MANAGEMENT OF ACUTE POISONING
Kent R. Olson, MDMedical Director
California Poison Control SystemSan 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
Negative InotropicEffects
DecreasedAutomaticity& Conduction
Dilated VascularSmooth Muscle
SVRSVRCOCOHRHRAV BlockAV Block
SHOCKSHOCK
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 Center1-800-222-1222 - 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”