The Poisoned Patient

1. The Poisoned Patient Core Clerkship in Emergency Medicine University of Colorado at Denver Health Sciences Center

2. Objectives • Apply general emergency medicine management principles to the poisoned patient • Review basic pharmacology and toxicology of common poisons • Utilize clues from the history, physical exam, and diagnostics to identify the poisons involved

3. First principle in poisoning management • Sick or not sick? • Poisoned patients can present with a broad spectrum of illness • If sick, start treatment • Resuscitation is always the first step- remember your ABCs

4. General principles of emergency management • Resuscitation/Stabilization • Evaluation • Rule out the life-threats • Identify what you can • Symptomatic care/monitoring • Prevention of deterioration • Treat symptoms • Antidotes

5. Case – Altered Mental Status

6. EMS Report • “This is a 57 yo male. We were called to his house by his son, who found him confused. The son is on the way here. • “On our arrival, we found a somnolent male who is not able to answer questions, is mildly diaphoretic, and had BP 135/75, HR 100, RR 32, and oxygen sat of 99% on room air. We have a 16 gauge IV in the left AC. D-stick was 95. • “Any questions for us before we leave?”

7. EMS Report • House was clean, no signs of an assault, etc. • No drug paraphernalia around • No medicalert bracelet or necklace • No open pill bottles near patient • Patient was found 5 ft from the bottom of a staircase

8. The patient’s son arrives… What would you like to ask his son?

9. His son tells you… • He talked to his dad yesterday, seemed normal • No significant PMH • PSHX: gallbladder taken out about 10 years ago • No medications except for something he occasionally takes for a “stomach flu bug” • SH: smoker : 40 pack/year hx, occasional social drinker • Wife died of cancer about a month ago—dad took her death “very hard”

10. Physical Exam • Vitals – T 38.2; BP 134/78; Pulse 102; RR 30; SaO2 98% on RA • Gen: Confused, drowsy • Skin: moist and flushed, no lesions, no cyanosis • Pupils: mid position (not constricted or dilated) and reactive • CV: tachy RR, no murmur/rubs/gallops • Lungs: CTA bilaterally • Bowel sounds: present • No evidence of trauma, neck is not stiff • Neuro: otherwise nonfocal

11. Sick or not sick?

12. Sick or not sick • Sick but stable • No immediate airway, breathing or circulation interventions required • But altered mental status may be due to a life-threatening condition that requires prompt intervention

13. What’s our differential diagnosis for this patient?

14. Broad Differential Diagnoses • Neurologic • Malignant • Endocrine • Infection • Trauma • Toxicologic

15. Altered Mental Status • Four life-threatening causes that require immediate treatment • Hypoxia (ruled out by normal pulse ox) • Hypotension/severe hypertension (ruled out by normal BP) • Herniation of the brainstem (ruled out by non-focal neurological exam) • Hypoglycemia (needs to be evaluated in every patient with altered mental status)

16. Get the best history possible • Often unreliable or unobtainable from patient • Rely on EMS, bystanders, family members and other physicians • Psychiatric files • Obtain bottles/medications from home • Any missing pills, amount, time of ingestion • Environmental setting • Check pockets, bags, belongings

17. Physical Exam • Thorough exam looking for clues: • Toxidromes- constellation of signs and symptoms of a particular poison • In the ED we always look for the “classic” presentation • Also look for signs of non-toxicologic causes: • Evidence of trauma, infection, metabolic or neurological causes, etc.

18. Common Toxidromes • Sympathomimetics • Anti-cholinergics • Cholinergics • Sedatives • Opiates

19. Sympathomimetics • Cocaine, Amphetamines, PCP • Hypertension • Tachycardia • Diaphoresis • Mydriasis • Agitation • Does this sound like our guy?

20. Anticholinergics • Antihistamines, some plants, side effect of many drugs • Tachycardia • Hyperthermia • Dry skin • Mydriasis • Decreased bowel sounds • Urinary retention • Delirium, agitation • Hot as a hare, Dry as a bone, Red as a beet, Mad as a hatter, Blind as a bat. • Does this sound like our guy?

21. Cholinergics • Organophosphates, Carbamates, Nerve agents • Effects both muscarinic and nicotinic receptors • Muscarinic effects • S- SALIVATION, SEIZURE • L- LACRIMATION • U- URINATION • G- GI DISTRESS (diarrhea & vomiting) • B- BRONCHORRHEA • A- ABDOMINAL CRAMPS • M- MIOSIS

22. Cholinergics • Nicotinic effects - MTWThF • M-Mydriasis • T-Tachycardia • W-Weakness • TH-Hyperthermia • F-Fasciculations • Does this sound like our guy?

23. Opiates Opiates, Clonidine • Miosis • Hypotension • Bradypnea • Bradycardia • Hypothermia • CNS Depression Does this look like our guy?

24. Sedatives Benzodiazepines, GHB “Coma with normal vital signs” • CNS Depression • Normotensive • Mild bradypnea or normal RR • Does this look like our guy?

25. Toxins and Vital Signs • Hyperthermia - aspirin, cocaine, anticholinergics • Hypothermia - opioids, sedatives • Hypertension - stimulants, tricyclics, antihistamines • Hypotension - blood pressure medications, opioids • Tachycardia - stimulants, vasodilators, anticholinergics • Bradycardia - beta-blockers, Ca Ch blockers, clonidine, digoxin • Tachypnea- aspirin, amphetamines, CO • Bradypnea- narcotics, clonidine, ETOH

26. Assessment • The history suggests an overdose, but we don’t know what • The physical exam is non-specific • No common toxidrome to suggest a diagnosis • Nothing to strongly suggest another cause • Time to gather more data….

27. Diagnostic Testing What diagnostics might be helpful in this case?

28. Diagnostics • General lab testing • Serum chemistry, blood gas to identify metabolic abnormalities • CBC, UA, CSF analysis to identify infection • Drug/alcohol screen to identify common drugs of abuse • Specific lab testing • Some poisons require specific testing

29. Labs • Na 135 K 3.5 Cl100 HCO3 15 Glucose 120 BUN 25 Cr 1.0 • ABG 7.50/15/90/16/-12 • EtOH undetectable • Urine drug screen negative for drugs of abuse • ECG – sinus tachycardia • Head CT – negative • CXR - normal

30. What is your assessment now? • What is the acid/base disturbance? • What is the differential for this acid/base disturbance? • Is this consistent with a common overdose? • How can we assess this problem? • Was the ECG, head CT, and CXR helpful?

31. Salicylism(Aspirin Poisoning) • Respiratory alkalosis • Direct stimulation of respiratory centers • Tachypnea • Metabolic acidosis • Aspirin is salicylic acid • Causes lactic acidosis by uncoupling oxidative phosphorylation • Causes ketosis by stimulating lipid metabolism • Confusion/cerebral edema

32. Evaluation • In most poisonings, symptoms do not correlate well with serum drug levels, so levels are not useful • Acute salicylate ingestion is one case where symptoms DO correlate with levels • Therapeutic is up to 30 mg/dl • This patient’s level was 75 mg/dl

33. Poisoning Management • Supportive and symptomatic care are required for all poisonings

34. Treating Common Poisoning Symptoms

35. Poisoning Management • Antidotal therapies are needed for only a few poisons. (Consult your EM book for detailed listings.) • Consider GI decontamination • Removal of drug or decrease absorption from GI tract

36. GI Decontamination • Ipecac syrup • No longer recommended for poisonings • Activated charcoal • Binds to most medications and potentially decreases GI absorption • Potentially useful within 1 hour of ingestion but no evidence of improved clinical outcomes • Aspiration is uncommon unless given by an NG tube or in patient with altered mental status

37. GI Decontamination • Gastric Lavage • Insertion of large orogastric tube into the stomach and lavaging with several liters of fluid • Potentially useful in life threatening ingestions < 1 hour • Aspiration occurs in around 5% of patients

38. Borrowed from Vik Bebarta, “One Pill Can Kill”

39. GI Decontamination • Whole Bowel Irrigation • Decreases GI transit time using PEG • Useful in life threatening ingestions when other methods not helpful

41. GI Decontamination • Would GI decontamination be useful in this patient? • Do you think that this patient has more drug in the GI tract?

42. GI Decontamination • He has a high salicylate level • He has been “confused for a couple of hours” • Probably not much drug left in the GI tract

43. Specific Treatments Very few poisons require specific treatments such as: • Dialysis • Diuresis • Chelation • Cardiac pacing

44. Salicylism - Treatment • Salicylate poisoning has a specific treatment • Alkaline diuresis – increase in urine pH favors movement of salicylate ion into urine • Dialysis for severe cases Is this patient sick enough to get dialysis?

45. Household bleach Cigarettes (<3) Cosmetics Glues/paste Hydrogen peroxide (medicinal) Matches Paint (indoor, latex) Shampoos, lotions Rat poison Detergents Chalk Laxatives Ink Antibiotics Antacids Non-Toxic Ingestions (Small amounts)

46. Summary • Always start with the ABCs • Target your history and physical for clues to the diagnosis • Labs and other testing may be useful • Most poisons only require supportive care • If you have questions call the Rocky Mountain Poison Center