and detergents are not toxic if ingested but can cause significant lung injury if they are inhaled or aspirated into the lungs.

First Aid


The first priority in helping a poisoned patient is for bystanders not to become poisoned themselves. People exposed to a toxic gas should be removed from the source quickly, preferably out into fresh air, but rescue attempts should be done by professionals. Special training and precautions must be considered to avoid being overcome by the toxic gases or chemicals during rescue attempts.

In chemical spills, all contaminated clothing, including socks and shoes, and jewelry should be removed immediately. The skin should be thoroughly washed with soap and water. If the eyes have been exposed, they should be thoroughly flushed with water or saline. Rescuers must be careful to avoid contaminating themselves.

If the person appears very sick, emergency medical assistance (911 in most areas of the United States) should be called. Bystanders should perform cardiopulmonary resuscitation (CPR) if needed (see First Aid: First-Aid Treatment). If the person does not appear very sick, bystanders can contact the nearest poison center for advice. In the United States, the local poison center can be reached at 800-222-1222. More information is available at the American Association of Poison Control Centers web site (www.aapcc.org). If the caller knows the identity of the poison and the amount ingested, treatment can often be initiated at home if this is recommended by the poison center.

Containers of the poisons and all drugs that might have been possibly taken by the poisoned person (including nonprescription products) should be saved and given to the doctor or rescue personnel. The poison center may recommend giving the poisoned person activated charcoal (see Poisoning: Treatment) before arrival at a hospital and, rarely, may recommend giving syrup of ipecac to induce vomiting, particularly if the person must travel far to reach the hospital. However, unless specifically instructed to, charcoal and syrup of ipecac should not be given in the home or by first responders (such as ambulance personnel). Syrup of ipecac has unpredictable effects, often causes prolonged vomiting, and may not remove substantial amounts of poison from the stomach.

Diagnosis


Identifying the poison is helpful to treatment. Labels on bottles and other information from the person, family members, or coworkers best enable the doctor or the poison center to identify poisons. Laboratory testing is much less likely to identify the poison, and many drugs and poisons cannot be readily identified or measured by the hospital. Sometimes, urine and blood tests may help in identification as well. Blood tests can sometimes reveal the severity of poisoning, but only with only a small number of poisons.

For certain poisonings, abdominal x-rays may show the presence and location of the ingested substances. Poisons that may be visible on x-rays include iron, lead, arsenic, other metals, and large packets of cocaine or other illicit drugs swallowed by so-called body packers or drug mules.

Prevention


In the United States, widespread use of child-resistant containers with safety caps has greatly reduced the number of poisoning deaths in children younger than age 5. To prevent accidental poisoning, drugs should be kept in their original containers. Toxic substances, such as insecticides and cleaning agents, should not be put in drink bottles or cups, even briefly. Other preventive measures include clearly labeling household products, storing drugs and toxic substances in cabinets that are locked and out of the reach of children, and using carbon monoxide detectors. Expired drugs should be disposed by mixing them with cat litter or some other nontempting substance and putting them in a trash container that is inaccessible to children. All labels should be read before taking or giving any drugs or using household products.

Limiting the amount of over-the-counter pain relievers in a single container reduces the severity of poisonings, particularly with acetaminophen, aspirin, or ibuprofen. The identifying marks printed on pills and capsules by the drug manufacturer can help prevent confusion and errors by people, pharmacists, and health care practitioners.

Treatment


Some people who have been poisoned must be hospitalized. With prompt medical care, most recover fully.

The principles for the treatment of all poisoning are the same:
  • Support breathing and blood pressure
  • Prevent additional absorption
  • Increase elimination of the poison
  • Give specific antidotes (substances that eliminate, inactivate, or counteract the effects of the poison), if available
  • Prevent reexposure

With prompt medical care, most people recover fully.

The usual goal of hospital treatment is to keep people alive until the poison disappears or is inactivated by the body. Eventually, most poisons are inactivated by the liver or are passed into the urine. There are no specific antidotes for many serious poisonings.

Stomach emptying (stomach pumping), once commonly done, is now usually avoided because it removes only a small amount of the poison and can cause serious complications. Stomach emptying rarely improves people's outcome. However, stomach emptying may be done if an unusually dangerous poison is involved or if the person appears very sick. In this procedure, a tube is inserted through the mouth or nose into the stomach. Water is poured into the stomach through the tube and is then drained out (gastric lavage). This procedure is repeated several times. If people are drowsy because of the poison, doctors usually first put a plastic breathing tube through the mouth into the windpipe (endotracheal intubation). Endotracheal intubation helps keep the gastric lavage liquid from running into the lungs. In the hospital, doctors do not give syrup of ipecac to empty the stomach because its effects are unreliable.

For many swallowed poisons, hospital emergency departments may give activated charcoal. Activated charcoal binds to the poison that is still in the digestive tract, preventing its absorption into the blood. Charcoal is usually taken by mouth but may have to be given through a tube that is inserted through the nose into the stomach. Sometimes doctors give charcoal every 4 to 6 hours to help cleanse the body of the poison. Not all poisons are inactivated by charcoal. For example, charcoal does not bind alcohol, iron, or many household chemicals.

If a poisoning remains life threatening despite the use of charcoal and antidotes, more complicated treatments may be needed. The most common involve filtering poisons directly from the bloodstream—hemodialysis (which uses an artificial kidney [dialyzer] to filter the poisons—see Dialysis: Hemodialysis) or charcoal hemoperfusion (which uses charcoal to help eliminate the poisons). For either of these methods, small tubes (catheters) are inserted into blood vessels, one to drain blood from an artery and another to return blood to a vein. The blood is passed through special filters that remove the toxic substance before being returned to the body. Sometimes a solution containing sodium bicarbonate (the chemical in baking soda) is given by vein to make the urine more alkaline or basic (as opposed to acidic). This can increase the amount of certain drugs (such as aspirin and barbiturates) excreted in the urine.

Poisoning often requires additional treatment, termed supportive care, designed to stabilize the heart, blood pressure, and breathing until the poison disappears or is inactivated. For example, a person who becomes very drowsy or comatose may need a breathing tube inserted into the windpipe. The tube is then attached to a ventilator, which mechanically supports the person's breathing. The tube prevents vomit from entering the lungs, and the ventilator ensures adequate breathing. Treatment also may be needed to control seizures, fever, or vomiting.

If the kidneys stop working, hemodialysis is necessary. If liver damage is extensive, treatment for liver failure may be necessary. If the liver or kidneys sustain permanent, severe damage, organ transplantation may be needed.

People who attempt suicide by poisoning need mental health evaluation and appropriate treatment.

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