Wilderness and Rescue Medicine 7th Edition Jeffrey Isaac, PA-C and David E. Johnson, MD

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Section V: Environmental Medicine

pain reliever hoping for a better result, not real- izing that both are brand names for the same acet- aminophen. The effects of a mild unintentional overdose are usually limited to accentuated side effects like gastrointestinal (GI) upset or drowsi- ness. Discontinuing the medication usually solves the problem. Intentional overdose is another matter. Even common over-the-counter medications like acet- aminophen or iron tablets can be lethal in high doses. Immediate generic treatment followed by emergency evacuation is indicated. In opioid or antihistamine overdose, the anticipated problem is respiratory failure due to loss of respiratory drive. Oxygen and positive pressure ventilation (PPV) can be lifesaving. Naloxone, an opioid antagonist, given by intranasal or IM injection can reverse the effects of most opioid medications.

Ingested Toxins A brief review of anatomy reminds us that our digestive system is essentially just a tube with the mouth at one end and the anus at the other. Whatever you swallow does not actually enter the body unless it is absorbed through the lining of the stomach or intestine. For example, a glass marble swallowed by a child will not be absorbed and will pass harmlessly through the gut. Although toxins are not inert like glass, we can try to keep more of the toxin in the gut with the marble, and speed its passage through, thereby reducing the amount absorbed by the intestinal lining. To reduce absorption, the provider should attempt to dilute the toxin using water, which will also help move the substance through the gut more quickly on its way to excretion. Activated charcoal at a dose of 25 to 50 grams orally may bind some of the substances in the gut, helping to prevent absorption by the intestinal mucosa. Although this treatment may be helpful, remem- ber that it is not definitive for high-risk toxins such as drug overdoses. Antidote and hospital care should be accessed urgently in these cases. Unfortunately, effective antidotes to toxins are not always available. Additionally, their use is limited to cases where the toxin is known, such as certain drugs and plants. The availability of an antidote may influence your evacuation and destination. If possible, contact a poison control center (1-800-222-1222 in the United States) or local medical facility for specific treatments. In any case, most toxins are excreted or metabolized by the body over hours or days. Drug Overdose You should know the risks associated with over- dose of any drug that you carry in quantity. The most likely source of a problem is overuse of over- the-counter pain medication, such as acetamin- ophen and ibuprofen, or prescription opioids like hydrocodone. Problems often occur when patients are confused about generic and trade names used for drugs. For example, a patient may take full doses of two different brands of

Ingested Toxins

General Principles

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American Association of Poison Control Centers www.aapcc.org 800-222-1222 Generic Treatment: • BLS, PROP • Remove and dilute: oral hydration. • Evacuate with ALS assistance as needed. • Contact poison control.

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ASPCA – for pets

www.aspca.org/apcc

888-426-4435

©2018WMA

Food Poisoning Food poisoning is another form of accidental toxic ingestion. The toxin is produced by bac- teria, such as staphylococci growing in poorly refrigerated food. There is usually no active infec- tion because bacteria are destroyed by stomach acid, but the toxin survives to be absorbed by the gut. Symptoms are usually limited to GI upset, including cramps, diarrhea, and vomiting. The disease is self-limiting, and the most common anticipated problem is shock from dehydration. Hydration and easily-digested food are the pri- mary treatment. Food poisoning is differentiated from bacte- rial infection of the gut by the absence of fever