Transcript Case: Young man, dance party, collapsed outside.

MANAGEMENT OF ACUTE
POISONING
Kent R. Olson, MD
Medical Director
California Poison Control System
San Francisco Division
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
Lesson:
Best antidote is good supportive care
(Love’s first kiss)
Case 1:
 Young woman found unconscious,
several empty pill bottles nearby
 Unresponsive to painful stimuli
 Shallow breathing
Initial management: ABCDs
 Airway
 Breathing
 Circulation
 Dextrose, drugs, decontamination
Airway issues
 Risks:
• Floppy tongue can obstruct airway
• Loss of protective reflexes may permit
pulmonary aspiration of gastric contents
 Major cause of morbidity in poisoned
patients
Assessing the airway
 “Gag” reflex
• Indirect measure
• May be misleading
• Can stimulate vomiting
 Alternatives
Breathing
 Assess visually
 pCO2 reflects ventilation - ABG useful
 pulse oximetry provides convenient,
noninvasive evaluation of O2
saturation
Pitfalls
 pO2 measures dissolved oxygen
• can be normal despite abnormal
hemoglobin states, eg COHgb, MetHgb
 Pulse oximetry also fails to detect CO
poisoning
Interventions
 Endotracheal intubation
• Protects airway
• Allows for mechanical ventilation
 Reverse coma?
• Naloxone: note T½ = 60 min
• Flumazenil?
Don’t forget GLUCOSE
 “A stroke is never a stroke until it’s
had 50 of D50” – Dr. Larry Tierney, 1976
 Give Thiamine 100 mg IM or in IV
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
Case 2
 47 year old man calls 911, suicidal
 BP 70/50, HR 50/min
 Junctional rhythm
 Hx: uses an antihypertensive
Circulation = plumbing
 Pump working?
 Enough volume (is it primed)?
 Adequate resistance (no leaks)?
Management of Hypotension
 Hypovolemia?
• IV fluid challenge
 Pump?
• Dopamine
 Inadequate vascular resistance?
• Norepinephrine, phenylephrine
Antihypertensives
 Diuretics
 Beta blockers
 Calcium channel blockers
 ACE Inhibitors
 Centrally acting agents
 Vasodilators
Calcium channel blockers
 Bad ODs!!
 Low Toxic:Therapeutic ratio
 High mortality
Decreased
Automaticity
& Conduction
Negative
Inotropic
Effects
Dilated Vascular
Smooth Muscle
HR
AV Block
CO
SVR
SHOCK
Calcium antagonists - treatment
 Calcium: most effective
• High doses may be needed
 Glucagon – variable results
 Insulin plus glucose? (experimental)
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
Common causes of seizures
 Amphetamines/cocaine
 Tricyclic and other antidepressants
 Isoniazid (INH)
 Diphenhydramine
 Alcohol withdrawal
 Many others . . .
30 minutes later, the ECG shows:
Tricyclic antidepressants
 Anticholinergic syndrome
 Seizures
 Cardiotoxicity
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
Case 4: now we’re cookin’
 24 year old man with Hx depression
 Agitated, confused
 BP 110/70 HR 120 RR 20 T 40.4 C
 Muscle tone increased, LE clonus
 Tox screen negative for cocaine,
amphetamines
Drug-induced Hyperthermia
 Heat Stroke
 Malignant Hyperthermia
 Neuroleptic Malignant Syndrome
 Serotonin Syndrome
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
Malignant hyperthermia
 Rare, familial myopathy
 Triggered by general anesthesia
• Succinylcholine
• Inhalational agents (eg, Halothane)
 Muscle rigidity, hypermetabolic state
 Treatment: dantrolene
Neuroleptic Malignant Syndrome
 Patient on dopamine-blocking drugs
• Haloperidol classic cause
• Also with newer agents (eg, clozapine)
 Rigidity (lead-pipe)
 Autonomic instability
 Hyperthermia
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
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
Gut decontamination after OD
 Goal: reduce systemic absorption
• Induce vomiting?
• Pump the stomach?
• Activated charcoal
Ipecac-induced emesis
 Easy to perform, but
not very effective
 Contraindicated:
• Comatose/convulsing
• Ingested corrosive or hydrocarbon
 Bottom line: nobody uses it anymore
Pumping the stomach
 Cooperation not required
 MD sense of
“control”
 Punitive value?
Gastric lavage
 May stimulate gagging, vomiting
 Risky if airway reflexes dulled
 Lack of proven efficacy
 Bottom line: used only rarely
Activated charcoal
 Finely divided powdered material
• Huge surface area
 Binds most drugs/poisons
• Exceptions:
• Lithium
• Iron
Activated charcoal
 More effective than SI, GL
 First choice for most ODs
Whole bowel irrigation
 Mechanical flush
 Balanced salt solution with PEG
• No net fluid gain/loss
 Good for:
• Iron
• Lithium
• Sustained-release pills,
foreign bodies
Antidotes:
 The best antidote is supportive care
 Examples of antidotes:
•
•
•
•
Digoxin-specific antibodies
Atropine & 2-PAM
N-acetylcysteine
Vitamin B-6 (pyridoxine)
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
“I don’t think we should go up there, especially without a paddle”