Transcript poisoning.ppt

Poisoning
Ali Alhaboo Assisstant Professor of
Pediatrics
PICU consultant
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Overview of pediatric
poisoning, diagnosis and
treatment
Summary of the most
encountered poisoning
Epidemiology
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Most of the toxic exposures have
only minor or no effect on the child
85% - 90% of pediatric poisoning
occurs in < 5 yrs of age
(accidental) usually single agent
10% - 15% in older age, mainly
adolescents (intensional) usually
several agents
3-4% of PICU admission are
because of toxic exposures
ED referral recommendations
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Serious exposures
Younger than 6 months
History of previous toxic ingestion
Questionable or unreliable history
Routes of exposures in
children
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Ingestion
Inhalation
Skin exposure
Common agents
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Cosmetics and
personal care product
Cleaning substance:
flash is more serious than
Clorox because it melts the
esophagus and destroys it.
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Plants
Analgesics: Paracetamol
is the commonest cause of
poisoning in children ( high
doses more than 200 mg/kg)
Note: OCPs are not harmful.
Less common but
serious
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Fe supplements:
2nd most
common in
females.
Antidepressants
Anti-diabetics:
causing severe
hypoglycemia and
LOC.
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Antihypertensive.
Pesticides:
organophosphates.
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Hydrocarbon
History
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Identification of the toxic agent
Age of the child.
What has been done to the child.
The time elapsed and the dose taken (if it was
unknown consider it serious).
The route of exposure
Underlying medical problems
The clinical effect (with few exceptions rapidity of
symptoms progression correlates with severity of
poisoning.e.g., acetaminophen)
? Trauma in addition to ingestion (change in LOC).
Physical Exam
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Weight (determine ? mg/kg ingested)
Vital signs
Check odors from the breath, skin, hair,
clothing
Thorough exam for any abnormal finding
General presentations suggestive
of poisoning
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Severe vomiting,
diarrhea
Acutely disturbed
consciousness
Abnormal behavior
Seizure
unusual odor
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Shock
Arrhythmias
Metabolic acidosis
Cyanosis
Respiratory distress
Clinical clues to the diagnosis
of unknown poisoning
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Odor
Skin
Mucous
membranes
Temperature
Blood pressure
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Pulse rate
Respiration
Pulmonary
edema
CNS
GI system
Odor
Signs or symptom
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Poison
Bitter almond
Acetone
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Oil of
wintergreen
Garlic
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Alcohol
Petroleum
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Cyanide
Isopropyl alcohol, methanol,
acetylsalicylic acid
Methyl salicylate
Arsenic, phosphorous, thallium,
organophosphates
Ethanol, methanol
Petroleum distillates
Skin
Sign or symptom
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Cyanosis
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Red flush
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Sweating
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Dry
Poison
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Methemoglobinemia secondary to
nitrates, nitrites, phenacetin,
benzocaine
Carbon monoxide, cyanide, boric
acid, anticholenergics
Amphetamines, LSD,
organophosphates, cocaine,
barbiturates
Anticholenergics
Mucous membranes
Signs or symptoms
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Dry
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Salvation
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Oral lesions
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Lacrimation
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Poison
Anticholenergics
Organophosphates,
carbamates
Corrosives, paraquat
Caustics, organophosphates,
irritant gases
Temperature
Signs or symptoms
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Hypothermia
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Hyperthermia
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Poison
Sedatives hypnotics, ethanol,
carbon monoxide, clonidine,
phenothiazines, TCAs
Anticholenergics, salicylates,
phenothiazines, cocaine,
TCAs, amphetamines,
theophylline
Blood Pressure
Signs or symptoms
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Hypertension
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Hypotension
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Poison
Sympathomimitics (especially
phenylpropanolamine in overthe-counter cold remedies),
organophosphates,
amphetamine, phencyclidine,
cocaine
Antihypertensives,
barbiturates, benzodiazepines,
beta blockers, Ca++ channel
blockers, clonidine, TCAs
Pulse rate
Signs or symptoms
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Bradycardia
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Tachycardia
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Arrhythmias
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Poison
Digitalis, sedatives hypnotics,
beta blockers, ethchlorvynol,
opioids
Antichlonergics,
sympathomimetics,
amphetamines, alcohol,
aspirin, theophylline, cocaine,
TCAs
Anticholenergics, TCAs,
organophosphates, digoxin,
phenothiazines, betablockers,
carbon monoxide, cyanide
Respirations
Signs or symptoms
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Depressed
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Tachypnea
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Kussmaul’s
sign
Wheezing
Pneumonia
Pulmonary
edema
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Poisoning
Alcohol, opioids, barbiturates,
sedatives/hypnotics, TCAs, paralytic
shelfish poisoning
Salicylates, amphetamines, carbon
monoxide
Methanol, ethylene glycol, salicylates
Organophosphates
Hydrocarbons
Aspiration, salicylates, opioids,
sympathomimetics
CNS
Sings or symptoms
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Seizures
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Fasciculation
Hypertonus
Myoclonus,
rigidity
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Poison
Camphor, carbon monoxide,
cocaine, amphetamines,
sympathomimetics,
anticholenergic, aspirin,
pesticides, organophosphates,
lead, PCP, phenothiazines, INH,
lithium, theophylline, TCAs
Organophosphates
Anticholenergics, phenothiazines
Anticholenergics, phenothiazines,
haloperidol
CNS
Sings or symptoms
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Poison
Delirium/psychos  Anticholenergics,
is
phenothiazines,
sympathomimetics, alcohol,
PCP, LSD, marijuana, cocaine,
heroin, heavy metals
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Alcohol, anticholenergics,
Coma
sedative hypnotics, opioids,
carbon monoxide, TCAs,
salicylates,
organophosphates
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Organophosphates,
Weakness,
carbamates, heavy metals
paralysis
EYE
Signs or symptoms
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Miosis
Mydriasis
Blindness
Nystagmus
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Poison
Opioids, phenothiazines,
organophosphates,
benzodiazepines, barbiturates,
mushrooms, PCP
Antichlenergics,
sympathomimitics (cocaine,
amphetamines, LSD, PCP), TCA,
methanol, glutethimide
Methanol
Diphenylydantoin, barbiturates,
carbamazepine, PCP,carbon
monoxide, glutethimide, ethanol
GI
Sings or symptoms
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Vomiting,
diarrhea
Poison
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Iron, phosphorous, heavy
metals, lithium, mushroom,
fluoride, organophosphates
Toxidromes of Common Pediatric
Poisonings
Toxin
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Anticholenergi
cs (atropine,
scopolamine,
TCAs,
antihistamines,
mushrooms)
Cholenergics
(organophosph
ates and
carbamate
insecticides)
Signs or symptoms
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Fever, flushed, warm, dry skin,
dry mouth, mydriasis,
tachycardia, arrhythmias,
agitation, hallucinations, coma
Salivation, lacrimation, sweating,
bronchorrhea, emesis, diarrhea,
miosis, bradycardia,
bronchospasm with wheezing,
confusion, weakness,
fasciculations, coma
Toxidromes of Common Pediatric
Poisonings
Toxin
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Opiates
Narcotic
withdrawal
Signs or symptoms
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Hypothermia,
hypoventilation, hypotension,
bradycardia, miosis, coma
Nausea, vomiting, diarrhea,
abdominal pain, lacrimation,
diaphoresis, mydriasis,
tremor, irritability, delirium,
seizure
Toxidromes of Common Pediatric
Poisonings
Toxin
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Signs or symptoms
Sedative/
hypnotics
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TCAs
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Hypothermia, hypoventilation,
hypotension, tachycardia, coma
Coma, convulsions, arrhythmias,
anticholenergic manifestations
Phenothiazines  Hypotension, tachycardia,
dystonia syndrome, oculogyric
crisis, trismus, ataxia, coma,
anticholenergic manifestations
Toxidromes of Common Pediatric
Poisonings
Toxin
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Salicylates
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Iron
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Sympathomimetics
(amphetamines,
phenylpropanolamie
, ephedrine, caffeine,
cocaine,
aminophylline)
Signs or symptoms
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Fever, hyperpnea, vomiting,
tinnitus, acidosis, seizure,
lethargy, coma
Hyperglycemia, shock,
hemorrhagic diarrhea
Tachycardia, arrhythmias,
psychosis, hallucinations,
nausea, vomiting,
abdominal pain
Laboratory tests
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Qualitative toxicology screening is rarely as helpful
as Hx and PE in determining the cause
Best done on urine and gastric aspirate samples
Quantitative serum level of known drug is indicated
when it can enable prediction of toxicity or
determination of treatment
ABGs with respiratory symptoms and to assess
acid-base balance
Blood glucose from 1st sample
Liver and kidney function (metabolism&excretion)
Serum electrolytes (anion gap, renal function)
Serum osmolar gap
CBC (anemia, hemolysis)
DIC panel when suspected
Routine Laboratory Tests That Can
Suggest Poisoning
- Decreased hemoglobin
saturation with normal
or increased PO2
- Elevated anion gap
metabolic acidosis
- Elevated osmolar gap
- Hyperglycemia
- Hypoglycemia
- Hypocalcemia
Agents causing methemoglobin (nitrates,
nitrites, benzocaine)
Methanol, ethanol, isopropyl alcohol,
ethylene glycol, salicylates, isoniazid,
paraldehyde, toluene, iron, phenformin,
CO, cyanide
Ethanol, methanol, isopropyl alcohol,
ethylene glycol
Salicylates, isoniazid,
organophosphates, iron
Insulin, ethanol, isopropyl alcohol,
isoniazid, phenfomin, acetaminophen,
salicylates, oral hypoglycemic agents
Ethylene glycol, methanol
- Oxalic acid crystalluria Ethylene glycol
- Ketonuria
Isopropyl alcohol, ethanol, salicylates
Drugs with clinically useful serum
level quantitation
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Acetaminophen
Anticonvulsants
Carbon
monoxide
Cholinesterase
Digoxin
Ethanol
Ethylene glycol
Heavy metals
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Iron
Isopropanol
Lead
Lithium
Methanol
Methemoglobin
Salicylate
Theophylline
Radiography indications
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If head trauma cannot be excluded
(skull and cervical spine film, head CT
if physical findings are suggestive)
If child abuse is suspected
(skeletal survey)
If patient is having respiratory distress
(CXRay)
If radiopaque substance is suspected
Common substances that are
radiopaque (CHIPES)
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Chloral hydrate
Heavy metals
Iodine
Phenothiazine
Enteric coated and extended
release medication
Salt tablets
(in Fe ingestion, serial films indicate movement and elemination)
Steps of management
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First you have to start with ABC, if hypotensive repeat ABCs.
Check the O2 saturation
Glucocheck for hypoglycemia. If hypoglycemic give 5-10%
dextrose (not higher than that because it might harm the
vessel). Dose: 2-5 ml/Kg.
Do toxicology screen.
LFT, U/E, RFT, coagulation profile (PT is the first to be affected,
if it was elevated give FFP or vitamin K) and albumin.
Give antidote as early as possible if available. (N-acetylcesteine
is the antidote for paracetamol. Desfuroxemine is the antidote
for iron.
Transfer the patient to the ICU, if there is no bed keep him in
the ER.
Treatment
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Airway: patency and protective mechanisms (if
absent, use nonspecific antidote of D10W 2cc/kg
and Naloxone 0.1mg/kg; if no response intubate.
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Breathing: clear secretions, give O2, continuous
O2 saturation, ABGs, CXRay, treat wheezing and
stridor, early controlled intubation prefered
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Circulation: frequent VS, continuous CR monitor,
fluids for low BP, do baseline ECG, watch for
arrythmias, PALS guidelines
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Neurologic status: frequent assessments, the
most common cause to admit intoxication to PICU,
use nonspecific antidotes, watch for seizures, rule
out metabolic causes of seizure
GI decontamination
Emesis-Syrup of Ipecac
Therapy
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Dosage in < 1 yr 10 ml
Young children 15 ml
Adolescents,
adults
30 ml
may repeat once
Contraindications
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Petroleum distillates
Caustic agents
Impaired
consciousness,
seizures
Rapid coma-inducing
agents (e.g.,
propoxyphene, TCAs)
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We use lavage when the patient presents
early and is stable.
If late presentation where the drug has
already passed to the duodenum use the
activated charcoal( through a NG tube)
where up to 1 million particles can adsorb
to the medication.
GI decontamination
Therapy
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Lavage
Large bore orogastric hose (28 Fr
for young children, 36-40 Fr for
adolescents)
Left recumbent Trendelenburg’s
position to reduce the risk of
aspiration
Lavage with saline or 1/2 NS until
return is clear
Most successful for toxins that
delay gastric emptying (aspirin,
iron, anticholinergics) and for
those forming concretions (iron,
salicylates, meprobamate)
Contraindications
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Corrosive
caustic agents
Controversial in
petroleum
distillates
ingestion
Stupor or coma
unless airway is
protected
GI decontamination
Therapy
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Activated Charcoal
Administer in all
cases after
emesis. It should
be only given for
conscious
patients.
Dosage:
- Children 1 g/kg
- Adults 50-100 g
Contraindications
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Corrosive agents:
charcoal interfers
with GI endoscopy
Most feared complication
is aspiration leading to
severe pneumonitis and
ARDS
GI decontamination
Therapy
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Cathartics
MgSO4 250 mg/kg/dose
P.O.(max dose 30 g) in
10%-20% solution
Sorbitol magnesium
citrate
Repeat above
doses every 2-4 hrs
until passage of
charcoal stained stools
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Contraindications
Avoid MgSO4 in
renal failure
Enhanced elimination
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Forced diuresis by administering 2-3 times the
maintenance fluid to achieve U.O = 2-5 cc/kg/hr
(contraindicated in pulmonary or cerebral edema and
renal failure)
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Urinary alkalinization to eleiminate weak
acids(salicylates, barbiturates and methotrexate), can
be achieved by adding NaHCO3 to the IV fluids, the goal
is urine pH of 7-8
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Serum alkalinization in TCAs toxicity
Hemodialysis in low molecular weight substances
with low volume of distribution and low binding to
plasma proteins
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Hemoperfusion, protein binding is not a limitation
Antidotal Therapy
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Only a small proportion of
poisoned patients are amenable to
antidotal therapy
Only a few poisoning is antidotal
therapy urgent (e.g., CO, cyanide,
organophosphate and opioid
intoxication)
Specific Intoxications and Their Antidotes
Poison
Antidote
Indications
Acetaminophen
N-Acetylcysteine
(Mucomyst)
Serum level in “probable”
hepatotoxic range
Anticholenergics
Physostigmine
SVT with hemodynamic
compromise
Beta blockers
Glucagon
Isopreterenol,
dopamine,
epinephrine
Flumazenil
Bradycardia
Bradycardia
Benzodiazepines
Symptomatic intoxication
Carbon monoxide O2
Level > 5-10%
Cyanide
Amyl nitrite,
sodium nitrite,
sodium thiosulfate
Symptomatic intoxication
Digitalis
Specific Fab
antibodies
Specific Intoxications and Their Antidotes
Poison
Antidote
Indications
Ethylene glycol
Ethanol
Osmolar gap and metabolic acidosis or
Serum level >20 mg/dl regardless of
symptomatology
Iron salts
Desferoxamine
Symptomatic patients
Serum iron > 350 g/ml or > TIBC
Positive deferoxamine challenge test
Isoniazid
Pyridoxine
(vit B6)
Methanol
Ethanol
Metabolic acidosis and elevated
osmolar gap regardless of symptoms
Methemoglobinemi Methylene blue
a producing agents
Symptomatic poisoning
Methemoglobin level > 30-40 %
Narcotics
Naloxane
Symptomatic intoxication
Organophosphate
insecticides
Atropine
Pralidoxime
Cholenergic crisis
Fasciculation and weakness
Phenothiazines
Diphenhydramine Symptomatic intoxication (oculogyric
crisis)
Acetaminophen
(paracetamol) poisoning
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Nausea, vomiting and malaise for 24 hrs
Improvement for 24-48 hrs
Hepatic dysfunction after 72 hrs (AST is the
earliest and most sensitive)
Death may occur from fulminant hepatic failue
Toxicity likely with ingestion of > 150 mg/kg
Rumack-Matthew nomogram defines the risk of
hepatic damage in acute intoxication (level at 4
hrs post ingestion)
Acetaminophen (paracetamol)
poisoning management
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GI decontamination
Activated charcoal within 4 hrs of ingestion
Antidote N-acetylcysteine is most effective if
given within 8 hrs of ingestion, total of 17
doses, P.O or IV (However, NAC should be
given even with > 24hrs presentation)
NAC should be given if serum acetaminophen
level is either in the “possible” or “probable”
hepatotoxic range
Salicylate toxicity
Clinical manifestations
Common
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Fever
Sweating
Nausea
Vomiting
Dehydration
Hyperpnea
Tinnitus
Seizures
Coma
Coagulopathy
Uncommon
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Respiratory
depression
Pulmonary
edema
SIADH
Hemolysis
Renal failure
Hepatotoxicity
Cerebral edema
Laboratory findings in salicylate
toxicity
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Metabolic acidosis
Respiratory alkalosis
Mixed (resp alkalosis
&metabolic acidosis)
Hyperglycemia,
Hypoglycemia
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Hypernatremia,
hyponatremia
Hypokalemia
Hypocalcemia
Prolonged PT
Ketouria
Prediction of acute salicylate
toxicity
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Ingested dose can predict the severity
< 150 mg/kg
toxicity not expected
(asymptomatic)
150-300 mg/kg
toxicity mild to moderate
(mild to moderate hyperpnea,
lethargy or excitability)
300-500 mg/kg
severe toxicity
(severe hyperpnea, coma
or semicoma, sometimes
with convulsions)
Management of salicylate toxicity
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GI decontamination
Correct dehydration and force diuresis
Urine alkalinization and acidosis correction with
IV NaHCO3
Monitor electrolytes, glucose, calcium
Vit K for hemorrhagic diathesis
Decrease fever with external cooling
Hemodialysis for severe intoxication (Dome
nomogram), severe acidosis unresponsive to
NaHCO3, renal failure, pulmonary edema and
severe CNS manifestation