The Poisoned Patient

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					The Poisoned Patient

    Core Clerkship in Emergency Medicine
University of Colorado at Denver Health Sciences
   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
   Sick or not sick?
      Poisoned patients can present with a broad
       spectrum of illness
   If sick, start treatment
      Resuscitation is always the first step-
       remember your ABCs
     General principles of emergency
   Resuscitation/Stabilization
   Evaluation
     Rule out the life-threats
     Identify what you can

   Symptomatic care/monitoring
     Prevention of deterioration
     Treat symptoms

     Antidotes
Case – Altered Mental Status
                    EMS Report
   ―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

   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
The patient’s son arrives…

  What would you like to ask his
            His son tells you…
   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
   Wife died of cancer about a month ago—dad
    took her death ―very hard‖
                  Physical Exam
   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
   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
   Sick but stable
   No immediate airway, breathing or circulation
    interventions required
   But altered mental status may be due to a life-
    threatening condition that requires prompt
 What’s our differential
diagnosis for this patient?
       Broad Differential Diagnoses
   Neurologic
   Malignant
   Endocrine
   Infection
   Trauma
   Toxicologic
           Altered Mental Status
   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)
        Get the best history possible
   Often unreliable or unobtainable from patient
   Rely on EMS, bystanders, family members and
    other physicians
   Psychiatric files
   Obtain bottles/medications from home
       Any missing pills, amount, time of ingestion
   Environmental setting
   Check pockets, bags, belongings
                  Physical Exam
   Thorough exam looking for clues:
     Toxidromes- constellation of signs and symptoms of
      a particular poison
     In the ED we always look for the ―classic‖
   Also look for signs of non-toxicologic causes:
       Evidence of trauma, infection, metabolic or
        neurological causes, etc.
          Common Toxidromes
   Sympathomimetics
   Anti-cholinergics
   Cholinergics
   Sedatives
   Opiates
   Cocaine, Amphetamines, PCP
     Hypertension
     Tachycardia

     Diaphoresis

     Mydriasis

     Agitation

   Does this sound like our guy?
   Antihistamines, some plants, side effect of many drugs
       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?
   Organophosphates, Carbamates, Nerve agents
   Effects both muscarinic and nicotinic receptors
   Muscarinic effects
       U- URINATION
       G- GI DISTRESS (diarrhea & vomiting)
       M- MIOSIS
   Nicotinic effects - MTWThF
     M-Mydriasis
     T-Tachycardia

     W-Weakness

     TH-Hyperthermia

     F-Fasciculations

   Does this sound like our guy?
Opiates, Clonidine
   Miosis
   Hypotension

   Bradypnea

   Bradycardia

   Hypothermia

   CNS Depression

  Does this look like our guy?
Benzodiazepines, GHB
   ―Coma with normal vital signs‖
     CNS Depression
     Normotensive

     Mild bradypnea or normal RR

   Does this look like our guy?
             Toxins and Vital Signs
   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,
   Tachypnea- aspirin, amphetamines, CO
   Bradypnea- narcotics, clonidine, ETOH
   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

   Time to gather more data….
Diagnostic Testing

 What diagnostics might be
   helpful in this case?
   General lab testing
     Serum chemistry, blood gas to identify metabolic
     CBC, UA, CSF analysis to identify infection

     Drug/alcohol screen to identify common drugs of
   Specific lab testing
       Some poisons require specific testing
 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
    What is your assessment now?

   What is the acid/base disturbance?
   What is the differential for this acid/base
   Is this consistent with a common overdose?
   How can we assess this problem?
   Was the ECG, head CT, and CXR helpful?
                         (Aspirin Poisoning)
   Respiratory alkalosis
       Direct stimulation of respiratory
            Tachypnea
   Metabolic acidosis
     Aspirin is salicylic acid
     Causes lactic acidosis by uncoupling oxidative
     Causes ketosis by stimulating lipid metabolism

   Confusion/cerebral edema
   In most poisonings, symptoms do not correlate
    well with serum drug levels, so levels are not
   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
         Poisoning Management
   Supportive and symptomatic care are required
    for all poisonings
       Treating Common Poisoning
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
   Antidotal therapies are needed for only a few
    poisons. (Consult your EM book for detailed listings.)
   Consider GI decontamination
       Removal of drug or decrease absorption from GI
             GI Decontamination
   Ipecac syrup
       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
            GI Decontamination
   Gastric Lavage
     Insertion of large orogastric tube into the stomach
      and lavaging with several liters of fluid
     Potentially useful in life threatening ingestions < 1
     Aspiration occurs in around 5% of patients
Borrowed from Vik Bebarta, ―One Pill Can Kill‖
            GI Decontamination
   Whole Bowel Irrigation
     Decreases GI transit time using PEG
     Useful in life threatening ingestions when other
      methods not helpful
           GI Decontamination
   Would GI decontamination be useful in this
   Do you think that this patient has more drug in
    the GI tract?
           GI Decontamination

   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
   Dialysis
   Diuresis

   Chelation

   Cardiac pacing
          Salicylism - Treatment
   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)
   Household bleach           Shampoos, lotions
   Cigarettes (<3)            Rat poison
   Cosmetics                  Detergents
   Glues/paste                Chalk
   Hydrogen peroxide          Laxatives
    (medicinal)                Ink
   Matches                    Antibiotics
   Paint (indoor, latex)      Antacids
   Always start with the ABCs
   Target your history and physical for clues to the
   Labs and other testing may be useful
   Most poisons only require supportive care
   If you have questions call the Rocky Mountain
    Poison Center