Poisoning Lec.
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Transcript of Poisoning Lec.
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Poisoning
Before YOU start:
This is Dr. Abdallah Shurman .
The outlines for this lectures is poisoning, important emergencies
such as scorpion stings & snakes bites& if there is enough time we
are going to talk about other bites & stings by BEES which weconsider it something simple but in fact it is not.
This lecture is about 83mins. It is very short & easy lecture.
Enjoy
Poisoning:Is one of the accidents that can be also initiated by the family &
this is what we call abuse , or non-accidental intentional
poisoning ,,, NOW we are not allowed to talk about the
intentional because we have no time, we are going to talk about
accidents only.
Incidence
:
It is the most common accident in children, with incidence
reaches up to 66.8% of all poisoning cases.It can cause death to patients; it is fatal in 2.7% of the cases.
The route of the poisoning is mainly by ingestion in a 75%
of the cases, other routes include the contact of the children
with the some plants or some chemicals (dermal) & its
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percentage is 8%, Inhalation in 7% of the cases & poisoning
including the eye (4ocular) in 5.8% of the cases.
History:
Here we need to take a good history & make good physical
examination, because any deviation from the normal in the
history or the examination can lead us to the cause of
poisoning, most of the families come to the ER telling them
that their child has ingested something that they dont know
what is it, & by good history & examination you can reach to
the possibilities of this poisoning such as aspirin,
acetamenophen, iron or others.
The history includes the name of the ingested materialif they
know it, the dose of this materialit is very important
because some families come to YOU & say that their child has
ingested accidentally 5 cc of paracetamol, these 5 cc contains
125 mg & the dose is 15 mg/kg/dose, & if we calculate the
dose for this child, well find that we need more than this
amount of material to have the therapeutic effect of this
drug!! , the time of ingestion
WHY the time of ingestion isimportant? Because the time determines which type of
emergency I will do for this child, for example, we can apply
the gastric lavage up to certain time after ingestion, after that
the toxic material will be absorbed from the stomach & I cant
apply gastric lavage.
Physical examination:
Vital signs:
The vital signs can lead us to the type of poisons that cause the
changes we have as the following:-
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1. Pulse
Bradycardia BB (beta blockers), CCB (calcium
channel blockers), Digoxin, 4 Opiates,5 Organophosphates.
Tachycardia Sympathomimetics (amphetamine, OTC
cough and cold medications),
Theophilline, TCA (tricyclic anti-depressants),4Anticholinergics, 5Antihistamines.
2. Respiration
Bradypnea Alcohol, Sedatives
Tachypnea Amphetamines, Caffeine, Ethylene
glycol, 4Methanol, 5Salicylates.
3. Blood pressure
Hypotension Antihypertensives, Barbiturates, BB,4CCB, 5cyanide, 6TCA.
Hypertension Amphetamines, Pseudoephedrine,
Antihistamines.
4. Temperature
Hypothermia Barbiturates, Ethanol, Hypoglycemic
agents, 4Sedatives.
Hyperthermia Amphetamines, Anticholinergics,
Antipsychotics, 4Salicylates, 5Theophylline.
Neuromuscular:
Ataxia Alcohol, Phenytoin, CO, 4Heavy metals,5
Organic solvents.Delirium Antihistamines, Ethanol, Pb, 4Steroids,5Theophylline, 6Sympathomimetics (OTC cold drugs).
Convulsions Amphetamines, Antihistamines,
Camphor, 4Isoniazid, 5Organophosphates,6Salycilates,7Theophylline.
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Paralysis Botulinum toxin, Organophosphates.
Coma Alcohol, Anticholinergics, Anticonvulsants,4CO, 5Organophosphates, 6Sulfonylureas,7TCAs.
Ophthalmologic:
Mydriasis Amphetamines, Anticholinergics
Carbamazepine.
Miosis Barbiturates, Ethanol, Mushrooms of the
muscarinic type, 4Organophosphates.
Nystagmus Barbiturates, Carbamazepine,
Phencyclidine,4
Phenytoin.
Skin:
Jaundice Acetaminophen, Cyclopeptide, Mushrooms,4Fava beans, 5Arsenic, 6Naphthalene.
Cyanosis (unresponsive to O2 as a result of
methmoglobinemia) Aniline dyes, Benzocaine,
Nitrates, 4Nitrites.
Dry Anticholinergics, Antihistamines.
Odors:
Acetone Acetone, Isopropyl alcohol, Salicylates.
Alcohol Ethanol, Isopropyl alcohol.
Garlic Heavy metals (arsenic, phosphorus),
Organophosphates.
Pears Chloral hydrate.
Carrots Water hemlock
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The approach to a child with poisoning:
1.
ABCs(Airway, Breathing, Circulation).2. Supportive treatment(IV fluid, ventilation).
3. Antidotes(sometimes there is specific antidote for certain drug
or chemical, we should give it to the child).
4.
Therapeutic intervention.
HOW to manipulate different types of poisoning?
Dermal exposure:
Remove the clothes.
Irrigation: by warm tap water for (15-30) mins.
Washing: with warm tap water & soap.
Inhalation exposure:
(like CO poisoning, solvent inhalation)
Adequate airway.
O2.
General support.
Ocular exposure:
We should irrigate with sterile normal saline.
No vinegar, no NaHCO3.
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Gastric decontamination (lavage):
Gastric decontamination is absolutely contraindicated in:
1. Petroleum derivatives (e.g. kerosene) are contraindications to do
gastric lavage, because these substances when enter the stomach,
they affect the airways, & if aspiration happened, it may cause
pneumonia, & if we do lavage, we extract these substances from
the stomach through the esophagus again & there will be
inhalation & thus increase the risk for pneumonia.
2.
Chemicals like acids & alkaline, because if we do lavage for them
we will let them pass again through the esophagus & thus cause
burns in it.
Otherwise we do gastric lavage in certain situations, such as in
comatose patient, & here we need cuffed tube, which is an
endotracheal tube, with a cuff (balloon) around it, if we inject
water or air in this balloon, it obstructs around the endotracheal
tube.
Ipecac: it was used 5-10 years ago to stimulate vomiting (gastric
lavage), but it is a toxic material, & there is an evidence that it
causes cardiac problems,,, SO there is NO value of Ipecac.
The use of Sorbitol to induce Catharsis is dangerous.
Activated charcoal:
It is an adsorbing agent which we can use in some materials like:
heavy metals.
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Me ications
The commonest toxins:
They contribute to 65% of all poisonings in children 1million, & also the
incidence of thrombocytosis is decreasing.
NOW, instead of aspirin we use
*Acetaminophen (Paracetamol, Revanin):
It is toxic when the dose is>150 mg/kg.
Presentation: Normal vital signsLethargyAffect liver
enzymes, & if it is taken in a large dose, it will cause liver failure.
Treatment: Charcoal within 60 mins, then N-acetylcysteine
(NAC) SO the antidote for Acetaminophen is NAC.
The other analgesic that causes toxicity is:
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**Ibuprofen:
The toxic doseis: 200mg/kg.
Treatment: Charcoal within 60 mins.
2)Cough & cold preparations:
They are over the counter drugs, & in our developing
countries, all the drugs are over the counter (Even the
morphine :P !!)
We have 3 types of them: Decongestants, antihistamines, &
cough suppressants, so we should check the composition.
Some cough & cold preparations
1. Phenylpropanolamine, the toxic dose is>10mg/kg.
2. Pseudoephedrine, the toxic dose > 180mg
Treatment for the 2 above drug toxicity is charcoal within 60
mins, if the patient developed hypertension, this is an
emergency case, & we need to decrease the blood pressure as
soon as possible by giving Nitroprusside.
3.Diphenhydramine: the toxic dose is >50 mg, it will
cause anticholinergic toxic syndrome, so we should treat
by Charcoal, & if the patient develops seizure we should
give Diazepam, & if we have serious anticholinergic
syndrome, we give Physostigmine.
Anticholinergic presentation in a child if he has
accidental ingestion of anticholinergic drug:
Mad as a hatter
Red as a beet (Flush face)
Blind as a bat)(
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Hot as a hare) (
Dry as a bone.
4.Dextromethorphan: usually not alone, we use
charcoal, if it is >4ouncesit may cause CNS depression
& in this case we give Naloxone.
3) Iron:
The second most commonafter acetaminophen.
The toxic dose is>20 mg/kgof elemental ironwhich
means that there is a composition of iron for example if
we have IronGluconate, the elemental iron of this
composition is 12 , if there is Iron Sulfate, the elementaliron is 20 ,& in the Iron Fumaratethe elemental iron is
33 .
It can cause vomiting, diarrhea, abdominal pain,4hematemesis, 5bloody diarrhea, 6shock, 7acidosis, &
8coma.
Treatment: Whole Bowl Irrigation (WBI) which consists of
isoosmotic, polyethylene glycol solution, & if the
concentration of iron is >500micg. /dl,we give chelatingagent which is Deferoxamine (IV),this drug is indicated in
thalassemic patient who has overload of ferrous (1000-
2000 micg./dl), but in acute poisoningif there is a drug
level of>500micg./dl, we must give IV Deferoxamine to
decrease the iron in the body.
4)
TC s
(Tricyclic Antidepressants):
The toxic dose is >10 mg/kg.
Treatment: Charcoal.
If the patient presents with ventricular arrhythmias
we must give him hypertonic NaHCO3or Phenytoin.
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Househol cleanin ro ucts:
If the patient presents with hypertension, we must
give nor epinephrine.
Bleach, all purpose ammonia containing, glass cleaners, we should
keep them away from the reach of the children.
1. Bleach:
It is 5.25 sodium hypochloride; usually it willbecome acid (chlorine) & ammonia (chloramine).
Treatment: Dilutional therapy.
If it affects the eye we do ocular irrigation by
normal saline & water.
On the skin, we use soap & waterto clean it.
It is contraindicated to do gastric lavage.
2.
Glass cleaners:
Bad taste& attractive.
It is composed of 90% water (3-6)%
Isopropyl alcohol (1-3)% ethylene glycol
monobutyl ether which causes RBCs hemolysis,
&>1% ammonium hydroxide.
Gastric decontamination is contraindicated here.
If it affects the eye, we do ocular irrigation.
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3.Ethylene Glycol Methanol:
We see this type of poisoning accidental in children &
intentional in adults.
Ethylene glycolis an automotive anti-freeze.
Methanol is an automotive windshield washer fluid.
They are extremely toxic that might present with
convulsion & coma.
Alcohol dehydrogenase converts them into metabolites
that cause metabolic acidosis.
Antidote: Ethanolwhich is a competitive inhibitor of the
enzyme (alcohol dehydrogenase), but it may inducehypoglycemia,, Fomepizole (Antizole) we wont talk
about it because it isnt found in Jordan.
4.Hydrocarbons:
They are classified into Aliphatic such as
Kerosene, Gasoline, & Lubricating oilswhich can
cause aspiration & pulmonary toxicity(local
manifestations) ,Aromatic such asBenzene,Camphor,Turpentine which can cause
systemic toxicity (CNS toxicity, convulsions,
coma).
DONT do gastric
decontamination.
What to do? Check for the ABC, if the patients
condition is stable then ask for chest x-ray, then
observe for 6 hours, 4after that if he has no signs
of respiratory distress & no fever, we can discharge
him& give him an appointment after 48 hours, 5if
after 48 hours he develops fever, respiratory
distress & leukocytosis, this means that he has
complicated bacterial pneumonia (secondary
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infection) & here we should admit him & give
antibiotics, but if he is from the beginning(the 1st6
hours) has fever & signs of respiratory distress, this
is Chemical Pneumonitis
& we should admit him
immediately to observe but we should delay the
antibiotics.
The treatment for pneumonitis is O2& PEEP.
5.Caustics:
Strong acids and alkalinesuch as: drain and oven
cleaners, rust removers, toilet bowl cleaners.
They cause airways swelling & obstruction, &burns to the esophagus that may lead to
esophageal perforation.
NO gastric lavage.
Treatment: NPOwhich is medical instruction to
withhold oral food and fluids from a patient,
chest x-ray& Endoscopy in the 1st 12 hours to
detect if we have circular or longitudinal burns in
the esophagus (the circular concerns us morebecause if we have scaring it may lead to
stricture) but the longitudinal is not dangerous.
If by endoscope we detect edema in the
esophagus we give antibiotics & corticosteroids.
6.Organophosphates Carbamates:
Sometimes it is intentional & sometimes
accidental.Pesticides cause irreversible inhibition of acetyl
cholinesterase (Organophosphates: Diazinon),
reversible (Carbamates: Baygon).
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Symptoms: DUMBELS Diarrhea, Urination,Miosis, Bronchospasm, Emesis, Lacrimation,
Salivation,,, & sometimes may present with coma
& convulsions.
Treatment: ABC, Atropine (symptomatic
antidote): we give it until we have Mydriasisthen
we stop it, the specific antidote is Pralidoxime
that affect the acetylcholine & decrease the
duration.
This table is very important we may have
many Questions from it:
Chemical Antidote
Acetaminophen NAC
Anticholinergics Physiostigmine
Benzodiazepine Flumazenil
BB glucagon
CCB CaCl /gluconate
CO Hyperbaric O2
Coumadin Vitamin K
Cyanide Sodium nitrite
Digitalis Sp. FAB Ab. frag
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Fe Deferoxamine
Isoniazid Pyridoxine
Methemoglobinemia Methylene blue
Organophosphates Atropine/pralidoxime
Sulfonylureas Octreotide
Done by: