Diagnosis of Poisoning

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Diagnosis of Poisoning

• Kent R. Olson, MD, FACEP
• Medical Director
• California Poison Control System,
• San Francisco Division
• University of California, San Francisco

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Lessons from history

• A young princess ate part of an apple given to
  her by a wicked witch
• She presented comatose and unresponsive (as if
  she was in a deep sleep)
• Airway positioning and mouth to mouth
  ventilations were performed, and she recovered

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Diagnosis of Poisoning

• Rule 1 Take good care of the patient
• ABCDs
• Airway
• Breathing
• Circulation
• Dextrose, Drugs Decontamination
• Rule out
• Head trauma, Meningitis, Sepsis
• Metabolic disorders

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Diagnosis of Poisoning

• Rule 2 Get a good history
• Check multiple sources
• Patient
• Family, Friends
• Paramedics, Pharmacy
• Circumstances
• What was taken?
• How much?
• When?

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Diagnosis of Poisoning

• Rule 3 Do a good physical exam
• Toxicologic physical exam
• Mental status
• Vital signs (all of them)
• Pupils
• Bowel sounds
• Muscle tone and activity
• Skin dry or diaphoretic?
• Look for an autonomic syndrome

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Autonomic Syndromes

• Sympathetic Cholinergic
• Blood Pressure /--
• Pulse Rate /--
• Pupils dilated pinpoint
• Peristalsis -
• Skin sweaty sweaty

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Autonomic Syndromes

• Sympathetic Sympatholytic
• Blood Pressure --
• Pulse Rate --
• Pupils dilated small
• Peristalsis - -
• Skin sweaty -

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Autonomic Syndromes

• Anticholinergic Cholinergic
• Blood Pressure /--
• Pulse Rate /--
• Pupils dilated pinpoint
• Peristalsis --
• Skin dry sweaty

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Autonomic Syndromes

• Sympathetic Anticholinergic
• Blood Pressure
• Pulse Rate
• Pupils dilated dilated
• Peristalsis - --
• Skin sweaty dry

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Case Study

• Two adolescents are brought to the ED by their
  parents because of agitation.
• 1 BP 150/100, HR 120, pupils dilated, jumpy,
  diaphoretic.
• 2 BP 130/90, HR 130, pupils dilated, distended
  bladder, dry flushed skin.

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Sympathomimetic Syndrome

• Common features
• Agitation, psychosis
• Hypertension, tachycardia
• Dilated pupils
• Diaphoresis
• Hyperthermia
• Common causes
• Cocaine
• Amphetamines (including MDMA - Ecstasy)
• Phencyclidine (PCP)
• Phenylpropanolamine (PPA) often causes severe
  hypertension with reflex bradycardia

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Anticholinergic Syndrome

• Common features
• Dilated pupils
• Dry, flushed skin
• Sinus tachycardia
• Ileus, urinary retention
• Confusion, delirium
• Common causes
• Atropine related drugs
• Plants (eg, jimson weed) mushrooms (eg, A.
  muscaria)
• OTC Rx antihistamines
• Tricyclic antidepressants

Mad as a Hatter Red as a Beet Blind as a Bat Dry
as a Bone
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Case Study

• A 28 year old woman presents groggy and confused.
  Pupils 7-8 mm. Skin dry and flushed. Bowel sounds
  diminished.
• 130/90 120/min 14/min 37.8 C
• Shortly after arrival she has a grand-mal
  seizure.
• ECG monitor QRS 0.16 sec, wide complex
  tachycardia

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Tricyclic Antidepressant Overdose

• Anticholinergic syndrome
• The three Cs
• Coma
• Convulsions
• Cardiac conduction abnormalities
• QRS gt0.12 sec is a better predictor of toxicity
  than the serum drug level

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Common Causes of Seizures

• Tricyclic antidepressants
• Newer antidepressants esp. Wellbutrin
• Cocaine, Amphetamines
• Diphenhydramine
• Isoniazid

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Case Study

• A 2 year old child is found unresponsive. The
  parents are suspected heroin users.
• BP 80/50 HR 70 RR 6, shallow
• Pupils 1 mm. Peristalsis decreased. Muscle tone
  flaccid. No sweating.
• There is no response to 0.4 mg naloxone.

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Case (cont.)

• Common causes of miosis
• Opioids
• Other sympatholytic drugs
• Phenothiazines
• Cholinergic agents
• CNS structural lesions

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Case (cont.)

• There was no response to repeated doses of
  naloxone to a total of 4 mg.
• There was no response to flumazenil (total dose
  1.2 mg).
• The parents found an opened bottle of clonidine
  0.1 mg on the kitchen floor.

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Common Sympatholytic Agents

• Opioids
• Clonidine
• Benzodiazepines
• Barbiturates
• Ethanol

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Case Study

• A 34 year old man drank an unidentified liquid.
  He vomited several times, and became weak and
  pale. In the ED
• BP 150/100 HR 110
• Pupils pinpoint. Profuse diaphoresis. Vomit has
  a chemical odor.
• He develops muscle fasciculations and has a
  respiratory arrest.

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Cholinergic Syndrome

• SLUD
• Salivation, Sweating
• Lacrimation
• Urination
• Diarrhea, Vomiting
• also muscle weakness paralysis

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Diagnosis of Poisoning

• Rule 4 Use the laboratory appropriately
• Routine labs
• Arterial blood gases
• Electrolytes anion gap
• Osmolality
• Toxicology testing
• Tox screening
• Specific stat quantitative tests

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Case Study

• A 44 year old man was found unconscious, with a
  suicide note and a half-empty bottle of whiskey.
• BP 110/80 HR 110 RR 32
• pH 7.47 pCO2 18 pO2 88
• Na 140 K 3.8 Cl 106 HCO3 18
• Ethanol 0.18 gm/dL

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Anion Gap

• Na - Cl - HCO3 8-12 mEq/L
• Causes of increased gap SALAD
• Salicylates
• Alcohols
• Lactic Acidosis
• Anuria
• DKA

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Salicylate Intoxication

• Typical mixed acid-base abnormality
• Respiratory alkalosis
• Metabolic acidosis
• Treatment
• Alkalinize urine, restore serum pH
• Hemodialysis

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Radiopaque Drugs Poisons

• Unreliable - useful only if positive
• Commonly radiopaque
• Iron
• Potassium
• Calcium
• Sometimes visible
• Chloral hydrate
• Phenothiazines
• Sustained-release preparations

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Case

• A 16 year old was brought to the ED by paramedics
  after an overdose of Tylenol with codeine
• She had small pupils, and was very sleepy/poorly
  responsive
• Naloxone 2 mg increased pupil size and she became
  combative but not fully awake

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Case, continued

• Her mother was questioned
• . . . I didnt say she overdosed. . . I told
  them I was worried about all the pain pills she
  was using for her headache. . .
• Rectal Temp 102.5 F
• LP pneumococcal meningitis!

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Important Rule-Outs

• ATOMIC
• Alcohol check ETOH consider alcoholism
• Trauma consider CT scan
• Overdose other drugs involved?
• Metabolic Na, glucose, O2, Thyroid, etc.
• Infection consider LP
• Carbon Monoxide obtain COHgb

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Case Study

• A 27 year old woman found obtunded with pinpoint
  pupils, awoke with IV naloxone, and admitted to
  ingestion of a few pain pills.
• Does this patient need a Tox Screen?
• She was treated with oral activated charcoal,
  observed for 4 hours, and released to psychiatry.

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Case (cont.)

• Three days later, she returned because of nausea,
  abdominal pain, and lethargy. She appeared
  jaundiced.
• AST 8,000 PT 28 sec Bilirubin 3.6
• Toxicology screen from the original visit
  revealed acetaminophen.

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Acetaminophen

• Pitfalls in Diagnosis
• History
• Not volunteered by patient
• Hidden ingredient in many products
• No initial specific symptoms
• Physical exam laboratory
• No initial specific findings
• Only reliable test STAT acetaminophen

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Comprehensive Toxicology Screening

• Problems
• Slow, expensive
• Many drugs not included
• Potential uses
• Forensic questions
• Possible brain death
• Quick drugs of abuse screens
• ? Useful - for JGP
• Many drugs not included know your hosps limits
• Should not use () test forensically unless
  confirmed

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Toxicology Laboratory

• Quantitative testing may be useful if
• results will return quickly, and . . .
• results will affect clinical management
• Examples of specific useful levels
• Acetaminophen
• Carbon monoxide
• Digoxin
• Salicylate
• Valproic acid

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Diagnosis of Poisoning - Summary

• Take good care of the patient
• Get a good history
• Do a good physical exam
• Use the laboratory appropriately
• Consult with the Poison Control Center
• 1-800-411-8080 or 1-800-222-1222