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Introduction to the Poisoned Patient

Introduction to the Poisoned Patient. Department of Emergency Medicine The Ottawa Hospital. Outline. Directed toxicology history Toxidromes Cases/Treatment. Toxicology - Objectives.

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Introduction to the Poisoned Patient

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  1. Introduction to the Poisoned Patient Department of Emergency Medicine The Ottawa Hospital

  2. Outline • Directed toxicology history • Toxidromes • Cases/Treatment

  3. Toxicology - Objectives • Determine whether poisoning has occurred, the substance involved, how severe the exposure was, how toxic it is likely to become, and the causticity of substance. • Perform supportive care, decontamination or prevention of further absorption, give antidote where indicated, and enhance elimination of the poison. • - Discuss special considerations in the management of poisoning with aspirin, acetaminophen, tricyclic antidepressants, and methanol.

  4. Clinical Timeline History Toxidrome Treatment Laboratory Confirm or refute Reassess

  5. When (most NB) What How How much? Method? Whose? Compliance Coingestants? Access Specifics Self treatment? Ipecac Induced emesis Ethanol Intent? Symptoms Directed Tox History Work hard to get it, then be suspect!

  6. Toxidrome What it is: • a clustering of symptoms and/or signs • consistent with a class of drugs/medications What it isn’t: • a way to identify a specific substance • a way to discriminate well among “contradictory agents” until repeated over time

  7. Common Toxidromes • Narcotic (coma resp depression, miosis) • Anticholinergic (mad as a hatter …) • Cholinergic (DUMBELS) • Sedative/Hypnotic (pupillary rxn spared) • Stimulant or Sympathomimetic • Hallucinogens • Extrapyrimidal • Serotonergic

  8. Anticholinergics • TCA’s, atropine, scopolamine, antihistamines • Mad as a hatter (delerium) • Hot as a hare (fever) • Blind as a bat (mydriasis) • Dry as bone (dry mucous membrane, urinary retention, decreased BS) • Red as beet (flushing) • Bowel and bladder lose tone and heart goes on alone) • Difference with adrenergics = • Bowel sounds present • Diaphoresis

  9. Cholinergics • Pheostigmine, organophosphtes (insecticides), and nerve gas (DUMBELS) • Diaphoresis, diarrhea, decreased BP • Urination frequent • Miosis • Bronchospasm, bronchorrhea, bradycardia • Emesis, excitation of skeletal muscle • Lacrimation • Salivation / seizures

  10. Sympathomimetics • Amphetamine, cocaine • Resemble paranoid schizophrenic • CNS stimulation • Seizures • Psychosis • Increased BP, pulse, Temp

  11. Hallucinogens: • Hallucinations • May be oriented to time / place / person • Tachy • HTN • mydriasis

  12. Opioids • Coma • Resp depression • Miosis (not with demerol)

  13. Sedatives • Barbituarates, ethanol, benzo’s, ethanol, GHM (gamma hydroxybutyric acid) • CNS depression • Resp depression • Coma • Pupil rxn usually spared

  14. Extrapyramidal • chlorpromazine, stemetil, halodol, metocloperamide • Dystonia (occulogyric crisis, laryngospasm, torticollis) • Akithesia • Parkinson like sx (tremor, ridgidity, akinesia, postural instability) • Dyskinesia (tic, spasm, chorea, myoclonus)

  15. Seratonergic • Mimics NMS (neuroleptic malignant syndrome) of increased BP, increased pulse, increased temp, increased resp rate (onset within 24 hours, hyperactive, clonus, hyperreflexic, clonus) • NMS (due to massive dopamine blockade) (FARMERS) • Fever • Autonomic changes (increased bp, pulse, sweating) / acidosis (rare) • Rigidity of muscles / rhabdomyolyis • Mental status changes (eg. Confusion) • Elevated BP, HR, pulse, RR • Rhabdomysolysis • Seizures • Onset days to weeks

  16. Case A 78 yo F presents with agitation and confusion. BP 180/105, P 110 RR 16 T 38.2 C. Physical exam reveals an acutely agitated pt, pupils 6 mm, CVS/resp normal except tachycardia. Is a toxidrome present? What are the treatment priorities? What tests do you want to order?

  17. Investigations • Serum levels • acetaminophen (4 hour level) • ASA • Ethanol • ingestion specific (eg phenytoin, digoxin level) • Electrolytes, BUN/Cr • EKG • Serum osmolarity

  18. What about a “Tox Screen”? • Urine immunoassays • lab determines which tests to include on the “screen” • Often clinically irrelevant • confuse the clinical picture • positive cocaine in a patient with an opioid toxidrome • “toxic” TCA level in a cyclobenzaprine (Flexeril) overdose Treat the patient, not the test!

  19. Case A 78 yo F presents with agitation and confusion. BP 180/105, P 110 RR 16 T 38.2 C. Physical exam reveals an acutely agitated pt, pupils 6 mm, CVS/resp normal except tachycardia. Is a toxidrome present? What are the treatment priorities? What tests do you want to order?

  20. Supportive treatment of the poisoned patient is the cornerstone of management

  21. A 20 yo F comes to the ED saying she just took a whole bottle (1.5 grams) of Elavil (amitriptylline). Her vital signs are normal. She is alert and exam is normal. Treatment considerations?

  22. Treatment • Elimination: • Activated Charcoal • Whole Bowel Irrigation • Removal: • Gastric Lavage • Antidotes

  23. Treatment • Elimination: • Activated Charcoal • Whole Bowel Irrigation • Removal: • Gastric Lavage • Antidotes

  24. Activated Charcoal • Ingestion < 1 hr • upto 2 hrs if delayed emptying, bad toxin • 1 g/kg or 10 g for each gram of OD drug • Ineffective • Pesticides • Hydrocarbons • Alcohols • Iron • Lithium • Alkali’s / acids (contraindicated)

  25. Activated Charcoal • CX • Aspiration • Gastric content aspiration worse than charcoal aspiration • But a lot worse if dump charcoal into lungs • Perforation if bowels not moving

  26. Cathartics • Sorbitol • available premixed with charcoal • can use for first dose • contraindicated if < 2 years • electrolyte problems • Used with charcoal to counteract its constipating effect

  27. To Give or Not to Give... An alert 36 year old M 2 hours post accidental ingestion of antifreeze

  28. To Give or Not to Give... An alert 36 year old M 2 hours post accidental ingestion of antifreeze A: Not indicated; 2hrs is too late (esp for liquid) and alcohols bind poorly

  29. To Give or Not to Give... A somnolent 45 yo F with ingestion of olanzapine (Zyprexa) and venlafaxine (Effexor) at an undetermined time.

  30. To Give or Not to Give... A somnolent 45 yo F with ingestion of olanzapine (Zyprexa) and venlafaxine (Effexor) at an undetermined time. • A: Not indicated; undetermined time (likely greater than 1 hr for toxicity to develop from these agents) and risk of aspiration given altered mental status.

  31. To Give or Not to Give... An intubated 37 yo F 30 min after collapsed after metoprolol OD.

  32. To Give or Not to Give... An intubated 37 yo F 30 min after collapsed after metoprolol OD. • A: Indicated; recent ingestion, (very) bad drug and airway is protected.

  33. Treatment • Elimination: • Activated Charcoal • Whole Bowel Irrigation • Removal: • Gastric Lavage • Antidotes

  34. Decontamination • Gastric Lavage • recent (< 1hr) • Life threatening ingestion • no antidote • not adsorbed by AC • sustained release • concretions • no emesis EasyLav

  35. Gastric Lavage • Large hose with blunt end (need this for tablets to pass) • LL decubitus position with pylorus pointing upwards • Has to have airway protected either intubated of fully conscious • Have bucket of warm water and bucket on floor

  36. Gastric Lavage • Give warm water through funnel / tube above pt … Percuss stomach … move tube below level of head to drain into bucket … repeat • Prevents drug from getting into small intestine as drain directly from stomach

  37. Treatment • Elimination: • Activated Charcoal • Whole Bowel Irrigation • Removal: • Gastric Lavage • Dialysis • Antidotes

  38. Whole Bowel Irrigation • Polyethylene glycol (eg. Golytely) • 1-2 L/hr via NGT until clear effluent • Do for 4 to 6 hours until clear effluent via rectal tube • SR preps, Lithium, iron, sustained release drugs • Body packers/stuffers

  39. A 20 yo F comes to the ED saying she just took a whole bottle (1.5 grams) of Elavil (amitriptylline). Her vital signs are normal. She is alert and exam is normal. Treatment considerations?

  40. Tricyclic Antidepressants - Sx • Block sodium channels • Neuro: • mental status changes • anticholinergic toxicity • seizures • Cardiac: • (lethal) arrhythmias • AV blocks • hypotension • QRS > 120 ms and ‘R” in aVR > 3mm predicts seizures/ arrhythmias

  41. Tricyclic Antidepressants - Mgmt • Activated Charcoal (no role for dialysis) • Alkalinization of blood (7.45 – 7.50) with sodium bicarbonate • Abolishes dysrhythmias and improves hypotension • Use if QRS > 100 msec • Administer as 1 – 2 mEq/kg IV push then 20 mEq / hr drip

  42. Enhanced Elimination • Diuresis • Alkaline • 3 amps NaHCO3 in 1 L D5W with 40 mmol KCl at 250 mL/hr • goal: urine pH 7.5-8 • E.g Salicylates, Phenobarbital • Neutral • Lithium

  43. Tricyclic Antidepressants - Mgmt • Seizure mgmt: • avoid dilantin (increases dysrhythmias) • Diazepam/lorazepam/ phenobarbitol • Hypotension • Crystalloid and alkalinization • Vasopressors if no response • Dysrhythmias unresponsive to bicarb • Lidocaine • Consider pacemaker insertion for blocks

  44. A 34 yo M presents 4 hours after ingesting 100 regular ASA pills. He complains of tinnitus, is vomiting and has an ASA level of 6 mmol/L. His vital signs are BP 132/78 P 85 RR 28 T 37.5° C Decontamination?Other treatment considerations?

  45. Commonly Dialysable Drugs • Isopropanol • Salicylates • Theophylline • Uremia • Methanol • Barbiturates • Lithium • Ethylene Glycol

  46. Salicylates - Symptoms • Causes metabolic acidosis .. Initially resp alkalosis as stimulates resp centre • Mild = ototoxicity (tinnitis, vertigo) • Severe = CNS stimulation followed by depression (confusion, delerium, seizures_ • Cardiac dysrhythmias, noncardiogenic pulmonary edema, renal failure, hemorrhage

  47. Salicylates – Treatment • Treatment is not dependant on specific serum level; it is a CLINICAL diagnosis • Done nomogram USELESS • Draw levels to ensure declining

  48. Salicylates – Evaluation • Decontamination with Activated charcoal • Consider gastric lavage if < 60 min • Alkaline diuresis with bicarb increases elimination of ASA (goal of urine pH 5 – 8) • See TCA OD for bicarb dosing • Hemodialysis is most effective means • Indications include renal failure, severe cardiac tox, rising ASA levels despite alkalinization, pulm edema, severe acidbase imbalance

  49. Case A 42 yo M presents after ingesting 30 grams of acetaminophen. He is asymptomatic. A serum level 4 hours after ingestion is 1625 mol/L.

  50. Antidotes

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