1. MANAGEMENT OF ACUTE POISONING
Kent R. Olson, MD
Medical Director
California Poison Control System
San Francisco Division

3. Lessons from history
A young princess ate part of an apple given to her by a wicked witch
She was found comatose and unresponsive, as if in a deep sleep
Airway positioning and mouth to mouth ventilation were performed, and she recovered fully

4. Best antidote is good supportive care
Lesson:
Best antidote is good supportive care
(Love’s first kiss)

5. Case 1:
Young woman found unconscious, several empty pill bottles nearby
Unresponsive to painful stimuli
Shallow breathing

6. Initial management: ABCDs
Airway
Breathing
Circulation
Dextrose, drugs, decontamination

7. Airway issues Risks: Major cause of morbidity in poisoned patients
Floppy tongue can obstruct airway
Loss of protective reflexes may permit pulmonary aspiration of gastric contents
Major cause of morbidity in poisoned patients

8. Assessing the airway “Gag” reflex Alternatives Indirect measure
May be misleading
Can stimulate vomiting
Alternatives

9. Breathing Assess visually pCO2 reflects ventilation - ABG useful
pulse oximetry provides convenient, noninvasive evaluation of O2 saturation

10. Pitfalls pO2 measures dissolved oxygen
can be normal despite abnormal hemoglobin states, eg COHgb, MetHgb
Pulse oximetry also fails to detect CO poisoning

11. Interventions Endotracheal intubation Reverse coma? Protects airway
Allows for mechanical ventilation
Reverse coma?
Naloxone: note T½ = 60 min
Flumazenil?

12. Don’t forget GLUCOSE
“A stroke is never a stroke until it’s had 50 of D50” – Dr. Larry Tierney, 1976
“Well, you could just do an Accuchek” ibid, 2002
Give Thiamine 100 mg IM or in IV

13. Case, continued…
The patient has no gag reflex, and does not resist intubation.
She remains unconscious and on a ventilator overnight
Awakens and extubated the next day
Dx: mixed sedative drug overdose

14. Case 2 47 year old man calls 911, suicidal BP 70/50, HR 50/min
Junctional rhythm
Hx: uses an antihypertensive

16. Circulation = plumbing
Pump working?
Enough volume (is it primed)?
Adequate resistance (no leaks)?

17. Management of Hypotension
Hypovolemia?
IV fluid challenge
Pump?
Dopamine
Inadequate vascular resistance?
Norepinephrine, phenylephrine

18. Antihypertensives Diuretics Beta blockers Calcium channel blockers
ACE Inhibitors
Centrally acting agents
Vasodilators

19. Calcium channel blockers
Bad ODs!!
Low Toxic:Therapeutic ratio
High mortality

20. SHOCK Decreased Automaticity & Conduction Negative Inotropic Effects
Dilated Vascular
Smooth Muscle
SVR HR CO
AV Block
SHOCK

21. Calcium antagonists - treatment
Calcium: most effective
High doses may be needed
Glucagon – variable results
Insulin plus glucose? (experimental)

22. Case 3:
An 18 month old takes some of his grandmother’s “sleeping pills”
Brought to the ER after a seizure
HR 150/min
Pupils dilated, skin flushed, mucous membranes dry

23. Common causes of seizures
Amphetamines/cocaine
Tricyclic and other antidepressants
Isoniazid (INH)
Diphenhydramine
Alcohol withdrawal
Many others . . .

24. 30 minutes later, the ECG shows:

25. Tricyclic antidepressants
Anticholinergic syndrome
Seizures
Cardiotoxicity

26. TCA overdose treatment (similar tox possible w/ massive diphenhydramine)
Stop the seizures
Benzodiazepines, phenobarbital
Treat cardiotoxicity
Sodium bicarbonate 1 mEq/kg IV
IV fluids
Dopamine and/or NE

27. Case 4: metabolic acidosis
Young man had a seizure at home
In ED: obtunded, another seizure
pH 6.94, pCO2 32
Recent immigrant, lives with extended family
Uncle being treated for TB

28. Metabolic Acidosis: MUDPILES
Methanol
Uremia
DKA
Phenformin (whaa?)
Isoniazid, Iron
Lactic acidosis
Ethylene Glycol
Salicylate

29. Isoniazid overdose  GABA Glutamate
Reduces brain pyridoxal 5-phosphate, a cofactor for glutamic acid decarboxylase:
Seizures common; acidosis often severe
Antidote: Pyridoxine (Vitamin B-6)
(excitatory)
(inhibitory)
Glutamate
 GABA
 GAD

30. Case 5: another acidosis
44 year old man, obtunded
BP 110/80 HR RR 24
pH pCO pO2 92
Na K Cl HCO3 18
EtOH 0.18 gm/dL (180 mg/dL)

31. Salicylate poisoning Typical mixed acid-base disturbance
Respiratory alkalosis
Metabolic acidosis
Large OD or enteric coated tablets may delay peak level
Treatment:
Urinary alkalinization, hemodialysis

32. Case 6: more acidosis 30 yo woman found comatose T 92 F, pH 6.9
Na 147, K 4.9, Cl 105, Bicarb 5 (AG 37)
Glucose 166, BUN 16, Cr 1.5
Measured Osm 331 (calculated 308)
EtOH: none detected

33. The Osmolar Gap Common causes of Osm Gap:
Osm = 2 (Na) + BUN/2.8 + Glucose/18
Gap = Measured - Calculated Osm = 0 + 5
Common causes of Osm Gap:
Ethanol
Methanol & Ethylene Glycol
Other alcohols, also aldehydes, ketones

34. METHANOL FORMALDEHYDE FORMIC ACID ELEVATED OSMOLAR GAP ANION GAP
ACIDOSIS
FORMIC ACID

35. Methanol or Ethylene Glycol:
Elevated Osm Gap
Anion gap
Low lactate, does not account for gap
Anion gap may be absent early after OD
Other clues (may be unreliable):
Methanol: blindness, visual disturbance
EG: urine crystals, fluorescence

36. Methanol or Ethylene Glycol:
Main DDx: alcoholic ketoacidosis
Anion and Osm gaps
Low lactate
Clues to AKA:
Gets better quickly w/ IV fluids, dextrose
[Ketones] +/- (mainly -hydroxybutyrate)

37. Case 7: now we’re cookin’
24 year old man with Hx depression
Agitated, confused
BP 110/70 HR RR 20 T 40.4 C
Muscle tone increased, LE clonus
Tox screen negative for cocaine, amphetamines

38. Drug-induced Hyperthermia
Heat Stroke
Malignant Hyperthermia
Neuroleptic Malignant Syndrome
Serotonin Syndrome

39. Drug-induced “heat stoke”
Altered judgment leads to excessive sun/heat exposure
Anticholinergic drugs prevent sweating
Excessive muscle hyperactivity from seizures, or from extreme agitation

40. Malignant hyperthermia
Rare, familial myopathy
Triggered by general anesthesia
Succinylcholine
Inhalational agents (eg, Halothane)
Muscle rigidity, hypermetabolic state
Treatment: dantrolene

41. Neuroleptic Malignant Syndrome
Patient on dopamine-blocking drugs
Haloperidol classic cause
Also with newer agents (eg, clozapine)
Rigidity (lead-pipe)
Autonomic instability
Hyperthermia

42. Serotonin Syndrome Current “hot” diagnosis Serotonin-enhancing Rx
SSRIs in OD or multiple combos
MAOI + serotonin-ergic drug
Hypertonicity/clonus (esp. lower extr.)
Autonomic instability
Hyperthermia

43. Hyperthermia treatment
Act quickly!
Remove clothing spray and fan
Sedation and anticonvulsants PRN
Neuromuscular paralysis if T >40 C
Dantrolene if NM paralysis ineffective
Consider bromocriptine, cyproheptadine

44. One more common one
A 17 year old boy takes a bottle of “aspirin” after he gets his SAT score
Next morning, he is vomiting
In the ED, normal vital signs
Aspirin (salicylate) = negative

45. Acetaminophen Very common overdose May be overlooked
“It’s just aspirin” (OTC’s can’t kill you..?)
Hidden ingredient in many drug combos
No specific findings after OD
Delayed illness/lab abnormalities

46. Acetaminophen (APAP) NAPQI NAC ++ Glucuronidation Sulfation
(non toxic)
Sulfation
(non toxic)
~ 5%
NAPQI
NAC ++
Glutathione + NAPQI
nontoxic product
Liver cell damage

47. N-acetylcysteine (NAC)
Start within 8 hrs if possible
Vomiting often interferes w/oral dosing
Antiemetics (ondansetron, etc)
Can dribble in by NG tube
IV form now available (Acetadote™)
Caution: hypotension w/rapid infusion

48. Gut decontamination after OD
Goal: reduce systemic absorption
Induce vomiting?
Pump the stomach?
Activated charcoal

49. Ipecac-induced emesis
Easy to perform, but not very effective
Contraindicated:
Comatose/convulsing
Ingested corrosive or hydrocarbon
Bottom line: nobody uses it anymore

50. Pumping the stomach Cooperation not required MD sense of “control”
Punitive value?

51. Gastric lavage May stimulate gagging, vomiting
Risky if airway reflexes dulled
Lack of proven efficacy
Bottom line: used only rarely

52. Activated charcoal Finely divided powdered material
Huge surface area
Binds most drugs/poisons
Exceptions:
Lithium
Iron

53. Activated charcoal More effective than SI, GL
First choice for most ODs

54. Whole bowel irrigation
Mechanical flush
Balanced salt solution with PEG
No net fluid gain/loss
Good for:
Iron
Lithium
Sustained-release pills, foreign bodies

55. Antidotes: The best antidote is supportive care Examples of antidotes:
Digoxin-specific antibodies
Atropine & 2-PAM
N-acetylcysteine
Vitamin B-6 (pyridoxine)

56. Call the Poison Center 1-800-222-1222 - 24 hours
Immediate consultation by clinical pharmacists
Back-up by MD toxicologists
Identify pills, discuss diagnosis & Rx

57. “I don’t think we should go up there, especially without a paddle”