012000 Ingestion of Toxic Substances by Children
Total Page：16
File Type：pdf, Size：1020Kb
The New England Journal of Medicine Primary Care of such agents in the home rather than their inher- ent toxicity. On the basis of hazard-factor analysis (in which the number of episodes of major toxic effects INGESTION OF TOXIC SUBSTANCES or death is divided by the total number of reported cases of exposure to the substance, normalized to the BY CHILDREN rate of major toxic effects or death for all substances in the age group in question), the substances asso- MICHAEL SHANNON, M.D., M.P.H. ciated with the greatest risk of death to children in- clude cocaine, anticonvulsant drugs, antidepressant drugs, and iron supplements.6 NGESTION of a harmful substance is among the TREATMENT most common causes of injury to children less The ability to reduce morbidity and mortality Ithan six years of age. Fortunately, in most cases, among children who have ingested a toxic substance the ingested agent has minimal or no clinically im- depends on prompt, appropriate intervention. A tele- portant toxic effect. Occasionally, however, such in- phone call by the parent to a physician or poison cen- gestion can be life-threatening or can even result in ter is often the first step in obtaining treatment. In death. Although preventive measures have been re- most circumstances, after the substance and its toxic- markably successful in reducing the frequency and ity have been identified and the amount ingested severity of poisoning in children, poisoning continues has been determined, treatment can be carried out at to occur and requires strategies for treatment and pre- home without the need for referral to an emergency vention that are safe and effective. In this review, I dis- department. cuss the management of poisoning in children, with In children brought or referred to a health care fa- an emphasis on current guidelines for treatment. cility, assessment and stabilization of vital signs are the initial steps of treatment. Rarely, emergency manage- EPIDEMIOLOGY ment involves the administration of an antidote (e.g., According to the Toxic Exposure Surveillance Sys- naloxone after an overdose of an opioid drug) or tem of the American Association of Poison Control measures to enhance the elimination of toxins that Centers, 1.08 million instances of ingestion of a tox- have already been absorbed (e.g., multiple doses of ac- ic substance by a child less than six years of age were tivated charcoal after an overdose of carbamazepine). reported to poison centers in 1998.1 However, the Laboratory analysis of serum or urine should be guid- proportion of incidents reported to poison centers is ed by the substance ingested, its anticipated degree estimated to be as low as 26 percent,2 suggesting a of toxicity, and the value of measuring these concen- true incidence of more than 4 million poisonings an- trations; there is rarely a need for toxicologic screen- nually. According to the Consumer Product Safety ing tests in children, since the ingested substance is Commission, approximately 85,000 young children usually known.7 were treated for poisoning in emergency departments The term “gastrointestinal decontamination” in- in the same year (Schroeder T: personal communica- cludes interventions that are used to prevent the ab- tion), for a projected incidence of 450 per 100,000 sorption of an ingested toxin. Gastrointestinal de- population. The toxic substances most commonly in- contamination has three distinct components: gastric gested by children are listed in Table 1. Substances emptying, administration of an adsorbent agent, and that are most accessible to children, such as cosmetics catharsis. and personal care products, cleaning products, anal- gesics, and cough and cold preparations, account for Gastric Emptying 58 percent of the products listed.1,3-5 In principle, if the contents of the stomach can be Table 2 lists the primary agents involved in deaths rapidly and completely evacuated after the ingestion from poisoning among children from 1995 through of a toxin, the toxin will not have the opportunity 1998. Medications, both prescription drugs and over- to enter the small intestine, the main site of absorp- the-counter drugs, were responsible for 52 percent tion. Consequently, the clinical effects of the poison- of the deaths from poisoning. The distribution of re- ing can be mitigated. Gastric evacuation can be ac- sponsible agents also reflects the common presence complished either by chemically induced emesis or by mechanical removal with a lavage tube. Emesis is mediated in the central nervous system, From the Division of Emergency Medicine and the Program in Clinical either by direct stimulation of the chemoreceptor trig- Toxicology, Children’s Hospital and Harvard Medical School; and the Mas- ger zone in the area postrema or by gastric irritation sachusetts Poison Control System — all in Boston. Address reprint requests mediated by vagal afferent fibers, with resulting stim- to Dr. Shannon at Children’s Hospital, 300 Longwood Ave., Boston, MA 8,9 02115, or at [email protected]. ulation of the vomiting center in the medulla. ©2000, Massachusetts Medical Society. Agents that have been used in children in the past for 186 · January 20, 2000 Downloaded from www.nejm.org at ST MATTHEWS UNIV SCH MED on May 29, 2004. Copyright © 2000 Massachusetts Medical Society. All rights reserved. PRIMARY CARE this purpose include parenteral apomorphine, copper TABLE 1. AGENTS MOST COMMONLY INGESTED sulfate, fluid extract of ipecac, hydrogen peroxide, and BY CHILDREN LESS THAN SIX YEARS OF AGE, ipecac syrup. Among these, ipecac syrup has proved 1995 TO 1998.* to be the safest, most reliable emetic agent; the others are contraindicated for the treatment of poisoning. NO. OF Ipecac syrup contains two active alkaloids, cephaline AGENT INGESTED CHILDREN and emetine. Both stimulate gastric sensory receptors Cosmetics and personal care products 568,856 linked to the vomiting center in the brain. In addi- Cleaning products 500,791 tion, cephaline acts at the chemoreceptor trigger zone. Analgesics 354,722 The primary advantage of ipecac syrup is its ease of Plants 322,991 administration by parents or caretakers. Cough and cold preparations 278,460 Foreign bodies 256,263 Emesis usually begins about 20 minutes after ipe- 10 Topical agents 234,997 cac syrup is given. Eighty-two percent of children Pesticides 164,277 will vomit after a single 15-ml dose, and 99 percent Vitamins 151,871 will vomit after two doses.11 The duration of vomit- Hydrocarbons 106,269 ing is typically one to two hours. Guidelines for doses are presented in Table 3. Administration can be re- 1,3-5 *Data are from Litovitz et al. peated if vomiting does not begin within 20 to 30 minutes. The administration of additional fluid after ipecac syrup does not appear to improve the efficacy of the agent.12 The use of ipecac syrup should be con- sidered in cases in which children have ingested a po- tentially toxic substance in the preceding hour. How- ever, the efficacy of ipecac syrup, even under these TABLE 2. PRIMARY AGENTS INVOLVED IN FATAL POISONINGS circumstances, has not been proved.10 Because un- AMONG CHILDREN LESS THAN SIX YEARS OF AGE, 1995 TO 1998.* controlled vomiting will occur for at least one to two hours, ipecac syrup should not be administered after CATEGORY the ingestion of certain substances or under certain (NO. OF DEATHS REPORTED)SPECIFIC AGENTS clinical conditions (Table 4). Analgesic drugs (11) Acetaminophen, ibuprofen, metha- Increasingly, both the safety and the efficacy of ip- done, oxycodone, salicylates, 10 morphine ecac syrup have been questioned. Although the drug Cleaning products (6) Corrosives, fluoride-based solutions has an impressive safety profile, there have been re- Electrolytes and minerals (6) Elemental iron ports of adverse effects, including prolonged vomit- Hydrocarbons (6) Gasoline, paint thinner, lamp oil ing, sedation, Mallory–Weiss syndrome, gastric rup- Antidepressant drugs (4) Amitriptyline, imipramine, desipra- ture, and fatal aspiration.13,14 The efficacy of ipecac mine syrup, measured in terms of the elimination of ingest- Insecticides and pesticides (4) Propoxur, organophosphates ed toxins or improvement in outcomes, also appears Cosmetics and personal care Ethanol, baby oil products (2) to be limited. In studies in animals, ipecac syrup re- Anticonvulsant drugs (2) Carbamazepine, valproate sodium moves 10 to 60 percent of an ingested substance; in Stimulants and illicit drugs (2) “Crack” cocaine, heroin clinical studies, within one hour after ingestion, a Plants (2) Cayenne pepper, pennyroyal tea mean of 30 percent of a toxin can be recovered.10 Foreign bodies (2) Activated charcoal† When administered 90 minutes or more after a toxic Sedatives and hypnotic drugs (2) Promethazine, chloral hydrate substance has been ingested, ipecac syrup has no iden- Cardiovascular agents (1) Nifedipine tifiable benefit.15 Saincher et al. have suggested that Tobacco (1) Cigarette butts ipecac syrup is no longer beneficial between 5 and 30 Cough and cold preparations (1) Phenylpropanolamine 16 Hormones and hormone antago- Glipizide minutes after the ingestion of a toxic substance. nists (1) Gastric lavage is an alternative method of remov- Chemicals (1) Diethylene glycol ing the contents of the stomach. For lavage to be Alcohols (1) Ethanol performed properly, competence of the gag reflex Gastrointestinal preparations (1) Bismuth subsalicylate should first be confirmed. Once properly restrained, *Data are from Litovitz et al.1,3-5 the child should be placed in a left lateral decubitus †Deaths were attributed to the administration of activated charcoal. Trendelenburg’s position in order to limit the move- ment of the gastric contents into the duodenum and minimize the risk of aspiration.17,18 A large-bore (24- to-32-French), single-lumen tube should be placed by an orogastric route. The proper placement of the tube is confirmed by the spontaneous or aspirated return of gastric contents or by auscultation of in- Volume 342 Number 3 · 187 Downloaded from www.nejm.org at ST MATTHEWS UNIV SCH MED on May 29, 2004.