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: