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”