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-word You 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 facility 1 of 8 require critical care admission  Mortality 2.1% < 6 years 8.1% < 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 experimentation Females >>> males Anorexia 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) Cosmetics13.3% Cleaning11.0% Analgesics7.6% Plants7.1% FB6.3% Cough/cold5.5% Topicals5.4% Insecticides3.9% Vitamins3.3% Antimicrobials3.1% GI preps3.0% Arts/crafts2.5% *Hydrocarbons2.2% Antihistamines1.9%

Epidemiology  Agents involved known in most cases In unknown cases, recognition of a toxic syndrome may help in management  Common toxic agents leading to hospitalization Caustics Rx Meds (antidepressants) Analgesics (acetaminophen) Heavy metals (lead)

Agents Leading to ICU  Rx meds TCA Anticonvulsants Digitalis Opiates  Alcohol  Hydrocarbon household products

Pediatric Pitfalls Suspicious 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 dose Use max amt of missing tablets or liquid Concentration of drug or chemical Child’s weight

Priorities  Assess for medical stability A, B, C, D’s  Airway/Breathing – Consider intubation? Upper airway obstruction Excessive bronchial secretions Loss of airway reflexes Respiratory 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  Disability Protect patient from self-harm Treat seizures and protect airway

Diagnosis via Toxidromes  Why don’t they work? Memorization? Not all clinical criteria may be present Polysubstance ingestion complicates clinical signs and symptoms

What Works? Exam  And what poison control wants to hear! Vital signs: Temp, HR, BP, RR, Sats Pupil size Skin (dry or wet) Level of Consciousness/Mental status

Let’s Work this Through Temperature  Fever Sympathomimetics/Anticholinergics ASA Neuroleptic malignant syndrome, MH  Hypothermia Depressants Alcohol Barbiturates

Let’s Work this Through Heart Rate  Tachycardia –Sympathomimetics/Anticholinergics –Antihistamines –TCA – Bradycardia Ca channel and beta blocker, pure alpha agonists Digoxin Opiates/Sedative hypnotics Clonidine Cholinergics/Organophosphates

Let’s Work this Through Blood Pressure  Hypertension –Clonidine? –Sympathomimetics/Anticholinergics –Trauma, CNS bleed from adrenergics  Hypotension Ca channel and beta blocker Barbiturates Opiates Sympatholytics - clonidine Vasodilators/Diuretics

Let’s Work this Through RR and O2 sats  Respiratory Depression Opiates Barbiturates  Respiratory distress ASA (metabolic acidosis) –Sympathomimetics/Anticholinergics –Organophosphates

Let’s Work this Through Pupil Size  Pupils Small (Miosis) Cholinergics Opiates Clonidine Organophosphates Sedatives/Barbiturates  Pupils Dilated (Mydriasis) Sympathomimetics/Anticholinergics Antidepressants (SSRI, TCA)

Let’s Work this Through Skin  Wet –Sympathomimetics –Organophosphates –Cholinergics  Dry Anticholinergics

Let’s Work this Through Mental Status  Agitated/Confused/Seizures Sympathomimetics/Anticholinergics Withdrawal syndromes  Depressed Alcohols Opiates/Barbiturates Sedatives/Hypnotics TCA

Laboratory Studies  Chem 10 Calculate serum anion gap  Pregnancy test  EKG  Sosm Calculate osmolar gap if alcohol suspect  LFTs, Coags  Blood gas  Urine pH  X-rays

Laboratory Studies  Blood levels useful to assess risk ASA, Tylenol, anticonvulsants, alcohol  Tox Screens Only occasionally reveals an unanticipated toxin Most 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 Naloxone Glucose Thiamine Flumazenil Physostigmine  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  HR 130  BP 150/90  RR 20  O2 sat 99% RA  What else?

Case #1  Pupils dilated, poorly reactive  Skin: Dry  Mental Status Agitated Paranoid Picking things from air

Case #1  Diagnosis?

Case #1  Anticholinergic syndrome  Drugs: TCA Antihistamines Belladona Others

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?  Physostigmine Ach-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  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 Status Depressed, 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 #2 Management  Depression  ? Migraine medication  Seizure  Anticholinergic syndrome  Tachycardia with QRS >0.1

Case #2  TCA = Tachycardia, Convulsions, Anticholinergic  Treatment?

Case #2 Treatment  Alkalinize the serum!!! NOT THE URINE  NaHCO3 IVP until QRS < 0.1 How much? As much as if takes!!!  If this symptomatic, start NaHCO3 drip once QRS narrowed, goal pH  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 #2 Still Seizing  DO NOT GIVE PHENYTOIN Na 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 > 0.1 Arrhythmias with QRS > 0.16 Rarely, 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  ASA Metabolic acidosis, but respiratory alkalosis Alkalinize 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