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Poisonings, Ingestions and Overdoses

Initial Management

Melanie Madsen, MD

last updated 12/96 for content, 9/97 for format

Outline

• Overview
• Initiation of therapy at home
• Initial Management at the Hospital
  • ABC
  • Seizures
  • Information
  • Examination
  • Studies
  • Prevent Absorption
  • Enhance Excretion
• Diagnostic Trials
• Toxic Syndromes
• Bibliography

Overview

• about 60% of reported poison exposures occur in children less than 6 years of age, but young children account for less than 4% of fatalities
• iron poisoning and hydrocarbons are the most common cause of mortality
• usually involve a single substance in small quantities; accidental and acute
• teenage exposure is often purposeful, often involving large quantities of more than one substance, with increased mortality rate
• poisonings occur by ingestion, inhalation, ocular exposure, dermal exposure, mucous membrane involvement, and parenteral exposures
• ingestions account for about 3/4 of exposures, and inhalation 14%

Initiation of Therapy at Home

Aim is to prevent absorption.

• external exposures:
  • remove clothing; skin exposed to insecticides, hydrocarbons, or acid or alkali agents should be flooded with water and washed with soap
  • if the eyes are involved, they must be washed immediately for 15-20 minutes
• internal exposures:
  • dilute acid or alkali with milk or water; NO EMESIS
  • emesis (syrup of ipecac) for children over 6 months if indicated (10 ml for < 1 yo, 15 ml for 1-12 yo, or 30 ml for > 12 yo); repeat the dose if > 1 yo if no emesis in 20 minutes
  • inducing emesis contraindicated if:
    • child has altered mental status, actively seizing, or has a bleeding diathesis
    • with acid or alkali substances
    • hydrocarbon ingestion that do not contain camphor, halogenated or aromatic products, heavy metals, or pesticides ("CHAMP")
    • ingestion involves a rapid-acting CNS affecting drug

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Initial Management at the Hospital

ABC

• assess the airway, ventilation and circulation.
• oxygen if altered mental status is present
• intubate if the patient has depressed respirations, depressed or impaired mental status
• IV access should be obtained for serious or potentially serious exposures
• follow blood pressure, perfusion, and heartrate; cardiorespiratory monitoring if indicated

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Seizures

• seizures can occur with a number of ingestions, as well as secondary to trauma (i.e. fall) due to the effectsof the ingestion
• rapid dextrostick for glucose determination
  • if hypoglycemia is present, administer glucose (2-4 cc/kg 25% dextrose IV)
• look for any focal neurologic signs (unequal pupils) or evidence of trauma
• benzodiazepine (lorazepam) is the agent of choice for seizure control, followed by phenobarbital or phenytoin

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Information

• identify the type of ingestion, amount consumed, time of ingestion, and current symptoms
• relate the amount ingested to the patient's weight
• if quantity of liquid ingestion is unknown, the average swallow of a young child is 5- 10 ml and that of an older child or adolescent is 10 - 15 ml
• treatment information can be readily obtained through: Poisindex (computer), Poison Control Center, toxicology textbooks, and pharmacist

Know your resources and use them

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Examination

• particular focus on the cardiopulmonary, respiratory, and neurologic status
• if patient is obtunded and etiology is unknown, look for physical signs such as scalp bruise or laceration (secondary to trauma), needle marks, breath smell, skin (warm, clammy), pupil size, etc.
• REMEMBER: some drugs have delayed onset of symptoms (i.e. acetaminophen)

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Studies

• blood or urine toxicology screens
• REMEMBER: polypharmacy overdoses and injections are common!
• drugs requiring emergency quantitative analysis: acetaminophen, salicylates, alcohols (methanol, ethylene glycol), iron, theophylline, lithium and carbon monoxide
• every hospital has different toxicology screens--know what the screen covers
• other often needed tests: ABG (acid-base status), electrolytes, glucose, CBC with differential and platelet count, clotting studies, LFT's, renal function tests, albumin and total protein
• toxic metabolic acidosis often caused by "MUDPILES": Methanol, Uremia, Diabetes mellitus, Paraldehyde, Isoniazid, iron, Lactic acidosis, Ethanol, ethylene glycol, Salicylates, starvation, strychnine, carbon monoxide, cyanide
• ·x-rays are useful (to determine presence and location) with: bezoars, bags of illegal drugs (smuggled), chloral hydrate, heavy metals, iodine, iron, phenothiazines, potassium compounds, enteric-coated tablets, batter ingestion

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Prevent Absorption

• external as described above
• internal:
• emesis: is most helpful within 1 hour, beyond that time is usually not indicated unless the drug delays gastric motility; see above
• lavage:
  • indicated for toxic ingestions within 1-2 hours of ingestion (unless delayed gastric motility), and for those with mental status changes
  • NOT for caustic or acid ingestions
  • 24-36 Fr tube (36-40 in adults) with patient in Trendelenburg and tilted slightly to the left; lavage with saline or half-normal saline at 100-200 ml per lavage in the adult (less for the child) ; repeat until clear
  • can be helpful in identifying pills
  • intubate before lavage in the patient with mental status changes
• activated charcoal:
  • indicated for:
    • analgesic/antiinflammatory drugs: acetaminophen, salicylates, nonsteroidals, morphine, propoxyphene
    • anticonvulsants/sedatives: barbiturates, carbamazepine, chlordiazepoxide, diazepam, phenytoin, sodium valproate
    • other: amphetamines, atropine, chlorpheniramine, cocaine, digitalis, quinine, theophylline, cyclic antidepressants
  • does NOT work for: iron, lithium, cyanide, strong acids or bases, and simple alcohols (ethanol and methanol)
  • wait 30 - 60 minutes after emesis (if drug-induced emesis)
  • can be given orally or through NG tube (minimum 12-16 Fr)
  • 1 gm/kg; repeated doses q 2-4 hours may be indicated
  • mixture with sorbitol also works as a cathartic
    • ideally, sorbitol should not be added after the initial dose (hypernatremic dehydration is a documented complication in children)
  • aspiration pneumonia secondary to aspiration of charcoal after emesis is well-documented--give anti-emetics if needed
• catharsis:
  • controversial efficacy
  • magnesium sulfate, magnesium citrate, bisacodyl, sodium sulfate, sorbitol
  • do NOT use with renal failure, severe diarrhea, adynamic ileus or abdominal trauma
• whole-bowel irrigation:
  • GoLYTELY or polyethylene glycol
  • used when large amounts of a toxic substance are ingested, a modified-release substance is involved, or the substance is not absorbed by charcoal
  • adults 1.5 - 2.0 L/hr, toddlers 500 ml/hr (until what comes out looks like what went in!)
  • patients must be able to protect their airway

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Enhance Excretion

• forced diuresis is usually not helpful (only a small number of drugs have a small volume of distribution and are renally excreted)
• indicated for salicylates and phenobarbital (alkalinize the urine)
• goal is 5.0 ml/kg/hr (watch fluids carefully--do not fluid overload)
• for alkaline diuresis:
  • want urine pH > 7.5
  • (1) NaHCO3 1 - 2 mEq/kg/dose IV over 1 hour (with K+ as needed);
  • (2) add 2 - 3 adult ampules (44.5 mEq NaHCO3 / ampule) to 1 liter of D5W
  • monitor electrolytes (usually supplemental potassium is needed)
  • contraindicated with cerebral edema or renal failure
• dialysis only after other treatments have failed
  • useful only in a limited number of drugs: phenobarbital, salicylates, theophylline, methanol, ethylene glycol and lithium
  • indicated when patient is unresponsive, significant acidosis is present, renal failure, visual symptoms, or when peak levels are > 50 mg/dl with methanol ingestion
• hemoperfusion is controversial and usually not used

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Diagnostic Trials (Administration of the antidote can indicate an etiology of toxin.)

• iron
  • deferoxamine
  • positive if urine turns "vin rose" color
• lead
  • Ca-EDTA
  • ratio of lead excreted/EDTA given > 0.5
• opiates
  • naloxone hydrochloride
  • improved consciousness
• organophosphates
  • atropine
  • pupilary dilation, secretions
• phenothiazine (dystonic reactions)
  • diphenhydramine
  • resolution of dystonia or oculogyria
• phenothiazine (neuroleptic malignant syndrome)
  • dantrolene
  • resolution of muscular rigidity and normalization of temperature
• insulin reaction
  • dextrose
  • improved consciousness
• isoniazid
  • pyridoxine
  • resolution of seizures and acidosis

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Toxic Syndromes

These are constellations of syndromes which are indicative of certain ingestions.

• Anticholinergics (Atropine, Scopolamine, glycopyrrolate)
  • peripheral symptoms:
    • neurologic: dilated pupils, hyperpyrexia
    • CV: tachycardia, dysrhythmias, hypertension, hypotension (late)
    • GI/GU: urinary retention, decreased bowel sounds
    • other: dry and flushed skin, dry mucous membranes, fever
  • central symptoms:
    • CNS: delirium: disorientation, agitation, hallucinations, psychosis, loss of memory, extrapyramidal movements, ataxia, picking or grasping movements,seizures, coma
    • cardiovascular collapse
    • respiratory failure
• Cholinergics (Acetylcholine, methacholine)
  • "SLUDGE": salivation, lacrimation, urination, diarrhea, GI cramping, and emesis
  • CNS: miosis, headache, restlessness, anxiety, confusion, coma, seizures
  • CV: bradycardia, tachycardia (also common)
  • respiratory: bronchorrhea, bronchospasm
  • other: sweating, muscle fasciculations and weakness
• Opiates (Morphine, Heroin)
  • CNS: euphoria, coma, seizures, miosis
  • CV: decreased heartrate, hypotension
  • respiratory: shallow respirations, decreased respiratory rate, pulmonary edema
• Organophosphates (Anticholinesterase-Physostigmine, Neostigmine are reversible forms)
  • CNS: sedation, coma, miosis
  • CV: increased or decreased heartrate, hypo- or hypertension
  • respiratory: bronchorrhea
  • GI/GU: urination, defecation
  • other: muscle twitching, flaccidity, salivation, lacrimation
• Phenothiazines (chlorpromazine)
  • CNS: sedated, coma, miosis, dystonic reactions, ataxia
  • CV: hypotension
  • other: hypothermic
• Salicylates (Aspirin, Doan's Pills - methyl salicylate)
  • CNS: disoriented, hyperexcitable
  • CV: tachypnea, increased depth of breaths
  • GI: vomiting
  • other: fever, tinnitus, metabolic acidosis, hypokalemia
• Sedative-Hypnotics (benzodiazepines)
  • CNS: sedated, coma, miosis, ataxia, nystagmus
  • CV: hypotension
  • respiratory: decreased respiratory rate, shallow breathing
  • other: slurred speech, hypothermic
• Sympathomimetics (doapmine, phenylephrine, tyramine, ephedrine)
  • CNS: agitated, psychoses, hallucinations, delirium, seizures, dilated pupils
  • CV: tachycardia, dysrhythmias, severe hypertension
  • GI: nausea, vomiting, abdominal pain
  • other: fever, sweating
• Tricyclics (amitriptyline, clomipramine)
  • CNS: agitation, coma, dilated pupils, seizures
  • CV: tachycardia, hypo- or hypertension, prolonged QRS interval, ventricular arrhythmias
  • other: fever
• Withdrawal
  • CNS: delirium, hallucinations, dilated pupils
  • CV: tachycardia, hypertension
  • GI: diarrhea
  • other: "goose flesh", cramps

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BIBLIOGRAPHY

Anderson, Angela C. Iron Poisoning in Children Current Opinion in Pediatrics, 1994, 6: 289-294.

Barkin, Roger M. and Rosen, Peter. Emergency Pediatrics. A Guide to Ambulatory Care
Mosby Year Book, St. Louis, 1994: 324-368.

Barkin, Roger M..et al. Pediatric Emergency Medicine. Concepts and Clinical Practice
Mosby Year Book, St. Louis, 1992: 463-530.

Blumer, Jeffrey L. A Practical Guide to Pediatric Intensive Care Mosby Yearbook, St. Louis, 1990: 660-739.

Conway Jr., Edward E. Recognizing Carbon Monoxide Toxicity Contemporary Pediatrics, Feb. 1994: 24-32.

Fuhrman, Bradley P. and Zimmerman, Jerry J. Pediatric Critical Care Mosby Yearbook, St. Louis, 1992: 1109-1153.

Henretig, Fred M. A Guide to Acute Medical Management of Intoxication in AdolescentsAdolescent Health Update, June 1994, 6(3).

Johnson, Kevin B. The Harriet Lane Handbook Thirteenth Edition. Mosby Year Book, St. Louis, 1993: 29-56.

Kulig, Kenneth. Initial Management of Ingestions of Toxic Substances The New England Journal of Medicine, June 1992, 326(25): 1677-1681.

Levin, Daniel L. and Morris, Francis C. Essentials of Pediatric Intensive Care Quality MedicalPublishing, Inc., St. Louis, 1990: 593-670.

Liebelt, Erica L. and Shannon, Michael W. Small Doses, Big Problems: A Selected Review of Highly Toxic Common Medications Pediatric Emergency Care, 1993, 9(5): 292-296.

Lovejoy, Frederick H. et al. Common Etiologies and New Approaches to Management ofPoisoning in Pediatric Practice Current Opinion in Pediatrics, 1993, 5: 524-530.

Mack, Ronald B. Dishwasher Detergent Toxicity--Here's Looking at You, Kid Contemporary Pediatrics, Nov. 1993: 49-58.

Tinker, Thomas D. Hydrocarbon Ingestion in Children: Its Sequelae and Management Oklahoma State Medical Journal, Feb. 1986: 95-100.

Woolf, Alan D. Poisoning in Children and Adolescents Pediatrics in Review, Nov. 1993, 14(11): 411-422.

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This page is meant for educational purposes only, practitioners should use readily available resources in their area when dealing with toxic ingestions and poisonings.

Comments regarding this outline should be directed to the author at the following address:

mmadsen@inet-serv.net

This page last updated for content 12/96, for format 9/3/97 at 0910 CDT