The Poisoned Patient
Core Clerkship in Emergency Medicine
University of Colorado at Denver Health Sciences
Center
Objectives
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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
First principle in poisoning
management
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Sick or not sick?
 Poisoned patients can present with a broad
spectrum of illness
If sick, start treatment
 Resuscitation is always the first stepremember your ABCs
General principles of emergency
management
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Resuscitation/Stabilization
Evaluation
Rule out the life-threats
 Identify what you can
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Symptomatic care/monitoring
Prevention of deterioration
 Treat symptoms
 Antidotes
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Case – Altered Mental Status
EMS Report
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“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?”
EMS Report
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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
The patient’s son arrives…
What would you like to ask his
son?
His son tells you…
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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”
Physical Exam
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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
Sick or not sick?
Sick or not sick
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Sick but stable
No immediate airway, breathing or circulation
interventions required
But altered mental status may be due to a lifethreatening condition that requires prompt
intervention
What’s our differential
diagnosis for this patient?
Broad Differential Diagnoses
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Neurologic
Malignant
Endocrine
Infection
Trauma
Toxicologic
Altered Mental Status
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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)
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Get the best history possible
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Often unreliable or unobtainable from patient
Rely on EMS, bystanders, family members and
other physicians
Psychiatric files
Obtain bottles/medications from home
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Any missing pills, amount, time of ingestion
Environmental setting
Check pockets, bags, belongings
Physical Exam
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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
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Also look for signs of non-toxicologic causes:
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Evidence of trauma, infection, metabolic or
neurological causes, etc.
Common Toxidromes
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Sympathomimetics
Anti-cholinergics
Cholinergics
Sedatives
Opiates
Sympathomimetics
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Cocaine, Amphetamines, PCP
Hypertension
 Tachycardia
 Diaphoresis
 Mydriasis
 Agitation
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Does this sound like our guy?
Anticholinergics
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Antihistamines, some plants, side effect of many drugs
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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?
Cholinergics
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Organophosphates, Carbamates, Nerve agents
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Effects both muscarinic and nicotinic receptors
Muscarinic effects
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S- SALIVATION, SEIZURE
L- LACRIMATION
U- URINATION
G- GI DISTRESS (diarrhea & vomiting)
B- BRONCHORRHEA
A- ABDOMINAL CRAMPS
M- MIOSIS
Cholinergics
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Nicotinic effects - MTWThF
M-Mydriasis
 T-Tachycardia
 W-Weakness
 TH-Hyperthermia
 F-Fasciculations
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Does this sound like our guy?
Opiates
Opiates, Clonidine
Miosis
 Hypotension
 Bradypnea
 Bradycardia
 Hypothermia
 CNS Depression
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Does this look like our guy?
Sedatives
Benzodiazepines, GHB
“Coma with normal vital signs”
CNS Depression
 Normotensive
 Mild bradypnea or normal RR
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Does this look like our guy?
Toxins and Vital Signs
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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
Assessment
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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
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Time to gather more data….
Diagnostic Testing
What diagnostics might be
helpful in this case?
Diagnostics
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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
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Specific lab testing
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Some poisons require specific testing
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
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What is your assessment now?
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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?
Salicylism
(Aspirin Poisoning)
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Respiratory alkalosis
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Direct stimulation of respiratory
centers
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Tachypnea
Metabolic acidosis
Aspirin is salicylic acid
 Causes lactic acidosis by uncoupling oxidative
phosphorylation
 Causes ketosis by stimulating lipid metabolism
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Confusion/cerebral edema
Evaluation
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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
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Poisoning Management
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Supportive and symptomatic care are required
for all poisonings
Treating Common Poisoning
Symptoms
Symptom
Treatment
None
Observation
Hypoglycemia
Glucose
Somnolence/coma
Intubation
Agitation/seizures
Sedatives (benzodiazepines)
Hypotension
Fluids/adrenergic pressors
Cardiac arrhythmia
Sodium bicarbonate, calcium,
anti-dysrhythmics, pacing
Vomiting
Anti-emetics, IVF
Poisoning Management
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Antidotal therapies are needed for only a few
poisons. (Consult your EM book for detailed listings.)
Consider GI decontamination
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Removal of drug or decrease absorption from GI
tract
GI Decontamination
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Ipecac syrup
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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
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GI Decontamination
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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
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Borrowed from Vik Bebarta, “One Pill Can Kill”
GI Decontamination
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Whole Bowel Irrigation
Decreases GI transit time using PEG
 Useful in life threatening ingestions when other
methods not helpful
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GI Decontamination
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Would GI decontamination be useful in this
patient?
Do you think that this patient has more drug in
the GI tract?
GI Decontamination
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He has a high salicylate level
He has been “confused for a couple of hours”
Probably not much drug left in the GI tract
Specific Treatments
Very few poisons require specific treatments such
as:
Dialysis
 Diuresis
 Chelation
 Cardiac pacing
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Salicylism - Treatment
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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?
Non-Toxic Ingestions
(Small amounts)
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Household bleach
Cigarettes (<3)
Cosmetics
Glues/paste
Hydrogen peroxide
(medicinal)
Matches
Paint (indoor, latex)
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Shampoos, lotions
Rat poison
Detergents
Chalk
Laxatives
Ink
Antibiotics
Antacids
Summary
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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