Download Toxicology Tidbits

Toxicology Tidbits
Howard Burns, MD, FACEP,
FACMT
Toxicology Tidbits
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Toxidromes?
New treatments?, HIET, Lipids, etc.
Widened QRS, Prolonged QT
Miscellaneous musings
Portmanteau ?
• The word toxidrome is a portmanteau
portmanteau
• A morph formed by the combination of two
or more morphemes
• ie. A word made by the combining of two
or more other word’s sounds and meanings
• Smoke +fog = smog, labradoodle, etc.
Toxidromes
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Anticholinergic and Muscarinic
Sympathomimetic, Opiate
Hallucinogenic
Sedative hypnotic
Toxidromes
• Taxis in Durham, NC ?
• Anticholinergic (Hot as Hades, red as a
beet, dry as a bone, blind as a bat, mad as a
hatter). Benadryl, tricyclic antidepressants
• Cholinergic- SLUDGE, organophosphates,
carbamates, sarin etc.
• DUMBELS
Mad as a Hatter ?
• Hg
Mad as a Hatter
Erethism?
• Hg poisoning triad of Stomatitis, tremors
and erethism
Sympathomimetic and Opiate
• Sympathomimetic- dilated pupils, elevated
BP & P, diaphoresis, Temp, ?
Hallucinations
• Opiate- pinpoint pupils, Depressed
everything, ?pulmonary edema
Sedative Hypnotic and
hallucinogenic
• Not very helpful
• Too many things cause sedation and
specific signs may not show early on.
• Most hallucination causing drugs have some
stimulant effect also.
• Beware as seizures may be next
deterioration.
Cannabinoid Toxidrome
Cannabinoid Toxidrome
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Dazed look
Smells like weed.
Poor time space awareness
Keeps asking for Doritos
Seratonergic Syndrome
Seratonine Syndrome
• Hunter’s Criteria
• Clonus plus serotonergic agent
• Diaphoresis, tremor, agitation, rigidity,
elevated temp
Seratonine Syndrome
• What do these people die from?
• Acutely?
Seratonine Syndrome
• Hyperthermia
• Rhabdomyolyses
• Aggressive Care can treat these problems if
they are recognized.
• Cooling, treat agitation (benzos), IV’s
hydration, cyproheptadine?
Cyproheptadine
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5-HT-2A inhibitor
12 mg (PO only) then 2mg q 2hr
Mortality 2-12%, about 100 deaths per year
Hyperthermia, rhabdomyolyses with renal
failure, DIC (? from hyperthermia)
• 0)
Seratonine Syndrome
• Can’t overemphasize need for close
monitoring of temp (core) and liberal use of
paralyses and intubation and external
cooling in the more critical of these
patients.
• Olanzapine, thorazine (chlorpromazine),
Haldol have all been used with some
success.
S-S vs NMS
• Concerns exist about using antipsychotics
for treating Seratonin Syndrome because of
difficulties differentiating NMS from SS.
• Benzodiazepines (valium, lorazepam, etc.)
are a good starting point for any agitated
delerium
Drugs causing seratonine
syndrome
Antidepressants,(SSRI’s,SNRI’s,
MAOI’s, bupropion, Li, etc. Opioids,
Stimulants (cocaine, amphetamines,
ie ADHD meds)
Herbals (St. John’s wort, gensing,
nutmeg, yohimbine)
Others- dextromethorphan,
odansetron
NMS vs SS
History of taking antipsychotic med?
Onset acutely vs. gradualy?
Dopaaminergic blockade vs.
Seratonine excess
SS vs NMS
• Don’t worry about differentiating the two
syndromes.
• More important to recognize hyperthermia,
and sedate patient adequately to control
agitation and delirium (benzo’s, Haldol?,
• If nothing working, paralyze and intubate,
hydrate and cool pt.
Libby Zion?
• Who was Libby Zion?
• What was the significance of her case?
Libby Zion Case
• Led to decrease in House Staff (MD
residents in training) hours.
• ? Overworked resident gave Libby (18 yo
agitated psych patient on Nardil-phenelzine,
MAOI) pethidine. She was thought to have
died from hyperthermia from drug
interaction in form of seratonine syndrome.
Libby Zion
• She also received Haldol to control her
agitation
• She also had restraints ordered
• One test showed positive for cocaine
• Her father was a lawyer
High Dose Insulin Therapy
• Also known as hyperinsulin euglycemic
therapy, HIET, HDI, etc.
• Doses as high as 10 Units/Kg/hr after a
bolus have been used.
• Glucose level is closely monitored and
dextrose given as needed.
When to use HDI therapy
• Any overdose of BB or CCB that doesn’t
respond to usual treatments or any serious
OD of that type
• Many toxicologists now consider this first
line treatment of these OD’s
• Many toxicologists are trying this on any
OD where myocardial activity is suppressed
in an unknown lngestion.
How do I do it?
• Bolus .5 to 1 unit/ kg
• Drip .5 to 2 U / kg / hr
• Some re commend as high as 10 U/kg/hr
drip if needed
• Frequently need a D10 drip along with this
especially with BB OD
How to do it
• CCB OD’s will cause insulin resistance in
pancreas and glucose levels are usually
higher in these OD’s and therefore Dextrose
needs lessened.
• Potassium levels will be lower at times also
because of insulin shifts to intracellular so
replacement may be required, however
these aren’t true losses and mildly
depressed levels can be tolerated.
Lipid Rescue
• Also known as LRT (lipid rescue therapy),
intralipid infusion therapy, intravenous fat
emulsion, etc.
• Intralipid 20% emulsion is used.
• Thought to work as lipid sink (ie fat soluble
drug is absorbed into fat emulsion from
circulation)
• Maybe works to supply lipid to cytochrome
chain to allow mitochondrial function to
How do we do it?
• Bolus 100 ml IV slow push (1.5 ml/kg)
• Drip if needed is 500 to 1 liter over 1-4
hours
• This isn’t a routine therapy and is generally
recommended for patients in extremis.
• Fat emboli and other complication potential.
• 2 cardiac arrests reported in one paper.
Some clinical thoughts: Opiates
• With push to get “life saving” narcan out to
the masses
• May see patients coming to your ED in
acute withdrawal
• They will be angry and want to leave
The Point? (opiates)
• These patients are at risk for delayed effects
since almost all opiate effects will outlast
narcan effects.
• ie they may well arrest away from medical
care and are a high liability patient, since
record will show you saw them shortly
before their death (hardly ever a good thing)
Some Clinical Thoughts: Case
Report
• 44 yo female ingests 200 aspirin tablets
(325 mg) 2 hours before arrival in your ED
• What treatments should you do?
• Your patient continues to deteriorate and
needs intubated
Clinical Thoughts
• 1. Almost no expert these days will criticize
you for not using lavage or charcoal.
• 2. This patient is or soon will be acidotic
• 3. You could easily have this patient arrest
during intubation if you aren’t careful to
keep them from worsening their acidosis
• 4. Try to avoid this with careful monitoring
of pH, giving bicarb, and hyperventilating
patient
Clinical thoughts: prolonged
QRS (Na channel blockade)
• We used to do this for TCA (tricyclic
antidepressant OD), but has now become
routine recommendation to do bicarb drip
for any tox related QRS widening
• With EMR it’s easier than ever to check an
old EKG, especially in elderly
• 2 amps bicarb in 1 L. sterile water at 150ml
an hour
Clinical Thoughts: QT
prolongation (K channel
blockade)
• Check Ca and Mg levels and replace if
necessary
• Consider giving Magnesium 2-4 GM if
worried about arrhythmia (Torsade)
Last week
Whats this?
What is fugu
• What toxin is associated with this fish?
• How potent is this toxin?
Tetrodotoxin
• Potent Na channel blocker from puffer fish
• Considered a delicacy (fugu) in Japan
• Must be licensed there to prepare this fish
as liver gonads etc. contain the toxin and
many people have died over the years from
improper preparation of this fish
• LD50 is 25 mg
E-Cigarettes
• How toxic is nicotine?
• LD 50 controversial probably around a
gram for an adult
• For comparison this would be similar to
Arsenic and about one tenth the toxicity of
strychnine
E-Cigs
• Unregulated at this point
• No safety caps on refill cartridges,etc.
• Concentrations up to 100mg/ml
• ie 10 ml potentially fatal even for an adult
• E-cigs also contain or give off propylene
glycol, formaldehyde, glycerine,
nitrosamines
E-Cigs cont.’
• Already one death of a 1 yo on NY who got
into a refill cartridge.
• Some pet deaths have been reported also.
• Siezures will be hard to control and
consider early paralyses and intubation
along with early aggressive antisiezure
meds
E-cigs
• One call to PCCs in 2010 up to 1351 in
2013.
• As Dr. Cantrell from California Poison
Control said “its not a matter of if a child
will be seriously injured or killed it’s a
matter of when”