Elliot Melendez, MD

Objectives Discuss Principles of Toxin Assessment

and Screening Discuss toxidromes and their management Discuss specific toxins

I will try not talk about decontamination or elimination of toxins

I will not follow Fuhrman word-for-wordYou should have read the 2 chapters (98,99)

Epidemiology > 2 million calls to poison control centers per

year~ 66% involve < 20 years~ 52% < 6 years

Only 25% require referral to a health care facility1 of 8 require critical care admission

Mortality2.1% < 6 years8.1% < 20 years

Epidemiology

Highest incidence in 1-3 year olds (accidental)Boys > girls Children with developmental delay or pica

Second peak in adolescents suicide attempt or experimentationFemales >>> malesAnorexia and psychiatric conditions risk

factors

Epidemiology Most occur when parents distracted at

home 2nd most common site is at grandparents’

homes

91% occur in the home

Many involve household products or meds that are left open and being used at the time

Pediatric Ingestions (< 6 yrs)Cosmetics 13.3%

Cleaning 11.0%

Analgesics 7.6%

Plants 7.1%

FB 6.3%

Cough/cold 5.5%

Topicals 5.4%

Insecticides3.9%

Vitamins 3.3%

Antimicrobials 3.1%

GI preps 3.0%

Arts/crafts2.5%

*Hydrocarbons2.2%

Antihistamines 1.9%

Epidemiology

Agents involved known in most casesIn unknown cases, recognition of a toxic

syndrome may help in management

Common toxic agents leading to hospitalizationCausticsRx Meds (antidepressants)Analgesics (acetaminophen)Heavy metals (lead)

Agents Leading to ICU

Rx medsTCAAnticonvulsantsDigitalisOpiates

Alcohol Hydrocarbon household products

Pediatric PitfallsSuspicious if: Altered mental status Multiple organ dysfunction New onset, afebrile sz Acute onset of presenting sx Hx of previous ingestions Current household stress/pregnancy/visitors

Pediatric Pitfalls

Difficult Hx: Uncooperative/preverbal patient Abuse Fear of parental discipline

Get the bottle!

Assessment of Poisoned Patient An accurate history is vitally important. Parents usually minimize the child’s

exposure to a toxin in order to deny threat of injury or assuage guilt

However, frequently, the precise time and toxin are accurately known.

Evaluating for the Unknown Substance

History

Obtain ingredients in suspected toxins Ask to see containers Assume the worst possible scenario in

calculating max doseUse max amt of missing tablets or liquidConcentration of drug or chemicalChild’s weight

Priorities

Assess for medical stability A, B, C, D’s

Airway/Breathing – Consider intubation?Upper airway obstructionExcessive bronchial secretionsLoss of airway reflexesRespiratory failure

Priorities Circulation

Assess and treat hypertension and tachycardia○ Typically if patient is agitated, use sedatives first○ Avoid non-selective blockers

Treat hypotension with fluids first, and if needed, use direct agonists

DisabilityProtect patient from self-harmTreat seizures and protect airway

Diagnosis via Toxidromes Why don’t they work?

Memorization?Not all clinical criteria may be presentPolysubstance ingestion complicates clinical

signs and symptoms

What Works? Exam

And what poison control wants to hear!Vital signs: Temp, HR, BP, RR, SatsPupil sizeSkin (dry or wet)Level of Consciousness/Mental status

Let’s Work this ThroughTemperature Fever

Sympathomimetics/AnticholinergicsASANeuroleptic malignant syndrome, MH

HypothermiaDepressantsAlcoholBarbiturates

Let’s Work this ThroughHeart Rate Tachycardia

– Sympathomimetics/Anticholinergics– Antihistamines– TCA

– BradycardiaCa channel and beta blocker, pure alpha

agonistsDigoxinOpiates/Sedative hypnoticsClonidineCholinergics/Organophosphates

Let’s Work this ThroughBlood Pressure Hypertension

– Clonidine? – Sympathomimetics/Anticholinergics– Trauma, CNS bleed from adrenergics

HypotensionCa channel and beta blockerBarbituratesOpiatesSympatholytics - clonidineVasodilators/Diuretics

Let’s Work this ThroughRR and O2 sats Respiratory Depression

OpiatesBarbiturates

Respiratory distressASA (metabolic acidosis)

– Sympathomimetics/Anticholinergics– Organophosphates

Let’s Work this ThroughPupil Size Pupils Small (Miosis)

CholinergicsOpiatesClonidineOrganophosphatesSedatives/Barbiturates

Pupils Dilated (Mydriasis)Sympathomimetics/AnticholinergicsAntidepressants (SSRI, TCA)

Let’s Work this ThroughSkin Wet

– Sympathomimetics– Organophosphates– Cholinergics

DryAnticholinergics

Let’s Work this ThroughMental Status Agitated/Confused/Seizures

Sympathomimetics/AnticholinergicsWithdrawal syndromes

DepressedAlcoholsOpiates/BarbituratesSedatives/HypnoticsTCA

Laboratory Studies Chem 10

Calculate serum anion gap Pregnancy test EKG

SosmCalculate osmolar gap if alcohol suspect

LFTs, Coags Blood gas Urine pH X-rays

Laboratory Studies

Blood levels useful to assess riskASA, Tylenol, anticonvulsants, alcohol

Tox ScreensOnly occasionally reveals an unanticipated

toxinMost commonly confirms what is suspected

from history and exam.

Tox Screens

Know you institutions screens and their limitations

Suboxone, methadone, and dextromethorphan do not show up on urine tox

Benadryl, Tegretol cross-react with TCA screen

ICU Management Mostly Supportive Very few antidotes Consider “Coma” Cocktail

NaloxoneGlucoseThiamine

FlumazenilPhysostigmine

Consult with local poison control

Specific Cases

16 y/o girl with history of anorexia is brought to ED for confusion, agitation

What do you want to know?

Case #1

Temp 100.3 HR 130 BP 150/90 RR 20 O2 sat 99% RA

What else?

Case #1

Pupils dilated, poorly reactive

Skin: Dry

Mental StatusAgitatedParanoidPicking things from air

Case #1

Diagnosis?

Case #1

Anticholinergic syndrome

Drugs:TCAAntihistaminesBelladonaOthers

Labs?

Labs Chem 7 normal CBC normal

Urine tox negative Serum tox negative

Tylenol, ASA, TCA, EtOH EKG normal

Mother asks, “Could this be from her new appetite stimulant medication.”

Management

Treat agitation with sedatives as needed

Diagnostic test?

Diagnostic Test?

PhysostigmineAch-ase inhibitor, transient

Risks:○ Seizures○ Asystole

○ Have atropine available!!!!

Case #2

16 y/o girl just broke up with her boyfriend, presents with seizure.

What do you want to know?

Case #2

Temp 100.3 HR 130 BP 150/90 RR 20 O2 sat 99% RA Seizing

What else?

Case 2

What do you mean what else?

Treat the seizure!!!

Ativan, Ativan seizure stops

Okay, now what else?

Case #2

Pupils dilated, poorly reactive

Skin: Dry

Mental StatusDepressed, intermittent agitation

Labs?

Labs

Chem 7 normal CBC normal Tox screens sent

EKG with QRS 0.12

Mother states no meds in home other than her migraine meds

Case #2

What do you do next?

Case #2Management

Depression ? Migraine medication

Seizure Anticholinergic syndrome Tachycardia with QRS >0.1

Case #2

TCA = Tachycardia, Convulsions, Anticholinergic

Treatment?

Case #2Treatment

Alkalinize the serum!!!NOT THE URINE

NaHCO3 IVP until QRS < 0.1How much? As much as if takes!!!

If this symptomatic, start NaHCO3 drip once QRS narrowed, goal pH 7.45-7.55.

If nonsymptomatic, NS infusion at 1.5 maintenance, with NaHCO3 at bedside

Case #2

Seizes again

Ativan doesn’t stop seizures after 2 doses.

Next?

Case #2Still Seizing

DO NOT GIVE PHENYTOINNa channel blocker, which is what TCA’s do

and can make things worse

Continue NaHCO3 push and Ativan, consider pentobarbital, Propofol

TCA Toxicity TCAs block Na channels leading to effects

Seizures correlated with QRS > 0.1Arrhythmias with QRS > 0.16Rarely, prolonged QTc (but not without QRS

widening)

You don’t have TCA toxicity without tachycardia.

If initially asymptomatic, and no symptoms by 6 hrs of ingestion, PICU monitoring not needed.

Other Notable Ingestions Serotonin Syndrome

Altered MS, Increased muscle activity, clonus, autonomic instability

Seen with SSRI overdoses, combination of ingestions leading to serotonin increase

ASAMetabolic acidosis, but respiratory alkalosisAlkalinize urine!!!If tinnitus, level > 30. Think of sources other than ASA

○ Bismuth, oil of wintergreen, topical acne meds

Summary

VS, Pupils, Skin, MS should give you a clue to agent

Tox screens rarely helpful

Look at AG and Sosm when appropriate