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Elliot Melendez, MD. Critical Care Mgmt of Poisonings. 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
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Elliot Melendez, MD Critical Care Mgmt of Poisonings
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) Cosmetics 13.3% Cleaning 11.0% Analgesics 7.6% Plants 7.1% FB 6.3% Cough/cold 5.5% Topicals 5.4% Insecticides 3.9% Vitamins 3.3% Antimicrobials 3.1% GI preps 3.0% Arts/crafts 2.5% *Hydrocarbons2.2% Antihistamines 1.9%
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.
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 ThroughTemperature • Fever • Sympathomimetics/Anticholinergics • ASA • Neuroleptic malignant syndrome, MH • Hypothermia • Depressants • Alcohol • Barbiturates
Let’s Work this ThroughHeart 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 ThroughBlood 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 ThroughRR and O2 sats • Respiratory Depression • Opiates • Barbiturates • Respiratory distress • ASA (metabolic acidosis) • Sympathomimetics/Anticholinergics • Organophosphates
Let’s Work this ThroughPupil Size • Pupils Small (Miosis) • Cholinergics • Opiates • Clonidine • Organophosphates • Sedatives/Barbiturates • Pupils Dilated (Mydriasis) • Sympathomimetics/Anticholinergics • Antidepressants (SSRI, TCA)
Let’s Work this ThroughSkin • Wet • Sympathomimetics • Organophosphates • Cholinergics • Dry • Anticholinergics
Let’s Work this ThroughMental 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 100.3 • 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 • 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 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 Status • Depressed, intermittent agitation
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 < 0.1 • How 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 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.