Management of the poisoning

 Management of the poisone

Management of the poisoned patient involves procedures designed to prevent the absorption, minimize the toxicity, and hasten the elimination of the suspected toxin. The prompt employment of appropriate emergency management procedures often can prevent unnecessary morbidity and mortality. 

A regional poison center is a practitioner’s best source of definitive treatment information and should be consulted in all poisonings, regardless of the apparent simplicity of the case. Contact the regional poison center in your area to learn of its staffing, resources, and capabilities before a need for its services arises. Well-qualified regional centers are certified by the American Association of Poison Control Centers. 

In all cases, every attempt should be made to accurately identify the toxin, estimate the quantity involved, and determine the time that has passed since the exposure. These data, plus patient-specific parameters such as age, weight, sex, and underlying medical conditions or drug use, will assist you and the regional poison center in designing an appropriate therapeutic plan for the patient. .

The techniques described below are intended for the initial management of the poisoned patient with the use of materials that should be readily available.

 TOPICAL EXPOSURES

 1. Immediately irrigate affected areas with a copious amount of water; use soap only if a stubborn, oily substance is the contaminant. Skin should be gently washed, not scrubbed, and special attention should be given to the hair, skin folds, umbilicus, and other areas where the contaminant might be trapped. 2. If the patient’s clothes have been contaminated, remove them during the irrigation and clean them before they are worn again or destroy them. Clothing can interfere with the irrigation process and serve as a reservoir of toxic material. 3. Do not attempt to “neutralize” the contaminant with another chemical (eg, acids and alkalis). Attempts at neutralization waste valuable time, are of no benefit, and might be harmful. 4. Do not cover the affected area with emollients. These can trap unremoved contaminant against the skin. Severely damaged skin may be temporarily covered with a light, dry dressing. 5. Protect yourself from contamination. Gloves, aprons, or a change of clothes might be necessary. 6. After the irrigation is complete, contact a regional poison center for definitive treatment information.

EYE EXPOSURES

 1. Immediately irrigate the eye; damage can occur within seconds. The stream of water from the tap or a pitcher should strike the patient on the forehead, temple, or bridge of the nose and then flow into the eye. 2. The eyelids should be open, with frequent blinking during the irrigation. 3. The irrigation should continue for at least 15 min (by the clock) to ensure adequate removal of the contaminant and normalization of the conjunctival pH. Body temperature water or saline may be substituted for tap water as the irrigation proceeds, but only if these can be obtained without interrupting the irrigation. 4. After the irrigation is complete, contact a regional poison center for definitive treatment information. 

INHALATION EXPOSURES

 1. Remove the patient from the suspected contaminated area, regardless of its apparent safety. Carbon monoxide, a common inhaled toxin, cannot be detected by sight, smell, or taste. 2. Institute artificial ventilation, if necessary, and provide supplementary humidified oxygen, if available and needed. 3. Protect yourself from contamination at all times. 4. Contact a regional poison center for definitive treatment information. 

INGESTIONS 

1. Remove any remaining contaminant from inside and around the mouth of the patient. 2. Give a small amount of water to clear the mouth and esophagus. 3. Contact a regional poison center for definitive treatment information. 4. In many cases, it will not be necessary to take additional steps. The following information can be used if additional care is recommended by the regional poison center. 

GASTROINTESTINAL DECONTAMINATION Gastrointestinal (GI) decontamination can be accomplished by the administration of activated charcoal, gastric lavage, ipecac-induced emesis, or whole-bowel irrigation. Indications for GI decontamination are ingestion of a known toxic dose, ingestion of an unknown dose of a known toxic substance, and ingestion of a substance of unknown toxicity. For all methods of GI decontamination, the value of the procedure diminishes rapidly with time. Some investigators now question the usefulness of gastric lavage or ipecac-induced emesis more than 1 hr after ingestion. None of these techniques should be presumed to provide complete removal or binding of the ingested toxin(s). Comparative experimental studies have shown only limited success with these techniques, and there is considerable interpatient variability in the results. In general, activated charcoal is the most useful agent for preventing absorption of ingested toxic substances. Other methods of GI decontamination may be considered if the ingested contaminant is not adsorbed by activated charcoal or if circumstances do not permit its prompt administration. 

ACTIVATED CHARCOAL

 Activated charcoal is a nonspecific absorbent that binds unabsorbed toxins within the GI tract. There is limited experience using activated charcoal in the home setting. Activated charcoal is not effective for absorbing strong acids and alkalis, cyanide, ethanol, methanol, ethylene glycol, iron, or lithium.

 1. Activated charcoal is administered orally or by gastric tube in doses that range from 30 to 120 g. 2. Activated charcoal is commercially supplied as a slurry in water or a concentrated solution of sorbitol. The water-based products are preferred because the large amount of sorbitol that accompanies a typical dose of activated charcoal can result in excessive sorbitol-induced catharsis, producing fluid and electrolyte imbalance. Gentle encouragement may be needed to make children swallow the charcoal. Having the child take the liquid through a drinking straw from an opaque container is sometimes helpful. 3. Activated charcoal administration is commonly followed by the administration of a cathartic (eg, sorbitol, magnesium citrate, or magnesium sulfate) to hasten the elimination of the activated charcoal–toxin complex. There is no evidence to support cathartic use. 4. Alert the patient that charcoal will cause the stools to turn black. 5. Repeated oral doses of activated charcoal (eg, 25 g q 2 hr) have been used to enhance the elimination of some drugs, most notably carbamazepine, dapsone, phenobarbital, quinine, or theophylline. Multiple-dose activated charcoal is suitable only for patients with active bowel sounds. Coadministration of a cathartic is not recommended during multiple-dose activated charcoal therapy. 

GASTRIC LAVAGE 

Gastric lavage can be used to remove toxic substances poorly adsorbed by activated charcoal. Lavage is contraindicated for patients who have ingested corrosives or aliphatic hydrocarbons (ie, gasoline) and for patients at risk for esophageal or gastric perforation due to underlying medical conditions (eg, esophageal varices).

 1. If the patient’s gag reflex is weak or absent, the airway must be protected by the use of a cuffed endotracheal tube. 2. The largest possible orogastric tube should be used (26–28 F for children and 34–42 F for adults): the larger the tube diameter, the more efficient the lavage. The tube should be introduced through the mouth with the aid of a water-soluble lubricant. Nasogastric passage is not recommended. 3. Gastric lavage may be done with water, but a solution such as 0.45% NaCl may be used to minimize the risk of dilutional hyponatremia, especially in children. Aliquots of fluid up to 100 mL in children and 200 mL

in adults are introduced through the tube and then removed by gravity or suction-assisted drainage. The lavage should be continued for several cycles after the returning fluid is clear. Warming the lavage fluid reduces the risk of hypothermia.

INDUCTION OF EMESIS 

Do not induce emesis if the patient is experiencing or is at risk for CNS depression, seizures, or loss of gag reflex, or if the patient has ingested a caustic substance or a hydrocarbon with high aspiration potential (eg, gasoline). 

1. Induce emesis only with syrup of ipecac. Salt water, mustard water, other “home remedies,” or gagging have no place in the management of the poisoned patient. These techniques are ineffective and can be dangerous. 2. The usual initial dose of syrup of ipecac is 30 mL in persons older than 12 yr, 15 mL in children 1–12 yr old, and 10 mL in children between 6 months and 1 yr. 3. Give the patient additional water to drink: 125–250 mL (4–8 fluid ounces) in children, 250–500 mL (8–16 fluid ounces) in adults. Activated charcoal should not be given until after ipecac-induced emesis has occurred. 4. Emesis usually occurs within 15–20 min. If 30 min have passed without emesis, administer an additional dose of syrup of ipecac and more water. 5. Have the patient vomit into a bowl or other container so that the vomitus can be inspected for the presence of the ingested toxin.

 WHOLE-BOWEL IRRIGATION 

Whole-bowel irrigation with an orally administered polyethylene glycol electrolyte solution (eg, GoLYTELY or CoLyte) is commonly used before bowel procedures. It has drawn attention as an alternative to other methods of GI decontamination in the management of acute poisoning. Results of studies are promising and the technique may have value in cases of ingestion of iron, enteric-coated or sustained-release products, foreign bodies, and drug-smuggling packets. Instillation rates have ranged from 500 mL/hr in children to 2 L/hr in adults. Typically, 4–6 L of fluid is administered. The endpoint is clearing of the rectal effluent. Contraindications to whole-bowel irrigation are persistent vomiting, adynamic ileus, bowel obstruction or perforation, and GI hemorrhage.