Emesis may be induced with syrup of ipecac. It is prepared from the Cephaelis plant, which contains the alkaloids emetine and cephaeline. These emetics induce vomiting via gastric irritation and stimulation of the vomiting center in the brainstem. The use of syrup of ipecac in the management of poisoned patients has declined. Several studies have found that use of syrup of ipecac has been associated with aspiration pneumonia, dehydration, a longer ED course, and more complications. In addition, no studies demonstrate that the use of ipecac in the treatment of acute poisoning changes or improves clinical outcomes. ⁴ The American Academy of Pediatrics no longer recommends home stocking of ipecac.

This agent has an unpredictable onset of action and intensity of effect. Violent, protracted vomiting after administration of ipecac predisposes the patient to fluid loss, acid-base abnormalities, electrolyte disturbances, and Mallory-Weiss tears and delays administration of activated charcoal and oral antidotes. Use of syrup of ipecac for hydrocarbon or caustic ingestion increases the incidence of oral, upper airway, and pulmonary injury.

Overall, the majority of clinical experts do not recommend the use of syrup of ipecac to induce vomiting for gastric decontamination in adult or pediatric patients.

The benefit of using gastric lavage to decrease absorption is limited. Generally, gastric lavage is considered only when a patient has ingested a potentially life-threatening amount of poison and the procedure can be initiated within 60 minutes of exposure. Gastric lavage may propel gastric contents past the pylorus, moving the poison into the small intestine, where most of the ingested agent may be absorbed. ²² Some clinical trials indicate that gastric lavage does not improve patient outcomes and increases the risk for complications, such as hypoxia and aspiration, when compared to those treated without gastric lavage. ²

Before initiating lavage, place the patient in a left lateral position to decrease risk for aspiration. Lavage should not be performed on patients who have ingested medications that may cause abrupt central nervous system (CNS) deterioration, such as tricyclic antidepressants (TCAs), unless the patient has been intubated. If the gag reflex is diminished, protect the airway with endotracheal intubation before lavage. Monitor for bradycardia secondary to vagal stimulation during tube placement. Lavage is not recommended for patients who have ingested a corrosive agent due to the increased risk for esophageal perforation. For adult patients with pill ingestion, insert a large-diameter (36 Fr to 40 Fr) orogastric tube with a bite block to prevent tube occlusion. Nasogastric tube aspiration may be effective in cases of liquid poisoning but is not adequate for ingestion of pills.

With mechanical suction or a catheter tip syringe, withdraw as much of the gastric contents as possible. To perform lavage, repeatedly instill and remove 200- to 300-mL aliquots of tepid tap water or normal saline until the return is clear; 2 to 5 L may be needed to achieve this goal. ¹¹ For pediatric patients, administer 10 to 15 mL/kg in 50-mL boluses through a 24- to 28-Fr orogastric tube.

Activated charcoal is the preferred means of GI decontamination for management of most toxic ingestions. Charcoal is “activated” by exposure to high temperatures that dramatically increase its surface area. This agent has an extensive network of interconnecting pores that are capable of binding and trapping chemicals within minutes of contact, thus preventing their absorption and toxicity. Binding prevents absorption into the bloodstream, allowing toxins to be eliminated in feces. Studies suggest that, used alone, activated charcoal administration is as effective as or even more effective than administration of activated charcoal after emesis or gastric lavage procedures.

Activated charcoal should be administered as soon as possible after the ingestion. Some clinical experts report it is most effective if administered within 60 minutes of the ingestion. 1. ^{and 2.} However, there is limited evidence to determine at what time frame activated charcoal is no longer beneficial. It may be effective for some agents beyond the 60-minute window, particularly for sustained-release preparations or anticholinergic medications.

Activated charcoal readily absorbs most poisons except heavy metals (e.g., lithium, iron) and alcohols (e.g., methanol, ethylene glycol). It is not recommended in patients who have ingested acidic or alkaline corrosives or who require endoscopy because charcoal will obstruct the view during the procedure. Substances poorly absorbed by charcoal include acids, alkali, cyanide, ethanol, fluoride, lead, mercury, mineral acids, organic solvents, and potassium. Contraindications to charcoal administration include bowel obstruction or bowel perforation. Adverse effects of activated charcoal include nausea, vomiting, GI obstruction, and pulmonary aspiration.

Activated charcoal is given orally or through a gastric tube in doses of 25 to 100 g (1 g/kg for children). The commercial product should be vigorously agitated before administration to resuspend all the activated charcoal. If the quantity of an ingested substance is known, give at least 10 times the ingested dose of toxin (by weight) to prevent desorption of the substance in the lower intestine. Administration of one or two follow-up doses at 1- to 2-hour intervals is common.

Activated charcoal is prepared as an aqueous solution with or without sorbitol. Sorbitol helps the toxins that are bound to the activated charcoal pass through the GI tract. Follow the recommendations of regional poison control centers for the type of activated charcoal to be used.

Binding agents limit the bioavailability of certain poisons. Magnesium hydroxide has been found to be effective in reducing serum iron levels. Sodium polysterene sulfonate, often used to treat hyperkalemia, has been effective in limiting serum lithium levels. Other specific binding agents may not be as clinically applicable due to limited availability (e.g., cholestyramine, fuller’s earth) Activated charcoal is often considered a binding agent because it limits absorption of many agents.

Whole bowel irrigation is a method of GI decontamination that entails administering polyethylene glycol orally or through a gastric tube until the resulting rectal effluent is clear. Polyethylene is not absorbed and is less likely to produce a fluid or electrolyte imbalance. Whole bowel irrigation is used to treat large ingestions of drugs not absorbed by activated charcoal (such as lithium and iron), large ingestions of enteric-coated or sustained-release tablets, and patients who have ingested packages of illicit drugs (body packers).

The dose is usually 2 L/hr for adults and 500 mL/hr for children until the rectal effluent is clear. Contraindications to its use include bowel obstruction, paralytic ileus, or GI hemorrhage.

Skin decontamination is indicated for dermal exposure to any toxic substance. Remove contaminated clothing and jewelry as soon as possible, and rinse areas of contact for 10 to 15 minutes with copious amounts of water or saline. It is important to rinse the toxic agent from the hair, ears, nose, and skin folds. Dry substances should be brushed from the body before washing. Neutralizing agents should not be applied because the resulting chemical reaction produces heat and can increase local tissue damage. Depending on the substance and amount, both clothing and irrigation fluids may be considered hazardous waste. Individuals with toxic dermal exposures also represent a risk to others. Health care personnel should wear appropriate personal protective equipment (e.g., gloves, gowns, and goggles) to avoid secondary contamination.

Ocular decontamination involves vigorous eye irrigation with copious amounts of water or normal saline. Prolonged flushing may be necessary after exposure to caustic substances, particularly alkalis. An ophthalmologist should be consulted if ocular complaints persist after irrigation. Refer to Chapter 45 for discussion of eye irrigation and ocular burns.