approach to poisonings

Approach to Poisonings

Robert J. Vinci, MD

Background

• 2 – 5 Million exposures per year

• 4% require hospitalization

• 96% minor or no effects

Background

• 93% involve a single substance• 67 % patients < 20 years of age• 53% children < 6 years of age• 25% children < 2 years of age• Bimodal Pediatric age distribution• Household products vs. pharmaceuticals

Fatalities

• Cleaning substances

• Analgesics

• Antidepressants

• Heavy metals, especially iron

• Street drugs

• Cardiovascular drugs

• Alcohols

How do Children Present?• Vague History• Change in mental status• Suspicion of Ingestion

– Open bottles– Pills on floor– Missing medications

• Directly Observed

Initial Evaluation

• History– When– How Much– Symptoms– Meds in the Home– Any other possible exposures– Observations from EMS personnel

Initial Evaluation

• History– Seizures

– GI symptoms

– Hallucinations

– Toxidromes

Initial Evaluation

• Physical Examination– ABC’s – Rapid deterioration– Review vital signs for clues– Mental Status– Pupils– Nystagmus– Skin Color/Skin Warmth

Initial Evaluation

• Laboratory Studies– Pulse Oximetry– EKG– Electrolytes/Blood Sugar– ABG’s– Toxic Screen/Drug Levels– Serum osmolality/osmolal gap

Increased Anion Gap Acidosis

• Methanol• Ethylene Glycol• Salicylates• Iron, INH, Ibuprofen• Drugs producing hypotension and lactic

acidosis (many serious ingestions)

Increased Osmolal Gap• Osmolal Gap = Osm (calc) – Osm (meas.)• Osmolal Calc. = 2 x Na + Gluc + BUN

18 2.6• Increased Osmolal Gap

– Ethanol– Methanol– Ethylene Glycol– Acetone

Radiographic Studies• CHIPES• C = Chloral Hydrate• H = Heavy Metals, especially Iron• I = Iodinated compounds (thyroxin)• P = Psychotropic, Packers• E = Enteric Coated Medications• S = Salicylates, Sustained Release

Toxidromes• Hyperthermia, agitation,

mydriasis, hypertensive hyperthermic

• Coma, Seizures, arrhythmia• Coma, respiratory depression,

myosis• Hallucinations, mydriasis, hot

dry skin, urinary retention, tachycardia

• Sympathomimetics

• Tricyclics• Opiods

• Anticholinergics

Serum Toxic Screens

• Aspirin

• Salicylates

• Alcohols

• Tricyclics

Urine Toxic Screens

• Benzodiazepines

• Barbiturates

• Opiates

• PCP

• Marijuana

General Management

• Supportive Care

• Oxygen

• Intravenous glucose

• Careful monitoring for potential side effects

Specific Management

• Gastric Emptying

• Decrease Absorption

• Enhance Elimination

• Specific Antidotes

Gastric Emptying

• Syrup of Ipecac– Stimulates Gastric Receptors linked to the CNS

vomiting center

– Emesis within 20 minutes

– 80% after a single dose

– 99% after two doses

– Vomiting persists for 1 – 2 hours and may delay use of oral antidotes and treatments

Syrup of IpecacShould it be Used?

• Adverse Effects– Uncontrolled vomiting/ Mallory Weiss Tear– Sedation– Fatal aspiration

• 30% recovered < one hour of ingestion. Minimal toxin recovered after 90 minutes

• No true evidence it improves outcome• Not studied well with delayed gastric

emptying or decreased peristalsis

When to Consider Ipecac

• Alert, conscious children > 6 months of age

• Ingestion of potentially toxic amount of poisoning

• Within 60 minutes of ingestion

• Perhaps at home or in pre-hospital setting

• Limited value in the hospital setting

Syrup of IpecacContraindications to Use

• Substance that produces rapid change in mental status

• Calcium channel blocker, digitalis, beta-blocker (worsen bradycardia of vomiting)

• Corrosives• Mental Status changes/Decreased Gag• Coagulopathy• Infants less than 6 months of age

IpecacAdverse Effects

• Protracted vomiting, sedation or diarrhea

• Forceful vomiting (Mallory-Weiss tears, pneumomediastinum, bradycardia)

• Sedation or seizures leading to aspiration

• Cardiomyopathy with chronic abuse

• May delay oral therapy, especially charcoal

Gastric Lavage• Need Presence of gag – now and during the

procedure• Left Lateral Decubitus/Trendenburg• Large Bore Single Lumen tube• After confirming position of tube, 10 – 15

ml/kg aliquots of saline until clear• Removes < 30 % of what is ingested (similar

to ipecac)• Similar contraindications to ipecac

Gastric LavageContraindications

• Corrosives

• Uncooperative child

• History of GI surgery/pathology

Gastric LavageTechnique

• Confirm presence of gag reflex• Left lateral decubitus position with head

lower than feet• Largest possible tube• Lavage with aliquots of 10 ml/kg until

clear

Charcoal - Adsorbent• Binding surface areas of 3000 m2/gm• Maintains attachment through covalent

bonding• If treatment occurs within one hour as much

as 75% of toxin is adsorbed• Dose is 10:1 ratio, however a fixed dose of 1 gram/kg is recommended• May mix with flavoring to hide taste• ?Use with NG tube????

Use of Charcoal• 1 gm/kg of body weight• Often pre-mixed as aqueous solution or with a

cathartic such as sorbitol• May flavor with cola, chocolate syrup in order

to make it more palatable• More effective than ipecac or gastric lavage• Greatest benefit if used within one hour of

ingestion

Charcoal “Contraindications”

• Hydrocarbons

• Alcohols

• Heavy Metals (Iron)

• Minerals

• Corrosives (makes endoscopy difficult)

• GI perforation

Multiple Dose Activated Charcoal

• Drugs which decrease gastrointestinal mobility

• Enterohepatic circulation• Gastric Dialysis• Give 0.5 mg/kg of charcoal without

sorbitol every 4 – 6 hours

Adverse Effects of Charcoal

• Aspiration

• Diarrhea, if used with sorbitol

• Fluid loss and electrolyte abnormality

Cathartics

• Osmotic Agents used to treat ingestions

• Increase Gastric Motility

• In pediatric patients the use of cathartics should be limited to the first dose of charcoal

Magnesium Citrate

• 4 ml/kg of 6% suspension

• Larger doses do not improve efficacy

• Magnesium does get absorbed

Sorbitol

• The most efficient osmotic agent

• 1 – 2 grams/kg

• Not recommended in children < 1 year

• May cause hypernatremic dehydration and cardiovascular collapse

Whole-Bowel Irrigation

• Polyethylene glycol-electrolyte solution• There is no absorption• Large volumes infused (500 – 1000 ml

per hour) until effluent is clear• Treatment of choice for agents which

are not well absorbed by charcoal

Indications

• Enteric coated pills• Sustained release tablets• Illicit drug packets• Drug concretions• Ingestions of substances poorly bound

by charcoal

Common Antidotes• Opiate Overdose• Acetominophen• Salicylates• Digoxin• Iron• INH• Ethylene Glycol• Tricyclics

• Narcan• N-acetylcysteine• Alkalinization• Fab Antibodies• Deferoxamine• Pyridoxine• Fomepazole• Sodium Bicarbonate

Approach to Patients

• Avoid the use of ipecac

• Gastric lavage has not been shown to be effective

• In general, activated charcoal is the sole intervention necessary to treat serious poisonings. This may be used with or without a cathartic

Poison Control Centers

• 1-800-222-1222

• 617-232-2120

• May be helpful in identification of toxins based on symptoms alone