The local actions of an ingested poison can have irritant, acidic (corrosive), or basic (caustic) effects at the site of contact.

Table 5-1.-Commonly Encountered Toxidromes

NOTE
There are two important categories of substances which act locally on the skin, eyes, or mucous membranes and cause damage through direct contact. These are acids (corrosives) and bases (caustics). Although these two categories are distinct and there are significant differences in the physiological effects of contact with them, the term "corrosive" is recognized as a generic term for the action that occurs upon contact with either an acid or a base. The terms "corrosive" and "noncorrosive," as used in this chapter, should be understood to represent the generic and not the specific. When specifically discussing acids or bases in this chapter, the terms "acid" or "base" (or "alkali"), respectively, will be used.

Ingested substances can be absorbed into the body and transported to a distant site with systemic action(s). In such situations, the poisonous substance may cause few effects-or even no effect-at the site of contact or absorption, but it may have severe systemic effects.

Ingestion of substances that do not produce local effects can be divided into two types:

nontoxic substances (latex paint, dirt, silica gel, spider plant), and

potentially toxic substances (poisonous fish, medications, heavy metals (lead, mercury), pesticides, and personal care products).
Episodes involving the ingestion of non-toxic substances do not require decontamination of the gut. (Swallowing a non-toxic foreign body, however, like a coin or button battery in a child, may result in choking and require prompt medical intervention.)

The toxicity range of absorbed poisons extends from essentially non-toxic to extremely toxic (remember Paracelsus' "dose"). Ingestion of substances with a low order of toxicity may result in the production of only minor systemic effects (nausea, vomiting, diarrhea), effects that are mild, self-limiting, and do not require significant medical intervention.

NOTE: Do not induce unnecessary vomiting to discourage a patient from repeating a voluntary ingestion again.

Noncorrosives
The many different noncorrosive substances have the common characteristic of irritating the stomach. They produce nausea, vomiting, convulsions, and severe abdominal pain. The victim may complain of a strange taste, and the lips, tongue, and mouth may look different than normal. Shock may also occur.
Examples of noncorrosives are listed in table 5-2.

First aid for most forms of noncorrosive poisoning centers on quickly emptying the stomach of the irritating substance. The following steps are suggested:

1. Maintain an open airway. Be prepared to give artificial ventilation.

2. Dilute the poison by having the conscious victim drink one to two glasses of water or milk.

3. Empty the stomach using emetic, gastric lavage, adsorbent, and/or cathartic.

a. Giving an emetic is a preferred method for yes">emptying the contents of the stomach.

style="mso-spacerun: yes">

Table 5-2.-Common Stomach Irritants and Possible Sources of Contact

It is quick and-except in cases of caustic or petroleum distillate poisoning, or when an antiemetic has been ingested-can be used in almost every situation when the victim is conscious. In most situations, a Hospital Corpsman will have access to syrup of Ipecac. This emetic acts locally by irritating the gastric mucosa and centrally by stimulating the medullary vomiting center in the brain. The usual adult dose is 15-30 cc, and the dose for a child (age 1 to 12 years) is 15 cc. The dosage should be followed immediately by a glass of water. Most people will vomit within 30 minutes. The amount of stomach contents (and poison) recovered will vary. In an emergency room, the medical officer can rapidly induce vomiting by the injection of various medications. If nothing else is available, tickle the back of the victim's throat with your finger or a blunt object. This procedure should induce vomiting.

b. Trained personnel may use gastric lavage by itself or after two doses of Ipecac syrup has failed to induce vomiting. After passing a large-caliber nasogastric tube, aspirate the stomach contents. Next, instill 100 ml of normal saline into the stomach, then aspirate it out again. Continue this flushing cycle until the returning fluid is clear. Gastric lavage is preferred when the victim is unconscious or-as in the case of strychnine poisoning-is subject to seizures.

c. Activated charcoal (AC) adsorbs many substances in the gut and prevents absorption into the body. After the substance is adsorbed to the AC, the bound substance moves through the gut and is eliminated with the production of a charcoal-black bowel movement. AC may be administered after emesis or lavage, or it may be used alone.

d. A cathartic (magnesium sulfate or sorbitol) may be used to "speed" the movement of the bound substance and minimize absorption.

4. Collect the vomitus for laboratory analysis.
5. Soothe the stomach with milk or milk of magnesia.

6. Transport the victim to a definitive care facility if symptoms persist.